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KEY MESSAGES

Updated at 1249 PM CDT Mon Sep 7 2026

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

- Very low chances for rain/storms across southeast Oklahoma on Monday.

- Possible pattern shift by late week with less dangerous heating and increasing rain chances late Wednesday into Thursday.

NEAR TERM

(Rest of today and tonight) Issued at 1249 PM CDT Mon Sep 7 2026

As it has been for weeks (months?) now, the main weather impact today and this evening will be the heat. While folks should be acclimated to the 100-107 heat indices, there is still an inherent danger to any outdoor Labor Day activities this afternoon if proper heat precautions (hydration, frequent shade break, etc). The greatest heat risk will be across the southeastern part of Oklahoma, where winds will be a little lighter and probabilities of breaking into the 106-110 heat index range are greater.

Across that same portion of southeast oklahoma, high-resolution guidance such as the HRRR and 3km NAM depict weak convection in the peak of daytime heating. Forecast soundings show an uncapped but only weakly unstable environment with up to 1,000 J/kg of MLCAPE. In all likelihood, the showers we see this afternoon and evening will be similar to the last several days - ephemeral, with little impact other than the occasional lightning strike, and mostly focused in NWS Tulsa's CWA.

The heat advisory remains in effect tonight with lows remaining in the upper 70s (10-15 degrees above normal).

Meister

SHORT TERM

(Tuesday through Wednesday night) Issued at 1249 PM CDT Mon Sep 7 2026

The seemingly unending heatwave has at least one more crescendo coming on Tuesday and Wednesday with highs surging back into the low- to-mid 100s area-wide. This will already put us into unprecedented territory in our area - if Oklahoma City hits 100 each of the next three days, as is currently explicitly forecasted, we will set a September record for most 100-degree days (current record: 7) by the 9th of the month.

As has usually been the case, the peak of the heating will be followed by a frontal intrusion. Currently that frontal intrusion looks to occur Wednesday evening/night in northern Oklahoma and just outside the range of the short-term forecast for the rest of the area. With westerly flow aloft leaking at least as far south as Kansas and a reasonably unstable (MLCAPE 1,000-2,000 J/kg) environment, scattered to widespread storm development will occur by late afternoon near the OK/KS border along the front. The environment doesn't look terribly impressive for severe weather impacts, though downbursts are certainly possible during the diurnal cycle. Perhaps of just as much importance, the LLJ strengthens and veers overnight. Global models and the NAM are rather bullish on continued instability (MUCAPE > 1,000 J/Kg) and show the most significant precip footprints we've seen in weeks north of I-40. Widespread drought relief in those areas? Perhaps not, especially if the mesoscale details don't support a more widespread MCS. But it is at least a glimmer of hope.

Meister

LONG TERM

(Thursday through Sunday) Issued at 135 AM CDT Mon Sep 7 2026

With models coming into alignment in bringing a cold front through late on Wednesday, confidence is increasing in heat relief on Thursday. North of I-40, we have 30-50% of temperatures below 90 degrees (virtually all ensemble members keep this area below 100). Southern Oklahoma and north Texas are likely to be warmer with 40-80% chance of highs below 100 degrees (0-20% chance for less than 90). Showers and storms will likely linger into Thursday morning with 20-30% chance for afternoon redevelopment (highest chances along the front). Temperatures will depend largely on progression of the front and extent of cloud cover and showers.

While models diverge greatly on what the synoptic pattern will look like over the weekend, they do have general agreement that the ridge will continue to exert some influence with positive 500mb height anomalies over us. Rain chances through this period range from 10-30% (highest in northern Oklahoma). Temperatures will likely be in the 90 to 105 degree range with the warmest temperatures more likely in southern Oklahoma / north Texas. Beyond Sunday, the interquartile spread increases to 15 to 25 degrees.

Day

AVIATION

(18Z TAFS) Issued at 1221 PM CDT Mon Sep 7 2026

VFR conditions are expected to continue into Tuesday with generally light south winds. Very low chances (10-30%) for showers and storms will be in place once again this afternoon for areas east of I-35, with the highest relative chance at KDUA where PROB30 was included for this afternoon.

FIRE WEATHER

Issued at 135 AM CDT Mon Sep 7 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 through midweek.

Wednesday will bring a northerly wind shift with the front along with 20-50% chance for wetting rains (lowest in north Texas, highest in northeast Oklahoma).

Day

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 77 101 78 101 / 0 0 0 10 Hobart OK 78 103 78 103 / 0 0 0 0 Wichita Falls TX 78 103 78 103 / 0 0 10 10 Gage OK 76 102 76 101 / 0 0 0 40 Ponca City OK 77 102 77 101 / 0 0 0 30 Durant OK 76 103 76 102 / 10 0 0 10

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory until 7 PM CDT Tuesday for OKZ006>008-011>013- 017>020-023>032-035>048-050>052.

TX...Heat Advisory until 7 PM CDT Tuesday for TXZ085-086-088>090.