textproduct: Norman

KEY MESSAGES

Updated at 652 PM CDT Sat Sep 12 2026

- Strong to severe thunderstorms are possible late this afternoon and evening across northern Oklahoma.

- Hot and humid conditions through at least midweek next week.

- Elevated to near-critical fire weather conditions possible Monday afternoon across the west.

NEAR TERM

(Through Tonight) Issued at 205 PM CDT Sat Sep 12 2026

Isolated showers and thunderstorms will remain possible early this afternoon across central Oklahoma, with additional storm development expected late this afternoon into this evening.

An outflow boundary pushing in from the northeast helped to develop scattered showers and storms across north central and central Oklahoma this morning. Since then, convergence along this boundary has weakened and only isolated showers/storms remain. The airmass north of this outflow boundary has also stabilized in the short term. So isolated showers/storms over central Oklahoma may persist early this afternoon, but the activity is on the decrease.

Farther west and south, convective inhibition is decreasing and many convective-allowing models show storms developing late this afternoon across northwest and perhaps central Oklahoma. MLCAPE is already 2000-3000 J/kg per SPC mesoanalysis. Deep layer shear of 30 to 40 knots is progged across northern Oklahoma late this afternoon which would support some organized thunderstorms. With that, the SPC did upgrade the severe weather outlook to Slight Risk for late this afternoon and evening which is reasonable. It is likely we will see thunderstorm redevelopment late this afternoon into this evening with severe weather possible, both hail and strong winds. Storms will likely not be widespread enough for significant drought relief in many areas, although heavy rainfall is possible in localized areas. The severe weather potential and storm coverage are expected to decrease late this evening or early Sunday morning.

SHORT TERM

(Sunday through Monday night) Issued at 205 PM CDT Sat Sep 12 2026

The upper ridge builds stronger over the area, and the heating trend returns to the area. A Heat Advisory will likely be necessary on Sunday, but there is a little question on if any outflow from overnight/morning thunderstorms may take enough off the heat to keep some areas below criteria, so will defer on issuing an advisory until the geography is more clear.

Another hot day is expected on Monday, but winds will be a little stronger in western Oklahoma as surface low pressure deepens in southeast Colorado. Although the minimum humidity is currently projected to be 20 to 25 percent, the higher wind speeds are still expected to push fire weather conditions into the elevated category on Monday afternoon across the west.

LONG TERM

(Tuesday through Friday) Issued at 210 AM CDT Sat Sep 12 2026

The subtropical ridge will remain centered across the southeast United States through at least the middle part of next week. Oklahoma and north Texas will be on the western periphery of the ridge with a strong low-level thermal ridge. Above-normal temperatures are likely to continue with high temperatures in the 90s to mid 100s deg F. Bias-corrected probabilistic guidance indicates little temperature spread through Wednesday (e.g., the 10th percentile is above-normal), which indicates high confidence of above-normal temperatures.

Northern and western Oklahoma will be close enough to stronger flow aloft (on the periphery of the ridge known as the ring of fire), where there will be occasional chances of showers and thunderstorms from remnant convection or nearby fronts.

Ensemble spread does increase by late next week into the following weekend (September 18-20), which indicates the potential for a pattern change with the subtropical ridge breaking down and a stronger cold front advancing southward into the area. It's not a guarantee, but there is a 40 to 70% chance of high temperatures below 90 deg F on Sunday, September 20 (40% south; 70% north). The coldest end of guidance even indicates a low to medium chance (10 to 40%) of high temperatures below 80 deg F.

Mahale

AVIATION

(00Z TAFS) Issued at 652 PM CDT Sat Sep 12 2026

Challenging first 6 hours of the forecast period as confidence with terminal-specific impacts from convection is relatively low at several sites... including KWWR, KCSM, KPNC, KSWO, and KOKC.

Currently, isolated to scattered thunderstorms are ongoing along a northwest to southeast oriented corridor from northwestern Oklahoma to southeastern Oklahoma. This activity should wane in the next couple of hours, but additional convective activity is expected to impact western and north Oklahoma later this evening. The chance of convection does appear to decrease after 06-08z.

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 75 101 77 100 / 20 0 0 0 Hobart OK 77 103 77 102 / 10 0 0 0 Wichita Falls TX 76 104 77 102 / 10 0 0 0 Gage OK 72 103 76 101 / 40 0 0 0 Ponca City OK 71 99 74 99 / 40 10 0 0 Durant OK 76 102 76 101 / 10 0 0 0

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory until 7 PM CDT this evening for OKZ021>025-027>048- 050>052.

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