textproduct: Norman

KEY MESSAGES

Updated at 621 PM CDT Sun Sep 13 2026

- Hot and humid conditions through at least midweek.

- Elevated fire weather conditions Monday afternoon across the west.

- Chance of showers and thunderstorms across northwestern Oklahoma Tuesday afternoon and Tuesday night. But no significant relief from the drought for most areas.

NEAR TERM

(Rest of today and tonight) Issued at 132 PM CDT Sun Sep 13 2026

The cold front that slid into northern Oklahoma has kept temperatures across the north a little lower than the last few days. The Heat Advisory may not pan out across northern Oklahoma, but there is sun and some time to warm temperatures, so will let the advisory ride for now.

The convection across western Oklahoma has dissipated, although a few small showers have recently developed in Woods County. The GFS and to some extent the HRW-FV3 show the potential of precipitation developing late this afternoon/early this evening across northwest Oklahoma along the surface front, but most models keep things dry this evening. Have added some 10 percent POPs across the northwest for this evening, but do not see enough signal to introduce mentionable POPs after 00Z.

SHORT TERM

(Monday through Tuesday night) Issued at 132 PM CDT Sun Sep 13 2026

The upper ridge shifts eastward tomorrow. With slightly lower heights/thicknesses, temperatures will be slightly lower tomorrow across much of the area. This will not be a significant cooling by any means, but may be enough to keep much of the area below heat advisory criteria on Monday. Southeastern Oklahoma remains closer to the upper ridge axis and will still be quite hot, so a heat advisory has been issued for this area again on Monday. There is certainly the potential that the Heat Advisory may need to be expanded across a wider area.

Winds increase across western Oklahoma Monday as a surface low develops across southeastern Oklahoma increasing the pressure gradient across the area. Minimum afternoon humidity in the west is expected to generally remain above 20 percent, but the increasing wind does push fire weather into the elevated level during the afternoon. The forecast weather conditions give some areas of near- critical fire weather in northwest Oklahoma, but this corresponds to areas that have had some recent precipitation, so mentioning elevated conditions in the fire weather forecasts still seems reasonable.

With the upper ridge shifted east, increasing southwest flow aloft will develop over the southern Rockies and into the southern and central High Plains. The High Plains convection on Monday/Monday Night is forecast to dissipate before reaching the forecast area, but convection on Tuesday/Tuesday night is expected to make more of a run toward northwestern Oklahoma Tuesday night as well as potential shower/storm development along a cold front moving south down the central High Plains and Kansas into northwest Oklahoma. NBM POPs are quite aggressive with POPs late Tuesday afternoon and Tuesday evening. The current NAM actually does not bring QPF into the forecast area Tuesday/Tuesday night. Will keep chances relatively high across the northwest with the front expected to be in the vicinity, but will decrease POPs from the 80% that NBM put in far northwest Oklahoma given the NAM signal.

LONG TERM

(Wednesday through Saturday) Issued at 205 AM CDT Sun Sep 13 2026

Above-normal temperatures will likely continue through at least Thursday as bias-corrected probabilistic guidance indicates little temperature spread with even the 10th percentile above-normal through that period. High temperatures will range from the mid 90s to the low 100s deg F.

Ensemble spread increases among the global models by late in the week into next weekend (September 18-20), which indicates the potential for a pattern change. There is a chance the subtropical ridge will break down as a mid-level trough digs across the Plains. This would drive a cold front southward into the Southern Plains. There is a 30 to 70% chance of high temperatures below 90 deg F by Saturday (30% southeast; 70% north). The coldest end of guidance indicates a low to medium chance (5% southeast; 50% north) of high temperatures below 80 deg F. These probabilities increase by 10 to 20% by Sunday (i.e., the chance of cooler weather increases later in the weekend).

Mahale

AVIATION

(00Z TAFS) Issued at 621 PM CDT Sun Sep 13 2026

VFR conditions are expected through the period with generally south winds. Expect winds to become gustier during the day Monday, especially across western/northwestern OK where gusts over 30 mph will be possible during the afternoon.

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 77 98 77 98 / 0 10 0 0 Hobart OK 78 100 78 100 / 0 0 0 0 Wichita Falls TX 78 102 77 102 / 0 0 0 0 Gage OK 76 100 77 99 / 10 0 0 50 Ponca City OK 74 97 76 97 / 0 0 0 10 Durant OK 76 102 76 102 / 0 0 0 0

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory until 7 PM CDT this evening for OKZ004>048-050>052.

Heat Advisory from noon to 7 PM CDT Monday for OKZ032-043-047- 048-051-052.

TX...Heat Advisory until 7 PM CDT this evening for TXZ083>090.