textproduct: Norman

KEY MESSAGES

Updated at 125 AM CDT Sun Sep 6 2026

- Ongoing heatwave continues through at least midweek with triple digit heat indices and lows well above normal.

- Very low chances for rain/storms this afternoon across northern and eastern parts of the forecast area on Sunday and Monday afternoons.

- Possible pattern shift by late week introducing low rain chances.

NEAR TERM

(Through Sunday) Issued at 125 AM CDT Sun Sep 6 2026

The near term will be marked be heat and isolated pop-up thunderstorms.

Morning lows will stay up in the mid to upper 70s, followed by afternoon highs reaching into the triple digits. Heat indices will largely follow the moisture gradient with the highest values along the Red River, within the festering heat box of north central Oklahoma, and east of I-35 (105-110 degrees), especially southeast Oklahoma. With drier air in place, northwest Oklahoma will see heat indices closer to 100. The current heat advisory is well configured with this forecast, so will not make any adjustments to the area.

The signal for rain this afternoon is weak, with a few CAMs showing very isolated convection. These will be diurnally driven pop-up thunderstorms with little chance of meaningful rainfall. Have included 10% PoPs for this possibility with most of the area expected to remain dry.

Overnight lows will again stay up in the mid to upper 70s, offering little relief from the daytime heat.

Day

SHORT TERM

(Sunday night through Tuesday night) Issued at 125 AM CDT Sun Sep 6 2026

Continuing under the blocking ridge, Monday appears very similar to Sunday both in terms of heat and low chance pop-up thunderstorms. Cumulative heat stress (including overnight lows running 5 to 10 degrees above normal) will put our heat risk into the major to extreme category across most of the area through Wednesday. For now, we've expanded the heat advisory into Monday.

The signal for diurnal thunderstorms disappears on Tuesday. While there is the caveat that this is now outside the CAM window, this does fit with the synoptic setup as the ridge shifts slightly eastward. Otherwise, our hot and dry pattern continues with similar heat indices to previous days (with a subtle trend toward 105+ heat indices covering a slightly larger area).

The aforementioned eastward shift of the ridge will allow a low chance (10-20%) for showers and storms to make it into northwest Oklahoma late Tuesday night / early Wednesday morning.

Day

LONG TERM

(Wednesday through Saturday) Issued at 125 AM CDT Sun Sep 6 2026

The ridge begins to flatten Wednesday as several waves begin to make their way through the northern flow. Most models (80-90%) depict Wednesday as hot and dry like previous days, though a few ensemble members (~10%) suggest that we could see thunderstorms approach northern Oklahoma from Kansas.

Thursday through the end of the week redevelops the ridge over the western conus, putting us in the path of several waves in the upper flow. This will bring back low chances for rain (10-30%) and a chance for some relief from the heat. High temperature uncertainty jumps on Thursday across northern Oklahoma--where the middle 50% (interquartile range) of potential outcomes spans a 10-degree range--before spreading farther south toward the weekend. Even with the potential cooling, the likelihood of daily highs reaching or exceeding 100 degrees remains moderate to high (50-80% probability, highest in north Texas) through Saturday. Key factors determining whether relief arrives and any rain chances will be the position / strength of the ridge and timing of approaching upper level waves.

Day

AVIATION

(12Z TAFS) Issued at 556 AM CDT Sun Sep 6 2026

VFR conditions will continue on Sunday, with a generally modest south-southeasterly breeze and diurnal cumulus expected during this time. Have maintained PROB30 mentions at terminals along/east of Interstate 35 in Oklahoma for Sunday afternoon and evening, though minimal terminal (and resultant category) impact remains expected.

Safe travels!

Ungar

FIRE WEATHER

Issued at 125 AM CDT Sun Sep 6 2026

While no particular day stands out as problematic (RH values generally stay above 25 percent), hot temperatures and very dry fuels (90th+ percentile ERCs) warrant keeping a close eye on conditions.

Day

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 100 76 100 77 / 10 0 10 0 Hobart OK 101 76 101 77 / 0 0 0 0 Wichita Falls TX 102 75 102 77 / 0 0 0 0 Gage OK 99 73 100 74 / 10 0 0 0 Ponca City OK 100 75 100 76 / 10 0 10 0 Durant OK 103 76 103 76 / 10 0 10 0

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory from noon today to 7 PM CDT Monday for OKZ006>008- 011>013-017>020-023>032-035-037>048-050>052.

TX...Heat Advisory from noon today to 7 PM CDT Monday for TXZ085-086- 088>090.