# GEMPAK Conversion GuideΒΆ

The popular meteorological plotting and analysis tool GEMPAK is no longer formally supported and Unidata is only producing occasional maintenance releases. To help GEMPAK users convert to the Python ecosystem we have compiled this list of GEMPAK programs, commands, parameters, etc. and their Python equivalents. These tables are continually updated as we add more functionality to MetPy as part of an National Science Foundation grant. Where issues have been filed, we have linked to them. Please feel free to tackle of these, comment on their importance in the issue tracker, or file a new issue.

Green rows represent implemented functionality, red is not implemented (with issue listed), blue is uncertain of parity, and white is unevaluated.

## GEMPAK Scalar Output/Scalar Grid

GEMPAK Function Description Python/MetPy Equivalent Grid Compatible? Tested against GEMPAK? Units?
ABS(S) Absolute value numpy.absolute Yes No Yes
ACOS(S) Arc cosine numpy.arccos Yes No
ASIN(S) Arc sine numpy.arcsin Yes No
ATAN(S) Arc tangent numpy.arctan Yes No
ATN2(S1, S2) Arc tangent numpy.arctan2 Yes No
COS(S) Cosine numpy.cos Yes No
EXP(S1, S2) Exponential to real S1**S2 Yes No Yes
EXPI(S1, S2) Exponential to integer (uses NINT) S1 ** S2.astype(int) Yes No
INT(S) Convert to integer S.astype(int) Yes No No
LN(S) Natural logarithm numpy.log Yes No Yes
LOG(S) Base 10 logarithm numpy.log10 Yes No Yes
NINT(S) Round to nearest integer numpy.round Yes No Yes
SIN(S) Sine numpy.sin Yes No
SQRT(S) Square root numpy.sqrt Yes No Yes
TAN(S) Tangent numpy.tan Yes No
NCDF(S1, S2, S3) Cumulative normal distribution for value, mean, std dev scipy.stats.norm.cdf
INCD(S1, S2, S3) Inverse cumulative normal distribution value given cumulative probability, mean, std dev scipy.stats.norm.ppf(scipy.stats.norm.cdf)
BNCDF(S1, S2, S3, S4) Cumulative binormal mixture distribution given value, mode, left sigma, and right sigma scipy.stats.multivariate_normal
IBNCDF(S1, S2, S3, S4) Inverse cumulative binormal mixture distribution value given cumulative probability, mode, left sigma, and right sigma
PAUB(S1, S2, S3) Combine probabilities (S1 or S2) with dependency parameter S3
MUL(S1, S2) Multiplication S1 * S2 No
QUO(S1, S2) Division S1 / S2 No
SUB(S1, S2) Subtraction S1 - S2 No
BOOL(S) Boolean function
SLT(S1, S2) Less than function S1 < S2 No
SLE(S1, S2) Less than or equal to function S1 <= S2 No
SGT(S1, S2) Greater than function S1 > S2 No
SGE(S1, S2) Greater than or equal to function S1 >= S2 No
SBTW(S1, S2, S3) Between two values function S1 > S2 and S1 < S3 No
SMAX(S1, S2) Maximum of S1 and S2
SMIN(S1, S2) Minimum of S1 and S2
MISS(S1, S2) Set missing values in S1 to S2
AVG(S1, S2) Average numpy.mean(np.array([S1, S2]), axis=0) Yes No No
AVOR(V) Absolute vorticity metpy.calc.absolute_vorticity
BVSQ(THTA) Brunt-Vaisala frequency squared in a layer metpy.calc.brunt_vaisala_frequency_squared (use with metpy.calc.mixed_layer to obtain layer average)
CROS(V1, V2) Vector cross product magnitude numpy.cross(V1, V2) No
DDEN(PRES, TMPC) Density of dry air metpy.calc.density(mixing=0) No
DDR(S) Partial derivative with respect to R metpy.calc.first_derivative No
DDT(S) Time derivative metpy.calc.first_derivative No
DDX(S) Partial derivative with respect to X metpy.calc.first_derivative No
DDY(S) Partial derivative with respect to Y metpy.calc.first_derivative No
DEF(V) Total deformation metpy.calc.total_deformation No
DIRN(V) Direction relative to north
DIRR(V) Direction relative to grid
DIV(V) Divergence metpy.calc.h_divergence No
DIVT(S, V) Divergence tendency (only for cylindrical grids)
DOT(V1, V2) Vector dot product numpy.dot(V1, V2) No
DTH(S) Partial derivative with respect to theta metpy.calc.first_derivative No
FCNT(S) Coriolis force at grid center (polar) metpy.calc.coriolis_parameter No
FOSB(TMPC, RELH, SPED) Fosberg index (Fire weather index frontogenesis) Issue #636
FRNT(THETA, V) Frontogenesis metpy.calc.frontogenesis No
GWFS(S, N) Filter with normal distribution of weights metpy.calc.smooth_gaussian Yes Yes
RDFS(S, DX) GWFS applied for given output resolution
HIGH(S, RADIUS) Relative maxima over a grid
JCBN(S1, S2) Jacobian determinant
KNTS(S) Convert m/s to knots .to('knots') No
LAP(S) Laplacian operator metpy.calc.laplacian No
LAV(S) Layer average (2-levels)
LDF(S) Layer difference (2-levels)
LOWS(S, RADIUS) Relative minima over a grid
MAG(V) Magnitude of a vector numpy.linalg.norm No
MASS Mass per unit volume in a layer from PRES
MDIV(V) Layer-avg. mass divergence
MIXR(DWPC, PRES) Mixing ratio metpy.calc.mixing_ratio No
MSDV(S, V) Layer-avg. mass-scalar flux divergence Issue #655
MSFC(V) Pseudo angular momentum (cross-sections) metpy.calc.absolute_momentum No
MTNG(V, LAT, LON, DIR, SPD) Magnitude of tangential wind Issue #653
NORM(V) Normal component (cross-sections) metpy.calc.normal_component No
NMAX(S, ROI) Neighborhood maximum value for a radius of influence
NMIN(S, ROI) Neighborhood minimum value for a radius of influence
PLAT(S) Latitude at each point (polar)
PLON(S) Longitude at each point (polar)
PLCL(PRES, TMPC, DWPC) Pressure of the lifting condensation level metpy.calc.lcl No
POIS(S1, S2) Solve Poisson equation of forcing function with boundary conditions Issue #651
POLF(S) Coriolis force at each point (polar) metpy.calc.coriolis_parameter No
PVOR(S, V) Potential vorticity in a layer metpy.calc.potential_vorticity_baroclinic
metpy.calc.potential_vorticity_barotropic
No
PVR3(S, V) 3-D potential vorticity for a level Issue #649
RELH(TMPC, DWPT) Relative humidity metpy.calc.relative_humidity_from_dewpoint No
RICH(V) Richardson stability number in a layer Issue #647
ROSS(V1, V2) Rossby number Issue #637
SAVG(S) Average over whole grid numpy.mean No
SAVS(S) Average over display subset area of grid numpy.mean No
SDIV(S, V) Flux divergence of a scalar Issue #646
SGMX(S) Maximum of S over GAREA numpy.nanmax No
SGMN(S) Minimum of S over GAREA numpy.nanmin No
SHR(V) Shearing deformation metpy.calc.shearing_deformation No
SM5S(S) 5-point smoother Issue #659
SM9S(S) 9-point smoother Issue #659
STAB(TMPC) Lapse rate over a layer in K/km
STR(V) Stretching deformation metpy.calc.stretching_deformation No
TANG(V) Tangential component (cross-sections) metpy.calc.tangential_component No
TAV(S) Time average
TDF(S) Time difference
THES(PRES, TMPC) Saturated equivalent potential temperature metpy.calc.saturation_equivalent_potential_temperature No
THTA(TMPC, PRES) Potential temperature metpy.calc.potential_temperature No
THTE(PRES, TMPC, DWPC) Equivalent potential temperature metpy.calc.equivalent_potential_temperature No
THWC(PRES, TMPC, DWPC) Wet bulb temperature metpy.calc.wet_bulb_temperature No
TLCL(TMPC, DWPC) Temperature of the lifting condensation level metpy.calc.lcl No
TMST(THTE, PRES) Parcel temperature along a moist adiabat metpy.calc.moist_lapse No
TMWK(PRES, TMPK, RMIX) Web bulb temperature in Kelvin metpy.calc.wet_bulb_temperature No
DSUB(V1, V2) DIRN(V1) - DIRN(V2)
UN(V) North relative u component
UR(V) Grid relative u component
VN(V) North relative v component
VOR(V) Vorticity metpy.calc.v_vorticity No
VR(V) Grid relative v component
WNDX(S1, S2, S3, S4) WINDEX (index for microburst potential) Issue #639
WSHR(V) Magnitude of the vertical wind shear in a layer
XAV(S) Average along a display subset grid row numpy.mean(a, axis=1) Yes No Yes
XSUM(S) Sum along a display subset grid row numpy.sum(a, axis=1) Yes No Yes
YAV(S) Average along a display subset grid column numpy.mean(a, axis=0) Yes No Yes
YSUM(S) Sum along a display subset grid column numpy.sum(a, axis=0) Yes No Yes

