textproduct: Norman

KEY MESSAGES

Updated at 250 PM CDT Mon Sep 28 2026

- Widespread beneficial and potentially flooding rainfall expected beginning late Tuesday through the end of the week.

- Chance of severe storms Wednesday afternoon and Wednesday night.

- Temperatures will remain above normal through mid-week, before cooling Thursday into the weekend.

NEAR TERM

(Today and tonight) Issued at 250 PM CDT Mon Sep 28 2026

A shortwave ridge aloft will result in another day of above- normal temperatures for late September with high temperatures ranging from the mid 80s (north) to the mid 90s (south). Isolated, diurnally-driven showers and thunderstorms may develop this afternoon with a weakly capped and moist air mass. The chance for a given location is low (10-20%), so most locations will remain dry today. The highest (relative) chance will be across southern Oklahoma near the Red River, where precipitable water values are >1.70 inches. If thunderstorms do occur, the primary hazards are cloud-to-ground lightning and strong wind gusts.

By tonight, a strengthening low-level jet associated with increasing isentropic ascent/warm air advection may result in isolated showers and thunderstorms across central Oklahoma.

Mahale

SHORT TERM

(Tuesday through Wednesday night) Issued at 250 PM CDT Mon Sep 28 2026

By Tuesday, a mid/upper-level trough will dig across the southwestern U.S. and consolidate with the remnants of Hurricane Polo, eventually forming a cutoff low. As the system closes off and decelerates, the strongest synoptic-scale ascent and highest rain chances will stay to our west on Tuesday. However, a lead wave ahead of the main trough will result in a chance of showers and thunderstorms across northern Oklahoma with the highest chance across northwest Oklahoma.

As the upper-level low slowly lifts northeast toward Plains, synoptic-scale ascent will shift to the east with the chance for showers and thunderstorms increasing Tuesday night into Wednesday morning across western Oklahoma and adjacent portions of western north Texas. High confidence exists for a heavy rainfall event bringing a risk of localized flash flooding from Wednesday through Thursday. Total rainfall amounts of 3 to 6 inches, with localized higher amounts possible, are most likely to occur along and to the southeast of I-44. Precipitable water values are forecast to be above the daily maximum in these locations, indicating the presence of anomalous moisture. To the northwest of I-44, generally 1 to 2 inches of rainfall are forecast. The dry slot should limit overall rain totals northwest of I-44 into western and southwestern Oklahoma and portions of western north Texas. In other words, there could be a sharp northwest to southeast gradient for the heaviest rainfall. Should the dry slot prove stronger than currently anticipated, rainfall totals along the I-44 corridor would likely be reduced. Conversely, a weaker dry slot could lead to higher rainfall amounts northwest of I-44.

In addition to heavy rainfall, there is also a risk for severe weather. A dryline is forecast to be near the 100th meridian Wednesday afternoon. Increasing instability in a highly sheared environment ahead of the dryline will result in a chance for strong to severe thunderstorms. However, convective development along the dryline remains uncertain due to potential cloudiness restricting surface heating. Depending on the amount of instability, the risk of severe weather may advance eastward Wednesday night into Thursday morning toward central Oklahoma in tandem with the dry slot. Damaging wind gusts, hail, and tornadoes are all potential hazards.

Mahale

LONG TERM

(Thursday through Sunday) Issued at 129 AM CDT Mon Sep 28 2026

As we go into the latter part of the week into the weekend, models differ on how they handle the upper low, but either solution(GFS or Euro) would keep precip chances in the forecast through the end of the week and through the upcoming weekend. Still heavy rainfall potential continues Thursday into Friday across south central and southeast parts of the state.

With this continuation of rain, associated cloud cover and frontal passage that will occur late in the week, temperatures will finally begin to feel more like fall instead of summer. Most areas from Thursday into at least Saturday will in the 70s and lower 80s. There is a chance for a few locations, especially Friday as cooler surface high pokes south into the area, to see highs only in the 60s.

AVIATION

(00Z TAFS) Issued at 537 PM CDT Mon Sep 28 2026

Outside of widely scattered rain and thunderstorms near KSPS through ~0100 UTC, much of tonight and Tuesday morning will be dry with scattered/broken coverage of mid and high ceilings.

Progressively lower ceilings, along with chances for additional rain and thunderstorms, will shift east/northeastward into portions of western and northern Oklahoma towards Tuesday afternoon. A south-southeasterly surface wind will also be gustier compared to today (Monday).

Safe travels!

Ungar

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 71 90 73 87 / 10 30 10 80 Hobart OK 72 90 72 85 / 10 20 50 90 Wichita Falls TX 72 94 73 91 / 20 10 20 90 Gage OK 68 83 67 81 / 0 50 80 70 Ponca City OK 66 85 70 82 / 0 50 20 70 Durant OK 70 94 72 93 / 20 0 0 50

OUN WATCHES/WARNINGS/ADVISORIES

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