04/09/08 NOW: OK/TX/KS/AR

[Alex Lamers]

Looks like we have the makings of a significant squall line developing in W TX. Latest MAF radar shows impressive quasi-linear system in it's infant stages from just south of Lamesa to near Midland to nearly the Rio Grande. Already moving forward to the NE/ENE @ about 45-55mph. This is occurring on the nose of 45-55kt 850 mb LLJ that is quite broad in nature and essentially spans TX south of the quasi-stationary boundary.

Meanwhile, massive amounts of convection in sort of a "blobular" fashion continue off to the N/NE of the current squall line. Would expect the northern end of the squall line to expand north as it moves into this region of widespread convection. Extrapolating the current line...not accounting for expansion...would take it south of a line from Aspermont to Wichita Falls to Ardmore.

00z RUC show nice 700-500mb flow rounding the base of the impulse and reaching the N TX region by 06-09z. This, coupled with increasing LLJ and deepening cyclone, should provide an incredible amount of directional wind shear in the warm sector. While I wouldn't be surprised to see some supercells in the warm sector...there does tend to be an overlap between bow echo/long-duration dmgg wind soundings and supercell soundings. Given increasing linear mode...I think we may see a damaging wind event begin to evolve northeastward into N TX and S OK.

AJL

 

[Bob Schafer]

Anybody keeping an eye on SW TX? 02Z Mesoanalysis indicates the most amazing 850-250mb Differential Divergence I have ever seen.

That has resulted in this:

 

[Scott Lincoln]

**NOTE: I just began using the GR2 with trial, so I am not sure how to get rotation, shear markers, or anything else with it.

If you want hail markers and meso/tvs markers then you want GR2Analyst Edition, not just GR2.


Watching the evolution of everything it is looking to me like the moderate risk may not 'verify' if you want to call it that. Not alot of reports yet. I know that many of the damaged areas will come to light by morning but it seems like most everything other than the one supercell of the night became one big MCS.

I should edit that to say that it does appear as if a few storms still might have some potential - such as the storm headed into central AR that is not Severe or Tornado warned.

 

[Bill Tabor]

Fairly intense cell showing decent rotation couplet and TVS nw of Abilene headed straight for my parents in Sagerton, but no tornado warning.

 

[David Draun]

Geez, David Drummond is parked just east of that nasty looking QLCS, he must be getting a crazy lightning show right about now. Some of those tops are pushing 60,000 feet. It appears that the line could break into individual supercells. Those winds are still backed along the dryline. There appears to be several mesovorticies along the leading edge of the storms. Looking at the storm radial velocity imagery, there is a well defined inflow notch in the squall line NW of Big Lake, TX, indicative of a possible mesovortex.

 

[Bob Schafer]

Geez, David Drummond is parked just east of that nasty looking QLCS...

Hi Dave D! Drummond will probably chase until dawn.

(To adhere to posting rules) There is a Siggy Tor bullseye of 8 adjacent to that line, SW of SJT. That's huge.
Supercell Composite Parameter of 66 in Mexico? 66? Freakin' 66??????? Are you kidding me???? I have never seen higher than 30 before, IIRC.

 

[mark plate]

Fairly intense cell showing decent rotation couplet and TVS nw of Abilene headed straight for my parents in Sagerton, but no tornado warning.

Since the current temp in Abilene is just 54, I would say that storm is elevated, and it looks deep enough in the cold air to preclude any chance of a tornado.

 

[David Draun]

I'm looking at the rear of the QLCS now. Adjacent to the inflow notch, near Big Lake, TX, which just keeps punching farther westward into the storms. Anyway, adjacent to that inflow notch, there appears to be a hook forming on the back side of that storm. TVS algorithm also showing up. Very interesting feature since I have never seen that in a squall line storm, unless it was on the tail end. I'm seeing lightning now on Drummond's webcam.

On a side note, this system is going to drag the dryline well eastward tomorrow. They mention it in the KLOT forecast discussion for tomorrow, in which they are NOT downplaying the severe threat tomorrow. A welcome change.

 

[Scott Lincoln]

Hi Dave D! Drummond will probably chase until dawn.

(To adhere to posting rules) There is a Siggy Tor bullseye of 8 adjacent to that line, SW of SJT. That's huge.
Supercell Composite Parameter of 66 in Mexico? 66? Freakin' 66??????? Are you kidding me???? I have never seen higher than 30 before, IIRC.

I've seen it almost hit 40 (supercell parameter) before.... but I think thats about it. I suppose there is some potential there if the squall line can break up a bit.

 

[Bob Schafer]

The most intense embedded cell of the SW TX squall now headed straight at SJT: Hail marker indicates 3" hail, 55kft top, VIL 74

 

[Bill Tabor]

Since the current temp in Abilene is just 54, I would say that storm is elevated, and it looks deep enough in the cold air to preclude any chance of a tornado.

Possibly. But did you look at the radar? I saw it on GR3. Hook, and distinct velocity rotation sig including Tvs on multiple frames and levels. Looked pretty scary to me for cold air. There are some crazy parameters at work.

Fortunately they are fine.

 

[David Draun]

The most intense embedded cell of the SW TX squall now headed straight at SJT: Hail marker indicates 3" hail, 55kft top, VIL 74

And it's running over Dave Drummond! He is parked at a convenience store, and getting hammered with wind and rain. That inflow notch is a bit less pronounced than it was a few scans ago.

 

[Bob Schafer]

Not really headed toward SJT now, but top is now 57kft. VIL is now 80kg/m2. The GR3 VIL scale only goes up to 75. Hail 3.25"

 

[Bob Schafer]

That squall line isn't even in the warm sector (until recently, anyway). Guess that's what happens when you have extreme low-level convergence and extreme upper divergence.

 

[Dave Kaplow]

Just had a look at the radar after about an hour away... Yikes! Now if that squall line isn't deserving of a High Risk in the areas directly in its path, I dunno what is. But maybe its presentation on radar is not representative of what's really happening on the ground... I know I wouldn't want to be in front of it. Well OK I guess I would, but you know what I mean. It's pretty gnarly looking.

On a side note, did anyone else notice the converging of 3 separate boundaries that kicked it off? It was a textbook example of storms firing at the intersection of two or more boundaries. Actually in this case there may have been as many as 4 boundaries involved: I noticed earlier in the day how the dryline, warm front, and cold front were all aligned in a Y-shape radiating out from the triple point, but there was another smaller more delicate boundary, presumably and OFB of some kind that came down from the NW. If you look at the radar loop you saw this very faint line approaching the others and when it hit, BOOM! The whole line just lit up. Too bad I couldn't save the COD radar loop, it was pretty cool to watch.