## Vector Output Grid

GEMPAK Function Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
AGE(S) Ageostrophic wind metpy.calc.ageostrophic_wind No
CIRC(V, S) Circulation (cross-section) Issue #662
DVDX(V) Partial x derivative of V metpy.calc.first_derivative No
DVDY(V) Partial y derivative of V metpy.calc.first_derivative No
GCIR(LAT, LON) Great circle from point to antipodal point
GCWV(LAT, LON, MASK) Great circle from point to antipodal point with land blocking algorithm MASK will usually be SEA
GEO(S) Geostrophic wind metpy.calc.geostrophic_wind No
GWFV(V, N) Filter with normal distribution of weights Issue #664
RDFV(V, DX) GWFV applied for given output resolution
ISAL(S) Isallobaric wind Issue #641
KCRS(V) Curl of V
KNTV(V) Convert m/s to knots .to('knots') No
LTRN(S, V) Layer-averaged transport of a scalar
NORMV(V) Vector normal wind (cross-section) metpy.calc.normal_component No
QVEC(S, V) Q-vector at a level metpy.calc.q_vector No
QVCL(THTA, V) Q-vector of a layer metpy.calc.q_vector (use with metpy.calc.mixed_layer to obtain layer average of each component)
ROT(angle, V) Coordinate rotation
SMUL(S, V) Multiply a vector's components by a scalar
SM5V(V) 5-point smoother Issue #659
SQUO(S, V) Vector division by a scalar
TANGV(V) Vector tangential wind (cross-section) metpy.calc.tangential_component No
THRM(S) Thermal wind over a layer
TNG(V, LAT, LON, DIR,SPD) Storm relative tangential wind Issue #658
VASV(V1, V2) Vector component of V1 along V2
VAVG(V) Average over whole grid
VAVS(V) Average vector over display subset grid
VECN(S1, S2) Create vector from north relative components
VECR(S1, S2) Create vector from grid relative components
VESD(SPD, DIR) Create vector from speed and north-rel direction
VLAV(V) Layer average for a vector
VLDF(V) Layer difference for a vector
VMUL(V1, V2) Multiple the components of two vectors
VQUO(V1, V2) Divide the components of two vectors
VSUB(V1, V2) Subtract the components of two vectors
VLT(V, S) Less than function
VLE(V, S) Less than or equal to function
VGT(V, S) Greater than function
VGE(V, S) Greater than or equal to function
VBTW(V, S1, S2) Between two values function
VMSK(V, S) Mask V based on S

## Logical Output Grid

GEMPAK Function Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
LT(S1, S2) Returns 1 if S1 < S2
LE(S1, S2) Returns 1 if S1 <= S2
GT(S1, S2) Returns 1 if S1 > S2
GE(S1, S2) Returns 1 if S1 >= S2
GTLT(S1, S2, S3) Returns 1 if S1 > S2 and S1 < S3
GELT(S1, S2, S3) Returns 1 if S1 >= S2 and S1 < S3
GTLE(S1, S2, S3) Returns 1 if S1 > S2 and S1 <= S3
GELE(S1, S2, S3) Returns 1 if S1 >= S2 and S1 <= S3
EQ(S1, S2, S3) Returns 1 if |S1-S2| <= S3
NE(S1, S2, S3) Returns 1 if |S1-S2| > S3
AND(S1, S2, ..., Sn) Returns 1 if all Sx > 0
OR(S1, S2, ..., Sn) Returns 1 if at least one Sx > 0
EOR(S1, S2, ..., Sn) Returns 1 if exactly one Sx > 0
NOT(S) Returns 1 if S ==0

## Ensemble Functions

GEMPAK Function Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
ENS_SAVG(input_arg1 & input_arg2) Compute the average of a scalar diagnostic field over an ensemble. This average is an equally weighted ensemble mean unless weights have been specified in the GDFILE entry as described above or in input_arg2. Input_arg1 specifies the scalar field to average and is a dynamic argument. Input_arg2 specifies the name of a weight grid to be used in the calculation.
ENS_SSPRD(input_arg1) Compute the spread (sample standard deviation) of a scalar diagnostic field over an ensemble. Input_arg1 specifies the scalar field and is a dynamic argument. The formula used to compute the spread is SQRT { [ SUM ( Xi**2 ) - ( SUM (Xi) ** 2 ) / N ] / ( N -1 ) } where SUM is the summation over the members, Xi are values of the scalar field from individual ensemble members, and N is the number of members. Note that the average of the squared deviations from the mean is computed by dividing the sum of the squared deviations by ( N - 1 ).
ENS_SSUM(input_arg1) Compute the non-weighted sum of the values of a scalar field over an ensemble. Note that this returns the number of members in the ensemble if "input_arg1"" is a logical function that always evaluates to 1 [e.g. gt(2<1)]
ENS_SWSPRD(input_arg1 & input_arg2) Compute the spred, similar to ENS_SSPRD, of a scalar diagnostic field over an ensemble. The spread is weighted and input_arg2 specifies the name of a weight grid to be used in the calculation. NOTE: For uniform weights ens_ssprd (input_arg1) might be expected to give the same result as ens_swsprd(input_arg1 & w1) where w1 is uniform field of 1. This does not happen because of the division by (N-1) in ens_ssprd. The same is also true in comparing ens_vsprd and ens_vwsprd results.
ENS_VAVG(input_arg1 & input_arg2) Compute the average of a vector diagnostic field over an ensemble. This average is an equally weighted ensemble mean unless weights have been specified in the GDFILE entry as described above or in input_arg2. Input_arg1 specifies the vector field to average and is a dynamic argument. Input_arg2 specifies the name of a weight grid to be used in the calculation.
ENC_VSPRD(input_arg1) Compute the spread (sample standard deviation) of a vector diagnostic field over an ensemble. Input_arg1 specifies the vector field and is a dynamic argument. The formula used to compute the variance for each individual component of a vector is the same as for ENS_SSPRD. The variances of the components are added, then the square root is taken to compute the vector spread, which is a scalar.
ENS_VWSPRD(input_arg1 & input_arg2) Compute the spred, similar to ENS_VSPRD, of a vector diagnostic field over an ensemble. The spread is weighted and input_arg2 specifies the name of a weight grid to be used in the calculation. Also, see NOTE for function ENS_SWSPRD.
ENS_SMAX(input_arg1) Compute the maximum of a scalar diagnostic field over an ensemble.
ENS_SMIN(input_arg1) Compute the minimum of a scalar diagnostic field over an ensemble.
ENS_SRNG(input_arg1) Compute the range of a scalar diagnostic field over an ensemble. The range is defined as the difference between the maximum and the minimum.
ENS_PRCNTL(input_arg1 & input_arg2 & input_arg3) At each grid point determine the value of input_arg1 such that it exceeds that found in P% of the members of the ensemble, where P is given by input_arg2. The first argument is a dynamic argument, the second is a static argument. Input_arg3 specifies the name of a weight grid to be used in the calculation. The value of P must range between 0 and 100, and it may vary from grid point to grid point. If the ensemble members are weighted, it is the sum of the weights associated with the order statistics that determines the value corresponding to the percentile. If the percentile falls between two members, the value is determined by interpolation
ENS_MODE(input_arg1 & input_arg2) At each grid point, determine the mode of a weighted ensemble distribution. The mode value is the first one found by a trisection algorithm. The algorithm uses a moving, shrinking data interval in which the weight sums for the data values are made in each of three subintervals. The largest weight sum determines the next interval, with ties decided in the direction of the data mean. The algorithm terminates when only the middle subinterval has a non-zero sum of weights. The weighted average of the data values in this lone subinterval is the mode. Input_arg2 specifies the name of a weight grid to be used in the calculation.
ENS_PROB(input_arg1) Compute the probability of the multi-variate expression given in the input argument. The expression in the input argument is composed of the logical functions AND, OR, and EOR operating on the logical arithmetic comparison functions LT, LE, GT, GE, GTLT, GELT, GTLE, and GELE. ENS_PROB computes the weighted average of the 1 or 0 logical evaluations over the members of the ensemble to yield the relative frequency, or probability, of occurrence.
ENS_CPRB(input_arg1 & input_arg2 & input_arg3 & input_arg4) At each grid point, determine the univariate cumulative probability that the value of a given function is less than or equal to a given value in an ideal ensemble. The input arguments are, respectively, the function to evaluate, the given value whose cumulative probability is sought, the lower bound below which values of the function are impossible, and the upper bound above which values of the function are impossible. If a value for input_arg2 is outside of a given bound, the result is a missing value. The first argument is a dynamic argument; the others are static. The last two are optional. To omit input_arg3 but include input_arg4, specify input as ( input_arg1 & input_arg2 & & input_arg4 ).All arguments may be functions that vary from one grid point to another. For an ideal ensemble, there is a 2/(N+1) probability of values falling outside of the ensemble envelope. The probability density function is piecewise linear with triangular extrapolations beyond the ensemble, limited by any bounding values given. The following example finds the cumulative probability o
ENS_CVAL(input_arg1 & input_arg2 & input_arg3 & input_arg4) At each grid point, determine the value of a given function such that the univariate cumulative probability of values less than or equal to the computed value is the given probability, assuming an ideal ensemble. The input arguments are, respectively, the function to evaluate, the given cumulative probability ranging from 0 to 1, the lower bound below which values of the function are impossible, and the upper bound above which values of the function are impossible. A computed value will never fall outside of a bounding value. The first argument is a dynamic argument; the others are static. The last two are optional. To omit input_arg3 but include input_arg4, specify input as ( input_arg1 & input_arg2 & & input_arg4 ). All arguments may be functions that vary from one grid point to another. If the value of the second argument is not between 0 and 1, inclusive, then a missing value is assigned at that grid point. For an ideal ensemble, there is a 2/(N+1) probability of values falling outside of the ensemble envelope. The probability density function is piecewise linear with triangular extrapolations beyond the ensemble, limited by any bounding values given.

