McIDAS User's Guide
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Contours surface hourly data from ISFC-schema point files.
map time day [keywords]
SFCCON par1-par2 map time1-time2 day1-day2 [keywords]
parameter to contour; valid parameters are those defined in the SFCCON.CORE, SFCCON.SITE and SFCCON.USER files; see the Remarks for more information and a list of the parameters in SFCCON.CORE (default=T)
map for the contour; see the MAP command for a list of valid predefined maps, for example, FL, MID, USA, WORL (default=do not draw a map; use the navigation of the frame specified with NAV keyword)
contour interval; specify 0 to let SFCCON compute a reasonable interval; specify your own interval as an integer or decimal value greater than zero (default=from the CONTOUR.DEF text file; if no file entry matches the parameter and units, default=0)
ADDE point dataset name and position; specify as group/descriptor.position or alias.position where position is a positive integer (absolute position), 0 or a negative integer (relative position), or ALL (default=RTPTSRC/SFCHOURLY.ALL)
units for the specified parameter; see the Remarks for defaults; run the CU LIST command to list the valid units and abbreviations for the parameters that can be changed
SFCCON builds and runs a PTCON command to display surface hourly data from ISFC-schema point files. SFCCON accepts all the keywords in the PTCON command except LAT, LON, MAP, PRO, SLAT, SLON and PARAM because they may conflict with SFCCON's parameters or keywords. You can use the PTCON SELECT keyword to limit the analysis to a specified list or range of values, but you cannot specify a different parameter, time, day or unit than those defined by the SFCCON parameters or keywords.
The table below lists the parameter name, default units and a description of each parameter defined in the SFCCON.CORE file. Default units enclosed in parenthesis cannot be changed. The .CORE file is supplied with McIDAS-X and should not be modified. The .USER file overrides the .SITE file, which overrides the .CORE file. This order of precedence allows you or your site to change existing parameters and/or add new parameters in your .USER or .SITE file. To create a .USER or .SITE file, copy the .CORE file from ~mcidas/data to your $HOME/mcidas/data directory (or another MCPATH directory), rename it, then edit the existing predefined parameters and/or add new ones.
|CHILL||(F)||wind chill index|
|TD||F||dew point temperature|
|THAE||(K)||equivalent potential temperature|
|PCP||IN||three- or six-hour precipitation total; three-hour total reported only at 3, 9, 15, 21 UTC; six-hour total reported only at 0, 6, 12, 18 UTC; see the Remarks|
|PCP3||IN||three-hour PCP total; reported only at 3, 9, 15, 21 UTC; see the Remarks|
|PCP6||IN||six-hour PCP total; reported only at 0, 6, 12, 18 UTC; see the Remarks|
|PCP24||IN||24-hour precipitation total; reported at 12 UTC; see the Remarks|
|SNO||IN||snow depth; reported only at 0, 6, 12, 18 UTC; see the Remarks|
|CAC||(code)||ceiling cloud amount; 0=clear, 5=few, 1=scattered, 2=broken, 3=overcast|
|CA1||(code)||first non-ceiling cloud amount; 0=clear, 5=few, 1=scattered, 2=broken, 3=overcast|
|CA2||(code)||second non-ceiling cloud amount; 0=clear, 5=few, 1=scattered, 2=broken, 3=overcast|
|CZC||FT||height of cloud ceiling|
|CZ1||FT||height of first non-ceiling cloud layer|
|CZ2||FT||height of second non-ceiling cloud layer|
The time default is the current hour for all parameters except PCP, PCP3, PCP6, PCP24 and SNO. Because PCP and SNO are not reported every hour in METAR reports, the default for these parameters is the most recent hour storing the data. PCP is reported every three hours starting at 0 UTC. PCP3 represents the three-hour totals in PCP; it is reported at 3, 9, 15, and 21 UTC. PCP6 represents the six-hour totals in PCP; it is reported at 0, 6, 12, and 18 UTC. PCP24 represents the 24-hour precipitation totals and is reported at 12 UTC only. SNO is reported every six hours at 0, 6, 12, and 18 UTC.
