Tuesday, January 18, 2011

11:00am Weather Update 11/18

This is a follow-up post from my previous entry. Thought I would go ahead and update the new numbers just in from NOAA's Global forecast model.

The 12z GFS model is putting down the following liquid precipitation amounts (the amount of moisture to work with):
  • Cape Girardeau, Mo - 0.23"
  • Evansville, In - 0.39"
  • Farmington, Mo - 0.32"
  • Jonesboro, Ar - 0.18"
  • Indianapolis, In - 0.22"
  • Paducah, Ky - 0.24"
  • St. Louis, Mo - 0.36"
Interesting to note that the GFS is a little colder than the NAM. This would take the snow ratio a little higher. The model is suggesting a ratio of 10:1 to 14:1. I think 14:1 is a little high. Maybe 13:1 would be more realistic. (The model is suggesting a 13:1 to 17:1 ratio for St. Louis and Indianapolis. I think the high end is not realistic at this point.)

We do the math and we get the following snowfall amounts.
(City - Liquid | 10:1 ratio | 13:1 ratio)
  • Cape Girardeau, Mo - 0.23" | 2.3" | 3"
  • Evansville, In - 0.39" | 3.9" | 5.1"
  • Farmington, Mo - 0.32" | 3.2" | 4.2"
  • Jonesboro, Ar* - 0.18" | 1.4" | 2"
  • Indianapolis, In* - 0.22" | 2.6" | 3.3"
  • Paducah, Ky - 0.24" | 2.4" | 3.2"
  • St. Louis, Mo* - 0.36" | 4.3" | 5.7"
*Adjusted for what I think is a more realistic snow to liquid ratio.

Generally, the liquid amounts are similar to what the NAM is suggesting.

The GFS is indicating the snow will begin to fall in St. Louis late Wednesday afternoon. It will start Thursday morning for Cape Girardeau, Farmington, Jonesboro, Indianapolis and Paducah.

I should mention that it appears the temperature is going to drop behind this system. Models are hinting at highs in the upper teens Friday (single digits in St. Louis and Indianapolis).

Note: The data listed above is from data provided by NOAA. I know there are portions of the KFVS viewing are not listed above. I have tried to include areas that are either in or surround southeast Missouri, southern Illinois, western Kentucky and northwest Tennessee. Look at the above list and find a location near you. Then find a second and you can extrapolate the information.

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