## Layer Functions

GEMPAK Function Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
LYR_SWTM(input_arg1 | levels) Computes the weighted mean of a scalar field. If the input argument is a single-level parameter or function, the weight is the depth of the layer extending from point halfway between the level and the next lower level and the point halfway between the level and the next upper level. If the input argument is a two-level function, then the weight is the depth of the two-level layer used in calculating the function. In isobaric coordinates, the logarithm of pressure is used to compute the depths. Input_arg1 specifies diagnostic function to average over the layers and output_arg is not required.
LYR_MXMN(argin & fldout [&argout] [|lvls] Computes the following over the specified range of levels... 1.The maximum or minimum value of a scalar quantity. 2.The value of a second output function coincident with the extrema of the input function. It might be a level, such as HGHT or PRES. It might be some other function, e.g. absolute vorticity.
LYR_FVONISFC(fvalu & fisfc & visfc & n & gradflag [|lvls] Computes the value of a function on a specified isosurface of a second function. The function will have the ability to traverse the atmosphere starting from the bottom level upwards or top level downwards and return either the 1st, 2nd, or nth level at which the isosurface threshold value exist.

## GUI Programs

Program Description Python/MetPy Equivalent
nfax Displays NMX 6 bit raster fax products
nmap Displays and animates different types of meteorological data on a geographic background.
nsharp Advanced interactive sounding analysis program
ntrans Displays and animates N-AWIPS graphics metafiles in an X-Window.
nwx Displays text products from the Family of Services (FOS) data feed.

## Decoders

GEMPAK Function Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
dcacars NetCDF ACARS data
dcacft Raw AIREP, PIREP, RECCO, and AMDAR reports
dcairm AIRMET (AIRman's METeorological Information) reports
dccosmic
dccsig Convective signet and convective outlook reports
dcffa Flash flood watch reports
dcffg Flash flood guidance data
dcgmos GFS MOS
dcgrib GRIB
dcgrib2 GRIB2
dchrcn Forecast/advisory reports for tropical depressions, tropical storms, and hurricanes for the Atlantic and Pacific oceans.
dcigdr IGDR data in BUFR format
dcisig SIGMET reports
dclsfc Land surface synoptic reports
dcmetr Raw SAO and METAR reports
dcmsfc Raw buoy, ship, C-MAN, and Coast Guard reports
dcncon Non-convective SIGMET reports
dcncprof NetCDF format profiler and RASS reports from NOAA/FSL
dcnexr2 CRAFT IDD data stream
dcnldn NLDN lightning data reports
dcnmos NGM MOS
dcprof BUFR format profiler reports
dcrdf Regional digital forecast (RDF)
dcredbook Creates displays of Redbook graphic format products
dcscd Supplemental Climatological Data reports
dcshef Raw SHEF reports
dcshef_comet Data feed (LDM) raw SHEF reports
dcstorm Severe storm reports from SPC
dcsuomi NetCDF format SUOMINET data
dcsvrl Severe local storm reports (tornado and severe thunderstorm watch reports)
dctaf Raw terminal aerodrome forecast (TAF) reports
dctama TAMDAR data in BUFR format
dctrop Hurricane/tropical storm reprots
dcuair Upper air sounding data
dcuspln USPLN lightning data reports
dcwarn Flash flood, tornado, and severe thunderstorm warning reports
dcwatch WWUS40 format severe thunderstorm and tornado watch box bulletins
dcwcp Tornado and severe thunderstorm Watch Corner Points (WCP) reports
dcwou Watch outline update reports
dcwstm Winter storm reports
dcwtch Tornado and severe thunderstorm watch box reports and watch status reports
dcxmos GFSX MOS

## Programs

GEMPAK Function Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
acprof Draws profiles of ACARS data
bfr2gp Transfers data from a Jack Woollen BUFR file into GEMPAK sounding and surface data files
bufrenc Processes ASCII input file to produce one or more BUFR output files
cpcgstn Searches for stations located inside specified area from a vector graphics file
gd2ndfd Converts a GEMPAK grid to an NDFD GRIB2 file
gdbiint Interpolates grids from one projection to another
gdcfil Creates a GEMPAK grid file
gdcntr Draws contour lines through a scalar grid matplotlib.axes.Axes.contour No
gdcross Displays a vertical cross section of scalar and/or vector grids
gddelt Deletes grids from GEMPAK grid files
gddiag Computes a scalar/vector diagnostic grid and adds it to the grid file
gdedit Reads grids from a sequential edit file and adds them to a GEMPAK grid file
gdfrzl Generates GFA FZLVLs in VG format from a scalar grid
gdgrib2 Computes a scalar diagnostic grid and adds it to a GRIB2 file
gdgrib Computes a scalar diagnostic grid and adds it to a GRIB file
gdgsfc Computes grid data and interpolates to stations in a GEMPAK surface file
gdinfo Lists information about GEMPAK grid files
gdlist Lists data from a scalar grid
gdmap Plots data from a scalar grid
gdmod Moves grids from one GEMPAK grid file to another
gdobscnt Creates a gridded sampling of the number of surface observations within a specified radius of each grid point.
gdomeg Computes grids of vertical motion and adds them to the grid file
gdplot2 Draws contour lines through scalar grids and/or wind barbs or arrows or streamlines through vector grids. Multiple sets of contours, vectors, and/or streamlines can be generated for each frame.
gdplot3 Draws contour lines through scalar grids and/or wind barbs or arrows or streamlines through vector grids. the program also plots contents of a text file and/or objects. Multiple sets of contours, vectors, streamlines, objects and/or text files can be generated for each frame.
gdplot Draws contour lines through scalar grids and/or wind barbs or arrows through vector grids. Multiple sets of contours and vectors can be generated for each frame.
gdprof Draws profiles of a scalar grid and/or a vector grid.
gdptpdf Raw cumulative probability or probability density at selected point and time at a single level.
gdpvsf Vertically interpolates grid data to an arbitrary surface.
gdstat Computes statistics on a time series of scalar grids
gdstream Draws streamlines through a vector grid
gdthgt Draws contours and wind barbs or arrows on a time selection at a point within a grid
gdtopo Creates a GEMPAK GRID file from a raster file of topography or land use values.
gdtser Draws a time series of a scalar at a single level
gdtspdf Draws contour or color fill of cumulative probability or probability density as a function of grid values and forecast time at a selected point and level or layer.
gdvint Performs interpolation between vertical coordinates
gdwind Displays a vector grid using wind barbs or arrows
gpanot Will allow the user to place objects at any location on the current graphic device
gpbox Draws a box around a region
gpclear Clears the current graphics device
gpclose Closes the specified graphics output window or file
gpcolor Changes the colors on a color device
gpend Terminates the GEMPLT subprocesses.
gpfax Creates a postscript, GIF, or TIFF file, or an X Windows display from a 6-bit fax file.
gpfront Version of GPMAP that plots map symbols interpreted from ASUS1 bulletins. Forecast front positions from FSUS2 bulletins can be plotted by specifying the forecast hour desired.
gpltln Draws a map, LAT/LON lines with a selected marker, and various image and graphic products
gpmap Draws a map, LAT/LON lines, and various images and graphic products.
gpnexr2 Displays NEXRAD level II products.
gpnids Plots NEXRAD level III products
gprcm Version of GPMAP that plots Radar Coded Message (RCM) bulletins
gpscat Draws scatterometer wave height and wind maps, LAT/LON lines, and various controllable image and graphic customizations.
gptcww Generates the track error watch/warn pilot for the TPC, using breakpoint information contained in a VGF file.
gptext Draws the contents of a text file to the output device.
gptpc Generates four hurricane graphics from the TPC. 1) Wind swath plot 2) Strike probability plot 3) Wind intensity graph 4) Wind speed table
gptraj Computes trajectories for gridded data files
gpwarn Version of GPMAP that plots filled county/zone regions from reports which use the universal generic county/zone identified lines.
grphgd Generates a grid either from contours drawn via NMAP product generation, or from a provided VGF file
img2gd Converts an image to a grid. The grid navigation specified may be different than that of the source image.
nagrib2 Converts gridded data in GRIB2 files to GEMPAK gridded data
nagrib Converts gridded data in GRIB files to GEMPAK gridded data
namsnd Transfers model profile output in BUFR to GEMPAK sounding and surface data files.
ndfdg2 Converts NDFD gridded data in GRIB2 files to GEMPAK gridded data
nex2gini Creates as GINI format image composite of NEXRAD level III products
nex2img Creates a GIF format image composite of NEXRAD level III products
nexr2rhi Displays NEXRAD level II vertical cross sections
nexrcomp Creates a GINI format image composite of NEXRAD level III products
oabox Draws a box around an objective analysis region
oabsfc Performs a Barnes objective analysis on surface data
oabsnd Performs a Barnes objective analysis on upper air data
oagrid Creates a GEMPAK grid file which can be used in a Barnes objective analysis program
sector Subsets a GINI satellite image in area and pixel resolution.
sfcfil Creates a new GEMPAK surface file
sfchck Reads a GEMPAK surface data file and produces a table of stations and an indicator showing whether each station reported data at each time in the file
sfcntr Plots surface station data on a map and optionally contours one of the fields being plotted
sfdelt Deletes data from a surface data file
sfdsl604 Lists data from a GEMPAK surface file in a fixed format for use on the AMS DataStreme website
sfedit Adds or changes data in a surface file using a sequential text file
sfgram Draws a meteorogram for surface data
sfl604 Lists data from a GEMPAK surface file in a fixed format
sflist Surface data from a GEMPAK surface data file
sfmap Plots surface station data on a map
sfmod Moves selected surface data from an input surface file to an output surface file
sfstns Modifies the station information in a surface file
sfvgsf Adds or changes data in a surface file using the elements found in a Vector Graphics File
sncfil Creates a new GEMPAK sounding file
sncross Draws cross sections through sounding data
sndelt Deletes data from a sounding data file
sndslist Lists upper air data from a sounding file for specified vertical levels and stations in a format used for the AMS DataStreme web site.
snedit Adds data in a sequential edit file to a sounding file
snhodo Draws a hodograph of upper air data
snlist Lists upper air data from a sounding file for specified vertical levels and stations
snmap Plots sounding data on a map
snmod Moves selected sounding data from an input sounding file to an output sounding file
snprof Draws profiles of upper air data
snstns Modifies the station information in the upper air file
sntser Draws a time series at a sounding station
vg2uka Converts VG files to ASCII files, using the UKMET browsable ASCII format.

