FXUS64 KBRO 242340 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 640 PM CDT Wed Apr 24 2024 ...New AVIATION... .SHORT TERM... (Tonight through Thursday night) Issued at 1259 PM CDT Wed Apr 24 2024 An upper level ridge currently situated over the Rocky mountains will continue to shift eastward through the period. This will allow an upper-level trough to move in from the West Coast and reach the Central Plains by the end of the period. As the trough traverses the western portion of the country, it looks to support cyclogenesis along a stationary front in the High Plains Thursday. A cold front associated with this system will then begin moving eastward into northwestern Texas. Additional forcing associated with a weak mid level disturbance will likely strengthen a surface low over Central Mexico Thursday. The net result of both of these surface low pressure systems to the west, and the broad surface high pressure over the eastern Gulf, will be enhanced pressure gradients and stronger winds starting Thursday. Wind Advisories may be needed for Cameron and Hidalgo counties Thursday afternoon, as DESI is showing >50% probabilities of wind gusts exceeding 40 mph. Deterministic guidance has been keeping wind gusts a bit lower, reducing confidence in issuing a Wind Advisory at this point. Rain chances look to remain near zero through the short term period, though some cloud cover is expected to stick around. Southeasterly winds through the period will support warmer weather, with low temperatures in the lower 70s tonight and Thursday night, and high temperatures in the upper 80s to mid 90s Thursday. Additionally, with stronger winds over the Gulf waters on Thursday expected to build higher seas, a High Risk of rip currents is forecast for local beaches Thursday. && .LONG TERM... (Friday through next Wednesday) Issued at 1259 PM CDT Wed Apr 24 2024 Key message: -The South Texas wind machine will switch on Friday through Sunday Generally quiet weather will dominate the long term forecast period. This pattern will be supported by surface high pressure influencing the region while significant storm systems move over the Plains late in the week and into the weekend. That doesn't mean we'll go without any local threats, however. The tighter pressure gradient accompanying the aforementioned pattern will allow strong southeast to south winds to develop. This will be especially true Friday and Saturday and possibly Sunday. As wave heights increase on the Gulf, the rip current threat will peg at high through Sunday or Monday just based off wave heights and may continue longer if heights remain moderate with longer period swells. Winds on Friday will be strong and could reach wind advisory criteria over the eastern third or so of the CWA. The fire weather threat will remain more restrained since the stonger winds will occur over eastern sections where relative humidity values will remain robust. Farther west, lower wind speeds and still decent relative humidity values will fall shy of critical fire weather indicators. The GFS introduces a small convective threat over the Ranchlands Friday afternoon and evening as the tail end of a cold front digs south. The threat is currently too low for mention in the grids. Wash, rinse, and repeat for Saturday as low pressure over North Central Mexico helps maintain a tight gradient. The threat of a wind advisory will return on Saturday, but there is still a bit of uncertainty regarding coverage and duration. Winds may decrease just a bit on Sunday as a cold front descends toward South Texas. That front will be a bigger issue for East Texas. Most of the energy over South Texas will be eroded by strong southeast inflow, keeping the boundary slightly to the north and lowering overall convective chances for the CWA. Nonetheless, the NBM does admit mentionable tstorm potential Monday afternoon through Tuesday afternoon. Instability in the mid-levels seems to increase while the previous ridge starts to break down. The NBM shows what looks like a training cell scenario Monday night across the mid Valley northeast through the Ranchlands. This signal was evident in yesterday's forecast, increasing confidence a bit. Can't rule Sierra Madre Oriental convection again Tuesday and Wednesday, but the threat seems to diminish from west to east, from the front range to the Rio Grande, and to the Ranchlands. Temperatures will run several degrees above normal through the forecast with no real interruptions. There will be a mix of clouds and sun, though windier days could support a slightly more robust low cloud regime. Otherwise partly to mostly cloudy. && .AVIATION... (00Z TAFS) Issued at 640 PM CDT Wed Apr 24 2024 VFR ceilings prevail this evening, with only brief periods of high end MVFR ceilings observed across the region. Persistent low level southerly to southeasterly flow should result in the development of MVFR ceilings after 04-06Z. Ceilings should begin to improve by Thursday morning. Otherwise, southeast winds will increase in speed by mid to late Thursday morning with gust ranging from 20-25 knots through the end of the TAF period. && .MARINE... Issued at 1259 PM CDT Wed Apr 24 2024 Tonight through Thursday night...Upper level disturbances resulting in the strengthening of surface low pressure systems over Central Mexico and the High Plains will combine with a broad Surface low over the eastern Gulf to produce tighter pressure gradients and stronger winds along the Lower Texas Coast Thursday. These stronger southeasterly winds will build higher seas, and likely lead to adverse conditions on the Laguna Madre and coastal Gulf waters. Small Craft Advisories will likely be needed on the Laguna Madre Thursday afternoon, and extending into the coastal Gulf waters Thursday night. Friday through Monday night...Strong southeast winds will prevail Friday through Saturday night, courtesy of interaction between Plains low pressure and higher pressure over the West Gulf. Small craft advisory conditions will be the norm. After Saturday night, winds will remain moderate to fresh. Although small craft should exercise caution conditions will be the norm on the Laguna Madre after Saturday night, wave models continue the elevated Gulf seas, meaning small craft advisory conditions will be possible through the end of the period. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 74 86 75 86 / 0 0 0 0 HARLINGEN 71 89 73 89 / 0 0 0 0 MCALLEN 73 90 75 91 / 0 0 0 0 RIO GRANDE CITY 72 92 73 94 / 0 0 0 0 SOUTH PADRE ISLAND 74 79 75 80 / 0 0 0 0 BAYVIEW/PORT ISABEL 72 85 73 86 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk from Thursday morning through Thursday evening for TXZ451-454-455. GM...None. && $$ SHORT TERM...60 LONG TERM....54 AVIATION...22-Garcia