FXUS64 KHGX 201826 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 126 PM CDT Mon Jul 20 2026 ...New AVIATION... .KEY MESSAGES... - Hot conditions persist through the week. We will need to monitor for potential Heat Advisories beginning as early as Tuesday or Wednesday. - NHC is monitoring the development of Tropical Depression Two, currently in the northeast Gulf. While forecast uncertainty remains fairly high, residents should monitor the latest forecasts and evolution of this system as it eventually tracks westward toward Texas Thursday and Friday. - Corresponding rain and temperature forecasts for the local area are subject to changes later in the week and highly dependent on the tropics. && .DISCUSSION... Issued at 1236 AM CDT Mon Jul 20 2026 High pressure remains fixed over our region bringing hot, sunny, dry conditions during the first half of the workweek. High temperatures are forecast to climb a few more degrees each day into midweek (95- 102 inland, 91-95 coast). Dry column of air in place should keep heat index readings from reaching advisory criteria today. This will need to be monitored Tuesday-Wednesday as higher moisture levels begin advancing into the region from the east allowing heat indices to possibly exceed 108+ degrees for parts of SE TX. Low temperatures should follow a slight uptick with the increasing moisture, but remain 70s inland and low 80s along the coast. Light winds primarily from the W and SW in the mornings, becoming more southerly in the afternoons with the seabreeze. The high pressure aloft will act as a major steering mechanism for Tropical Depression Two. It should linger in the northeastern and north central Gulf for the first half of the week. Mid level ridging should gradually build north of the system, eventually driving it (possibly a TS) more to the west and toward Texas. Corresponding rain and temperature forecasts across the area will depend on its eventual track and finer details that still need to be ironed out and subject to change. BSM/47 && .AVIATION... (18Z TAF Issuance) Issued at 117 PM CDT Mon Jul 20 2026 Mostly VFR conditions and light winds are expected through the forecast period. There is a chance for MVFR vis/cigs tomorrow morning. This has been hinted at via the 6SM BR SCT015 prevailing lines in most of the TAFs during the morning hours tomorrow. && .MARINE... Issued at 1236 AM CDT Mon Jul 20 2026 Light to moderate southwest and southerly winds, 2-4 foot seas, hot, and dry conditions are expected through midweek. Mariners should keep tabs on Tropical Depression Two, currently situated in the northeast Gulf, as the week progresses. It is forecast to eventually strengthen into a tropical storm as it approaches southeast Louisiana toward midweek, then possibly toward the Texas coast Thursday and Friday. Considerable forecast uncertainty exists and track and intensity changes are subject to change. 47/BSM && .TROPICAL... Issued at 1236 AM CDT Mon Jul 20 2026 Tropical Depression Two over the northeast Gulf is forecast to become a tropical storm as it get closer to the SE LA area toward midweek. General consensus and the NHC forecast suggests it'll eventually become steered by mid level ridging to its north...and possibly impact Texas later in the week. There is considerable forecast uncertainty at the moment...which is common with weak, unorganized, slow moving, and newly formed systems. TD Two will be encountering some drier air and moderate shear aloft at times. Residents should keep a watchful on on the latest NHC forecasts. For planning purposes, current forecasts reflect the potential for the arrival of some TS winds across parts of the region on Thursday. There's generally less than a 1-out-of-10 chance (10%) they'd arrive any earlier than Wednesday night. BSM/47 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 74 99 77 101 / 0 0 0 0 Houston (IAH) 76 100 78 100 / 0 0 0 0 Galveston (GLS) 80 94 81 94 / 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory from 11 AM to 8 PM CDT Tuesday for TXZ163-164- 176>179-195>200-210>214-226-227-235>238-300-313-335>338- 436>439. GM...None. && $$ DISCUSSION...BSM AVIATION...Self MARINE...BSM