271 FXUS64 KBRO 250345 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 1045 PM CDT Wed Sep 24 2025 ...New DISCUSSION, MARINE... .KEY MESSAGES... Updated at 1041 PM CDT Wed Sep 24 2025 -Isolated strong to severe thunderstorms are possible across the northern ranchlands into early Thursday. -Heavy rainfall will be possible into early Thursday across the northern ranchlands. -A frontal boundary slowly works south, bringing an increased chance of showers and thunderstorms across Deep South Texas into Friday. && .DISCUSSION... Issued at 1041 PM CDT Wed Sep 24 2025 A frontal boundary continues working south into Thursday, bringing an increased threat for showers and thunderstorms to Deep South Texas. Confidence is low in where this front stalls. Earlier convection across Brooks County yielded up to 3 inches of rain and gusty winds near 50 mph well out ahead of the front. The WPC ERO has shifted further north, now a marginal (level 1 of 4) risk across the northern half of the northern ranchlands. Our sounding at 00z showed a bump in PWATs above 2 inches. The SPC has dropped severe chances below the marginal risk for all of Texas. Still, the radar has become more active across the CRP CWA and most CAMs expand coverage across the ranchlands late tonight into mid Thursday morning as the front stalls. Heavy rainfall and gusty to damaging winds are possible in any activity, with sounding data showing abundant CAPE, DCAPE, slightly increasing shear, a thickening column of moisture, and steepening low level lapse rates. After some sunshine and early heating on Thursday, boundary collisions between the front, sea breeze, or convective outflows should increase or continue convection into Thursday afternoon. Most CAMs highlight the lower to mid valley, especially Cameron County Thursday afternoon with scattered showers and thunderstorms. Have still shaved NBM POPs down a bit to scatter coverage a little more. A lot depends on where the front ends up though, with most model guidance pushing it further south into Friday. Over the weekend, a weak coastal trough sets up along the western Gulf with a bit of a brief Omega block at 500mb before the next shortwave on Monday into Tuesday. Expect seasonal temperatures to continue through the forecast period, a little warmer Friday and Saturday behind the front with drier conditions. Isolated rain chances drop off a bit this weekend, but come back scattered next week, mainly along typical sea breeze locations. && .AVIATION... (00Z TAFS) Issued at 627 PM CDT Wed Sep 24 2025 An approaching frontal boundary will increase the chance of showers and thunderstorms late tonight through the day on Thursday. Expect VFR conditions into late tonight with MVFR to briefly IFR conditions late morning through the afternoon near any convection. && .MARINE... Issued at 1041 PM CDT Wed Sep 24 2025 Generally favorable winds and seas continue offshore, with increased chances for showers and thunderstorms after daybreak and into Thursday night. Winds and seas may be elevated near any showers or thunderstorms. Waterspouts may also be possible, especially near the edges of showers or thunderstorms, with lighter winds and abundant low level moisture. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 95 79 92 76 / 20 20 70 50 HARLINGEN 97 75 91 72 / 20 20 70 40 MCALLEN 100 79 93 76 / 10 10 70 30 RIO GRANDE CITY 102 76 92 72 / 10 20 70 30 SOUTH PADRE ISLAND 89 81 87 80 / 10 20 80 50 BAYVIEW/PORT ISABEL 93 77 88 75 / 10 20 70 40 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...56-Hallman LONG TERM....56-Hallman AVIATION...56-Hallman