GEMPAK Manual |
Programs | Parameters
SFPARM
SFPARM is a list of surface parameters to be used in a surface
program.
The four-character parameter names must be separated by semicolons.
For example:
SFPARM = TMPF;DWPF;WTHR
If a parameter is not present in a data set, the program will
attempt to derive it from those parameters which are present.
For example, relative humidity can be computed from the temperature
and dewpoint temperature. Note that STHA, STHE, and SMXR are
computed from PALT.
In plotting programs, the position of the parameter determines
where it will appear with respect to the station location.
The first position is centered on the station. The other
positions are shown below:
18 14 8 16 22
19 2 10 4 23
12 3 1 5 13
20 6 11 7 24
21 15 9 17 25
In the example above, WTHR is plotted in position 3.
Functions can be used to modify/qualify the output parameters.
These functions must follow the parameter name and are applied in
the order given; however, arithmetic operators must precede the
other operators. The function symbols must precede the qualifying
value and are defined as follows:
* multiply = equal to
/ divide $ direction
+ add < less than or equal to
- subtract > greater than or equal to
In the case of weather symbols, the size, line width and other
information needed to draw the symbol may be specified following a
colon after the symbol name and after the function specifications
if any exist. The drawing attributes are separated by colons. For
all the symbols, the information is entered as:size:width;for arrows
and barbs the information is entered as :size:width:type:headsiz,
where the headsiz applies only to arrows. The type is a three-digit
number, ABC, interpreted digit by digit as follows:
A B C
1 = plot calm wind 1 = start at stn 1 = not filled
2 = ignore calm wind 2 = center at stn 2 = filled
3 = start on sky symbol 3 = not filled with box
4 = filled with box
Calm winds are plotted as a circle or an arrowhead for barbs and
arrows, respectively. Arrowheads and 50-unit barb flags are filled
if C=2 or 4. A box is plotted with background color if C = 3 or 4.
For example, if TYPE=132, a barb will be plotted as a circle if the
wind is calm; it will begin on the edge of the cloud cover symbol,
and 50-unit flags will be filled. The default is 111 unless sky
symbols are being plotted in which case it is 131.
The text size and line width can also be specified for plotting numerical
data such as temperature and dewpoint. These follow the parameter name,
or condition, delimited by colons. For example, TMPF:2.5:3 , would
cause temperatures to be plotted with a text size of 2.5 and a
line width of 3. Text sizes that are positive cause the data to be
plotted at the location they would appear if they were being plotted
with the largest specified text size (ie. farther from the center of
the station model than they would normally appear). Text sizes that are
negative cause the offsets from the center of the station model to be
computed based on the specified text size. NOTE: A large range of
negative text sizes may result in some degree of overplotting.
When using hardware fonts, text sizes may be named sizes. For example,
tiny, SMALL, m, -m, -LARGE, etc, are all valid specifications.
If no text size is provided for a particular data type, that data will
be plotted with the default text size specified in the TEXT parameter.
For all symbols ( weather, cloud, pressure tendency, sky cover, past
weather, icing, combination, etc. ) and wind barbs and arrows, the area
immediately surrounding the symbol may be blanked out. The resulting
effect allows the object to be more easily identified. This capability
may be invoked by adding the additional blank-out width (*100) to the
object width. For example, to blank-out an extra 8 width units
around the weather symbols of size 2 and width 3, specify the SFPARM
as WSYM:2:803.
A special value of M may be used for the = function to denote a
missing value, so that values will be plotted only when a specific
parameter is missing. For example, to plot an X when the visibility
is missing, specify SFPARM=MARK:16;VSBY=M.
Aliases are available to make it easier for the user to plot typical
surface data by using pre-set parameters and colors. To use an alias,
enter the alias name for SFPARM and leave COLORS blank. If the user
does not leave COLORS blank, the selected colors will be used instead
of the pre-set alias colors.
See PRMLST.TBL for a list of current aliases for surface data.
