We’re now into the 48 hour window of computer models, so still room for error, but we’re getting closer to narrowing things down. From what I discussed last night, not much has changed. An upper level storm system will pivot into the state late Friday and combined with a warm front draped somewhere near the I-40 corridor, it places that area and points south of it in a risk area for severe storms capable of producing tornadoes. Models will likely struggle with the final placement of that boundary because it depends on how much rain falls north of it. So the answer to the greatest threat area may not be able to be given until Friday morning, but I’ll do my best before hand.
The surface pattern evolution is going to be key. New data suggests a stronger surface low forming NW OK stretching the front from Woodward SE through the OKC metro and then trailing east along I-40 from there. Yesterday it had the surface low in SW OK. That’s a pretty big difference. Regardless of those discrepancies, the warm sector is still across OKC, meaning the instability. A dry line will surge in from the SW and a dryline bulge will set up just SW of town. Storms love to fire on this bulge. If they did, that would place OK county in the most prime area. And as the model shows, not such a favorable outcome.
The threat would stretch from C to SE OK in the brighter colored shading above. The sounding forecast below, still looks troublesome. With a combination of the placement of the upper jet, the hard turning of the winds with height called directional shear, and especially the speed increasing, called speed shear, really cranks out the parameters for tornadic development.
All that said, this is still only Wednesday. Things can and likely will still change until Friday morning. Many things can happen to make this turn out not to be such a big deal, the primary one, is if it rains all morning and afternoon which forces the warm front to stay closer to Red River. That’s on the table as a possible solution, for now anyway. So remember, this is only one computer model and do not panic and do not worry about tomorrow, or Friday. Just today. Live today.
Oh by the way should be a few severe storms in far W and SW OK tomorrow, late afternoon/early evening so stay alert in that area. The threat is for all three: hail, wind and an isolated tornado. -AT