Thickness Spaghetti Plot - Winter Precip Type

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Andrew Revering
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Thickness Spaghetti Plot - Winter Precip Type

Post by Andrew Revering » Tue Oct 17, 2006 12:01 pm

You can create a precip type forecast by making a thickness spaghetti plot by overlaying all of the thickness contours but limiting the plots to only the single line that is used as a 'rule of thumb' for the rain/snow line at that thickness.

Anything on the 'cool side' of these spaghetti plots would be snow, anything on the warm side would be rain.

Here's how you set it up:

Go into preferences and set the following maps to have a Max and Min value of the same value. This same value for both max and min will limit the program to plotting just that single line, rather than all contours.

Here are the rules of thumb for rain/snow lines for each map:

1000-500mb Thickness: 5400
1000-700mb Thickness: 2840
1000-850mb Thickness: 1300
850-500mb Thickness: 4100
850-700mb Thickness: 1540
700-500mb Thickness: 2560

You can also add the following maps with a 0 value for max and min, which will just display the freezing line:

850mb Temperature: 0
700mb Temperature: 0
Warmest Vertical Temperature: 0

Of course if the warmest vertical temperature is 0, you can definately expect all snow since the entire sounding is frozen.

Then when mapping, just turn on all of these layers, especially the thickness layers, all at once, so you get the spaghetti plot.
Andrew Revering
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wxthomson
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Post by wxthomson » Fri Oct 20, 2006 10:54 am

Andrew, thanks for the tip. I like the idea of a Cool Tricks section. Hopefully other experienced users will post things they have developed.
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Andrew Revering
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Post by Andrew Revering » Sun Dec 09, 2007 10:14 pm

I've found that another cool way to find precip type is to overlay the Temperatures @

3000m down to 1000m (I think there are 11 maps). Set each map to only contour the 0 degree line by going in the options and limit the range from 0 to 0.

Then you end up with another spaghetti plot... basically if you're cooler than all lines its all snow. If you're 'south' of just 1 line, you should get 70% snow. If you're 'south' of 2 or more of the lines it should be either a mix or all rain, depending on what the low levels are doing. At that point check your surface temp.
Andrew Revering
F5Weather
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