FXUS64 KHGX 171715 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1215 PM CDT Fri Jul 17 2026 ...New AVIATION... .KEY MESSAGES... - Last day of mentionable rain chances for the next week or so. - Increasing temperatures through next week with triple digit heat indicies. - Greater heat stress generally around Tuesday-Thursday of next week. Heat Safety should be practiced. && .DISCUSSION... Issued at 1056 AM CDT Fri Jul 17 2026 SE Texas finds itself sandwiched between two features aloft. One is an upper level low over West TX/New Mexico, and the other a ridge centered over the northwestern Gulf coast. Midlevel heights within the ridge are currently forecasted around 592-595 dam. Satellite derived PWs range from around 1.6-2.0 inches, though low level RH is forecasted to be fairly low each day (~40%). CAMs are pinging on convection developing today, generally northeast of the city of Houston (North I-10, east of I-45), likely a combination of a lingering diffuse boundary, passing impulses and stronger heating over that region. A few additional coastal showers are also hinted at by the cams, though still fairly sparse. Either way, this looks to be the best rain chances throughout the whole forecast period. The synoptic pattern & forecast experience some slow and subtle changes over the next several days. Midlevel heights will decrease Sunday into early next week, though PWs will also fall in tandem throughout this period, dropping to 1.0-1.4 inches by Monday. 850mb temperatures will be trending upward over these next few days as well, climbing to 19-22C by early next week. Tuesday-Thursday is anticipated to generally be the warmest period in the forecast (so far). The center of the ridge shifts over the TX/OK Panhandle, with midlevel heights climbing to 594-596 dam, generally around the 90th- 99th climatological percentile for this time of the year. 850mb temperatures during this period also increase and remain around 21- 23C. Bottom line, expect hot weather with low rain chances and increasing temperatures into next week. Highs will be in the upper 80s/mid 90s this afternoon, climbing to the upper 90s next week. Heat indices will be in the triple digits daily. Heat stress is anticipated to be High to Extreme from Tuesday-Thursday with heat index values of 103 to potentially 111. Cannot rule out heat headlines for these days, but regardless heat safety should be practiced. Make sure to wear light, loose fitting cloths and drink plenty of water. Limit time outdoors during the hottest parts of the day. 03 && .AVIATION... (18Z TAF Issuance) Issued at 1209 PM CDT Fri Jul 17 2026 VFR conditions w/ S to SE 7-12 knot winds expected this afternoon. Conditions appear favorable for some shra/tsra development along the sea / bay breeze boundary later this afternoon. Uncertainty exists regarding the area of most-likely shra/tsra development. However, there is a signal in the hi-res guidance for shra/tsra in the vicinity of northern and eastern Harris County and eastern Montgomery. Thus, we've added PROB30 -TSRA late this afternoon for IAH, DWH, and CXO. In addition, there's some evidence on satellite that a few showers may try to develop near the coast. Thus a PROB30 for SHRA was added for early afternoon at GLS. Mostly VFR and light winds expected tonight, though a few spots could find themselves falling to MVFR, particularly in our northern zones. && .MARINE... Issued at 1056 AM CDT Fri Jul 17 2026 SSE-S winds 10 to 15 knots and 2-4 foot seas should prevail across the coastal waters today into Saturday. With high pressure moving into the northwest Gulf later in the weekend, look for wind speeds to diminish and take on a more southwesterly component at night and in the mornings until the seabreeze kicks in. Corresponding wave heights will also trend down closer to 2 feet Sunday and beyond. 47 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 75 91 74 92 / 0 0 0 0 Houston (IAH) 78 95 76 96 / 20 0 0 0 Galveston (GLS) 83 90 82 91 / 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...03 AVIATION...Self MARINE...47