10/21/07 NOW: OK

[Brandon Sullivan]

Numerous thunderstorms, some severe developing in central OK. This line is Northwest of KTLX from Osage Southeast to Commanche Counties. Logan, Payne, Kingfisher storms exhibiting some rotation. Storms are moving rapidly Northeast at over 55 MPH. Large hail is indicated by radar in excess of 1.5 inches with these storms..

To the south in Caddo county. A severe thunderstorm warning has been issued. This storm is producing hail indicated at around .5 inches by radar, and moving NE at 50 mph..

Tops on all cells approaching 40K Feet.

AS OF NOW the storms are appearing to weaken somewhat. The cell SE of Kingfisher still exhibiting large hail, and multiple meso indicators.

Logan/Payne/Noble Counties just went severe warned. Moving NE at 60 MPH!!! Hail will likely cover the ground!!

 

[Brandon Sullivan]

Impressive Radar returns of 72 dbz.. Hail indicators over a large area indicating 2.50 inch hail. This cell is in Logan County, right over pleasant valley

 

[Jeff Snyder]

Strong shear in place along with marginal MUCAPE suggests that some elevated supercell characteristics are possible. The TLX VWP indicates that the cold air is about 5000 feet deep, so there isn't a tornado threat. The most interesting thing to me is the periodicity of the convection... There have been ~6-7 cells lined about ~25-30 miles apart in a SW-NE fashion. As cells move off rapidly to the northeast, new ones develop back in southwestern OK. I can only think that there is some sort of (intertial?) instability associated with this very strong shear that is supporting such regular and consistent intervals between the convective cells.

 

[BrianBaker]

I also find the radar presentation interesting. The way the storms continue to form in mini line segments in a NW to SE orientation is really neat to watch on radar loops. Looks like waves in the ocean moving toward shore with your view being from above. I agree with Jeff that the periodic occurrence of the storms in very intriguing.

 

[Kevin Scharfenberg]

Impressive Radar returns of 72 dbz.. Hail indicators over a large area indicating 2.50 inch hail. This cell is in Logan County, right over pleasant valley

This is a good example of how the single-radar 88D hail algorithms tend to overestimate, particularly when there is high reflectivity indicative of copious amounts of small, wet hail (as was actually reported with this cell). Not to brag, but our new NSSL multi-radar/multi-sensor hail algorithm was right on the money with a swath of 3/4" to 1" maximum hail size.

I agree the radar loops are great, and it's very cool how there appear to be left moving cells splitting off the north end of many of the segments. See the OKC TDWR loop here: http://wdssii.nssl.noaa.gov/web/wdss2/products/radar/tdwrloop_refl2.html