Friday, March 26, 2010

"Cold Core" Set up in Oklahoma for Saturday?

As with most of the storm systems to move through the Southern Plains this year, tomorrow’s event will be lacking a major necessity, moisture. Wednesday’s storm system has scoured most of the low level moisture and dewpoints will be hard pressed to reach the middle 50s across East Texas. However, the system moving into the Southern Plains is very dynamic and I look for at least a broken squall line to develop ahead of a dryline East of I-35 tomorrow afternoon. The threat for tornadoes is very small however, we could see an isolated strong wind gust.
There is an area under the 500 mb low near the Oklahoma Kansas state line that has my interest for the possibility of tornadoes tomorrow afternoon. Models are not forecasting very high dewpoints with this system however, with the very cold mid level temperatures associated with the upper level low, low level instability will be increasing throughout the afternoon.

The WRF-NMM 5km is showing a good deal of Instability tomorrow afternoon as the upper low moves over the Kansas Oklahoma state line. LIs by 1PM are approaching -6 near Tonkawa, OK as the image below shows.

The next image continues to show good instability in this area along with another area of increased instability near Ada, OK with LIs approaching -8 by 4PM.

The next big question for tomorrow's event is will there be enough moisture. The image below shows dewpoints approaching 50 degrees by 1PM tomorrow.

By 4PM dewpoints are progged to be in the lower 50s under the 500 mb low, image below. Both the GFS and NAM are a little farther east with the low and have dewpoints about 5 degrees cooler.

So will we see any severe weather with this set up? If the WRF verifies, I believe we will see a few low topped supercells develop near the triple point and an isolated tornado or two seems possible. I would also look for a broken line of storms to develop along the dryline east of I-35 down into East Texas. We could see some hail and gusty winds with these storms. The next three images show storms developing around 1PM through 6PM.

I am going to wait until I get a good look at all the 12Z model data but it looks at this time Tonkawa, OK will be a good starting point. I will have to leave around 6AM to get there an hour or so before initiation. We shall see what happens.

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