Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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883 FXUS64 KBRO 271727 AAB AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1227 PM CDT Sat Apr 27 2024 ...New AVIATION... .SHORT TERM... (Today through Sunday) Issued at 250 AM CDT Sat Apr 27 2024 The next bout of low pressure swings into the Plains today into Sunday, maintaining the tightened pressure gradient across Deep South Texas into this evening. The LLJ strengthens toward 40-45 kts this afternoon, with frequent 40 mph wind gusts likely mixing down into Cameron and Willacy counties. DESI probabilities spiked above 50 percent for wind gusts over 40 mph across central to western Cameron County mid-afternoon, keeping the strongest winds south of Kenedy County and west of the coast. Have issued a Wind Advisory for inland portions of Cameron and Willacy counties, leaving out the coastal portions and Kenedy County at this time. A weak pre-frontal trough of low pressure or dryline may work into the brush country into Sunday afternoon, finally breaking the persistent elevated southeasterly winds. A frontal boundary across Central Texas may kick up a couple of showers or thunderstorms Sunday afternoon. Chances of thunderstorms or outflow boundaries making a run into our CWA generally remain less than 30 percent, with a short window of convective activity across the ranchlands Sunday afternoon. Elevated surf, with increasing wave periods, will maintain a high risk of rip currents through the weekend. Have extended the High Risk of Rip Current Statement through Sunday afternoon. Expect clouds to break by mid-afternoon for most locations, with slightly above normal high temperatures and well above normal lows. && .LONG TERM... (Sunday night through Friday) Issued at 250 AM CDT Sat Apr 27 2024 An upper-level trough will be exiting the region allowing for zonal flow aloft to set up for the next couple of days. A weak mid-level ridge will move over the region mid-week, that that will then be replaced by another upper-level trough by the end of the period. To further aid the development of convection, on the surface southerly to southeasterly flow will continue to persist that will bring in more moist, warm air to Deep South Texas and the Rio Grande Valley. However, rain chances remain 20 to 30 percent through the long term forecast period. While there are a few different opportunities for showers and thunderstorms to develop over the long term forecast period. The first possibility for rain will be at the start of the long term forecast period with a stalled out cold front towards the northwest. The showers and thunderstorms could develop along the frontal boundary and then move into the region. However, there does not appear to be a lot of instability for showers and thunderstorms to work with, thus limiting chances that said showers and thunderstorms will be able to make it south. The second possibility will occur Monday night into Tuesday, as a mid- level shortwave will bring a source of forcing that will help develop showers and thunderstorms along the Sierra Madre Mountains. It is possible that some of these showers and thunderstorms make it into Deep South Texas and the Rio Grande Valley, the environment will not be as favorable. These means that any showers and thunderstorms that try to move into the region are likely to dissipate before they make it very far. This cycle is likely to repeat on Tuesday night and Wednesday as more shortwaves move into the region. Towards the end of the period, a cold front start to approach Deep South Texas and the Rio Grande Valley, which will be another chance for showers and thunderstorms to develop, but doesn`t look to push through the region based the current model guidance. This is scenario is different than the previous model run output. Since this event is nearly a week out and the changing models runs, confidence with how the models are resolving this cold front is not high. As for temperatures, the previously mentioned southerly to southeasterly flow will keep the temperatures rather warm. High temperatures are expected to be in the 90s for most of the area, while areas along the coast and the island will be in the upper 80s. On the other hand, the low temperatures will be in the 70s through the period. && .AVIATION... (18Z TAFS) Issued at 1209 PM CDT Sat Apr 27 2024 MVFR at the TAF sites due to ceilings. Southeast to south winds are increasing this afternoon, and some scattering out will be possible. Otherwise, MVFR ceilings will build in again this evening and tonight. Winds will diminish a bit tonight and won`t be as strong on Sunday. Ceilings will scatter out to the west on Sunday, and may include the TAF sites by late Sunday afternoon. && .MARINE... Issued at 250 AM CDT Sat Apr 27 2024 Today through Sunday...Low pressure across the Plains and high pressure east will maintain increased southeasterly winds through the weekend, with winds diminishing gradually from west to east. Small Craft Advisories are in effect through tonight for all coastal waters, shifting to just offshore Gulf waters through Sunday night. There is a slight chance of thunderstorms across northern coastal waters Saturday afternoon. Sunday Night through Friday...Hazardous conditions are expected for Sunday night into Monday, due to elevated seas that will require Small Craft Advisory. During the day on Monday, conditions will start to improve as the winds weaken and the seas decrease. Small Craft Exercise Caution might be needed for short periods of time for the rest of the period as the pressure gradient becomes enhanced due to several passing upper level shortwaves. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 90 76 92 76 / 0 0 10 0 HARLINGEN 92 74 94 74 / 0 0 10 10 MCALLEN 93 76 95 76 / 0 0 10 0 RIO GRANDE CITY 96 75 94 73 / 0 0 10 0 SOUTH PADRE ISLAND 82 76 82 76 / 0 0 10 10 BAYVIEW/PORT ISABEL 88 75 90 75 / 0 0 10 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Wind Advisory until 7 PM CDT this evening for TXZ254-255. High Rip Current Risk through Monday morning for TXZ451-454-455. GM...Small Craft Advisory until 7 AM CDT Sunday for GMZ130-132-135. Small Craft Advisory until 7 AM CDT Monday for GMZ150-155-170- 175. && $$ SHORT TERM...54-BHM LONG TERM....23-Evbuoma AVIATION...54-BHM