textproduct: Norman

KEY MESSAGES

Updated at 1244 AM CDT Thu Sep 18 2025

- Periods of rain and thunderstorms are expected today and tonight, with the best rain chances gradually moving south and eastward.

- Above-normal temperatures through the weekend before potentially cooling down on Tuesday.

NEAR TERM

(Through Thursday) Issued at 1244 AM CDT Thu Sep 18 2025

Radar and surface observations show an outflow boundary located roughly around I-44. A second boundary is entering northern Oklahoma from the north. While there is modest instability in front of the boundaries, storm coverage near/behind them is expected to be minimal early this morning. The more robust chance for early-morning storms will come as a cluster currently ranging from the Panhandles up into southeast Colorado swings south and east into northern and western Oklahoma. Severe weather is not anticipated early this morning, but heavy rainfall and gusty winds are possible.

Storm evolution this morning will impact how much the outflow boundaries are reinforced, which in turn will determine where the composite boundary is located this afternoon when storms redevelop. Most weather models are likely to end up too far north with the boundary and redevelopment zone, given that a preferred landing spot for the convergence zone was around I-40. The HRRR might provide one of the better "progressive" examples, with CI occurring further south into southern Oklahoma and adjacent north Texas. Deep-layer shear will be modest (40 knots of cloud-layer shear) and instability will be modest (up to 1,500 J/kg of MLCAPE). Overall, this should favor clusters and multicells, with severe wind/hail and minor flooding possible with the strongest cores.

Temperatures today will be sharply bifurcated - extensive cloud debris near/north of the composite boundary will keep highs closer to 80, while the open warm sector makes another run at 90.

Meister

SHORT TERM

(Thursday night through Saturday night) Issued at 1244 AM CDT Thu Sep 18 2025

Model guidance suggests at least a modest eastward shift of the LLJ tonight compared to previous nights this week. That could make all the difference in the world, providing a forcing mechanism for showers and storms to keep developing in central or southern Oklahoma.

The upper trough responsible for this disturbed weather will lift northeastward during the day on Friday. Widespread height rises are anticipated, so we look to have a reprieve from at least more widespread storm chances. Temperatures will also warm back up 3-6 degrees during the day on Friday in response to those height rises.

The subtropical ridge will shift a little westward on Saturday, which will give some leeway to the prevailing northwest flow to potentially initiate storms on the high terrain. This means the usual - a medium chance of storms especially across the northern half of the area, with storm chances peaking late Saturday night/early Sunday morning. Above-normal temperatures continue.

Meister

LONG TERM

(Sunday through Wednesday) Issued at 1244 AM CDT Thu Sep 18 2025

The upper-level flow pattern becomes more zonal on Sunday. This will likely encourage stronger return flow and a downslope element to winds that will bring a dose of summertime temperatures to much of the area (especially the southwestern quarter of it). Simultaneously, thunderstorm chances will occur across much of the area Sunday afternoon as temperatures breach the convective temp. Storm chances will persist into Monday as the next trough prepares to eject into the central Plains.

It is this trough that will trigger a cooldown - not toward "fall", per se, but at least cooler than the rest of the coming week. Temperatures on Tuesday and Wednesday look to be in the low to mid 80s across the area. precipitation chances are lower on those days than most of the rest of the coming week, but at least low chances for storms will continue along and southeast of I-44.

Meister

AVIATION

(06Z TAFS) Issued at 1052 PM CDT Wed Sep 17 2025

Showers and thunderstorms are expected to increase in coverage across northwest Oklahoma after midnight. This activity will gradually shift eastward overnight with the potential for redevelopment Wednesday afternoon. PROB30s were included at most terminals to account for this (the exception being KSPS). Gusty winds and brief reductions in visibility are possible with the most intense storms.

A northerly wind shift will enter northwest Oklahoma tonight and gradually move to the southeast. Ahead of this, winds will remain light and somewhat variable (though mostly from the south/southeast).

Mahale

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 86 65 87 69 / 30 40 10 10 Hobart OK 89 62 91 69 / 20 40 0 10 Wichita Falls TX 92 67 92 70 / 30 30 10 0 Gage OK 76 57 85 65 / 60 10 0 10 Ponca City OK 81 62 85 66 / 40 40 10 20 Durant OK 93 68 90 68 / 30 50 30 0

OUN WATCHES/WARNINGS/ADVISORIES

OK...None. TX...None.