541 FXUS64 KOUN 050632 AFDOUNArea Forecast Discussion National Weather Service Norman OK 132 AM CDT Fri Sep 5 2025
...New NEAR TERM, SHORT TERM, LONG TERM...
.KEY MESSAGES... Updated at 129 AM CDT Fri Sep 5 2025
- Strong cold front passage today with much cooler temperatures behind it.
- Severe storms possible this evening/tonight along and south of the cold front near the Red River.
- Cooler, below average temperatures this weekend into early next week.
&&
.NEAR TERM... (Through Friday) Issued at 129 AM CDT Fri Sep 5 2025
At the time of the writing of this AFD, the immediate concern is an area of storms forming along the nose of the LLJ from northwest to central Oklahoma. MUCAPE is currently in the 500-1,500 J/kg range as that LLJ advects in an EML aloft. Elevated thunderstorms have access to ample deep-layer shear thanks to an 80-kt jet streak just below the tropopause. Therefore, there will be a non-zero risk for hail up to the size of quarters and wind gusts in the 50-60 mph range. These storms have shown a tendency to expand and propagate southeastward over the course of the night, a trend that is expected to continue.
Further isentropic development of showers and thunderstorms will occur by early morning in advance of the approach of yet another cold front. This front will barrel into our area during the morning hours. By noontime, the front will reach the Red River, where a weak surface low will stall its progress. In advance of and in a narrow zone immediately behind the front, sufficient instability will be in place for surface-based storms to develop. Wonky wind profiles will occur due to the front and veering of winds immediately in advance of it, but vertical wind shear will be more than adequate for updraft organization. A marginal (level 1 of 5) risk for severe weather is in place in far southern Oklahoma and adjacent western north Texas for today and this evening along that front.
The other thing to watch will be the drastic reduction in temperatures in the postfrontal airmass. The gradient in highs will be particularly notable today; near the Red River, where the front may not pass until late this afternoon, we are forecasting highs in the upper 80s to low 90s. In northern Oklahoma, highs will fail to make it out of the 60s. With such a sharp gradient in forecast highs, users are cautioned that potential forecast errors could easily be larger than normal today (ie, somewhere could be 5-10 degrees warmer than forecasted if the front stalls further north, or else locations could be 10 or more degrees cooler than forecasted in the Red River region if the front is faster).
Meister
&&
.SHORT TERM... (Friday night through Sunday night) Issued at 129 AM CDT Fri Sep 5 2025
Welcome to fall! At least that`s what it will feel like the atmosphere is telling you if you happen to be out and about during the day tomorrow. Rain chances will end early in the morning and skies will clear out from north to south between daybreak and noon as the latest lobe of the Great Lakes trough departs and 500 mb heights begin to rise. Surface winds will remain light out of the northeast on the periphery of an expansive Great Plains surface high, so cold/dry advection will continue. We anticipate the final result to be a classic preview of fall weather in the afternoon - sunny skies, highs in the 70s, and comfortable humidity.
On Sunday, model guidance depicts an attempt on the part of the subtropical ridge to shift its focus from the Gulf toward the Four Corners. The translational phase will bring the core of the ridge across the Southern Plains during the day on Sunday. For the most part, our area will continue to be influenced by the Great Lakes trough to a greater degree than the subtropical ridge, so temperatures should only warm a couple of degrees. However, the southwestern corner of the CWA could warm up a little bit more than other spots.
Meister
&&
.LONG TERM... (Monday through Thursday) Issued at 129 AM CDT Fri Sep 5 2025
The main story for the long term period looks to be a gradual return to drier and closer-to-normal conditions next week. The biggest reason for the pattern shift is that (finally!) the Great Lakes trough looks to get kicked out by a more active wave packet on Monday and Tuesday. This will allow shortwave ridging to dominate the Plains by the middle of the week. In a sign that the seasonal transition really is upon us, guidance shows that ridge maxing out at 588-591 dam even though it looks plenty amped. The one window for storm chances that is apparent to us at this range is early Monday - a northwest flow wave is showing on the GFS/NAM in advance of the ridge. This could set off a round of upslope convection and increase thunderstorm chances in our northwestern counties especially.
Meister
&&
.AVIATION... (06Z TAFS) Issued at 1102 PM CDT Thu Sep 4 2025
Showers and thunderstorms are developing from southwest Kansas into northwest Oklahoma, with scattered storms continuing overnight into Friday morning across the north and potentially into central Oklahoma as well. Non-convective low-level wind shear will also be an issue overnight at most of the TAF sites with southwest winds of 30 to 40 knots about 500 to 1000 feet AGL above light surface winds. A cold front will move south through the area overnight and tomorrow and it looks like the front will push through southern Oklahoma and north Texas faster than the 00Z TAFs forecast. Some stratus will develop north of the front with areas of MVFR ceilings, especially across the northern half of Oklahoma.
&&
.PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 75 55 74 59 / 20 20 10 0 Hobart OK 80 55 78 59 / 20 20 10 10 Wichita Falls TX 92 59 78 63 / 30 20 10 10 Gage OK 67 49 75 56 / 50 30 0 10 Ponca City OK 69 51 77 54 / 60 30 0 0 Durant OK 93 61 79 64 / 30 50 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. &&
$$
NEAR TERM...04 SHORT TERM...04 LONG TERM....04 AVIATION...26
NWS OUN Office Area Forecast Discussion