FXUS64 KHGX 041731 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1231 PM CDT Sat Jul 4 2026 ...New DISCUSSION, MARINE... .KEY MESSAGES... - Dangerously hot conditions expected today. A Heat Advisory remains in effect for Harris County for heat indices between 105-110F (41- 43C) through 7 PM this evening. - Low (10-20%) shower and thunderstorm chances today and again on Sunday. Chance of isolated to scattered sea breeze showers/storms increases slightly early next week. - High pressure builds into the area by midweek, reducing precipitation chances for the second half of the workweek. && .DISCUSSION... Issued at 1231 PM CDT Sat Jul 4 2026 Mid-level heights will be maximized over the area today as a mid- level ridge strengthens and hovers over the Southern High Plains. This will cause unseasonably warm temperatures this afternoon for much of the area, especially in and around the Houston metro. With that said, heat stress and heat exhaustion will continue to be the primary concerns today and likely through the remainder of the holiday weekend. A Heat Advisory remains in effect for inland and coastal Harris County through 7 PM this evening. Despite the strengthening ridge, enough low-level moisture and lift will still support isolated seabreeze showers and thunderstorms (10-20% chance) through this afternoon, though overall coverage should be much more limited than previous days. Main impacts with seabreeze activity will be brief heavy downpours and cloud-to-ground lightning. For outdoor activity purposes today/tonight, any convection that develops this afternoon should be winding down by or before sunset. Otherwise, no weather impacts are expected this evening and overnight tonight. The mid-level ridge begins to retrograde over far west Texas and the Dessert Southwest beginning tonight. Simultaneously, an elongated trough, with embedded shortwave troughs, will eject off the Rockies and slide over the Plains/Midwest Region late tonight, Sunday, and into Monday. Majority of the precipitation associated with this trough looks to stay north and east of the forecast area through this time period. However, models and ensembles show the southern periphery of this trough extending over southeast Texas through the first half of the upcoming workweek. Unfortunately, it does not look like there will be very much relief from the summer-like temperatures and apparent temperatures. Low precipitation chances (10-30%) are forecast to continue from Sunday through at least Tuesday, with chances peaking each afternoon with seabreeze activity. The weak troughing aloft will begin lifting northward on Wednesday and ridging will build right back into the area for the latter half of the week. This will result in mostly unseasonably hot and dry weather, with additional heat headlines possibly needed for at least some portions of the forecast area. && .AVIATION... (12Z TAF Issuance) Issued at 606 AM CDT Sat Jul 4 2026 Patchy fog has been developing over the last hour or so. This will lead to brief MVFR vis through 13/14Z. Otherwise, VFR conditions will prevail through this TAF cycle. Recent CAMs hint at very isolated convection late this morning through the afternoon. With confidence being low in coverage, have opted to leave any mention of TS out of the TAFs with this update. Winds will remain light, 5-10 knots, through this TAF cycle. && .MARINE... Issued at 1231 PM CDT Sat Jul 4 2026 Generally light onshore flow will persist through the remainder of the weekend and into early next week. Overall, Gulf seas are expected to average 1 to 3 feet. Isolated coastal and Gulf showers will be possible each morning, with a chance of isolated thunderstorms along the sea breeze in the afternoon. Winds and seas begin to increase by the middle to later part of next week, with a gradually steepening pressure gradient. Onshore winds are forecast to increase to 10 to 15 knots by Tuesday and Wednesday, before increasing further to the 15 to 20 knot range by Thursday. Seas may increase to 3 to 4 feet by the end of the upcoming week. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 77 95 77 95 / 0 0 0 10 Houston (IAH) 79 96 79 95 / 10 10 0 20 Galveston (GLS) 83 90 83 89 / 0 0 0 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory until 7 PM CDT this evening for TXZ213-313. GM...None. && $$ DISCUSSION...Mejia AVIATION...Castillo MARINE...Mejia