Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
762 FXUS64 KHGX 171129 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 629 AM CDT Sun Aug 17 2025 ...New AVIATION... .KEY MESSAGES... Issued at 1232 AM CDT Sun Aug 17 2025 - Hot and humid today and Monday (as if it`s not ever hot and humid here in August, but just maybe a little moreso). Take it easy if you have outdoor plans. - Some isolated to maybe scattered late day showers and thunderstorms. - Looks like a somewhat active weather week in regards to daily rain chances. && .DISCUSSION... Issued at 1232 AM CDT Sun Aug 17 2025 Hot temperatures are expected today and Monday with mid-upper ridging stretching from MO-TX. This will provide enough subsidence to at least delay any onset of precip to the late afternoon hours and allow things to heat up. Heat index values will peak in the 104- 108F range. Some individual locations will probably flirt with heat advisory criteria (108+), but limited duration and areal extent will preclude the issuance of one at this time. Will let the next shifts watch trends and issue if need be. Another thing the next shift or two will need to keep an eye on is tstm potential later today. Other than the typical isolated seabreeze cell or two, a mix of incoming 00z guidance (GFS, ARW, FV3) shows the potential for some late afternoon and evening development popping up to our northeast as convective temperatures are reached. Don`t have a lot of confidence either way, but have nudged NBM suggestions up to at least include the mention. Some localized, healthy wind gusts are not out of the question should any strong cells materialize. Mid-upper ridge migrates toward the Four Corners area during the early and middle parts of the week. With heights falling locally, we should see high temps trend downward a touch. And with a light flow regime, PW`s in the 1.9-2.3" range, daytime heating, seabreeze, and intermittent disturbances rotating into the area around the periphery of the ridge...we should see ample opportunities for showers and storms pretty much each day. It`s a tough pattern to narrow down the details on a daily basis as a lot of it will be run on the mesoscale. Not everyone will see rain each day, but suspect you`ll end up with some. We will, however, need to keep an eye on those sneaky stronger sw movers as well as plentiful boundary interactions that could produce some localized heavy downpours and elevated wind gusts. 47 && .AVIATION... (12Z TAF Issuance) Issued at 626 AM CDT Sun Aug 17 2025 Areas of IFR/MVFR this morning should improve to VFR by 14-15Z. Light and variable winds this morning expected to become SE 7-10 kt this afternoon. Isolated shra/tsra expected. But low coverage results in low confidence of shra/tsra impacting TAF sites. So no mention of shra/tsra in the TAFs though the radar will need to be monitored closely in case amendments are needed. Some guidance suggest there could be shra/tsra moving into our region from the east this evening. But confidence on this is low. Could not rule out areas of IFR/MVFR again late tonight into tomorrow morning. && .MARINE... Issued at 1232 AM CDT Sun Aug 17 2025 Weak surface high pressure in the vicinity will keep winds light and seas low over the next several days. With such a light pressure gradient we should see an evident landbreeze and seabreeze circulation emerge on a daily basis with light offshore winds late at night and in the mornings followed by an onshore direction in the afternoons and evenings. We might need to keep an eye out for some evening storms in the Galveston Bay area this evening should any storms develop to our northeast and survive the trek to the southwest before decaying. There is a wide mix of model guidance in these regard (storms/no storms), but mariners are encouraged to take this potential into account. Shower and thunderstorm chances will be a possibility each day this upcoming week. Some days will be more active than others. 47 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 98 76 98 76 / 10 10 30 20 Houston (IAH) 97 79 97 79 / 20 30 50 30 Galveston (GLS) 92 82 93 82 / 10 20 40 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Adams AVIATION...Self MARINE...Adams