## Parameters

GEMPAK Description Python/MetPy Equilvalent Grid Compatible? Tested against GEMPAK? Units?
Temperature Parameters
TMPC Temperature in Celsius
TMPF Temperature in Fahrenheit
TMPK Temperature in Kelvin
STHA Surface potential temperature in Kelvin
STHK Surface potential temperature in Kelvin
STHC Surface potential temperature in Celsius
STHE Surface equivalent potential temperature in Kelvin
STHS Surface saturation equivalent potential temperature in Kelvin
THTA Potential temperature in Kelvin
THTK Potential temperature in Kelvin
THTC Potential temperature in Celsius
THTE Equivalent potential temperature in Kelvin
THTS Saturation equivalent potential temperature in Kelvin
TVRK Virtual temperature in Kelvin
TVRC Virtual temperature in Celsius
TVRF Virtual temperature in Fahrenheit
THTV Virtual potential temperature in Kelvin
TDXC Maximum 24 hour temperature in Celsius
TDNC Minimum 24 hour temperature in Celsius
TDXF Maximum 24 hour temperature in Fahrenheit
TDNF Minimum 24 hour temperature in Fahrenheit
T6XC Maximum 6 hour temperature in Celsius
T6NC Minimum 6 hour temperature in Celsius
T6XF Maximum 6 hour temperature in Fahrenheit
T6NF Minimum 6 hour temperature in Fahrenheit
DMAX Daily weather map maximum temperature in Fahrenheit
DMIN Daily weather map minimum temperature in Fahrenheit
SSTC Sea surface temperature in Celsius
SSTF Sea surface temperature in Fahrenheit
LTMP Temperature in Celsius of surface air lifted to 500 or !x mb
Moisture Parameters
DWPC Dew point in Celsius
DWPF Dew point in Fahrenheit
DWPK Dew point in Kelvin
DPDC Dew point depression in Celsius
DPDF Dew point depress in Fahrenheit
DPDK Dew point depression in Kelvin
MIXR Mixing ratio metpy.calc.mixing_ratio
MIXS Saturated mixing ratio metpy.calc.saturation_mixing_ratio
SMXR Surface mixing ratio
SMXS Surface saturated mixing ratio
RELH Relative humidity metpy.calc.relative_humidity_from_dewpoint No
TMWK Wet bulb temperature in Kelvin metpy.calc.wet_bulb_temperature(pressures, temperatures, dewpoints).to('K') No
TMWC Wet bulb temperature in Celsius metpy.calc.wet_bulb_temperature(pressures, temperatures, dewpoints).to('degC') No
TMWF Wet bulb temperature in Fahrenheit metpy.calc.wet_bulb_temperature(pressures, temperatures, dewpoints).to('degF') No
VAPR Vapor pressure in millibars metpy.calc.vapor_pressure
VAPS Saturation vapor pressure in millibars metpy.calc.saturation_vapor_pressure
LHVP Latent heat of vaporization metpy.constants.water_heat_vaporization
PWTR Precipitable water at a given level metpy.calc.precipitable_water
Height Parameters
HGHT Height in meters
HGTM Height in meters
HGTK Height in kilometers
HGTD Height in decameters
HGFT Height in feet
HGFH Height in hundreds of feet
HGFK Height in thousands of feet
HGML Height in miles
DHGT Dry hydrostatic height in meters
MHGT Moist hydrostatic height in meters
STDZ Character standard height convention used on ua charts
RSTZ Numeric standard height convention used on ua charts
ZMSL Estimated height at a pressure level
Pressure and Altimeter Parameters
PRES Station pressure in millibars
PMSL Mean sea level pressure
PALT Surface pressure in millibars from ALTI
ALTI Altimeter setting in inches of mercury
ALTM Altimeter setting converted to millibars
SALT Abbreviated standard altimeter setting
SMSL Abbreviated mean sea level pressure in millibars
SALI Abbreviated altimeter setting in inches of mercury
RMSL First 3 digits left of decimal of PMSL * 10
RSLI First 3 digits left of decimal of ALTI * 100
RSLT First 3 digits let of decimal of ALTM * 10
PTND Pressure tendency
PTSY Graphics symbol for pressure tendency
P03C 3-h numeric pressure change
P03D Pressure tendency and change group, appp
P24C 2y-h numeric pressure change
PANY Returns PMSL if available, if not, returns ALTM
RANY Computes the 3 digit display of pressure
SANY Creates a 3 character string from integral part of PMSL or ALTM
Winds
UWND u wind in m/s
VWND V wind in m/s
UKNT U wind in knots
VKNT V wind in knows
DRCT Wind direction in degrees
SPED Wind speed m/s
SKNT Wind speed knots
SMPH Wind speed mph
PSPD Packed direction and speed m/s
PKNT Packed direction and speed in knots
GUST Wind gusts in knots
GUMS Wind gusts in m/s
PWDR Peak 5 -second wind direction in degrees
PWSP Peak 5-second wind speed in m/s
PWHR Hour of 5-second peak wind
PWMN Minutes of 5-second peak wind
WNML Wind component toward a direction 90 degrees CCW from specified direction
WCMP Wind component toward a specified direction
BARB Barb m/s
BRBM Barb m/s
BRBK Barb knots
BRBS Barb mi/hr
ARRW Arrows m/s
ARRM Arrows m/s
ARRK Arrows knots
DARR Wind direction arrows of uniform length
Lifted Condenstaion Level
TLCL Temperature in Kelvin at the LCL from the given level metpy.calc.lcl
PLCL Pressure in millibar at the LCL from the given level metpy.calc.lcl
Stability Indices
BRCH Bulk Richardson number Issue #628
BRCV BRCH computed using CAPV
BVFQ Brunt-Vaisala frequency in a layer metpy.calc.brunt_vaisala_frequency (use with metpy.calc.mixed_layer to obtain layer average)
BVPD Brunt-Vaisala period in a layer metpy.calc.brunt_vaisala_period (use with metpy.calc.mixed_layer to obtain layer average)
BVSQ Brunt-Vaisala frequency squared in a layer metpy.calc.brunt_vaisala_frequency_squared (use with metpy.calc.mixed_layer to obtain layer average)
CAPE Convective available potential energy metpy.calc.cape_cin
CAPV CAPE computed by using virtual temperature
CINS Convective inhibition metpy.calc.cape_cin
CINV CINS computed using virtual temperature
CTOT cross totals index Issue #633
EQLV equilibrium level metpy.calc.el
EQTV EQLV computed using virtual temperature
KINX K index Issue #631
LAPS temperature lapse rate in a layer Issue #638
LCLP pressure in millibars at the LCL from surface metpy.calc.lcl
LCLT temperature in Kelvin at the lcl from the surface metpy.calc.lcl
LFCT level of free convection by comparing temperature between a parcel and the environment metpy.calc.lfc
LFCV LFCT computed using the virtual temperature
LIFT lifted index Issue #632
LFTV LIFT computed using the virtual temperature Issue #632
LHAN low elevation Haines index Issue #635
MHAN middle elevation Haines index Issue #635
HHAN high elevation Haines index Issue #635
MLMR mean mixed layer MIXR
MLTH mean mixed layer THTA
PWAT Precipitable water for the entire sounding metpy.calc.precipitable_water
RICH Richardson number in a layer Issue #647
SEPA Isentropic pressure thickness in a layer
SHOW Showalter index Issue #630
SHRD wind shear direction in a layer
SHRM wind shear magnitude in a layer
STAB THTA lapse rate in a layer
STAP THTA change with pressure in a layer
SWET SWEAT index Issue #634
TOTL Total totals index Issue #633
VTOT vertical totals index Issue #633
Cloud Parameters
xCLD Character cloud coverage code
TCLD xCLD at maximum cloud coverage
xCLO Fractional cloud coverage
TCLO xCLO at maximum cloud coverage
CLCx Numeric cloud coverage
CLCT CLCx at maximum cloud coverage
CLDS combined cloud coverage short code from three levels
CMBC combined cloud coverage numeric from three levels
CLHx cloud height in hundreds of feet
CLDx combined cloud height and short code
CLDT CLDx at maximum coverage level
CLDB CLDx at the lowest ceiling/layer
COMx numeric combined cloud height and coverage combined
COMT COMx at maximum coverage level
CHCx Numeric combined cloud height and coverage combined
CHDx combined cloud height and short code
CEIL ceiling in hundreds of feet
CFRL fraction of celestial dome covered by all low and mid level clouds from WMO code 2700
CTYL low-level cloud genera from WMO code 0513
CTYM mid-level cloud genera from WMO code 0515
CTYH high-level cloud genera from WMO code 0509
CBAS cloud base height from WMO code 1600
CSYL cloud graphics symbol for CTYL
CSYM cloud graphics symbol for CTYM
CSYH cloud graphics symbol for CTYH
CSYT cloud graphics symbol for first level reporting clouds
CFRT cloud coverage number from CLCT (maximum clouds)
SKYC cloud coverage graphics symbol for CFRT
SKYM sky coverage symbol with wind barbs m/s
SKYK sky coverage symbol with wind barbs knots
XVFR categorical identification of flight rules
Weather Codes
WCOD character weather code
WNUM numeric weather code
WTMO character WMO weather code
WWMO numeric WMO weather code
WSYM graphics weather symbol corresponding to WWMO
PWTH character past weather WMO code or graphics symbol for it
PWWM numeric past weather WMO code
Station Parameters
