FXUS64 KHGX 221344 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 844 AM CDT Wed Jul 22 2026 ...New TROPICAL... .KEY MESSAGES... - Very dangerous heat is expected today with dangerously heat indices across all of southeast Texas. An Extreme Heat Warning has been issued from 11 AM - 8 PM. - Widely scattered showers and storms are possible late this afternoon. Some storms may produce frequent lightning and gusty winds. - A Tropical Storm Watch is in effect for the Upper Texas coast and adjacent waters through early Friday. Tropical Storm Bertha is forecast to weaken as it approaches southeast Texas Thursday afternoon into Thursday night. - 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 1248 AM CDT Wed Jul 22 2026 Very dangerous heat continues across the area today. Ridging builds in across the southern Plains with the ridge centered over northern Texas into Oklahoma. This coupled with the subsidence on the outer edges of Tropical Storm Bertha will lead to very hot temperatures across southeast Texas today. High temperatures will likely reach or exceed the century mark away from coastal locations. Areas closer to the coast will still reach the mid to upper 90s. Dew points in the 70s will combine with these temperatures to produce heat index values up to 115. This heat will be extremely dangerous for those outdoors for extended periods of time, especially without hydration and air-conditioned breaks. Please limit your time outdoors if possible. Lows tonight won't provide much relief either as they settle only in the upper 70s to mid 80s. Outside of today's heat, a weak boundary will slide in from the northeast late this afternoon into the early evening. There will be enough moisture to work with as well as plenty of instability to produce isolated/widely scattered showers and storms along this southwestward moving boundary. These storms will also be capable of some strong downburst winds as DCAPE (downdraft CAPE) is in excess of 1000 J/kg. Thus, wouldn't be surprised to see a few strong to perhaps an isolated severe storm late in the afternoon into early evening. By Thursday, we'll have increasing influence from Tropical Storm Bertha, but significant impacts are not expected. We still expect Bertha to weaken on approach, if it survives the dry air, wind shear, and land interaction over the next 24-36 hours. For more details on Bertha, see the tropical discussion below. Increasing clouds could help hamper the heat somewhat Thursday, but it's possible we may still reach advisory levels with our heat indices around 105-110 with temperatures still in the mid 90s for most, except lower 90s near the coast. Some rain bands from Bertha may affect mainly coastal areas Thursday, but this remains lower confidence. Ridging builds across much of the central and western US again into early next week, meaning the hot, dry weather likely rolls along. && .AVIATION... (12Z TAF Issuance) Issued at 625 AM CDT Wed Jul 22 2026 VFR conditions are expected throughout the TAF period. Winds will be light and VRB through Wednesday evening, turning west to northwest by the mid morning hours. Scattered showers and thunderstorms are anticipated this afternoon, after 20Z and may impact coastal and metro terminals. Otherwise, VFR conditions throughout the rest of the period. Davis/Bailey && .MARINE... Issued at 1248 AM CDT Wed Jul 22 2026 High pressure over the western Gulf continues to bring gentle to moderate breezes to the waters today. Winds may briefly approach cautionary levels late this afternoon and early this evening over the eastern waters. Influence from Bertha will begin Thursday with potentially increasing winds and seas. However, Bertha is forecast to weaken on approach, and most impacts from Bertha would be limited to small craft operators. There is a low (near 10%) chance of sustained tropical storm force winds (34 knots or greater) over the open Gulf waters. Seas will build in response to about 3 to 5 feet. All of this is dependent on Bertha's strength and track. Beyond Thursday, light to moderate southerly flow is expected with 2 to 3 foot seas. && .TROPICAL... Issued at 828 AM CDT Wed Jul 22 2026 A weakening Tropical Storm Bertha will approach Southeast Texas Thursday into Friday. A Tropical Storm Watch has been issued for Bolivar Peninsula, Brazoria Islands, Chambers, Coastal Brazoria, Coastal Galveston, and Galveston Island. As of 7 AM CDT, the center of Bertha was located off the Mississippi coast and is expected to move westward near 5 mph along the central Gulf coast during the next couple of days. Latest data from Bertha indicated maximum sustained winds remaining near 50 mph with higher gusts. As Bertha moves westward into the northwestern Gulf today and Thursday, atmospheric conditions will continue to be not favorable for future strengthening as the storm encounter higher wind shear, increasing subsidence from the building high pressure, and deals with land interaction along the central Gulf Coast. Therefore, it is expected to weaken and become more disorganized as it approaches our region. The current forecast has Bertha approaching late Thursday morning or early afternoon as a weak Tropical Storm, before becoming a Tropical Depression once it makes landfall. Regarding impacts for Southeast Texas, Tropical Storm force wind gusts can be possible under the Watch area with gusts up to 40 to 45 mph. Highest probabilities are expected along the immediate coast and coastal waters from High Island to Freeport. Elsewhere in Southeast TX, little to no impact is anticipated. Periods of scattered showers and thunderstorms can also be expected through the day; however, the threat of flooding rain is low. For marine and beach conditions: elevated winds and building seas up to 6 ft can be expected. Tropical storm force winds up to 40 knots possible offshore as early as this evening through early Friday. There will be a high risk of rip currents along all Gulf-facing beaches. Significant coastal flooding is not expected at this time, but minor coastal flooding cannot be ruled out during times of high tide north of Port Bolivar. Please, remain weather aware and prepared, especially if you are under the Watch area. Continue to monitor the latest forecast for any updates on Bertha at www.hurricanes.gov and www.weather.gov/houston. JM && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 102 81 97 79 / 0 20 0 0 Houston (IAH) 103 82 96 81 / 30 30 10 30 Galveston (GLS) 96 83 90 82 / 10 40 60 50 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Tropical Storm Watch for TXZ214-337-338-437>439. Extreme Heat Warning until 8 PM CDT this evening for TXZ163-164- 176>179-195>200-210>214-226-227-235>238-300-313-335>338- 436>439. GM...Tropical Storm Watch for GMZ335-355-375. Small Craft Advisory until 6 AM CDT Friday for GMZ350-370. && $$ DISCUSSION...Young AVIATION...Bailey MARINE...Young TROPICAL...JM