777 FXUS64 KBRO 301124 AAA AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 624 AM CDT Mon Aug 30 2021 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...VFR prevails for all terminals sites today and tonight with high pressure dominating the region. Light to moderate south to southeast winds with few gusts approaching 20 knots. && .PREV DISCUSSION... /issued 258 AM CDT Mon Aug 30 2021/ SHORT TERM (Now through Tuesday): High pressure over Texas, including Deep South Texas, is anchored between Hurricane Ida and Tropical Storm Nora over Northwest Mexico. Subsidence and a relative dry airmass associated with the ridge will provide the CWA with rain free and very hot conditions today and Tuesday. Just some passing high clouds, occasionally thick at times, but still plenty of sun to heat up the daytime to seasonal normals mid to upper 90s to lower 100s. The drier air in the mid-layers will partially mix to the surface during the day lowering dew points keeping the heat indices from going overboard. At this time, no heat advisories are expected today or Tuesday but it will still feel very hot and with highest index values running slightly higher than the ambient temperatures reaching 102-107 each afternoon. Overnight lows do not show much relief, even though the early evening may be somewhat comfortable with humidity at its minimum, dew points will likely recover steadily overnight keeping temperatures from falling below normal with mid to upper 70s the best we can do. As for the coastal impacts, Long periods swells continue to roll across the Western Gulf with buoys indicating 13-15 second periods but swell heights underachieving at a modest 4 to 6 feet. In any case, will be extending the rip current statement (High Risk) and the coastal flood statement through at least 7 pm due to this long period high energy swell. LONG TERM (Tuesday Night through Sunday): Persistent midlevel ridging will be the theme of the long term. The center of the 500mb high will set up over central Oklahoma, helping to maintain the pattern of ridging but also allowing for low-end thunderstorm chances each day, mainly along the sea breeze during the late morning and afternoon hours. Moisture at midlevels will be a limiting factor through much of this week, precluding chances for more robust and widespread storm development. The best chances for rain or storms looks to set up across coastal areas each day through early next week. Inverted troughing may develop on Sunday which would favor higher rain chances across the CWA, but confidence remains fairly low at this time. Temperatures each day will remain near or slightly above normal to start the long term, with temperatures falling back to near seasonal normals by the weekend. This will also favor heat indices of 103-109 degrees through much of the period. MARINE (Now through Tuesday): Buoy 42020 has been reporting south winds 8 to 10 knots with occasional gust to 14 knots with seas shy of 4 feet with a period of 13 to 16 seconds much of the night. A long but low to moderate rolling swell train will continue to be directed towards the Lower Texas coast today with a gradual subsiding trend tonight into Tuesday as Hurricane Ida continues to move inland and weaken. With western Gulf buoys not indicating swells high enough to warrant Small Craft Advisories will cancel the Marine Weather Warning produce and substitute in Exercise Caution for the outer waters today. Otherwise, light south to southeast winds today and Tuesday with a slight sea Tuesday. Tuesday Night through Friday: The surface pressure gradient remains fairly weak across the lower Texas coastal waters through much of the period due to broad high pressure settling over the Gulf. Favorable marine conditions can be expected through the weekend with light to moderate southeast winds and lower seas. Showers and thunderstorms will be possible each day across the waters, with thunderstorms presenting themselves as the primary concern for marine interests. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 95 79 94 80 / 0 0 10 10 BROWNSVILLE 97 79 96 81 / 0 0 10 10 HARLINGEN 98 77 98 79 / 0 0 10 10 MCALLEN 100 78 101 79 / 0 0 10 10 RIO GRANDE CITY 103 77 101 78 / 10 10 10 10 SOUTH PADRE ISLAND 89 82 89 83 / 0 0 10 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk through this evening for TXZ256-257-351. GM...None. && $$ This product is also available on the web at: https://weather.gov/rgv Short Term/Aviation...59-GB Long Term/Radar...55-Adams