Saturday, February 13, 2010

More Like It

I am just looking over the data from last night's runs of the computer models. It looks like the models are coming back towards reality.

Here is the data from NOAA's NAM forecast model.

A couple of items to take note of when compared to the data from yesterday morning.

1) First and foremost... Not as much precipitation. During the time period from Saturday night through Sunday morning the NAM is putting out around 0.06" of liquid. Snow wise, that would be about 0.5". During the Sunday afternoon through Monday morning time period the model is putting out 0.23" liquid. The model is showing some of that falling as rain. Snow wise, that would be around 2.2".

You can look at the type of precipitation by looking at the colored vertical bars. Green indicates rain. Blue indicates snow.

2) Temperature profile... The models keep the idea of "warm" air being at the surface. By warm, I am referring to temperatures above the freezing mark (0°C/32°F). With the warmer temperatures whatever falls will have a hard time accumulating. Either it will melt as it reaches the surface or it will be very wet/slushy.

The yellow lines indicate air temperatures at different altitudes. The temperatures are shown in celsius.

This run of the NAM brings in warmer temperatures at the surface. If this model is correct, temperatures could climb in to the upper 30's Sunday afternoon. Hence, the model is indicating rain. You can look at the surface temperature by looking at the red line. The line is shown in fahrenheit.

All totaled the NAM is putting down 2"-3" of snow for the two rounds. To compare, the NOAA's global forecast model is putting down 2.5"-3.5" of snow for the same two rounds. The same models are putting down a total of 3"-4.5" for the Farmington, Missouri area.

The data is much closer to what I was thinking in yesterday's post. As I said earlier, clipper systems historically don't put down a lot of snow around here. This clipper is a little different than most clippers due to the path. Typically, clippers slide through Illinois and Indiana. This one will slide further west and south going through Missouri, southern Illinois, and western Kentucky.

I am thinking 2"-3" of snow starting tonight through Monday morning for the northern half of southeast Missouri (up to 4" around Farmington/Ste. Genevieve), 2"-4" (maybe 4.5") for southern Illinois, 2"-3.5" is a good call for the northern half of western Kentucky.

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