The Weather Forecasting Forum

Hi All;

While this is my first post to this group, I have been observing for quite awhile. My question is; is there any method to plot the demarcation/contours around areas of different precipitation types (eg. rain, snow, freezing rain,etc)? This used to be a feature in the old Weathergraphics and DA which I found useful. However, I haven't been able to do this with DAW. Maybe there is a script??

Thanks In Advance;

Gary

Hi Gary,

we are working on a script, but at time the results are to strange, so we will need some time.
I`m coming back to you later.

Best regards,
Stefan

Hi Gary,

the same problem we have described about the "1000-500 hPa thickness" in DAW is the reason for some strange markings in the "SNOW-Script".
North of the green marking (in the dashed area) the precipitation will be snow and rain and north of the red line (red dashed area) it will only snow.

Here is the script
ANALYZE,OVER FILL LSTN=1530 COLOR=255:200:255 FILS=2 SDIF=1,2 STOR=2 HGHT H850 STOR=1 HGHT H700
ANALYZE,OVER FILL LSTN=1290 FILS=0 COLOR=255:200:255 SDIF=1,2 STOR=2 HGHT H000 STOR=1 HGHT H850
ANALYZE,CONT EQUA=1530 LINE=2 COLOR=0:213:53 SDIF=1,2 STOR=2 HGHT H850 STOR=1 HGHT H700
ANALYZE,CONT EQUA=1290 LINE=2 COLOR=255:0:0 SDIF=1,2 STOR=2 HGHT H000 STOR=1 HGHT H850
#ANALYZE,CONT EQUA=5400 COLOR=55:90:250 LINE=2 CONT LSTN=5400 COLOR=55:90:250 CONT CINT=60 DASH COLOR=200:0:0 SDIF=1:2 STOR=2 HGHT H000 STOR=1 HGHT H500
ANALYZE,CONT EQUA=5400 COLOR=55:90:250 LINE=2 CONT LSTN=5400 COLOR=55:90:250 CONT CINT=60 DASH COLOR=200:0:0 SDIF=1:2 STOR=2 HGHT H000 STOR=1 HGHT H500

If the 1000 hPa-level is negative, the WMO sets a "5" in front of the coded level and a "6" if the level is more than 100 meters below the station-level.
So the term "509" means a level of "-9" gpdm.
In the calculation of the "1000-500 hPa thickness" the term "509" are subtracted from the full 500-hPa-level with some very curious maps (see the following map).



Here is the corrected map:



You can make the corrections with the "Quality Control Panel".
You mark the area with the wrong data and start the "Quality Control Panel".
You will find some stations with values like "549" in the field "Height".
You delete the value "5" and set a "minus" instead of it, Accept Entry and afterwards make a new run of the "SNOW-Script" and you will have the corrected map.
Anyone else who has made these experiences?

With best regards,
Stefan Lichius + Jens Waterboer

Hi Stefan;

Thanks for your response.
I was thinking more on the lines of surface depiction of actual weather reports. The old Weathergraphics and DA programs would enclose areas (colour coded) where particular types of precipitation were reported. It was much the same as the IFR/MVFR plots. I can't come up with a script to do this.

Thanks;

Gary