Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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191 FXUS64 KBRO 071126 AAA AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 626 AM CDT Fri Jun 7 2024 ...New AVIATION... .SHORT TERM... (Today through Saturday) Issued at 235 AM CDT Fri Jun 7 2024 The mid-level ridge of high pressure continues to weaken slightly into the weekend and settle into the north-central Gulf of Mexico, as the surface high also pivots into the eastern Gulf. This breaks the heat dome slightly across Deep South Texas, with slightly drier air keeping peak Heat Indices between 105 to 109 degrees today and Saturday. Highs still top off in the upper 90s for most, with some triple digit heat across the upper valley and brush country. The best chance of rain remains offshore late tonight into Saturday morning as winds turn more southeasterly, with streamer showers or storms briefly possible, mainly beyond 20 nautical miles. Patchy fog and haze are possible each night and early morning, reducing visibility to less than 5 miles. Overall a hot start to the weekend, but not as hot as it has been, with beautiful conditions expected along the beaches of the lower Texas coast. && .LONG TERM... (Saturday night through Thursday) Issued at 235 AM CDT Fri Jun 7 2024 Key Message: * Despite changes in the 500 mb pattern, very warm to hot and humid conditions with little to no rain chances are expected to persist Changes to the 500 mb pattern as indicated by the global weather models and ensembles are expected during the long-term forecast period. These changes include the weakening/flattening of a persistent 500 mb ridge (associated with a southward advancing yet weakening cold front) over the region taking place Saturday night through Tuesday, followed by the re-amplification or re-emergence of a strong 591 dam sub-tropical, Sonoran heat dome (on the order of 1- 2 STDEVs above normal) taking place Wednesday and persisting through the remainder of next week. Overall, not much in the way of changes to our sensible weather here in the long- term with very warm to hot and humid conditions, and little to no rain chances continuing. We open up the long-term period Saturday night where a trough over the central U.S. will be shifting south-southeast. This will effectively allow for the 500 mb ridge that`s plagued Deep South Texas and the Rio Grande Valley to weaken/flatten Saturday night through Tuesday. In conjunction with the trough will be a surface cold front that will also be advancing southward from the central Plains during this time period. Forecast models has it that the trough and associated surface cold front will weaken as it advances south and will not make it as far south as Deep South Texas. In fact, the frontal boundary is expected to slow/stall out over central Texas in the Monday or Tuesday timeframe. So again not much change is expected as far as our sensible weather here in Deep South Texas and the Rio Grande Valley given the situation. We could see temperatures a couple of degrees cooler (Monday or Tuesday), but still running warmer than normal. Winds will maintain a southeasterly component during this time or through Monday of next week. This will help in keeping the atmosphere largely unchanged (very warm to hot and humid) with highs staying in the upper 90s to lower 100s and dewpoints in the 70s through Tuesday. There could be a rogue shower or thunderstorm on Monday, but much of the area should remain rain-free as the better forcing and short wave energies/impulses traversing along the aforementioned frontal boundary will be to our north. Wednesday through Friday of next week, forecast models and ensembles are depicting the re-emergence of the 591 dam sub-tropical, Sonoran heat dome centered over northern Mexico, but possibly encompassing the region. This will again re-enforce the very warm to hot and humid conditions over the region during this time period. Dry weather conditions will persist during this time period with strong subsidence associated with the feature (the 500 mb heat ridge) in place. && .AVIATION... (12Z TAFS) Issued at 614 AM CDT Fri Jun 7 2024 MVFR conditions have settled into HRL, with VFR holding so far at BRO and MFE. Over the next couple of hours, expect any mixed bag of conditions and visibilities to improve to VFR through the remainder of the TAF period. Easterly winds gradually turn southeast into Saturday. && .MARINE... Issued at 235 AM CDT Fri Jun 7 2024 Now through Saturday...High pressure maintains generally favorable marine conditions into the weekend, with light easterly winds and low seas. Some haze or smoke may limit visibility at times, especially late at night or early in the morning. Offshore streamer showers and storms may increase beyond 20 nautical miles Saturday morning as winds turn more southerly. Saturday night through Friday...Favorable marine conditions (light to moderate southeasterly winds and mainly light seas) are expected through this period. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 96 78 95 81 / 10 0 10 0 HARLINGEN 97 74 97 77 / 0 0 0 0 MCALLEN 100 77 99 80 / 0 0 0 0 RIO GRANDE CITY 99 75 98 78 / 0 0 0 0 SOUTH PADRE ISLAND 87 81 87 82 / 0 0 10 0 BAYVIEW/PORT ISABEL 92 77 92 80 / 0 0 10 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...56-Hallman LONG TERM....23-Evbuoma AVIATION...56-Hallman