Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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951 FXUS64 KBRO 252342 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 642 PM CDT Wed Sep 25 2024 ...New AVIATION... .SHORT TERM... (Tonight through Thursday night) Issued at 230 PM CDT Wed Sep 25 2024 The approach of an upper level trough is expected to also result in the development of a closed low over the Central Mississippi River Valley tonight. The forcing from this system should also support a cold front pushing through Deep South Texas and the Rio Grande Valley late tonight and into tomorrow morning. With PWAT values over 1.5 inches and CAPE around 1000 J/kg, the environment ahead of the front is supportive of the development of showers and thunderstorms both ahead and along the cold front itself. With a good amount of shear and instability in the environment, some thunderstorms could be strong, and there is even a low chance of severe thunderstorms possible as well. SPC does have a marginal risk for northern Kenedy County, while keep the rest of the area in a general thunderstorm outlook. As for the temperatures, starting with the high temperatures for tomorrow, they are expected to be in the range of upper 80s to low 90s. Thanks to the passage of the previously mentioned cold front, the the temperatures will be lower than they have been recently. In addition the heat indices will also be much lower in the 90s as well for tomorrow. The low temperatures for tonight are expected to be mostly in the 70s, meanwhile the for Thursday night, the lows are expected to be mostly in the 60s with a few places in the Lower Rio Grande Valley in the low 70s. Finally, the swell from Hurricane Helene is expected to arrive tomorrow along the Lower Texas Coast. This will likely lead to a higher risk of rip currents and some minor coastal flooding at area beaches. && .LONG TERM... (Friday through next Wednesday) Issued at 230 PM CDT Wed Sep 25 2024 A midlevel low over the Mississippi Valley will ingest the remnants of Hurricane Helene before slowly lifting to the northeast this weekend and into next week. At the same time high pressure over the Desert Southwest into the Great Lakes will and slowly expand into Deep South Texas through next week. At the surface, high pressure will dominate in wake of a cold front that moves through tomorrow morning. This will allow for much drier air to filter into the region on Friday, leading to dry conditions through the weekend. Moisture begins to return by midweek, with chances for rain along the seabreeze returning. Along the coast, long period swell from Helene will result in increased wave heights and adverse beach conditions on Friday. Enhanced rip current risk and minor coastal flooding will be possible at beaches along the Lower Texas Coast. As for temperatures, near normal temperatures will prevail through the period, and along with lower humidity and dewpoints will feel much more pleasant than previous weeks. Heat indices will remain below 100 degrees through the period. && .AVIATION... (00Z TAFS) Issued at 627 PM CDT Wed Sep 25 2024 Currently, clear skies are being observed at BRO and HRL while a few clouds are reported over MFE due to a dissipating shower that passed just to the west, which should continue to clear within the hour or two. Leading up to, and for a few hours following sunset, winds are expected to diminish to light and variable as well as skies should remain mostly clear with the exception of a few clouds with more scattered coverage over KHRL and KBRO, remaining at VFR. Overnight, a weak cold front will advance from the north, increasing cloud coverage for all terminals and chances of showers or thunderstorms for MFE. A TEMPO has been added for HRL and BRO to account for broken VFR and a PROB30 has been put in for MFE for the 08Z to 09Z Thursday time range, as visibility could drop to 4 SM for a brief period of time as convection quickly moves through. Tomorrow morning, a light north- northwesterly breeze will pick up along with clearing skies, becoming breezy in the afternoon, particularly for HRL and BRO. && .MARINE... Issued at 230 PM CDT Wed Sep 25 2024 Tonight through Tuesday Night...While mostly favorable conditions are expected for tonight with light to moderate onshore flow and low to moderate seas are expected for tonight. Swells from Hurricane Helene and winds picking up after a cold frontal passage tomorrow are likely to bring adverse conditions to the Lower Texas Coast, thus Small Craft Exercise Caution headlines will be likely needed for Thursday. Small Craft Advisories for the Gulf waters might also be needed as well due to the larger wave heights. Friday through Monday...Swell from Helene will lead to elevated seas on the Gulf waters for Friday into early Saturday. Small Craft Should Exercise Caution headlines or Small Craft Advisories may be needed for the Gulf waters Thursday and Friday as wave heights look to reach 6-7 feet. Seas are expected to subside over the weekend, with favorable marine conditions prevailing through the remainder of the period. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 76 88 71 90 / 20 20 0 0 HARLINGEN 73 89 67 92 / 10 20 0 0 MCALLEN 77 93 71 95 / 20 10 0 0 RIO GRANDE CITY 74 91 68 93 / 30 0 0 0 SOUTH PADRE ISLAND 79 86 78 87 / 20 20 10 0 BAYVIEW/PORT ISABEL 75 86 71 88 / 20 20 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk from Thursday morning through late Friday night for TXZ451-454-455. GM...None. && $$ SHORT TERM...64-Katz LONG TERM....68-McGinnis AVIATION...65-Irish