The GEMPAK surface parameters and the corresponding four-character
abbreviations are:
TEMPERATURE
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 equiv. pot. temp. in Kelvin
TVRC - Virtual temperature in Celsius
TVRF - Virtual temperature in Fahrenheit
TVRK - Virtual temperature in Kelvin
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 - Temp. in Celsius of surface air lifted to 500 or !x mb
MOISTURE
DWPC - Dewpoint in Celsius
DWPF - Dewpoint in Fahrenheit
DWPK - Dewpoint in Kelvin
DPDC - Dewpoint depression Celsius
DPDF - Dewpoint depression Fahrenheit
DPDK - Dewpoint depression Kelvin
SMXR - Surface mixing ratio in g/kg
SMXS - Surface saturated mixing ratio in g/kg
RELH - Relative humidity in percent
TMWK - Wet bulb temperature Kelvin
TMWC - Wet bulb temperature Celsius
TMWF - Wet bulb temperature Fahrenheit
VAPR - Vapor pressure in millibars
VAPS - Saturation vapor pressure in millibars
PRESSURE AND ALTIMETER
PRES - Station pressure in millibars
PMSL - Mean sea level pressure in millibars
PALT - Pressure in millibars from altimeter
ALTI - Altimeter setting in inches of mercury
ALTM - Altimeter setting converted to millibars
SALT - Abbreviated altimeter in millibars
SMSL - Abbreviated mean sea level pressure
SALI - Abbreviated ALTI
RMSL - First 3 digits left of decimal of PMSL * 10
RSLI - First 3 digits left of decimal of ALTI * 100
RSLT - First 3 digits left of decimal of ALTM * 10
PTND - Complete pressure tendency with symbol
PTSY - Pressure tendency symbol only
P03C - Pressure change over 3 hours
P03D - Pressure tendency and change group, appp
P24C - Pressure change over 24 hours
ZMSL - Estimated height at PMSL
Z000 - Estimated height at 1000 mb
Z850 - Estimated height at 850 mb
Z800 - Estimated height at 800 mb
PANY - Returns PMSL, if avaliable, 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
WIND
ARRW - Wind arrow (m/s)
ARRM - Wind arrow (m/s)
ARRK - Wind arrow (knots)
BARB - Wind barb (m/s)
BRBM - Wind barb (m/s)
BRBK - Wind barb (knots)
BRBS - Wind barb (mi/hr)
DARR - Wind arrows of uniform length
UWND - U component of the wind in meters/second
VWND - V component of the wind in meters/second
UKNT - U component of the wind in knots
VKNT - V component of the wind in knots
DRCT - Wind direction in degrees
SPED - Wind speed in meters/second
SKNT - Wind speed in knots
SMPH - Wind speed in miles/hour
PSPD - Packed speed and direction (ddfff) in meters/second
PKNT - Packed speed and direction (ddfff) in knots
GUST - Wind gusts in knots
GUMS - Wind gusts in meters/second
PWDR - Peak 5-second wind direction in degrees
PWSP - Peak 5-second wind speed in meters/sec
PWHR - Hour of 5-second peak wind
PWMN - Minutes of 5-second peak wind
CLOUD
For the following parameters, the character x may be
replaced by L, M, or H, indicating low, middle or high
clouds. The character T indicates the value of the parameter
at the level of maximum cloud coverage.
xCLD - Character cloud coverage
TCLD - Character maximum cloud coverage
xCLO - Fractional cloud coverage
TCLO - Fractional maximum cloud coverage
CLCx - Numeric cloud coverage
CLCT - Numeric maximum cloud cover
CLDS - Combined cloud coverage from three levels
CMBC - Numeric combined cloud coverage from three levels
CLHx - Cloud height in hundreds of feet
CLDx - Combined cloud height and coverage
CLDT - Maximum value of CLDx
CLDB - Lowest ceiling; if no ceiling, then height of lowest layer.
Height combined with short code for coverage.
COMx - Numeric combined cloud height and coverage
COMT - Maximum value of COMx
CEIL - Ceiling in hundreds of feet
For the next two cloud parameters the x can be replaced by
1, 2, or 3 and represents the cloud report number.
CHCx - Numeric combined cloud height and coverage
CHDx - Combined cloud height and short code
The following numeric cloud parameters are WMO standard
codes.
CFRT - Fraction of celestial dome covered by cloud from WMO
Code 2700
CFRL - Fraction of celestial dome covered by low or mid
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 - Low cloud type symbol
CSYM - Middle cloud type symbol
CSYH - High cloud type symbol
CSYT - Cloud type symbol on first reported level
SKYC - Sky coverage symbol
SKYM - Sky coverage symbol with wind barbs in m/s
SKYK - Sky coverage symbol with wind barbs in knots
The following numeric parameter follows the guidelines in
the National Weather Service Operations Manual, Chapter D-31.