STID character station identifier
STNM station number
SLAT station latitiude in degrees
SLON station longitude in degrees
SELV station elevation in meters
RANG range in kilometers
AZIM azimuth in kilometers
LATI latitude in degrees from range/azimuth
LONG longitude in degrees from range/azimuth
DELT delta time in seconds
Model Output Statistics
MXMN maximum or minimum temperature in Fahrenheit
TNTF night temperature fcst in Fahrenheit
TNCF night temperature climatology in Fahrenheit
TNAF night temperature anomaly in Fahrenheit
TDYF day temperature fcst in Fahrenheit
TDCF fay temperature climatology in Fahrenheit
TDAF day temperature anomaly in Fahrenheit
CL12 prevailing total sky cover fcst for a 12-hr period
SK12 maximum sustain surface wind spped fcst for 12-hr period
PP06 probability of precip fcst in 6-hr period
PP12 probability of precip fcst in 12-hr period
PP1C probability of precipitation climatology in a 12-hr period
PP1A probability of precipitation anomaly in a 12-hr period
PP24 probability of precipitation fcsr in a 24-hr period
PP2C probability of precipitation climatology in a 24-hr period
PP2A probability of precipitation anomaly in a 24-hr period
QP06 Quantitative precipitation fcst in a 6-hr period
QPX2 Maximum amount of precipitation in inches fcst in a 12-hr period. Values are same as QP12.
QP12 Quantitative precipitation fcst in a 12-hr period
QP24 Quantitative precipitation fcst in a 24-hr period
TS06 Unconditional probability of thunderstorms occurring in a 6-hr period
TS12 Unconditional probability of thunderstorms occurring in a 12-hr period
TS24 Unconditional probability of thunderstorms occurring in a 24-hr period
TC06 Unconditional probability of severe weather occurring in a 6-hr period
TC12 Unconditional probability of severe weather occurring in a 12-hr period
PCPT Categorical forecast of precipitation
POZP Conditional probability of freezing precipitation
POSN Conditional probability of snow
SN06 Categorical forecast of snow amount falling in a 6-hr period
SN12 Categorical forecast of snow amount falling in a 12-hr period
SN24 Categorical forecast of snow amount falling in a 24-hr period
PZ12 Conditional probability of freezing precipitation in a 12-hr period
PS12 Conditional probability of snow in a 12-hr period
PR12 Conditional probability of mixed liquid/frozen precipitation in a 12-hr period
PC12 Categorical forecast of precipitation type in a 12-hr period
FCIG Categorical forecast of ceiling height conditions
FVIS Categorical forecast of visibility conditions
FVSA Categorical forecast of visibility conditions (for new MOS)
OVIS Categorical forecast in plain language of obstructions to vision
WXPB Categorical weather precipitation probability or areal coverage determined by the precipitation parameter having the highest probability or areal coverage in WNUM.
TAF Parameters
TDRC Temporary/probability wind direction in degrees
TSKN Temporary/probability wind speed in knots
TGST Temporary/probability wind gusts in knots
BRGK Gust barb feathered in knots
TCHx Temporary/probability numeric combined cloud height and coverage, as for CHCx
TCEL Temporary/probability ceiling in hundreds of feet, as for CEIL
TSKC Temporary/probability cloud coverage graphics symbol, as for SKYC
TXVF Temporary/probability categorical identification of flight rules, as for XVFR
TWNM Temporary/probability numeric weather code, as for WNUM
TWSY Temporary/probability graphics weather symbol corresponding to TWNM, as for WSYM
TVSB Temporary/probability visibility in statute miles
PPRB Probability for TAF forecast change indicator
VWNM Vicinity numeric weather code, as for WNUM
VWSY Vicinity graphics weather symbol corresponding to VWNM, as for WSYM
TVWN Temporary/probability vicinity numeric weather code, as for WNUM
WSKC Worst case cloud coverage graphics symbol, as for SKYC
WXVF Worst case categorical identification of flight rules, as for XVFR
TPWN Temporary/probability/vicinity numeric weather code, as for WNUM
TPWS Temporary/probability/vicinity graphics weather symbol corresponding to TPWN, as for WSYM
AWNM Prevailing/temporary/probability/vicinity numeric weather code, as for WNUM
AWSY Prevailing/temporary/probability/vicinity graphics weather symbol corresponding to AWNM, as for WSYM
LLWS Low level wind shear forecast flag
MOTV Mountain obscuration threshold value in hundreds of feet
CMSL Ceiling converted to mean sea level in hundreds of feet
MOBS Mountain obscuration threshold met indicator
TCMS Temporary/probability ceiling converted to mean sea level in hundreds of feet
TMOB Temporary/probability mountain obscuration threshold met indicator
WCMS Worst case ceiling converted to mean sea level in hundreds of feet
WMOB Worst case mountain obscuration threshold met indicator
TCTL Temporary/probability low-level cloud genera from WMO Code 0513, as for CTYL
TCSL Temporary/probability cloud graphics symbol for TCTL, as for CSYL
Marine Parameters
WHGT Wave height in meters
WHFT Wave height in feet
WPER Wave period in seconds
HOWW Height of wind wave in meters
POWW Period of wind wave in seconds
HOSW Height of predominant swell wave in meters
POSW Period of predominant swell wave in seconds
DOSW Direction of predominant swell wave in degrees
HOS2 Height of secondary swell wave in meters
POS2 Period of secondary swell wave in seconds
DOS2 Direction of secondary swell wave in degrees
WAV2 Combined wind wave period and height in feet ("2 group")
WAV3 Combined predominant and secondary swell wave direction in tens of degrees ("3 group")
WAV4 Combined predominant swell wave period and height in feet ("4 group")
WAV5 Combined secondary swell wave period and height in feet ("5 group")
WPHM Combined wave period and height in half meters
WVSW Combined swell wave direction, period and height in half meters
SWEL Character combined swell wave direction, period and height in half meters
DAWV Swell wave direction arrows of uniform length
IDTH Thickness of ice on ship in meters
ROIA Rate of ice accretion on ship from WMO Code 3551
IGRO Rate of ice accretion on vessel in salt water in inches per three hours
DIGR Character rate of ice accretion in inches per three hours
SHPD True direction from which ship is moving (for 3 hours before obs) in degrees
SHPK Ship's average speed (for 3 hours before obs) in knots
DASH Ship's true direction arrows of uniform length
PMN1 Lowest 1-minute average pressure in previous hour in mb
PMNT Time of lowest 1-minute average pressure, as hhmm
PKWD Direction of 1-minute peak wind in previous hour in degrees
PKWK Highest 1-minute mean wind speed in previous hour in knots
PKWS Highest 1-minute mean wind speed in previous hour in m/sec
PKWT Time of highest peak 1-minute wind in previous hour, as hhmm
BRPK Wind barb (knots) for highest peak 1-minute wind
Aircraft Parameters
TURB Amount of turbulence
TBSE Base of turbulence in feet
TTOP Top of turbulence in feet
HBOT Base of turbulence in meters
HTOT Top of turbulence in meters
FQOT Frequency of turbulence
TPOT Type of turbulence
TBSY Graphics symbol for turbulence
ICNG Amount of airframe icing
IBSE Base of icing in feet
ITOP Top of icing in feet
HBOI Base of icing in meters
HTOI Top of icing in meters
TPOI Type of icing
ICSY Graphics symbol for icing
WBSE Base of weather in feet
WTOP Top of weather in feet
HBWX Base of weather in meters
HTWX Top of weather in meters
CLC1 Numeric cloud coverage 1
CBS1 Cloud base 1 in feet
CTP1 Cloud top 1 in feet
CB1M Cloud base 1 in meters
CT1M Cloud top 1 in meters
CLC2 Numeric cloud coverage 2
CBS2 Cloud base 2 in feet
CTP2 Cloud top 2 in feet
CB2M Cloud base 2 in meters
CT2M Cloud top 2 in meters
ACRT Aircraft report type
SELV Flight level in meters
FELV Flight level in hundreds of feet
ITSY Icing type symbol
TTSY Turbulence type symbol
TFSY Turbulence frequency symbol
ACTP Character aircraft type
ATP1 Numeric aircraft type
Miscellaneous Parameters
VSBY Visibility in statute miles
VSBK Visibility in kilometers
VSBN Visibility in nautical miles
VSBF Character visibility in fractions of statute miles for visibilities between 0. and 1.
VSBC Character visibility in fractions of statute miles for all visibility numbers
PnnI Precipitation over last nn hours in inches
PnnM Precipitation over last nn hours in millimeters
DPRC Character daily weather map precipitation in inches
PR24 Precipitation over last 24 hours in inches, as sum of four successive 6-hour precip amounts
