FXUS64 KHGX 301820 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 120 PM CDT Sun Aug 30 2026 ...New DISCUSSION, AVIATION, MARINE, TROPICAL... .KEY MESSAGES... - Temperatures will be running 2-5F above normal today and Monday, then a bit closer to seasonable norms after that. - NHC continues to monitor an area of low pressure drifting WNW in the north central Gulf. Increased chances for rainfall in our area Tue/Wed, some locally heavy. - Daily chances for isolated to scattered showers/storms continues beyond midweek. && .DISCUSSION... Issued at 120 PM CDT Sun Aug 30 2026 If you're only here to read more about what's going on in the Gulf, skip ahead to the next two paragraphs and check out the Tropical discussion below. A 595 dam mid-level high remains centered around the Red River (TX/OK border) which leaves us in broad easterly flow aloft. PW values remain on the low side ranging from 1.3-1.6", which is vaguely around the 25th percentile (~1.41"). Daytime heating and the seabreeze should be enough for spotty coverage of showers and maybe an isolated storm or two. Best chances for seeing rain today will be along and south of I-10 in the afternoon hours. High temperatures this afternoon will top out mostly in the upper 90s...and wouldn't be entirely surprised to see a couple of spots flirt with the 100 degree mark. Moisture begins to gradually increase going into Monday as an area of low pressure approaches from the east (more on that below). This increase in moisture will likely bump up the coverage of showers/storms in the afternoon. Temperatures on Monday afternoon will also be mostly in the upper 90s with the potential for a few spots reaching the triple digits. Heat indices both today and on Monday will peak in the 104-108F range. While some locations may reach the Heat Advisory threshold, this will be brief and not widespread enough to warrant an issuance at this time. Going into Tuesday is when an influx of tropical moisture pushes in with PW values surging well above 2" and approaching the MAX percentile (~2.45"). This comes from an area of low pressure that the NHC is monitoring for potential tropical development over the next few days as it drifts westward. If this system were to develop, it would do so rather slowly so it's potential appears to be limited. There remains quite a bit of uncertainty in how the system itself will evolve. In terms of the trajectory of this low, model guidance (deterministic and ensembles) has a general consensus on somewhere between southwestern Louisiana and the Upper Texas coast. At the very least, the increase in moisture will bring greater chances for showers and storms...some of which may be locally heavy especially east of I-45. Forecast rainfall totals will likely fluctuate over the next day or so until there's a better consensus on how this system will evolve. As of right now, our latest forecast reflects 2-4" between Monday night and Wednesday for areas east of I-45, but higher totals certainly cannot be ruled out. Rainfall rate in tropical environments can typically exceed 3-4"/hr, so localized instances of flash flooding are certainly plausible. WPC has outlined portions of Southeast Texas in a slight risk (level 2 of 4) of excessive rainfall on Tuesday. Be sure to stay up to date on the latest forecasts. For additional details on the tropics, see the Tropical discussion down below. This elevated moisture looks to stick around going into at least Thursday and potentially longer depending on which model you believe. Increased chances of showers/storms will persist in the afternoon hours through the end of the work week as a result. Beyond midweek, the mid-level high and ridge axis transitions eastward towards the east coast. Hot and humid conditions will persist though with high temperatures generally in the mid to upper 90s and heat indices peaking above 100 degrees. The ridge axis does look to slide back westward going into the weekend, which explains the gradual increase in temperatures. Batiste && .AVIATION... (18Z TAF Issuance) Issued at 120 PM CDT Sun Aug 30 2026 VFR conditions to start this TAF period. Satellite shows some low level scattered cumulus, which are expected to lift and dissipate by the evening. Winds out of the SE at 6-10 kts this afternoon become light and VRB overnight. Winds remain light into tomorrow morning, then increase and turn ESE at 5-8 kts by tomorrow mid afternoon. Early tomorrow morning, some intermittent low level clouds and patchy fog could effect terminals to the north, but the chances of reaching MVFR thresholds are low. Both today and tomorrow, chances for precipitation remain low, but some isolated showers/thunderstorms can't be ruled out, mainly towards the coast along the afternoon seabreeze. MLG && .MARINE... Issued at 120 PM CDT Sun Aug 30 2026 Light southeasterly winds and low seas (1-3 ft) will persist through Monday. Going into Monday night, winds transition to southwesterly to westerly as an area of low pressure moves in from the east. The National Hurricane Center is monitoring this system for potential tropical development. Chances for development are not overly high, but this system at the very least will bring increasing chances for showers and storms especially for marine zones east of Freeport Tuesday and Wednesday. Mariners should monitor the latest forecasts for updates. Isolated to scattered showers/storms will be possible beyond this system through the end of the week. Batiste && .TROPICAL... Issued at 120 PM CDT Sun Aug 30 2026 The National Hurricane Center continues to monitor showers/storms associated with an area of low pressure in the north central Gulf. This system has gotten better organized compared to what we saw on Saturday. Slow development of this system is still possible over the next few days as it drifts west-northwestward towards the Louisiana/Upper Texas coasts. A short-lived tropical depression or tropical storm cannot be entirely ruled out before it reaches the coast Tuesday. At the very least, increased moisture from this system will increase our chances for rainfall, some of which may be locally heavy. Uncertainty remains in how this system will evolve over the next few days, so exact impacts are still tough to nail down as of right now. The probability of tropical development as of early Sunday afternoon is 50% (medium). Please continue to monitor the latest updates from the National Hurricane Center at www.hurricanes.gov. Batiste && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 76 99 77 97 / 0 0 0 40 Houston (IAH) 78 98 79 92 / 10 20 30 80 Galveston (GLS) 83 91 82 90 / 0 20 70 80 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Batiste AVIATION...MLG MARINE...Batiste