XVFR - Categorical identification of flight rules
0 = Low Instrument Flight Rules (LIFR)
1 = Instrument Flight Rules (IFR)
2 = Marginal Visual Flight Rules (MVFR)
3 = Visual Flight Rules (VFR)
WEATHER
WTHR - Character weather code from any numeric code
WCOD - Character weather code
WNUM - Numeric weather code
WSYM - Present weather symbol
WTMO - Character weather code from WMO
WWMO - Numeric WMO weather code
PWTH - Past weather symbol
PWWM - Numeric past weather in WMO code
STATION VARIABLES
STID - Character station identifier
STNM - 5-digit station identifier
SLAT - Station latitude in degrees
SLON - Station longitude in degrees, West is negative
SELV - Station elevation in meters
SPRI - Station priority
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 - Day temperature climatology in Fahrenheit
TDAF - Day temperature anomaly in Fahrenheit
CL12 - Prevailing total sky cover fcst for a 12-hr period
1 = CL = mostly clear
4 = OV = mostly overcast
7 = PC = mixed clouds and clear skies
SK12 - Maximum sustained surface wind speed fcst for a 12-hr period
5 = light 0 - 12 knots
15 = Moderate 13 - 21 knots
25 = Strong 22 - 33 knots
40 = High greater than or equal to 34 knots
PP06 - Probability of precipitation fcst in a 6-hr period
PP12 - Probability of precipitation fcst in a 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 fcst 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
QPX2 - Maximum amount of precipitation in inches fcst in a 12-hr
period. Values are same as QP12
QP06 - Quantitative precipitation fcst in a 6-hr period
1 = 0.01 - 0.09 inches
2 = 0.10 - 0.24 inches
3 = 0.25 - 0.49 inches
4 = 0.50 - 0.99 inches
5 = 1.00 - 1.99 inches
QP12 - Quantitative precipitation fcst in a 12-hr period
0 = no precipitation expected
1 through 5 same as QP06
6 = greater than or equal to 2.00 inches
QP24 - Quantitative precipitation fcst in a 24-hr period
0 through 5 same as QP12
6 = 2.00 - 2.99 inches
7 = greater than or equal to 3.00 inches
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 - Conditional probability of severe weather occurring
in a 6-hr period
TC12 - Conditional probability of severe weather occurring
in a 12-hr period
PCPT - Categorical forecast of precipitation
0 = R = rain
1 = S = snow
2 = Z = freezing
POZP - Conditional probability of freezing precipitation
(not included during the warm season)
POSN - Conditional probability of snow
(not included during the warm season)
SN06 - Categorical forecast of snow amount falling in a 6-hr
period
0 = no snow
1 = trace to less than 2 inches
2 = greater than or equal to 2 inches
SN12 - Categorical forecast of snow amount falling in a 12-hr
period
0 and 1 same as SN06
2 = 2 to less than 4 inches
4 = 4 to less than 6 inches
6 = greater than 6 inches
(not included during the warm season)
SN24 - Categorical forecast of snow amount falling in a 24-hr
period
0 = no snow or a trace
1 = greater than a trace to less than 2 inches
2 = 2 to less than 4 inches
4 = 4 to less than 6 inches
6 = 6 to less than 8 inches
8 = greater than 8 inches
(not included during the warm season)
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
0 = R = liquid
1 = S = frozen
2 = Z = freezing
3 = RS = mixed liquid and frozen precipitation
4 = RZ
5 = SZ
6 = RSZ
FCIG - Categorical forecast of ceiling height conditions
1 = less than 200 feet
2 = 200 - 400 feet
3 = 500 - 900 feet
4 = 1000 - 1900 feet
5 = 2000 - 3000 feet
6 = 3100 - 6500 feet
7 = 6600 - 12,000 feet
8 = greater than 12,000 feet or unlimited
FVIS - Categorical forecast of visibility conditions
1 = less than 0.5 miles
2 = 0.5 - 0.875 miles
3 = 1.0 - 2.75 miles
4 = 3.0 - 5.0 miles
5 = greater than 5.0 miles
FVSA - Categorical forecast of visibility conditions (for new MOS)
1 = less than 0.5 miles
2 = 0.5 mile to less than 1.0 mile
3 = 1.0 to less than 2.0 miles
4 = 2.0 to less than 3.0 miles
5 = 3.0 to 5.0 miles
6 = 6.0 miles
7 = greater than 6.0 miles
OVIS - Categorical forecast in plain language of obstructions
to vision
0 = N = none of the following
1 = FG or F = fog or ground fog (vis. less than .625 mile)
2 = HZ or H = haze, smoke, dust
3 = BR = mist (fog with visibility greater than .625 mile)
4 = BL = blowing dust, sand, snow
WXPB - Categorical weather precipitation probability or areal
coverage determined by the precipitation parameter having
the highest probability or areal coverage in WNUM
For probability:
1 = slight chance
2 = chance
3 = likely
4 = occasional
5 = definite
For areal coverage:
1 = isolated
2 = widely scattered
3 = scattered
4 = numerous
5 = widespread
TERMINAL AERODROME FORECAST (TAF)
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
30 = PROB30 - 30 percent probability condition
40 = PROB40 - 40 percent probability condition
50 = TEMPO - temporary condition
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
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 table 3551
IGRO - Rate of ice accretion on vessel in salt water in inches
per 3 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
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 - Turbulence symbol
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 - Icing symbol
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
DDEN - Density of dry air in kg/(m**3)
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
nn = 01, 03, 06, 09, 12, 18 or 24
PnnM - Precipitation over last nn hours in millimeters
nn = 01, 03, 06, 09, 12, 18 or 24
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
HEAT - Heat index in Fahrenheit
HMTR - Humiture (apparent temperature) in Fahrenheit
WCEQ - Wind chill equivalent temperature in Fahrenheit
WCHT - Revised wind chill temperature in Fahrenheit
MSUN - Duration of sunshine in minutes
FFnn - Flash flood guidance for next nn hours in inches
nn = 01, 03, 06, 12 or 24
TOST - Type of station (manned or automatic)
0 = automatic
1 = manned
STIM - Report hour and minutes as hhmm
TEXT - Undecoded data
SPCL - Undecoded special reports
MARK - Markers
DTNM - Sea ice drifting distance in nautical miles
FOSB - Fosberg index, also called fire weather index
SPACING
SPAC - Plot a space, accounted for in FILTER
BLNK - Plot a blank, not accounted for in FILTER