Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
174 FXUS64 KHGX 181134 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 634 AM CDT Mon Aug 18 2025 ...New AVIATION... .KEY MESSAGES... Issued at 1245 PM CDT Sun Aug 17 2025 - Hot and humid again today with heat indicies peaking in the 104- 108F range. - Shower and thunderstorm chances return to the forecast this afternoon and continue on a daily basis for the rest of the week. && .DISCUSSION... Issued at 1235 AM CDT Mon Aug 18 2025 Overall, very little change from the ongoing forecast/reasoning this week. The weather pattern for Southeast Texas will be dominated by a gradual shift in the upper-level ridge over the area that will be moving towards the Four Corners region through the early and middle parts of the week. Though daytime heat will briefly flirt with near advisory criteria today, look for a gradual decrease in high temperatures for our area as the week progresses as heights fall and increased clouds/rain work in some of their magic. Scattered tstm development is anticipated this afternoon into the evening. Though widespread strong-severe cells are not anticipated, the atmospheric profile is such (inverted-v type sounding) whereas I wouldn`t be surprised to see some very localized 25-45mph gusts in association with any of the more robust cells as they collapse. Most activity should diminish with the loss of heating later this evening. Fairly similar set-up Tuesday, though we might see a bit more coverage near the coast and offshore as an upper disturbance crosses that region from the ene to wsw. We can expect a fairly active and repetitive pattern of showers and thunderstorms pretty much every day...with best overall rain chances probably in the Thurs-Fri timeframe. This is due to a combination of factors: a light wind pattern, increasing moisture levels, daytime heating, the influence of the daily sea breeze, and small disturbances rotating around the periphery of the departing ridge. Forecasting the exact timing and location of these storms each day will be challenging as the pattern will likely be driven by smaller, mesoscale features. While not everyone will see rain on a given day, it is highly likely that most areas will receive some rainfall by the end of the week - very broadly averaging 0.5-2.0". Though activity should mostly be diurnally driven, we`ll need to monitor for any currently unforeseen stronger impulses embedded in the flow aloft that been known to occur in this type of pattern, as well as interactions between different boundaries that could lead to localized heavy downpours and gusty winds. But, there`s not much skill trying to pinpoint these several days in advance. 47 && .AVIATION... (12Z TAF Issuance) Issued at 630 AM CDT Mon Aug 18 2025 Localized areas of IFR/MVFR should improve to VFR over the next 2-3 hours. Winds light and variable this morning become E to SE 5-10 knots by the afternoon. Isolated to widely scattered shra/tsra expected this afternoon. Best chance of tsra between 21-24Z. Any tsra should diminish this evening. Winds become light and variable again overnight. Localized IFR/MVFR possible after 06Z tonight. && .MARINE... Issued at 1235 AM CDT Mon Aug 18 2025 A weak pressure gradient will remain in place for a good part of the week which will lead to a prevailing landbreeze and seabreeze circulation featuring variable to offshore wind directions late at night and in the morning and a more moderate onshore winds in the afternoons and evenings. Models are indicating the potential for some scattered strong storms during the first part of Tuesday with a passing upper disturbance. We`ll be monitoring trends. Otherwise, a somewhat unsettled weather pattern is expected as the week progresses with chances of showers and thunderstorms on a daily basis. 47 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 98 76 98 76 / 30 30 40 10 Houston (IAH) 99 79 97 79 / 40 40 50 20 Galveston (GLS) 94 82 92 82 / 20 30 60 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...47 AVIATION...Self MARINE...47