FXUS64 KHGX 220554 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1254 AM CDT Wed Jul 22 2026 ...New DISCUSSION, MARINE, 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. - Tropical Storm Bertha is forecast to weaken as it approaches southeast Texas Thursday afternoon into Thursday night. While significant impacts are not expected, continue to monitor the latest forecast updates. - 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... (00Z TAF Issuance) Issued at 607 PM CDT Tue Jul 21 2026 Mainly VFR conditions expected throughout the TAF period. Winds will be light and VRB through early Wed, turning W to NW during the mid morning hours. Winds will be light and VRB again Wed evening. There is some uncertainty with respect to rain chances on Wed, will not add the mention of SH/TS for this TAF issuance and will re-evaluate for the 06Z issuance. Cotto && .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 1248 AM CDT Wed Jul 22 2026 As of 1 AM CT, Tropical Storm Bertha was centered off the Alabama coast with maximum sustained winds of 50 mph. Overall, the forecast thoughts have not changed significantly. We still expected Bertha to move westward along the Louisiana coastline through the day Wednesday night into Thursday, then approach southeast Texas Thursday evening as a tropical depression. However, it is possible that Bertha does not survive as an organized tropical system. It has continued to battle wind shear and dry air with the center becoming exposed every now and then. This will continue to be the case as it moves westward, which makes its prospects for survival questionable, especially once adding in potential land interaction. As it approaches southeast Texas, significant impacts are not expected. Winds may be a bit breezy Thursday and Friday. Chances for tropical storm force winds (39 mph or greater) are low (10-20% for points over the water and less than 10% for locations south of I- 10). Rainfall will also be hard to come by with totals only around 0.5 inch or less. Chances of seeing more than an inch are low (less than 30%). Coastal flood impacts are also not anticipated. All that being said, continue to monitor the forecast for any changes over the next day or so. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 101 81 97 79 / 10 10 0 0 Houston (IAH) 103 82 99 82 / 10 10 10 10 Galveston (GLS) 96 83 92 82 / 10 30 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Extreme Heat Warning from 11 AM this morning to 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...None. && $$ DISCUSSION...Young AVIATION...Cotto MARINE...Young