2/27/11 FCST: KS, OK, TX, MO, IL, AR, LA, MS

[Brandon Lawson]

Indeed, Michael. Right now I'm considering northwest, Oklahoma, somewhere between Enid and Woodward or points just north of that line. If it is a question of getting daytime initiation, the best chance may be further west where the forcing will arrive sooner and provide the best upper-level cooling. Latest visible satellite already shows clouds clearing off, too. This is collocated in an area of favorable low-level shear on the north/northeast side of the surface low and dryline bulge. The last few runs of the RUC have been painting a nice combination of parameters there, resulting in good EHI values. Having said that, initiation is still a concern. Right now, I'm trying to make heads or tails of water vapor imagery. It looks like the wave is already moving into Oklahoma and I worry that it's too early. In that case, targets further east might be better?

EDIT: oops. for clarification, I was originally responding to Michael Okeeffe

 

[Andrew Stoller]

Severe parameters are quite high in NW OK per the RUC, which is usually a bit optimistic. It's something to consider though. 2,000 J CAPE and 1KM SRH at or above 450 juxtaposed in the same area along with abundant moisture convergence on the nose of the surface low/triple point. There's enough clearing behind the cold front that might make it's way over the area to provide good heating. I like the area from Fairview OK to Medicine Lodge KS and points to the east along the warm front in southern KS. Chase terrain is decent in that area as well, especially KS.

FWIW, the RUC does break out substantial precip in far north northwest OK/south central KS in the area mentioned above and along the warm front in southern KS by 02z Mon.

The 15Z HRRR has what looks like a discrete supercell firing in NW OK and moving northeast towards Wichita.

 

[Greg Blumberg]

Since everyone else has beaten the RUC to death with the analysis stick, I'll stick with the current observations.

Agreeing that a near the warm front/triple point play is good in North-Central OK/KS border area. I'm agreeing with what Mike Smith has said regarding the PVA arriving faster. This is exactly what I've been seeing since last night when I was watching the water vapor imagery. No model could initialize the shortwave trough well because there were no upper air stations to gather wind data near the base of the trough. Combining that along with the warm air advection nearby the warm front to diagnose potential upward motion, I see no reason why we shouldn't have initiation. Just from looking at the 12 UTC sounding, I'd say we're set. The only thing is watching the breaking of the clouds, which is happening right now across the warm sector. Also, after checking the vertical wind profilers, I'm seeing a very strong jet streak (95 knots) at 6 km (approx 500 mb) exiting out of eastern New Mexico, and the data is persistent in increasing the wind speeds at this level.

http://www.spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=15&parm=vadprof#

The 16 UTC RUC has wind speeds like this further west than where they're being observed. It's definitely underestimating the jet.

Given the synoptic setup, I would not be surprised to see strong pressure falls across the target area in the coming hours.

 

[Mike Smith]

Wow, take a look at this: TCU from Greensburg to GAG already with nice clearing in SW OK.

However, with the temperature already 68° at Winfield, KS, not sure how much clearing we will actually need.

And, this is the RUC sounding for 3pm 25 nm. WSW of END. Wow. Note the 155kt jet at 230mb.

SPC's forecast tools indicated 1,500j of MUCAPE already over much of northern and western OK and it is only lightly capped.

 

[Trey Thee]

Wow, take a look at this: TCU from Greensburg to GAG already with nice clearing in SW OK.

However, with the temperature already 68° at Winfield, KS, not sure how much clearing we will actually need.

And, this is the RUC sounding for 3pm 25 nm. WSW of END. Wow. Note the 155kt jet at 230mb.

SPC's forecast tools indicated 1,500j of MUCAPE already over much of northern and western OK and it is only lightly capped.

Wow, this new data seems to suggest there could be one or two significant tornadoes in north central OK this afternoon...

 

[RMacDonald]

Just updated my severe weather graphics, seeing the my MDT/High threat stretching back to the Enid areas, lining up with the RUC model. Thinking NC OK through NE OK to SE KS are going to see some potential for Tornadic Development. Just ran a quick output for the Enid to PNC line, alerting me of very high threat for significant tornado potential there, good pressure falls in that area over last few hours.

Graphic: http://smartwxmodel.net/usa.gif
END output http://smartwxmodel.net/KEND.pdf

 

[Mike Smith]

ICT WSR-88D appears to be down again at 1900Z. TDWR working fine.

 

[Jeff Duda]

Recent HRRR runs are not predicting any kind of squall line or MCS to form out of really any convection anywhere in the risk area today. That model seems to think once the KS/OK stuff passes and the AR/TN stuff does its thing, that'll pretty much be it.

 

[RMacDonald]

Here is a 21Z SmartModel Threat graphic, I just ran with the new surface observations. Some of the sites have a value output of .71 to .75. On my model a 1 means 100% of all favorable tornadic parameters have been met.