Wednesday, February 18, 2009

2/19/09 Forecast

The pattern appears to be similar. Mostly zonal flow across the country at 250mb. However, that includes "mostly." There is a ridge/trough pattern shown at 250 and 500 mb. These links provide a look at the maps presently. The nice thing about this is it should break the clouds in DeKalb. It will also provide clear skies in Alton (but this is also due to the frontal passage). There is also some high pressure in the Dakotas and Canada that will move in with this. This will bring the sun! The surface chart shows the basic set up (from what data I had) as of 4:00 pm Feb. 18, 2009.
The trick was looking at MOS guidance for highs and lows. DeKalb is a mess. We should have clear skies under high pressure, and IR satellite imagery shows clouds moving out at this time. MOS shows cloudy. Therefore, I am not confident with its results for DeKalb. It is slightly better for Alton, as in it shows clouds moving out, but not quick enough.

It all (with a lot more not included in this discussion) comes down to this for Thursday:

DeKalb: Sunny. Windy (due to the pressure gradient), with winds around 20mph. High should be about 21 degrees. The low will be about 12 degrees.

Alton: Sunny. Winds should be about 15 mph (the pressure gradient is slightly weaker). High should be 32, with a low of 20.
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1 comment:

  1. Chuck Richie IIFebruary 18, 2009 at 9:14 PM

    Explanation of some erased marks on the maps.

    I accidentally drew a few features on the map wrong. The faint low in Texas is one. There is also a remnant of the original cold front I drew in. I drew the cold front in, and thinking "mid-latitude cyclone" tried to figure out the best location for a low. I forgot that the wind barbs showed winds from the north, and almost drew a weird cyclone. The other error is on the 1008 mb line. Hint for isoplething, look at the entire map. I forgot to plot New England as I was working westward from the low, and in the process forgot my 1008, 1012, and 1016 line. I quickly closed the 1008 off. Explanations for a less than neat surface map.

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