FXUS64 KHGX 180504 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1204 AM CDT Thu Jun 18 2026 ...New DISCUSSION... .KEY MESSAGES... - The threat for tropical storm conditions has ended as Arthur dissipated. Any lingering coastal flooding will end early this morning. - Dangerous heat will impact southeast Texas through early next week, especially today and Friday. Those planning outdoor activities should prepare for increased heat stress from dangerous heat indices. && .DISCUSSION... Issued at 1204 AM CDT Thu Jun 18 2026 Tropical Storm Arthur is no more as of early this morning, the weakened and elongated surface low now far separated from any organized convection and now shifting away from the area. All Tropical Storm Watches and Warnings have been canceled. Lingering minor coastal flooding is also subsiding as we move past the high tide cycle, and the remaining Coastal Flood Advisory will be allowed to expire early this morning. The next major focus will be increasing heat stress in the wake of Arthur. A lingering soupy airmass, with CAM ensembles supporting dewpoints as high as 80-81F (around 27C) at times and incrasing high temps, will support heat index readings in the 108-112F (42-44C) range today and again on Friday. During the overnight, temperatures will only fall to the upper 70s and lower 80s (26-28C) providing limited recovery from the daytime extremes. A Heat Advisory remains in effect through Friday. At least scattered convection will be possible mainly from late Friday through the weekend, though there is at least a chance for a period of greater rain coverage within this time frame. A stalling surface front over the Red River Valley will serve as a focus for convective development Thursday into Friday. While the front will not make it close to our area, some of the resulting storms and outflow from prior storms may move into our area Friday afternoon into Friday night. A few strong storms cannot be ruled out, and there are some guidance solutions showing greater rain coverage persisting Friday night through the day Saturday as well. Scattered convection will remain possible into Sunday, before strengthening mid level ridging increasingly limits rain chances early next week. Outside of interference from clouds/rain, heat stress will continue to be elevated through early next week, with potential for triple digit (38C+) heat indices each day. Additional heat advisories may eventually be needed. && .AVIATION... (00Z TAF Issuance) Issued at 659 PM CDT Wed Jun 17 2026 Gusty ESE winds around Tropical Storm Arthur continue into early tonight before Arthur pulls away, allowing winds to gradually return to Southerly. The best chance for a passing shower will remain along the coast. Ceilings higher end MVFR to VFR early this evening before MVFR ceilings return tonight with a low chance of some IFR ceilings away from the immediate coast. Ceilings gradually improve Thursday morning with winds out of the South. && .MARINE... Issued at 124 PM CDT Wed Jun 17 2026 Tropical Storm Arthur will move through the marine zones over the next several hours, bringing winds between 35 and 40kts, with gusts as high as 50 kts. Seas 6 to 9 feet will persist until this evening, with winds and waves subsiding as TS Arther moves inland into SW LA this evening. Onshore flow will become light to moderate by Thursday and persist into the weekend. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 80 93 78 91 / 10 30 50 60 Houston (IAH) 81 93 79 92 / 0 10 30 30 Galveston (GLS) 84 90 84 89 / 0 0 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory from 11 AM this morning to 10 PM CDT Friday for TXZ163-164-176>179-195>200-210>214-226-227-235>238-300-313- 335>338-436>439. Coastal Flood Advisory until 3 AM CDT early this morning for TXZ438-439. GM...Small Craft Advisory until 9 AM CDT this morning for GMZ330-335- 350-355-370-375. && $$ DISCUSSION...DL AVIATION...WFO MARINE...JTC