Area Forecast Discussion

KEY MESSAGES

- Dangerous heat will continue through at least Wednesday afternoon with widespread heat index values of 108 to 115 degrees expected.

- An Extreme Heat Warning and Heat Advisory remain in effect across North and Central Texas, with heat concerns likely to continue through the remainder of the week.

SHORT TERM

(This evening through Wednesday) Issued at 111 PM CDT Tue Jul 21 2026

Significant and hazardous heat will continue to afflict North and Central Texas this afternoon through Wednesday, as a large ridge of upper level high pressure dominates the Rockies and Southern and Central Plains. Subsidence in association with this ridge will lead to substantial heating in the lower portions of the atmosphere, which, coupled with relatively high dewpoints, will produce heat indices in excess of 110 degrees in many areas. The primary region of concern this afternoon will be be generally along and east of I-35, and north of I-20, where an Excessive Heat Warning will remain in effect. Elsewhere, a Heat Advisory will remain in effect for heat indices above 105.

Cooling will be limited tonight in the central urban cores where the heat island effect will be maximized. Some locations may only manage lows in the lower to middle 80s prior to daybreak Wednesday.

Short-range guidance continues to advertise a backdoor front sliding southward across the Red River into portions of Eastern and North Central Texas after daybreak Wednesday. This will promote a wind shift to the northeast across much of the area by late morning and early afternoon. Unfortunately, moisture convergence along and ahead of this boundary will likely send heat indices above 110 degrees over most of North and Central Texas Wednesday, particularly along and east of I-35. As a result, the Excessive Heat Warning will expand to include roughly the eastern two thirds of our forecast area Wednesday, the only exception being the extreme northeast and southwest counties. Even in these separated locales, relief will be minor, with Heat Advisories still warranted.

Latest extended runs of the HRRR are beginning to feature some isolated showers across North Texas later Wednesday afternoon, due possibly to some elevated moisture convergence behind the backdoor surface front. Elected not to bite on this precipitation at this time in the current forecast, but wouldn't rule out some isolated activity eventually occurring, assuming this limited forcing persists.

LONG TERM

(Wednesday night through next Monday) Issued at 111 PM CDT Tue Jul 21 2026

No appreciable changes in the longer term forecast, as the expansive upper ridge holds sway over much of the Southern Rockies, Central and Southern Plains, and parts of the Southeast U.S. through the period. By and large, the presence of strong subsidence and limited cloud cover will promote daily highs above the century mark through the weekend, into early next week. The only wildcard will be the future progression of Bertha. Some longer range models bring the remnants of this system into Southeast Texas by Thursday and Friday. Depending on the scope of the remnant moisture, some clouds and limited chances for precipitation may need to be introduced to some of the Central Texas zones in the Thursday through Saturday period. This would also tend to knock daytime temps down slightly within these areas. Much uncertainty remains concerning the future track and evolution of Bertha, so confidence in this portion of the forecast remains moderate at best.

AVIATION

(00Z TAFS) Issued at 701 PM CDT Tue Jul 21 2026

VFR conditions will continue through the period. The primary aviation concern will be a wind shift from southerly overnight tonight to north/northeasterly late Wednesday morning as a weak front pushes through the region. Wind speeds will remain below 10 knots behind the front. A few CAMs are showing the potential for isolated convection developing near and southwest of the Metroplex tomorrow afternoon, confidence in any impacts at the TAF sites remains too low to warrant inclusion in the forecast.

SPOTTER INFORMATION STATEMENT

Spotter activation is not expected at this time.

PRELIMINARY POINT TEMPS/POPS

FWD WATCHES / WARNINGS / ADVISORIES

Heat Advisory until 8 PM CDT this evening for TXZ091-100>102- 115>117-129>135-141>148-156>162-174-175.

Extreme Heat Warning from noon to 6 PM CDT Wednesday for TXZ091>093-100>105-107-115>123-130>135-143>148-157>162-174-175.

Extreme Heat Warning until 8 PM CDT this evening for TXZ092>095- 103>107-118>123.

Heat Advisory from noon to 6 PM CDT Wednesday for TXZ094-095-106- 129-141-142-156.