Wednesday, January 19, 2011

What's More Important 1/19

I sent out a message over Twitter this morning that seems appropriate... "Just waking up. What's more important cereal or weather data? Hmm..."

The first round of data coming in is always NOAA's North American Mesoscale Model aka the NAM. The NAM is in and lets look at the data.

The model appears to have come in a little drier with the storm for Thursday. This takes my confidence level in the model up a notch as the NAM has been going a little gangbusters with the precipitation numbers in the last couple of days.

Here is the liquid precipitation the model is depicting for the area through Friday morning.

  • Cape Girardeau, Mo - 0.13"
  • Evansville, In - 0.21"
  • Farmington, Mo - 0.25"
  • Jonesboro, Ar - 0.28"
  • Indianapolis, In - 0.26"
  • Paducah, Ky - 0.13"
  • St. Louis, Mo - 0.24"
I have also noted that the model is trying to bring in slightly warmer air to the surface. For places like Cape Girardeau and Paducah it keeps the temperature around 30 degrees versus the middle 20's it was showing yesterday. This would keep the snow ratio a little lower than the model was advertising yesterday. This has been something I figured would be the case, lower snow/liquid ratio, for this system.

Time for a little math... I am thinking snow ratios will be anywhere from the general 10:1 to 13:1 across the KFVS viewing area. Over some of the northern counties of the KFVS viewing area it could creep up to 15:1. For St. Louis and Indianapolis snow ratios will be around 15:1 to 16:1.

(City - Liquid) | 10:1 | 13:1 | 15:1 | 16:1
  • Cape Girardeau, Mo - 0.13" | 1.3" | 1.7" | 2"
  • Evansville, In - 0.21" | 2.1" | 2.7" | 3.2"
  • Farmington, Mo - 0.25" | 2.5" | 3.3" | 3.8" | 4"
  • Jonesboro, Ar - 0.28" | 2.8" | 3.6"
  • Indianapolis, In - 0.26" | 2.6" | 3.4" | 3.9" | 4.2"
  • Paducah, Ky - 0.13" | 1.3" | 1.7"
  • St. Louis, Mo - 0.24" | 3.1" | 3.6" | 3.8"
Overall, the NAM has taken the snow numbers down from the last two runs. (Last evening's run. Yesterday morning's run.) Is the model on to something new or is it having trouble resolving the storm as the storm is not out of the Rocky Mountains yet?

I still believe there will be a narrow band of heavy snow setting up somewhere north of the KFVS viewing area. It may include the St. Louis area over to Terre Haute, Indiana or Vincennes, Indiana over through south central Indiana.

Here is a regional view of the snow accumulation from this morning's NAM.

Click the map to see a larger version.

I am going to stay the course with my initial thoughts as to how much snow we will see.

KFVS Viewing Area: Generally 2" to 4" of snow. I wouldn't be surprised if we get a few 5" snow amounts from some of the northern counties (St. Francois, Ste. Genevieve, Randolph, Washington (IL), Jefferson, Wayne (IL), Perry (IL), Franklin and Hamilton). The duration of snow will be around 10-11 hours starting early Thursday morning and ending Thursday afternoon. Snow over the southern counties (northwest Tennessee/Missouri bootheel) might range from 1" to 2".

St. Louis: Snow will start later this evening and last through late morning Thursday. I am thinking 3"to 6" will be possible in the St. Louis metro area with higher amounts on the north/northwest side.

Central Indiana: Areas around the Indianapolis metro area will be 2" to 4" 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".

Moisture is beginning to breakout over Nebraska and Kansas so the storm is developing as we speak. You can check out the moisture by clicking on the "Radar" tab at the top of the website. You can move/zoom around the country to see where the rain/snow is located.

We will get a couple of more model runs in before the snow starts to fall so keep checking back for updates through the day.

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