SNOW Snow depth in inches
SNEW Amount of new snow in inches
SNRT Forecast snow and ice pellet accumulation to watch threshold ratio
SI12 Forecast snow and ice pellet 12-h accumulation in inches
SNIP Snow and ice pellet watch threshold in inches
FZRT Forecast freezing rain accumulation to watch threshold ratio
FZ12 Forecast Freezing rain 12-h accumulation in inches
FZRN Freezing rain watch threshold in inches
WEQS Water equivalent of snow on the ground in inches
HAIL Hail flag
HLSZ Hail size in centimeters
DDEN Density of dry air in kg/(m**3) metpy.calc.density(mixing=0)
PSYM Montgomery stream function in m**2/(100*s**2) metpy.calc.montgomery_streamfunction
HEAT Heat index in Fahrenheit metpy.calc.heat_index
HMTR Humiture (apparent temperature) in Fahrenheit
WCEQ Wind chill equivalent temperature in Fahrenheit metpy.calc.windchill
WCHT Revised wind chill temperature in Fahrenheit
MSUN Duration of sunshine in minutes
FFnn Flash flood guidance for next nn hours in inches
TOST Type of station (manned or automatic)
STIM Report hour and minutes as hhmm
TEXT Undecoded data
SPCL Undecoded special reports
MARK Markers
FOSB Fosberg Index, also called Fire Weather Index
Spacing Parameters
BLNK Plot a blank, not accounted for in FILTER
SPAC Plot a space, accounted for in FILTER
ADDSTN Logical variable which indicates whether stations which are in STNFIL, but not already included in the data file, should be added to the data file.
AFOSFL The name of the AFOS graphics file to be displayed.
AIRM The ending valid time for the airmet, the colors for the instrument flight rules, mountain obscuration, turbulence, icing, sustained winds and low-level wind shear, and flags for plotting symbols or airmet type, the end time, and the flight levels on the map.
ANLYSS The average station spacing and the grid extend region.
ANOTLN The line attributes for annotation.
ANOTYP Specifies the fill type for annotation.
AREA The data area. Only data within the area specified will be processed.
ASCT The ending valid time for the AScat wind data, the speed intervals and colors, the wind barb size and width and plotting flags. Skip is a value that indicates how many rows and data points to skip when plotting. The flags include High Wind Speed, Low Wind Speed, KNMI Quality Control Fail, Redundant Data.
ASDI The ending valid time for ASDI data, the mode of the display, the time increments (in minutes going back from the ending time) and the corresponding colors for the ASDI data.
ATCF The initial time for the ATCF forecast tracks, the colors for each model track, the model names, flags for plotting the time, the storm name or number, the forecast wind speeds and markers at each forecast time, and an optional specific storm identifier.
AWPSFL The name of the AWIPS graphics file to be displayed.
BND Specifies the parameters needed for processing bounds areas.
BORDER The color, line type and line width of the background and underground plot.
BOUNDS Specifies the bound area(s) to consider when performing the graph-to-grid procedure.
BOXLIN Line attributes for a box drawn around a region
BUFRFIL The BUFR output file names.
CALIMG Allows the user to select whether to use the calibration values supplied with an image, or raw pixel values.
CATMAP A string that contains "label=value" pairs.
CBTOP User estimated cloud top height in meters. The default value is 8000 m.
CENTER Allows the GD2NDFD user to specify the originating or generating center ID and sub-center ID, as well as the Generating Process/Model ID.
CINT The contour interval, minimum and maximum values and number of digits.
CLEAR A logical variable which determines whether the graphics screen is cleared before plotting.
CLRBAR Specifies the characteristics of a color bar associated with contour fill.
CNTRFL The name of the file containing contour information.
CNTR Specifies the plot attributes for Cell Centroid movement barbs (knots).
CNTRPRM The SFPARM to contour.
COLORS Specifies a list of color numbers.
COLUMN Specifies the number of columns for plotting the contents of an ASCII text file specified by TXTFIL.
COMPRESS A flag to determine whether the output will be written in compressed format.
CONTUR Sets attributes for the contour algorithms.
CPYFIL Identifies the location of the grid navigation and analysis information to be stored in a grid file, as well as an optional subarea.
CSIG The ending valid time for the convective sigmet and convective outlook, the colors for the initial hour (0-hr) CSIG, extrapolated 1-hr CSIG, extrapolated 2-hr CSIG, and outlook, and flags for plotting the 0-hr CSIG sequence number, end time, direction/speed, flight level, intensity, 1-hr CSIG sequence number, and 2-hr CSIG sequence number on the map.
CTLFLG A logical flag which indicates whether control characters are included in a raw surface data set to be decoded.
CTYPE Specifies the contouring algorithms to use.
CURVE A number corresponding to the method to be used to fit the curve.
CXSTNS Defines the x-axis for a cross-section plot.
CYCLE The cycle name tag put into the VGF files.
DATOUT The date and time which will be assigned in the output file.
DATTIM The date and time to be used by GEMPAK programs.
DELTAN The average station spacing in degrees of latitude. The Barnes objective analysis programs use this number to compute weights for data interpolation.
DELTAX The spacing between grid points in the x direction on CED grids. This value is in degrees longitude.
DELTAY The spacing between grid points in the y direction on CED grids. This value is in degrees latitude.
DELZ The user chosen average height difference between pressure levels to be used in the vertical interpolation. The default value is 500 m.
DESIRE The value of the output vertical coordinate variable to which the input variables should be interpolated.
DEVICE Specifies the graphics device.
DISCRETE A string that contains "value1-value2=value3" pairs.
DITHER Used to specify the plotting behavior of the reflectivity intensities.
DLINES Indicates whether the direction of lines (order of points) should be taken into consideration when performing a graph-to-grid contour analysis.
DTAAREA Defines the area over which station data will be input to the Barnes objective analysis.
ECHO Specifies whether to plot the grid box intesities.
EDGEOPTS An option which allows users to specify boundary conditions for the analysis.
EDR Starts with the ending valid time for EDR data followed by corresponding colors for the EDR data over the time limit specified.
ENCY The initial time for the ENCY forecast tracks, the colors for each model track, the model names, flags for plotting the time, the forecast pressures and markers at each forecast time.
EXTEND Specifies the numbers of grid points beyond the GRDAREA which define the grid extend area in the Barnes objective analysis. The first pass is computed on the extend area to reduce edge effects on the GRDAREA.
FAXFIL The name of a 6-bit FAX product.
FFA The ending valid time for the flood watches, the colors for the flash flood and areal flood watches, a flag for plotting the start and stop times, a flag for plotting the zone names for the storms on the map, a flag for plotting the immediate cause for the flooding, and a flag to outline the zone.
FHOUR The forecast hour, e.g., 18, or 24, which defines the "f" value in the BUFRFIL name.
FHR The forecast hour of freezing levels. FHR can be a single hour or a range.
FILTER A logical variable or real number which controls the filtering of data in order to eliminate plotting of overlapping data.
FILTYP The filter type.
FINT The contour fill interval, minimum and maximum values.
FLINE The color and fill type to be used for contour fill.
FXYTBL The FXY table file names.
G2DIAG Allows for detailed GRIB2 message section information, entry-by-entry, to be printed out for selected GRIB2 messages.
G2DRT Specifies the scaling and packing options when encoding the GRIB2 message.
G2IDS A list of integers that are encoded into the GRIB2 Identification Section ( Section 1 ) that identifies the source and type of data packed in the GRIB2 message.
G2IS A list of integers that are encoded into the GRIB2 Indicator Section ( Section 0 ) that identify the discipline and version of the GRIB2 message.
G2PDT Can be used to specify any or all of the values in the Product Definition Template (PDT), describing the grid in the output GRIB2 message.
