Area Forecast Discussion
Issued by NWS Brownsville, TX
Issued by NWS Brownsville, TX
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603 FXUS64 KBRO 211951 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 251 PM CDT Tue May 21 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Wednesday night) Issued at 243 PM CDT Tue May 21 2024 The main trend of the short term forecast period will be hot and hot. A Heat Advisory is already in effect for Deep South Texas and the Rio Grande Valley except along the coast and on the barrier island. As the mid-level ridge continues to dominate the weather for the region the temperatures are going to continue to be hot. The expected high temperatures are in the range of upper 90s along the coast, the island, and the Lower Rio Grande Valley, while the rest of the region is in the triple digits. To add on to that, the southeasterly winds will continue to bring in low-level moisture that will keep the air humid. This will result in elevated heat indices of around 111 to 113 for most of the area. A Heat Advisory is likely to be issued for tomorrow as the heat indices are in the range of 111 to 113. While the previously mentioned low-level moisture will help develop some low-level clouds, the chances of rain are very low. Due to the mid-level ridge in place, the middle and upper levels of the atmosphere are very stable and there is also plenty of dry air as well. This will keep any showers and thunderstorms away from the region. As for the night time temperatures, do not expect too much relief there as the sensible low temperatures will be in the upper 70s to low 80s, but it will feel like being the in the low to mid 80s for both nights. The haze is expected to continue to persist with the ongoing agricultural fires in southeast Mexico and the southeasterly flow allowing to spread over the region. If you happen to be going to the beach, there is a moderate risk of Rip Currents through tomorrow. && .LONG TERM... (Thursday through next Tuesday) Issued at 243 PM CDT Tue May 21 2024 As it was with the short term forecast period, the long term forecast period can be mostly summarized as being hot and hot. High temperatures are expected to mostly in the in the triple digits with a few areas along the coast, the barrier island, and Lower Rio Grande Valley in the upper 90s. However the heat indices are expected to climb even further around Friday and through the early work week to be in the range of 117 to 120. This will mean that Excessive Heat Warnings and Watches will need to be issued by later shifts. Night time low temperatures are expected to be in the range of upper 70s to low 80s for each night. With the mid-level ridge still very much in place for the duration of the long term forecast period, rain chances remain very low. While the southeasterly flow will allow for moisture to move into Deep South Texas and the Rio Grande Valley, the dry and stable middle and upper levels of the atmosphere will work to prevent the development of showers and thunderstorms. There is perhaps an opportunity for showers and thunderstorms to develop towards the end of the long term forecast period with the passage of a mid-level shortwave trough. However, that is a long time out and the forecast models may change their tune on this mid-level shortwave trough. && .AVIATION... (18Z TAFS) Issued at 1228 PM CDT Tue May 21 2024 Mostly MVFR conditions are expected to occur off and on during the TAF cycle at all TAF sites. VFR conditions are expected to last through the afternoon and into the evening hours before giving away to mostly MVFR. Southeasterly winds are expected to hold through the period while being gusty during the afternoon. The winds are expected to weaken during the evening hours and remain light through the overnight hours before picking back up again late in the morning again tomorrow. && .MARINE... Issued at 243 PM CDT Tue May 21 2024 Tonight through Wednesday Night...A locally enhanced pressure gradient due to a thermal low over Mexico and high pressure over the Gulf, is expected to persist through Wednesday night that will result in moderate to fresh southeasterly winds with slight to moderate seas. Small Craft Exercise Caution is possible during the afternoon. Thursday through Next Tuesday...The interaction between a thermal low over Mexico and high pressure over the Gulf of Mexico will generate a locally enhanced pressure gradient that will produce moderate to fresh southeasterly winds with slight to moderate seas. Small Craft Exercise Caution is likely to be needed each day during the afternoons, but a Small Craft Advisory can not be ruled out either for those days as well. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 81 96 81 99 / 0 0 0 0 HARLINGEN 77 99 78 98 / 0 0 0 0 MCALLEN 80 100 80 100 / 0 0 0 0 RIO GRANDE CITY 79 103 78 103 / 0 0 0 0 SOUTH PADRE ISLAND 81 87 82 89 / 0 0 0 0 BAYVIEW/PORT ISABEL 79 95 80 97 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory until 6 PM CDT this evening for TXZ248>255-353. GM...None. && $$ SHORT TERM...64-Katz LONG TERM....64-Katz AVIATION...64-Katz