This means, for example, that the time default for PCP is 0 if the current time is between 0:00 and 2:59 UTC; the time default for PCP3 is 3 if the current time is between 3:00 and 8:59 UTC; the time default for SNO and PCP6 is 6 if the current time is between 6:00 and 11:59 UTC. The time default for PCP24 is 12 UTC today if the current time is between 12:00 and 23:59 UTC, and is 12 UTC yesterday if the current time is between 0:00 and 11:59 UTC.
Parameter advection or divergence is done by appending ADV or DVG to the parameter name, e.g., TADV and SPDDVG. Parameters with their default units enclosed in parenthesis in the table above (e.g., CHILL, MIX and THA) and advected or diverged parameters cannot be used with the differencing options (par1-par2, time1-time2 and day1-day2).
If you specify
both a time difference (time1-time2) and a day difference (day1-day2),
SFCCON contours the values equal to the parameter at time1,day1 minus
the parameter at time2,day2. If you specify a parameter difference
(par1-par2) with a time difference and day difference, SFCCON contours
the values equal to the parameter difference at time1,day1 minus
the parameter difference at time2,day2. For example,
SFCCON T-TD MID 0-12 2000123-2000122 contours the values equal to the dewpoint depression at 0UTC,day2000123 minus the dewpoint depression at 12UTC,day2000122.
In the PTYPE keyword, specify either PMSL or SLP for sea-level pressure, and ALT, ALTM or ALTIM for altimeter setting. The keyword is valid only with the calculated options that contain station pressure in their equations (PSTN, MIX, THA and THAE). Altimeter setting is the default because it's correct to use it (rather than sea-level pressure) when computing station pressure for use in the equations.
This entry contours the temperature for the current day and time using the navigation of the current frame.
SFCCON PCP3 UNIT=MM
This entry contours the most recent three-hour precipitation totals in millimeters using the navigation of the current frame. For example, if the current time is 19 UTC, the 15 UTC data is plotted since three-hour precipitation totals are reported only at 3, 9, 15 and 21 UTC.
SFCCON SNO MID 12 UNIT=CM COLOR=7 LABEL='12 UTC Midwest snow depth, in centimeters' 7 420 150
This entry contours snow depth in centimeters at 12 UTC over a map of the Midwest. The contours are drawn in graphics color level 7. The default label below the plot is replaced with the text 12 UTC Midwest snow depth, in centimeters near the center of the frame in graphics color level 7. LABEL is a PTCON keyword.
TE COLD "-20 -10 0 10 20 25 30 32 35
SFCCON T CINT=COLD DASH=NEG
The TE command creates a string called COLD containing contour values for the SFCCON entry. The SFCCON entry draws the -20, -10, 0, 10, 20, 25, 30, 32 and 35° Fahrenheit temperature contours for the current day and time using the navigation of the current frame. The -20° and -10° contours are dashed; the others are solid. Do not specify a pound sign (#) before the string name in the CINT keyword.
SFCCON PMSL NA 6 12/JAN/1996 DATASET=CLIMATE/1996
This entry contours sea-level pressure over a map of North America at 6 UTC on 12 January 1996 using the data in the dataset CLIMATE/1996.
SFCCON TDADV KY
This entry contours dewpoint temperature advection over a map of Kentucky.
SFCCON VIS MID 12-0 2000131-2000130
This entry contours the 36-hour visibility change from 0 UTC, day 2000130 to 12 UTC, day 2000131 over a map of the Midwest.
SFCCON THA USA PTYPE=PMSL
This entry calculates and contours potential temperature over a map of the United States for the current day and hour. Mean sea-level pressure is used when computing station pressure for use in the potential temperature calculation. This may yield some error in the values, with higher station elevations usually having larger errors.
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