Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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323 FXUS64 KBRO 171939 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 239 PM CDT Tue Sep 17 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Wednesday night) Issued at 236 PM CDT Tue Sep 17 2024 Midlevel high pressure over Texas will continue to slowly dry out the midlevels and minimize rain chances today and tomorrow. Any showers and thunderstorms that do develop will be isolated in nature and most likely develop along the sea breeze. With that said, PWATs on this mornings KBRO sounding were still abnormally high at 2.33 inches with forecasted PWATs only falling to around 2 inches by Wednesday afternoon. Any showers or thunderstorms that do develop over the next few days will be capable of producing heavy rainfall that could lead to minor flooding along low lying and poor drainage areas, especially with the ground being saturated in many areas. Temperatures will continue to warm over the next few days. Overnight lows will be in the mid to upper 70s. Tomorrow will be slightly warmer than today and heat indices will rise to 105-110 degrees. A few locations could reach 111+ degrees briefly, mainly in southern Hidalgo county. A Special Weather Statement may suffice but will continue to monitor for potential for a Heat Advisory. && .LONG TERM... (Thursday through next Tuesday) Issued at 236 PM CDT Tue Sep 17 2024 The long-term period will feature warmer-to-hotter than normal temperatures and mainly dry/rain-free conditions through the end of the week before a slight cool down ensues over the weekend into next week. Global deterministic forecast models and ensembles continue to depict a 591 dam heat dome/ridge over northeastern Mexico into Deep South Texas Thursday through Friday. Atmospheric moisture content will be lower compared to previous days/weeks with precipitable water (PWAT) values between 1.5-2.0 inches. However, it should be adequate enough to support a rogue or isolated chance for a shower or thunderstorm nearly each day. Subsidence, however, with the aforementioned mid-level ridging in place, will help to keep things mostly suppressed through the period. That said, expect for mainly dry or rain-free conditions to prevail through the long-term period with an isolated chance for a shower or storm nearly each day. Temperature anomalies will run slightly warmer/hotter than mid-late September standards Thursday and Friday. High temperatures are expected to be in the mid to upper 90s for much of the region. Moderate HeatRisk can be expected for the most part through the extended. There could be areas of major HeatRisk developing, especially in the Thursday-Friday timeframe. Heat indices are expected to range between 105-115F Thursday and Friday. That said, Special Weather Statements (SPS) to Heat Advisories may be needed during this time period. The heat ridge is progged to break down over the weekend as a trough out west shifts southeastward, which will allow for temperatures (the warmth) to relax some over the weekend into next week. && .AVIATION... (18Z TAFS) Issued at 1212 PM CDT Tue Sep 17 2024 VFR conditions will prevail through the forecast period. Some showers and thunderstorms have already developed around KBRO and isolated activity is possible through the rest of the afternoon across all terminals that could briefly lower visibility to MVFR. If a heavy shower or thunderstorms passes directly over a terminal brief IFR conditions can not be ruled out but confidence is low at this time on direct impact. && .MARINE... Issued at 236 PM CDT Tue Sep 17 2024 Now through Wednesday Night...Generally favorable marine conditions will prevail with light winds and seas around 1 to 2 feet. Chances of showers and thunderstorms will continue at times through the forecast period that could lead to locally enhanced winds and seas. Thursday through Tuesday....Outside of any convection, favorable marine conditions (light to moderate winds and light seas) are expected to prevail Thursday through next Tuesday. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 79 92 79 93 / 10 10 10 30 HARLINGEN 75 93 76 95 / 0 20 0 30 MCALLEN 79 97 80 99 / 10 10 0 10 RIO GRANDE CITY 77 95 77 97 / 10 10 0 10 SOUTH PADRE ISLAND 82 88 82 89 / 10 20 10 20 BAYVIEW/PORT ISABEL 78 90 78 92 / 10 20 10 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...68-McGinnis LONG TERM....23-Evbuoma AVIATION...68-McGinnis