G2TBLS Allows for specification of the GRIB2 decoding tables.
GAIRM Makes provision to plot the G-AIRMET snapshots in 3-hour time bins.
GAMMA The convergence parameter, is a multiplier for the weight and search radius for passes after the first pass of the Barnes analysis programs.
GAREA The graphics area.
GBDIAG Allows for detailed GRIB message section information, byte-by-byte, to be printed out for selected GRIB messages.
GBFILE The name of the file which contains gridded data in GRIB messages.
GBTBLS Allows for specification of the GRIB decoding tables.
GCENTER Sets the center latitude-longitude on the ETA model domain.
GDATTIM The date/time for the grid.
GDEFIL The name of the grid edit file which will be used to update a grid file.
GDFILE The name of the file which contains gridded data.
GDNUM Allows the user to select grids by number.
GDOUTF The output grid data file name.
GDOUTL The output vertical level in the target vertical coordinate.
GDPFUN Specifies a grid diagnostic function which yields either a scalar or vector quantity.
GFUNC Specifies a grid diagnostic function which yields a scalar quantity.
GGLIMS The parameter which controls the grid value limits and values.
GGVGF The name of the VGF file.
GLEVEL The vertical level for the grid.
GPACK The packing type and the number of bits (or data precision) to be used to pack the grid data.
GPOINT The grid location to be used for the plot.
GRDAREA Specifies the area to be covered by the grid.
GRDHDR A list of the valid grid header flags.
GRDLBL The color number to be used in plotting the grid index numbers.
GRDNAM The parameter name for the grid.
GRDTYP The type of a diagnostic grid.
GSKIP Allows the NDFDG2 user to specify a skip factor in order to reduce the resolution of the resulting GEMPAK grid.
GSPACE Sets the grid spacing of the ETA model domain.
GUESFUN Specifies one or more grid diagnostic functions that compute the first guess grid for a Barnes objective analysis.
GUESS The name of the file which contains the first guess gridded data for objective analysis programs.
GVCORD The vertical coordinate of the grid to be selected.
GVECT Specifies a grid diagnostic function which yields a vector quantity.
GVOUTC The vertical coordinate of the output grid.
HILO Contains the information for plotting relative highs and lows.
HISTGRD Toggles the writing of the graph-to-grid history grid to the GEMPAK grid file.
HLSYM Defines the characteristics for the HILO symbols.
HRCN The ending valid time for the tropical disturbance, the colors for the hurricanes, tropical storms, tropical depressions and directional arrows, the symbols for the hurricanes, tropical storms and tropical depressions, and flags for plotting the center located time, the name and minimum central pressure, the speed, the wind and sea quadrant radii, and the forecast track on the map.
IDNTYP Sets character or numeric station identifiers to be used for input or output.
IJSKIP Used to control subsetting of the internal grid by declaring bounding index values and numbers of points to skip in each index direction, I and J.
IMCBAR Specifies the characteristics of a color bar for images.
IMGFIL The name of an image file.
IMGTIM The date and time to be used.
IMJM Sets the number of grid points for workstation eta in the N-S and E-W direction.
INDXFL The name of the file which contains the GRIB message header information.
INFO The information needed to define the object to be plotted.
INTERP A logical variable which determines whether interpolation between sweeps will occur.
ISIG The ending valid time for the international SIGMET, the colors for the thunderstorms, turbulence, hurricanes, tropical storms, tropical depressions, volcanic ash clouds, marked mountain waves, tropical cyclones, squall lines, CAT, icing, hail, duststorms, sandstorms, cumulonimbus, and low level wind shear, flags for plotting symbols or storm names, the start and end times, the message id, the direction and speed, and the flight level or the central pressure and maximum wind speed associated with a tropical cyclone on the map.
KEYCOL Indicates which contour lines to process.
KEYLINE Indicates which contour lines to process based on VGTYPE and SUBTYP.
KXKY Specifies the size of a grid as two numbers.
LAT Specifies the latitude grid lines to be drawn.
LATLON Specifies the latitude and longitude grid lines to be drawn.
LEVELS Specifies the vertical levels to be extracted from the data set.
LINE The color, line type, line width, line label frequency, smoothing separated by slashes, and flag to suppress small contours.
LOCI The point(s) needed to place the object to be plotted.
LON Specifies the longitude grid lines to be drawn.
LSTALL A flag indicating whether the full contents of a file are to be listed.
LSTPRM Specifies a field to list on the side of the display. Stations are added to the list if they are filtered from the map.
LTNG The ending valid time for lightning data, the time increments (in minutes going back from the ending time) and the corresponding colors for the lightning data, and the positive and negative markers to display.
LUTFIL Specifies a lookup table file name used to enhance the colors for satellite or radar images.
LVLINCR Specifies the freezing level increment.
MAPFIL The name(s) of the map file(s) to be used for maps drawn by GEMPAK programs.
MAP The map color, line type and line width.
MARKER Specifies the marker color, type, size, line width and hardware/software flag.
MAXGRD The maximum number of grids that can be stored in the grid file being created.
MAXTOP Specifies the color and filter attributes for cell top annotations (feet).
MESO Specifies the plot symbol and filter attributes for mesocyclones.
MIXRLN Specifies the color, line type, line width, minimum, maximum, and increment for the background mixing ratio lines on thermodynamic diagrams.
MRGDAT A logical variable indicating whether sounding data is to be merged or unmerged.
MSCALE Specifies the characteristics of a scale legend associated with map projections.
MXDPTH The user estimated mixed layer depth in meters.
NCON The ending valid time for the non-convective sigmet, the colors for the icing, turbulence, duststorm and sandstorm, and volcanic ash, and flags for plotting symbols, the end time, the message id, and the flight levels on the map.
NDVAL The data value to be used where NIDS products report "ND" (none detected).
NPASS Controls the number of passes for the Barnes objective analysis.
NTRACE The number of traces to be drawn in SFGRAM.
OAATTR Contains attributes to use for objective analysis in the graph to grid function.
OABND Specifies the bounds file(s) to use for 'blocking'.
OAGUESS Contains the information to use as a first guess for objective analysis in the graph to grid function.
OLKDAY The day of the extended oulook.
OSCT The ending valid time for the OScat wind data, the speed intervals and colors, the wind barb size and width and plotting flags.
OUTFIL The name of an output satellite image file.
OUTPUT Determines the output devices.
OVERWR Allows the user to specify whether existing GEMPAK grids in a file should be overwritten or left unchanged.
PANEL Specifies the panel location, panel outline color, line type and width.
PDSEXT A logical flag which only becomes applicable when a PDS extension exists in the GRIB message.
PDSVAL Provides a way to enter explicitly PDS numbers identifying a grid by parameter, level, vertical coordinate type, and time.
PIXRES The input for how many pixels and lines to include in the new image.
PLUS Specifies the size and width of a plus sign.
PMAX Defines the maximum possible pressure from which data may be interpolated to the output vertical coordinate.
POSN The position number and the format of the text to be used to plot data in GDMAP.
PRBTYP Specifies the probability type.
PRECSN The binary or decimal precision to be preserved in the packing of the gridded data.
PROJ The map projection, projection angles, and margins.
PTYPE The type of y axis plot to be used, the height-to-width ratio of the plot, and the margins.
QCNTL The quality control threshold values.
QSCT The ending valid time for the QuikScat or ambiguity wind data, the speed intervals and colors, the wind barb size and width and plotting flags.
RADDUR The length of time (in minutes) prior to RADTIM for which data will be used in composites.
