3/21/05 NOW: TX, OK, AR, LA, MS

[Alex Lamers]

Towers starting to go up a little quicker now over NE TX but we'll concern ourselves with that area once things get cooking a little later.

Looks like the Okmulgee County cell has an excellent cyclonic circulation on bs SRM and its sitting right underneath a relatively deep and lowering mesocyclone. Could set down a tornado here relatively soon. I have it reaching Okmulgee by 4:51 and Morris by 5:03. Hail up to 1 inch per storm attributes. Looks like hail core will head to the north of Okmulgee. If you are chasing this stay south or east of that town.

...Alex Lamers...

 

[rdale]

I think that storm is getting too far into the cool side to worry about touchdown... 3D X-Sect from Level II data isn't terribly impressive, show a nice broad rotation but nothing tight.

 

[Alex Lamers]

True...but the McIntosh and Okmulgee County cells both have seen SE Quad inflow increase significantly over the past couple scans. Decent MESOs so I would imagine theres at least a wall cloud or visible rotation of some sort.

Still waiting for a report out of this area...anyone know of any webcams?

...Alex Lamers...

 

[Jason Montano]

Lance reported three touchdowns on the cell that started in Seminole Co. and continued into Okfuskee and Okmulgee Co's. One of them I think he said was rainwrapped.

 

[Amos Magliocco]

I'm not surprised about the success of the storms from OKC to TUL, but I am about how long they've stayed isolated, relatively speaking. Also interesting how poorly the Texas storms are faring thus far, an indication of the weaker instability due to cloud cover versus the insolation up north under the dry slotting.

Seemed like many chasers had indeed elected for an OKC area cold-core target so we may have plenty of imagery. I was told last hour that Dean Cosgrove has filmed one of these tornadoes and that should be seen on The Weather Channel some time in the next several hours.

This new storm near McAlester on the southern end of the group might bear watching as it should have a favorable motion relative to the low level flow.

 

[rdale]

The one north of McAlester looks horribly lame to contain a tornado, and the Okul storm is about dead, but the one in between still has very nice rotation. Surprised that the SVS's out of Tulsa don't contain any ground truth (even something saying spotters don't report any rotation.) Looks like all these have is some 3/4-1" hail.

 

[Mike Peregrine]

I'm not surprised about the success of the storms from OKC to TUL, but I am about how long they've stayed isolated, relatively speaking. Also interesting how poorly the Texas storms are faring thus far, an indication of the weaker instability due to cloud cover versus the insolation up north under the dry slotting.

Another big factor that is probably playing into this is the lack of good quality, deep layer moisture. Moisture is prevalent in the boundary layer, but still relatively shallow. Dr. Forbes mentioned the fact that dry air aloft may be inhibiting initiation further to the south ... it's just really early in the year yet for that good, deep juice -

 

[Amos Magliocco]

Dr. Forbes mentioned the fact that dry air aloft may be inhibiting initiation further to the south ... it's just really early in the year yet for that good, deep juice -

You can get the good deep moisture in March, but these stacked lows can veer low level (meaning sfc to 850) winds too soon, and today we saw the 850s swing out of the ssw then southwest well before the warm sector could handle that sort of scouring, "CAPE-robber" scenario. So when the dryline pushed into that air, there wasn't much to work with because of the mixing down of drier air. I guess stacked lows can often present several equally unappealing choices, but today the cold-core target really paid off for a few chasers.

 

[Rockwell Schrock]

Here are some pictures of the action in Texas. Try not to cry.

http://www.wunderground.com/wximage/viewsi...HER#slideanchor
http://www.wunderground.com/wximage/viewsi...HER#slideanchor
http://www.wunderground.com/wximage/viewsi...HER#slideanchor

 

[beaudodson]

Thanks for the images! Those tell the tale.

 

[Amos Magliocco]

Maybe the trucker should have stayed with that storm a little longer. Darin Brunin reports a small tornado on the storm in Lamar County, Texas about forty minutes ago. He said the tornado was about six miles south of Paris.

 

[beaudodson]

http://www.wunderground.com/wximage/viewsi...HER#slideanchor

 

[Scott Currens]

Eric Nguyen and I observed two tornadoes in N OK near Wakita. The first was an long rope tornado with a tiny circulation at the ground. A the surface it was smaller than many dust devils. Eric should have pictures online soon.

www.mesoscale.ws

 

[beaudodson]

Eric Nguyen and I observed two tornadoes in N OK near Wakita. The first was an long rope tornado with a tiny circulation at the ground. A the surface it was smaller than many dust devils. Eric should have pictures online soon.

www.mesoscale.ws

Great photos. Congrats!

 

[Jeff Snyder]

Dr. Forbes mentioned the fact that dry air aloft may be inhibiting initiation further to the south ... it's just really early in the year yet for that good, deep juice -

You can get the good deep moisture in March, but these stacked lows can veer low level (meaning sfc to 850) winds too soon, and today we saw the 850s swing out of the ssw then southwest well before the warm sector could handle that sort of scouring, "CAPE-robber" scenario. So when the dryline pushed into that air, there wasn't much to work with because of the mixing down of drier air. I guess stacked lows can often present several equally unappealing choices, but today the cold-core target really paid off for a few chasers.

I'm not entirely sure this was the case, however. The models had been forecasting near-60 Tds along the Red River (with low 60s from I20 southward), and the obs that I looked at showed this to be the case. Heck, there were some low 60s in places east of Gainesville. In addition, after sitting in Sherman for a couple of hours this afternoon, cloud cover wasn't really that much of a deal either. There was decent insolation immediately ahead of the dryline, save for a narrow band of cirrus. Otherwise, there were scatter TCU building along and slightly ahead of the dryline, but not much else in the way of cloud cover. The storm that later went on to produce the Paris TX tornadoes which we saw started out southeast of Sherman... The updraft looked rock solid for quite some time, indicating that dry air in the mid-levels wasn't affecting it too much, or else we would have seen less solid updrafts (more mushy updrafts) owing to dry air entrainment along the updraft sides... So, what do I think was the main problem? Too little CAPE/instability! The 18z soundings from around the region showed pretty poor mid-level lapse rates. Despite the forecast for decent lapse rates, there really wasn't much... Therefore, we weren't really able to develop much instability. This again is supported by what we saw, as, despite the rock-hard appearance, the updraft was incredibly tilted / leaning. There was just not enough instability to set significant vertical velocities/accelerations above the low-level mesocyclone. Not surprisingly, when the updraft was able to go more vertical near Paris, the storm put down two tornadoes. For what it's worth, while the storm looked very poor on radar, the visual appearance of the storm was quite impressive, albeit highly tilted.