textproduct: Norman

KEY MESSAGES

Updated at 542 AM CDT Sat Aug 15 2026

- Low rain/storm chances linger over northwest Oklahoma through Sunday, with chances increasing and expanding over north- central Oklahoma on Sunday night.

- Frontal boundary will results in a brief reprieve in extreme heat for northern Oklahoma on Sunday and Monday.

NEAR TERM

(Through Saturday) Issued at 220 AM CDT Sat Aug 15 2026

Showers and thunderstorms continue this morning across far northwest Oklahoma. Although most of the convection will remain farther north in Kansas or farther west in the panhandles, a few of these storms could still brush northwestern Oklahoma early this morning.

A shortwave moving through the central/northern Plains today will help nudge a cold front south through Kansas today. The front will more than likely remain north of the forecast area through the day, but looks to get close enough to the state border that there will likely be some pre-frontal compressional warming across northern Oklahoma today. With warmer 850 mb temperatures forecast today by most models compared to yesterday, and the potential for compressional warming ahead of the front, the NBM forecast for temperatures to be slightly lower today seems odd and have gone slightly above the NBM forecast for highs.

Many areas look to hit a heat index of 105 today (except for some of the slightly higher elevations of west central Oklahoma) so the Heat Advisory is still good, although have expanded it to include a few more counties of the southwest for today.

With the front expected to remain north and northwest of the forecast area, the potential of showers and storms will primarily be across northwest Oklahoma yet again. The NBM has targeted the right general area correctly over recent days, but has not been aggressive enough with the probabilities or the area, and looking at specific model forecasts (especially the HRRR), the same may be true today as well, so have expanded the area in northwest Oklahoma where showers/storms are mentioned compared to NBM.

SHORT TERM

(Saturday night through Monday night) Issued at 220 AM CDT Sat Aug 15 2026

The front over Kansas finally slides into Oklahoma Saturday night and Sunday. This will bring "not as hot" temperatures to northern Oklahoma on Sunday as well as the somewhat higher precipitation chances near and north of the boundary Sunday and Sunday night. Although it will be "not as hot" in the north, forecast heat index values still reach 105 across north central Oklahoma, so the Heat Advisory still looks reasonable for Sunday as well. Monday, heat index values will "only" be in the 99-104 range across much of northern and central Oklahoma, but will still likely reach advisory criteria in southern Oklahoma and northern Texas Monday afternoon. A continuation of the Heat Advisory will be likely be needed in the south on Monday, but the specific geography will depend on how far south the front moves, so will address this Sunday or Monday.

LONG TERM

(Tuesday through Friday) Issued at 220 AM CDT Sat Aug 15 2026

The hot temperatures will spread back north on Tuesday as the front dissipates and southerly flow returns across the area.

The operational medium-range models and many of the ensemble members are now trending toward the upper ridge shifting to the west and northwest flow aloft developing over the central and southern Plains by late in the week, so we may be trending toward seeing some lower temperatures late in the week. NBM still keeps temperature higher late next week than this pattern would suggest, but that will start catching up if this signal shows more run-to- run consistency. Despite the model trend showing this potential of shifting to northwest flow aloft, the precipitation chances associated with this shift are still a little uncertain and dependent on how much of the ridge still reaches into the southern Plains.

AVIATION

(12Z TAFS) Issued at 542 AM CDT Sat Aug 15 2026

All terminals expected to remain in a VFR category through the entire forecast period. A low-level jet will be weakening late this morning but will keep low-level wind shear through 15Z only at terminals KOKC & KOUN. Otherwise surface winds will veer southwesterly by 15Z at 10-15 kts with mixing gusting 20 kts. Surface winds may back more southerly by 20Z gusting 15-20 kts, then backing slightly by 01Z at 5-10 kts. A weak summer cold front will be moving across the Central Plains during the afternoon & evening hours pushing into terminals KWWR in northwest Oklahoma by 07Z eventually reaching terminal KCSM by 11Z. There will be a northerly wind shift behind this surface boundary at these two terminals through the forecast although wind speeds will only be around 10 kts. Also after 22Z there could be some storm activity in southwest Kansas & the Oklahoma Panhandle near terminal KWWR but probabilities are too low (15%) to be in their forecast, but mentionable for this discussion.

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 102 78 102 75 / 0 0 20 20 Hobart OK 104 78 104 74 / 0 0 20 20 Wichita Falls TX 104 78 104 76 / 0 0 0 0 Gage OK 104 72 96 67 / 20 10 20 40 Ponca City OK 105 78 101 73 / 0 0 20 30 Durant OK 103 78 104 77 / 0 0 0 0

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory until 7 PM CDT this evening for OKZ004-005-010- 033>035.

Heat Advisory until 7 PM CDT Sunday for OKZ006>008-011>013- 017>020-023>032-036>048-050>052.

TX...Heat Advisory until 7 PM CDT this evening for TXZ083-084-087-088.

Heat Advisory until 7 PM CDT Sunday for TXZ085-086-089-090.