Severe Event Today - S OK & N TX

2030Z UPDATE: SPC is really upping the ante for a tornado event in the Red River Valley area north of I-20 and roughly the I-35 corridor eastward. The heating has been strong as well as deep moisture in place with CAPE in the 1500-2000 range. LCLs will be a little high early on due to the pronounced dewpoint depressions, but that will quickly change as the sun sets. Even the NWS-FTW is hitting the tornado threat too in their afternoon AFD. I agree....tough to argue with this one. This is going to be a wild ride. Watch box and text follows:

BOX: http://www.spc.noaa.gov/products/watch/ww0783_overview.gif

DISCUSSION...AIR MASS CONTINUES TO DESTABILIZE ALONG/AHEAD OF SURFACE DRYLINE EXTENDING SWD THRU WRN OK INTO NORTHWEST TX. SFC DEW POINTS ARE INCREASING NWD TOWARD THE RED RIVER REGION AND SFC PRESSURES ARE BEGINNING TO FALL RAPIDLY ACROSS CENTRAL OK INTO N CENTRAL TX. SPECIAL 19Z RAOB FROM FWD SHOWS RUC MODEL IS PRETTY CLOSE IN ESTIMATING THAT MLCAPE WILL BE AROUND 1500-1800 J/KG E OF THE I-35 CORRIDOR WITH THE PRESENCE OF STRONG VERTICAL SHEAR PROFILES. STORMS ARE EXPECTED TO INITIATE ALONG/JUST AHEAD OF THE DRYLINE DURING THE NEXT FEW HOURS WITH THE POSSIBILITY ALSO OF DISCRETE SUPERCELLS/TORNADOES OUT AHEAD OF IT LATER THIS AFTN AND EVENING.

19Z UPDATE: Dryline a little more sluggish in it's eastward advance, but it appears to be picking up steam now as mixing is kicking in. Field of enhanced cumulus from near San Angelo up to near Duncan, OK is indicative of convection ready to fire up in an hour or two.

Now that clouds have cleared out across N TX and the tropical moisture surges northward bringing mid 60Td to the Red River Valley and temps jumping into the mid 80's, instabilities are increasing rapidly. Latest SPC mesoanalysis shows SB CAPE of 2000 within the aforementioned cumulus field. Skies here in N Dallas have become partly cloudy with lots of puffy cumulus indicative of ample, deep moisture and peaking instabilities. So, I see no reason whatsoever that CAPE values indeed will reach 2000-2500 across N TX and into S OK for this event.

With the 0-1km and 0-3km SREH values exceeding 300, the stage is set for a significant severe weather event including several tornadoes....possibly one or two intense. Folks in the DFW metro area need to pay close attention!!!

I expect to see a few cells erupt between Weatherford and Waurika by 4:30pm and quickly go severe and rotate. i wouldn't be surprised to see the first tornado warning go out by 5:30.

Latest model runs of the RUC and NAM pretty much bullseye the Red River Valley today. Both models have shifted the jet energy further south across this area with impressive SRH values from 300-400 with troopical moisture rapidly surging into this area by 00Z. CAPE values at that time should be near 1500 which is sufficient. Also, both models put the brakes on the eastward surging dryline and lining up near the I-35 corridor. This is always a dangerous setup in that repeated or stationary supercell generation occurs over the same area. However, will the storms be able to get rooted along it and not race off to the NE? It's a tough call, but I think storms will fire repeatedly along the dryline and zip of to the NE. The shear is way too strong with only 1500 CAPE to allow stationary supercells to root on the dryline.

I agree with the SPC 10% tornado threat, but would extend it a tad west to around Ardmore to Fort Worth. It is certainly going to be wild ride this evening and overnight for N TX and S OK areas to the NE into Arkansas and E OK. My target today? McKinney, Texas....my house. LOL!! I am thinking that the Red River counties of Texas are in the hot spot. Wow. Chasing in my own backyard here in the latter half of September. That sounds like some far-fetched B-movie plot. ;-)

I'll update this afternoon if I can.