####018005241#### FXUS64 KBRO 130918 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 418 AM CDT Mon May 13 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Tuesday) Issued at 338 AM CDT Mon May 13 2024 The main concerns in the short term will be the heat and the low probability for strong to severe thunderstorms today. Southerly winds and elevated 850mb tempeatures of 24 to 25(C) to allow for surface temperatures to climb 5 to 10 degrees above normal. Highs today are expected to range from the 80s near the coast to the triple digits across the Rio Grande Plains. The daily records at Brownsville 96 in 2011 and Harlingen 98 in 2011 may be reached. In addition, the much warmer temperatures and high humidity will allow heat index values to up 114 degrees, especially along and east of the I-69C/US 281 corridor, for a few hours this afternoon. Hence, a Heat Advisory is in effect from 1 pm the afternoon until 7 pm this evening for Inland Cameron, Hidalgo, Inland Willacy and Inland Kenedy Counties. A dryline is expected to push into the far western counties this afternoon which may keep the heat indices slightly lower, 105 to 110, with highs to reach into the lower 100's. Warm and humid conditions are expected again tonight with lows in the 70s to around 80 at the beaches. High temperatures on Tuesday will range from the lower 80s at the beaches, low to mid 90s across the Rio Grande Valley and the upper 90s to around 100 degrees across the Rio Grande Plains. Will lean towards a blend of the NBM and previous forecast for temperatures and dewpoints for today through Tuesday, as the NBM appears a little too warm. Low rain chances (20 to 30 percent) are forecast for this morning into the afternoon with an elongated mid-level disturbance passing overhead. Brownsville radar currently indicates some activity moving across the Upper Valley and the northern ranchlands. The atmosphere remains conditionally unstable with a strong low level cap (stronger eastern counties) and elevated MUCape of 3000+ J/kg. There is a low probability (20 percent) for strong to severe thunderstorms today which is highly dependent on the track of the mid-level disturbance and if the cap weakens. The Storm Prediction Center /SPC/ has all of Deep South Texas in a marginal risk for the entire area for today and tonight. Finally, continued slightly elevated seas will result in a Moderate Risk of rip currents at the local beaches through Tuesday. && .LONG TERM... (Tuesday Night through Sunday) Issued at 338 AM CDT Mon May 13 2024 A weak cold front is forecast to intrude into the BRO CWFA on Friday. When combined with a series of disturbances riding within a west-southwest to east-northeast 500 mb flow, isolated showers and thunderstorms will result, mainly in the Wednesday through Friday time frame. Above normal daytime highs and overnight lows are also anticipated, and highs on Thursday through Sunday, combined with relative humidity percentages, may require a Heat Advisory for portions of Deep South Texas and the Rio Grande Valley on those days. && .AVIATION... (06Z TAFS) Issued at 1227 AM CDT Mon May 13 2024 Low MVFR stratus and light southeast winds prevail across Deep South Texas early this morning. BRO radar indicates some isolated convection northeast of HRL. These showers and thunderstorms will continue to move to the northeast and are not expected to impact the RGV aerodromes. Otherwise, MVFR ceilings should remain in place through the overnight hours. There could be brief instances of IFR ceilings as well late tonight. Ceilings are expected to improve to VFR levels mid to late morning. MVFR ceilings may return late in the period at BRO, around 04Z. && .MARINE... (Today through Tuesday) Issued at 338 AM CDT Mon May 13 2024 Weak to moderate southerly flow and moderate seas of 2 to 4 feet will prevail along the Lower Texas Coast through Tuesday. Isolated to scattered showers and thunderstorms will be possible today which could lead to locally higher winds and seas. (Tuesday Night through Sunday) A couple of weak cold fronts are still expected to intrude into the western Gulf of Mexico waters during the period, but high pressure will still generally prevail. Light to moderate winds and generally moderate seas will occur along the Lower Texas Coast. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 95 78 92 78 / 20 10 10 0 HARLINGEN 98 75 93 74 / 20 10 10 0 MCALLEN 100 78 97 77 / 10 10 10 0 RIO GRANDE CITY 102 76 97 75 / 10 10 10 10 SOUTH PADRE ISLAND 85 79 85 79 / 20 10 10 0 BAYVIEW/PORT ISABEL 93 77 89 76 / 20 10 10 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory from 1 PM this afternoon to 7 PM CDT this evening for TXZ251-253>255-353. GM...None. && $$ SHORT TERM...Caceres-63 LONG TERM/UPPER AIR...Tomaselli-66