textproduct: Norman

KEY MESSAGES

Updated at 220 PM CDT Sun Aug 23 2026

- Excessive heat continues into early next week.

- Strong to severe storms are possible Monday morning across north central Oklahoma and along the I-40 corridor Monday afternoon and evening. Damaging wind gusts are the main hazard.

- Elevated fire weather conditions are expected across southwest Oklahoma into western north Texas Monday afternoon.

NEAR TERM

(Rest of today and tonight) Issued at 220 PM CDT Sun Aug 23 2026

Hot and humid conditions are ongoing across Oklahoma and north Texas this afternoon with the most dangerous heat across southern Oklahoma and western north Texas this afternoon.

A few high-based thunderstorms may develop across the Oklahoma and Texas panhandles this afternoon with a chance that the remnants of the activity will move into northwest Oklahoma this evening.

For tonight, increasing isentropic ascent/warm air advection associated with the low-level jet will result in showers and thunderstorms developing across Kansas, Missouri, and northeast Oklahoma after midnight. The I-35 corridor in Oklahoma will on the southwest/western periphery of the strongest ascent with the potential for isolated development as far southwest as south central Oklahoma. Strong to low-end severe thunderstorms are possible, especially across north central Oklahoma.

Mahale

SHORT TERM

(Monday through Tuesday night) Issued at 220 PM CDT Sun Aug 23 2026

A surface low and attendant cold front will advance southeast into Oklahoma on Monday. The location of the cold front/surface low could be impacted by the morning showers and thunderstorms and whether convective outflow, post-frontal clouds, and/or rain advance the effective cold front farther to the south.

The cold front will likely be very close to the I-40 corridor with the potential for a sharp north-to-south temperature gradient somewhere in that zone. For example, the most aggressive model with the cold front is the 12Z NAM with abundant post-frontal cloud cover. As a result, it has a high temperature of 96 deg F in Oklahoma City. In contrast, the National Blend of Models (NBM) has 108 deg F with Oklahoma City in the pre-frontal torch ahead of the front. For those who live in north central Oklahoma (i.e., near Ponca City), we have high confidence that you will be on the cooler side of the front. If you live in western north Texas, (i.e., near Wichita Falls, Seymour, Vernon, Knox City, etc.), we have high confidence you will be on the hot side of the front. It is the middle/I-40 corridor where uncertainty is the highest.

Given the uncertainty on the exact location of the cold front, we opted to keep the location for the Extreme Heat Warning and Heat Advisory relatively small for tomorrow afternoon. For now, we issued an Extreme Heat Warning across all of western north Texas into parts of southwest Oklahoma. To the north of Extreme Heat Warning, we issued a Heat Advisory for a row or two of counties. These are the locations that we have the highest confidence to meet Heat Advisory and/or Extreme Heat Warning criteria. We may have to expand both products farther north depending on the location of the cold front tomorrow.

There is the potential for isolated thunderstorms along the cold front tomorrow afternoon. Any thunderstorms that develop will be capable of producing strong to wind gusts from downbursts given the very hot conditions ahead of the front.

With the veered low-level flow and very hot temperatures ahead of the cold front tomorrow, relative humidity values are forecast to fall to around 15 to 20% across southwest Oklahoma into western north Texas. This will result in elevated fire weather conditions to perhaps locally near-critical fire weather conditions (depending on the winds). With the ongoing drought and very dry fuels, the total fire environment (weather + fuels) will be susceptible to at least initial attack fires. Therefore, at the very least, a Fire Danger Statement (RFD) will be needed once again tomorrow. A Red Flag Warning (RFW) could be needed if there is a corridor of higher fire weather conditions. One area that will have to be monitored carefully is near the location of the cold front, where there will be a wind shift and the potential for isolated thunderstorms that would pose a threat for gusty/erratic winds and dry lightning.

For Tuesday, there will likely still be a north-to-south temperature gradient with the cold front likely stalling in the area. The hottest temperatures will continue to be across southern Oklahoma and western north Texas with less hot conditions across northern Oklahoma.

By Tuesday night, a complex of thunderstorms is expected to approach from the northwest. The remnants of this complex may produce a threat for strong to severe wind gusts across northwest Oklahoma.

Mahale

LONG TERM

(Wednesday through Saturday) Issued at 128 AM CDT Sun Aug 23 2026

As the second shortwave moves across the area on Wednesday, not out of the question to see a few widely scattered showers/thunderstorms. Latest medium range model runs of both the GFS and ECMWF show the upper ridge drifting further southwest as we go through the second half of the upcoming week. This will allow modest northwest flow to continue through the end of the week and possibly into the weekend with periodic shortwave troughs traversing the Southern Plains and at least some rain chances continue.

With this retrogression of the upper ridge, it should allow temperatures to cool from the peak of the heating that will be see earlier in the week. However, it still appears that above normal temperatures will continue.

AVIATION

(00Z TAFS) Issued at 556 PM CDT Sun Aug 23 2026

VFR conditions are forecast to persist through the period, though low chances for rain/thunder are introduced into the initial hours of Monday morning. The best chance for terminal impact will be at KPNC, though potential is forecast to extend as far south as near the OKC metro area.

Otherwise, a front will move southeastward during the day on Monday, settling somewhere near the I-40 corridor by the afternoon and offering varied wind direction by this time. A period of gusty winds is likely in advance of this feature as well.

Safe travels!

Ungar

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 78 105 77 102 / 10 20 20 10 Hobart OK 80 111 77 106 / 0 20 20 10 Wichita Falls TX 82 111 81 109 / 0 0 10 10 Gage OK 75 100 71 99 / 20 0 20 10 Ponca City OK 72 96 72 96 / 30 10 0 10 Durant OK 79 108 79 107 / 0 10 20 0

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory until 8 PM CDT this evening for OKZ005-006-009>012- 014>020-023>032-040>042.

Extreme Heat Warning until 8 PM CDT this evening for OKZ021-022- 033>039-043>048-050>052.

Extreme Heat Warning from noon to 8 PM CDT Monday for OKZ033-036- 037-044-045.

Heat Advisory from noon to 8 PM CDT Monday for OKZ034-035-038- 039-041-046>048-050>052.

TX...Extreme Heat Warning until 8 PM CDT this evening for TXZ083>090.

Extreme Heat Warning from noon to 8 PM CDT Monday for TXZ083>090.