Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
806 FXUS64 KHGX 222346 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 646 PM CDT Fri Aug 22 2025 ...New AVIATION... .KEY MESSAGES... Issued at 1056 AM CDT Fri Aug 22 2025 - Showers/thunderstorms continue today with locally heavy rainfall possible. Areas of minor flooding is expected, but a few instances of flash flooding cannot be rule out - Rain chances lower over the weekend, but isolated showers and storms will still be possible. - Increase in coverage of the showers and storms should rise again midweek next week as another weak boundary approaches the area. && .DISCUSSION... Issued at 1056 AM CDT Fri Aug 22 2025 A stationary boundary situated over the region has led to the development of scattered showers and thunderstorms this morning, which are expected to persist through at least this evening. Exactly where the storms are developing is largely dependent on boundary interactions from preceding storms, so really almost anywhere in the CWA will have a fair shot of seeing a thunderstorm today. And where these storms develop, they are producing locally heavy rainfall with rain rates of 1-3"+ per hour, and storm movement is almost zero. This will lead to areas of minor flooding, mainly ponding in area of poor drainage, but a few instances of flash flooding cannot be rule out if rainfall is heavy enough or if multiple storms move over the same area. The trend today has been that the storms that do develop and produce heavy rainfall end up raining themselves out within 30-45 minutes of development, which has helped ward off most flooding concerns so far. Thunderstorm activity is expected to wane after sunset with the loss of daytime heating, but some redevelopment over the coast is expected overnight tonight. The near stationary boundary over the area today will still be near the coast tomorrow, and with PWATs still around 2", it is likely that there will be additional pop-up showers and thunderstorms. Coverage will likely peak during the afternoon hours along the coast where the highest PWATs are located. Rain chances lower Sunday and Monday, but do not become zero, and isolated afternoon is possible along the sea breeze each day. Another weak, slow moving boundary is expected to approach the region Tuesday into Wednesday of next week leading to an increase in shower and thunderstorm chances. This boundary may eventually end up stalling along the Gulf coast, which combined with weak disturbances embedded in the northwesterly flow aloft will lead to continued rain chances through the remainder of the week. As for temperatures, Sunday and Monday will likely be the warmest days of the forecast with the least coverage of showers and storms expected leading to temperatures rising into the mid 90s for much the area area. Otherwise, expected continued summer-time heat with highs generally in the 90s and lows in the 70s. Fowler && .AVIATION... (00Z TAF Issuance) Issued at 633 PM CDT Fri Aug 22 2025 Showers and storms will gradually diminish by 01-02Z Saturday. Another round of showers and storms can be expected on Saturday, with the best chances for terminals along and south of I-10 (IAH coastward). SHRA/TSRA will also be possible across the northern terminals in the afternoon; however, it was not included for this set of TAFs due to low confidence in occurrence and timing. Erratic gusty winds and reduced visibility due to heavy rain will be possible near any strong storms. Overall, light NE winds in the morning will transition to the E/ESE in the afternoon. JM && .MARINE... Issued at 1056 AM CDT Fri Aug 22 2025 A diffuse frontal boundary will meander along the coast through Saturday, but with a very weak pressure gradient in place we will continue to see a prevailing landbreeze and seabreeze circulation. Expect light offshore wind directions late at night and in the mornings followed by light onshore winds in the afternoon and evenings with the passing seabreeze. A daily risk of scattered showers and thunderstorms continues through the weekend and through much of next week. Coverage will likely be the lowest Sunday into Monday as our current stalled boundary moves out of the area, but then increase Tuesday and beyond as another diffuse boundary moves in from the north. Locally higher winds and rougher seas will be possible in the vicinity of any thunderstorm. Fowler && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 74 93 72 95 / 20 40 10 10 Houston (IAH) 76 91 75 94 / 30 40 10 30 Galveston (GLS) 80 88 81 90 / 50 70 50 50 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Fowler AVIATION...JM MARINE...Fowler