RADIUS The search radius (in meters) for which data will be considered.
RADMODE Allows the user to select whether to include radar data from sites operating in (P) precipitation/storm mode, (C) clear air mode, and/or (M) maintainence mode.
RCMFIL The RCM data file.
REFVEC Specifies the size and location on the screen of the.reference arrow.
REGION Specifies an areal location.
RESPOND A logical variable indicating whether the user will respond interactively to GEMPAK programs.
ROTATE The angle of rotation for the coordinate axes.
RTRAJ A logical variable which determines whether the trajectory will start or end at the specified GPOINT.
SATFIL The name of a satellite image file.
SCALE The scaling factor for the data.
SEARCH Controls the search radius in an objective analysis program.
SFEFIL The name of the surface edit file to be used to update a surface file.
SFFILE The name of the surface data file to be accessed.
SFFSRC The surface file source.
SFOUTF The output surface data file.
SFPARM A list of surface parameters to be used in a surface program.
SFPRMF Specifies the packing information for the surface file to be created.
SGWH The ending valid time for the significant wave height data, the height intervals and colors.
SHAPE The object that the user wishes to plot on the current graphics device.
SHIPFL A logical variable which indicates whether the surface file contains stations which are not at a fixed location, such as moving ships, aircraft, or floating buoys.
SKIP A variable which determines the contour points or plot points to skip.
SKPMIS A logical variable which indicates whether non-reporting stations will be listed.
SNBUFR The name of the BUFR model sounding file to be used as input to create GEMPAK sounding and surface data files using program NAMSND.
SNEFIL The name of the sounding edit file to be used to update a sounding data file.
SNFILE The filename for an upper air data set.
SNOUTF The output sounding data file.
SNPARM A list of upper air parameters to be used in an upper-air program.
SNPRMF Specifies the packing formation for the sounding file to be created.
SOURCE Indicates whether the data used to compute the average station spacing are to be read from a surface or sounding file.
SPLINE A logical for using splines to interpolate the data to height levels.
SQUALL The length of the squall line used for the air and moisture flux calculations.
STARTL The level in the input data file at which to begin the search for the output vertical level in gdpvsf.
STAT The issuing status of the GFA freezing levels.
STATION The station to use in SFGRAM.
STNCOL Specifies the color for the station identifier, time and the parameters specified in STNDEX.
STNDEX The list of stability indices or station parameters for upper-air data.
STNFIL The name of a file which contains station information which includes the character identifier, number, name, state, country, latitude, longitude and elevation for each station.
STNPLT Allows the user to plot station markers and station information.
STNTYP Used to select the data reporting characteristic of a station.
STOPL The level in the input data file at which to end the search for the output vertical level in gdpvsf.
STREAM Controls several parameters dealing with the overall streamline calculation and display.
STRMID Specifies the storm identifier used by programs GPTPC and GPTCWW.
SVRL The ending valid time for the SLS watches, the colors for the severe thunderstorm and tornado (SLS) watches, a flag for plotting the start and stop times, a flag for plotting the county names for the watches on the map, and a flag to outline the county.
SYSTEM The system (storm) speed (m/s) and direction.
TAG Used to identify a group of GFA FZLVL elements.
TAXIS Contains the range, increment and location for labels on a time axis.
TCMG The ending valid time for the tropical disturbance, the colors for the disturbance symbol, the arrows, and the storm danger area, and the name of the center issuing the graphic.
TEXT The size, font, text width and hardware/software flag for graphics text.
THTALN Specifies the color, line type, line width, minimum, maximum, and increment for the background dry adiabats (potential temperature lines) on thermodynamic diagrams
THTELN Specifies the color, line type, line width, minimum, maximum, and increment for the background moist adiabats (equivalent potential temperature lines) on thermodynamic diagrams
TILT The Radar beam elevation/tilt angle.
TIMSTN Contains the maximum number of times to include in a file and the number of stations to be included in addition to the stations in STNFIL.
TITLE The title color, title line, and title string.
TOPOFL The topographic input file.
TRACE Specifications for each trace on the meteogram.
TRAK The ending time for the Altimetric Satellite Ground Track Prediction data, and the color of the prediction.
TROPHT The user estimated tropopause height in meters.
TRPINT The user chosen distance above (and below) the tropopause which is used for layer calculations.
TSTEP Specifies the time step, in minutes, for the calculation of updated position of the parcel within the grid domain.
TVS Specifies the plot symbol and filter attributes for tornado vortex signatures.
TXTCOL Specifies the color number for text, NOAA or NWS logo.
TXTFIL Specifies an ASCII text file to be read and displayed to the current device driver.
TXTLOC Specifies the start location for plotting the contents of an ASCII text file specified by TXTFIL.
TXTYPE Specifies the text attributes.
TYPE Specifies the processing type for the GDPLOT2 GDPFUN parameter.
UKAFIL The intermediate input/output ASCII file.
VCOORD Specifies the vertical coordinate system of the levels to process.
VERCEN Allows the GDGRIB user to specify the contents of bytes 4, 5, 6, and 26 of the GRIB PDS.
VGFILE The name of the Vector Graphics File (VGF) to be displayed or processed.
WARN The ending valid time for the warnings, the colors for the severe thunderstorm, tornado and flash flood warnings, a flag for plotting the start and stop times, a flag for plotting the county names for the warning on the map, a flag to outline the county, and a flag to plot warning polygon.
WATCH The ending valid time for the watches, the colors for the severe thunderstorm and tornado watches and a flag for plotting the start and stop times for the watch on the map.
WAVLEN the wavelength for the gravity or lee wave in kilometers.
WAVSPD The wave speed in m/s. This is used for calculating the SCORER parameter.
WCN The ending valid time for the watch county notification(WCN), the colors for the county bounds, a flag for plotting the start and stop times, a flag for plotting the county names for the WCN on the map, a flag to outline the county or union, a flag to fill the county or union, and a union flag.
WCP The ending valid time for the watches, the colors for the severe thunderstorm and tornado watches and flags for plotting the start and stop times and watch numbers for the watches on the map.
WEIGHT The Barnes weighting parameter.
WIND Specifies the wind symbol, size, width, type, and head size.
WINPOS Specifies the position for plotting winds for vertical profile plots.
WMOHDR Allows specification of a WMO header for a GRIB message.
WOU The ending valid time for the watch outline update (WOU), the colors for the county bounds, a flag for plotting the start and stop times, a flag for plotting the county names for the WOU on the map, a flag to outline the county or union, a flag to fill the county or union, and a union flag.
WSAT The ending valid time for the WindSAT wind data, the speed intervals and colors, the wind barb size and width and plotting flags.
WSPDA The ending valid time for the Altika wind speed data, the speed intervals and colors, and time stamp intervals and colors.
WSPDALT The ending valid time for the altimeter-derived wind speed data, the speed intervals and colors, and time stamp intervals and colors.
WSTM The ending valid time for the winter storms, the colors for the storm warning, watch and advisory, a flag for plotting the start and stop times, a flag for plotting the zone names for the storms on the map, and a flag to outline the zone.
XAXIS Contains the left bound, right bound, label increment, and frequency information.
YAXIS Contains the lower bound, upper bound, label increment, and frequency information.