Dec 29, 2009

Christmas Storm

A monstrous Christmas storm which set snowfall records from Bismarck, ND to Dallas, TX dumped over two feet of snow on the northern Plains and over four feet in the Black Hills of South Dakota. It wasn't just the snow that set records but also the rain. At Little Rock, Arkansas, 9.60" of rain pushed the annual total to 81.76, breaking the old record of 75.54 set in 1882. The storm also produced a significant tornado outbreak from Texas to Mississippi including an EF3 on the night of December 23rd in Lufkin, Texas.

At it's peak, the storm maintained a minimum pressure of 985 mb (29.09 inches) for a solid 12 hours.
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But what made this storm so unusual was how far south the strong dynamics were able to penetrate. I remember seeing the barometer reading at Del Rio, TX (on the Mexican Border) being at 29.53 inches (1000 mb)...long before the storm bottomed out in Iowa. Water vapor imagery of the storm at it's peak strength tells the whole story:
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Note that lightning is also plotted and is visible along the gulf coast and over Oklahoma during the blizzard. Here is a longer loop:A full six day loop of the entire event:

Higher resolution available here.

This is how the watches/warnings looked at the height of the storm (blizzard warnings in red).I have never seen such a large area under a blizzard warning at one time. Those blizzard warnings were extended westward into most of the rest of Nebraska the following day as the storm retrograded through Iowa.At Kansas City, where the first blizzard warning in 27 years was issued, 3.7 inches on Christmas was enough to break the record of 2.5 inches set in 1895. The storm total for the Kansas City area was in the 6-12" range. New Christmas snowfall totals were established at Grand Island, Ne (7.8") and Hastings, Ne(9.2"). The storm total was 12.2" at Grand Island and 14.3" at Hastings where the snow drifts were big enough to bury a car at the Weather Service Office:Omaha, Lincoln, and Norfolk all set new snowfall records for December, and Topeka, KS may be next. Snowfall from this storm was 12.9" at Lincoln, 11.5" at Omaha, and 19.1" at Norfolk. Accumulations were as high as 3 feet in the Sand Hills area and up to 52" in the Black Hills in South Dakota. At Sioux Falls 19.0" was the 4th highest storm total ever recorded. 2 foot snow accumulations were reported in the Sioux Falls area, in several areas elsewhere in South Dakota,
and especially around Grand Forks, ND. Even Bismarck, ND set a Christmas snowfall record (9.2"). Oklahoma City received 14.1", - the highest 24 hour total ever. Dallas had 3" which was the only measurable snow on Christmas eve since 1898.

The next storm is already on the way, and winter weather advisories are now active for most of Oklahoma and northern and western Texas going all the way down to Sonora. A winter storm warning has been issued for El Paso.

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