Area Forecast Discussion

KEY MESSAGES

Updated at 1200 AM CDT Tue Sep 15 2026 - A Heat Advisory is in effect for the coastal plains, Williamson, and Travis Counties today from noon to 7 PM.

- Near critical fire weather conditions are forecast for the southern Edwards Plateau and the Rio Grande Plains.

- Low rain chances in the coastal plains through late week, spreading further inland Thursday.

- Humid morning conditions and above average temperatures continue through the the week.

SHORT TERM

(Today through Wednesday) Issued at 1200 AM CDT Tue Sep 15 2026

Hot and breezy conditions continue today with widespread highs from the mid 90s to around 103 degrees. Humid conditions in the east bring heat index values back into the 108-110 degree mark notably for locations in the northeast portion of the forecast area, though values from 105-108 degrees are still noted elsewhere. A Heat Advisory remains in effect for today from noon to 7 PM for portions of the area, though all should take heat precautions as the summer isn't over yet. We may finally be able to break the Heat Advisory streak on Wednesday with a slight decrease in highs expected, though we cannot rule out one just yet.

As mentioned previously, breezy southeasterly wind increases by the afternoon and continues into the evening. Gusts may range between 20- 30 mph at times before decreasing late tonight. A decrease in winds is noted on Wednesday.

Ridging over the southeast US will keep conditions mostly dry through the short term period with only low rain chances over the coastal plains each afternoon/evening.

LONG TERM

(Wednesday night through Monday) Issued at 1200 AM CDT Tue Sep 15 2026

A westward drifting upper-level ridge will elongate over South Central Texas Thursday before an upper low in the Gulf and a trough to the west eventually force this feature south of the area late this weekend. With southerly flow at the surface, increased moisture continues over the area this week most notably Thursday and and Thursday night as a surge of higher PWAT values moves inland over South Central Texas. While rain chances extend over much of the area during this time, we are not expecting widespread shower and thunderstorm activity as the upper ridge continues to influence the area. Upper ridging looks to linger over the area through much of the weekend keep rain chances either out of the area or low during this time. Towards the very end of the forecast period, a series of shortwaves could impact Texas and could bring some additional rain chances and possibly a slight decrease in temperatures, but details remain uncertain.

AVIATION

(06Z TAFS) Issued at 1250 AM CDT Tue Sep 15 2026

A large upper ridge over the Deep South states and A TUTT low moving NW into Deep South TX and into the western periphery of the upper ridge will again help with onshore winds today as it had already done so Sunday. DRT/SAT/SSF all stand a chance to see a gusts to near 30 knots today, as a few reports of 28-29 knot gusts were noted at DRT and SAT.

The gusty winds are sending overnight Gulf moisture deep into inland portions of the forecast area, and this will elevate the RH and allow for some long residence times of MVFR CIGs, similar to what we might expect in the late spring. VFR skies should take over by or shortly after 16Z and stay VFR to close to midnight. The well mixed air will make it difficult to concentrated updrafts and we are showing no signals for showers today, even over the Coastal Plains areas to the east. More MVFR CIGs are projected for the pre-dawn hours Wednesday.

FIRE WEATHER

Issued at 1200 AM CDT Tue Sep 15 2026

Minimum RH will be lowest today in the west with the Rio Grande values dropping into the 20 to 25 percent range today. Meanwhile, southeasterly wind peaks in the afternoon from 10-20 mph with gusts up to 30 mph, bringing elevated to near critical fire weather conditions to portions of the Rio Grande Plains and southern Edwards Plateau. Hot conditions continue through the week with little rainfall expected, so more fire weather impacts are possible through at least mid-week. Low precipitation chances leading to isolated wetting rains will mainly be over the coastal plains through late week only moving inland Thursday. Southerly wind eases slightly after today but gusty wind may still be seen each afternoon and evening with the seabreeze.

PRELIMINARY POINT TEMPS/POPS

EWX WATCHES / WARNINGS / ADVISORIES

Heat Advisory from noon today to 7 PM CDT this evening for TXZ173-192>194-209-225.