Wednesday, January 19, 2011

11:45am Weather Update 1/19

The most important morning numbers are in. I have been waiting to see what NOAA's Global forecast model would show for Thursday's storm. Mainly to see if the model trended drier like the NAM did earlier, stayed the course or increased the moisture in this system.

Similar to the NAM, the GFS has taken surface temperatures a little higher for places like Cape Girardeau, Mo, Paducah, Ky and Jonesboro, Ar. This means that the all important snow/liquid ratio won't be as high compared to places like Farmington, Mo and St. Louis, Mo where it will be colder.

The GFS is cranking out the following liquid moisture amounts:

  • Cape Girardeau, Mo - 0.19"
  • Evansville, In - 0.23"
  • Farmington, Mo - 0.29"
  • Jonesboro, Ar - 0.19"
  • Indianapolis, In - 0.23"
  • Louisville, Ky - 0.27"
  • Paducah, Ky - 0.19"
  • St. Louis, Mo - 0.39"
You can compare those numbers to this morning's NAM run and last night's GFS run. In some places it was a little drier compared to last night's GFS and in some places it is about the same. I think it is more the model honing in on the storm.

Snow ratios for the locations listed above will range from 9:1 to as much as 18:1 according to the GFS. Knowing that, time to do some math...
  • (City - Liquid) | 10:1 | 13:1 | 15:1 | 16:1 | 18:1
  • Cape Girardeau - 0.19" | 1.9" | 2.5" | 2.9"
  • Evansville, In - 0.27" | 2.7" | 3.5" | 4"
  • Farmington, Mo - 0.29" | 2.9" | 3.8" | 4.4" | 4.6" | 4.9"*
  • Jonesboro, Ar - 0.19" | 1.7"* | 2.1"*
  • Indianapolis, In - 0.23" | 2.3" | 3" | 3.5" | 3.7" | 4.1"
  • Louisville, Ky - 0.27" | 2.7" | 3"*
  • Paducah, Ky - 0.19" | 1.0" | 2.2"*
  • St. Louis, Mo - 0.39" | 3.9" | 5.1" | 5.8" | 6.2" | 7"
*Numbers calculated with an adjusted snow/liquid ratio.

Here is a view of the national snow accumulation map generated from the GFS model.

Click the map to see a larger version.

The model continues the trend of producing a narrow band of large snow totals that run along I-70 through Missouri and just south of I-70 through south central Illinois and through south central Indiana.


I should note that the European forecast agency's computer model just came in and is putting out approximately the following liquid amounts: Cape Girardeau - 0.30" St. Louis - 0.42" Indianapolis - 0.25".

My thoughts on snow amounts haven't changed much.

KFVS Viewing Area: Generally 2" to 4" of snow. I think we could get a few 5"+ amounts in northern parts of the KFVS viewing area (St. Francois, Ste. Genevieve, Randolph, Washington (IL), Jefferson and Wayne (IL)). An isolated 6" isn't out of the question. Snow over the southern counties (northeast Arkansas, the Missouri bootheel and northwest Tennessee) could see 1" to 2".

There are some indications we could see snow falling over Iron, Reynolds, St. Francois, and Ste. Genevieve counties in southeast Missouri as early as 8:00pm CT this evening. The bulk of the snow will start early Thursday morning and end Thursday afternoon lasting around 10-11 hours.


St. Louis: Snow will start later this evening and last through late morning Thursday. I am thinking 4"to 6" will be possible in the St. Louis metro area. I wouldn't be surprised to hear of a few 7" amounts around St. Louis.

Central Indiana: Areas around the Indianapolis metro area will be 3" to 5" with the lower amounts on the northside. The further south from Indianapolis the higher the amounts will be. Places like Columbus, Bloomington and Seymour could see 3" to 6".

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