005 FXUS64 KBRO 071809 AAB AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1209 PM CST Sun Nov 7 2021 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...Due to a 500mb ridge, satellite images show clear skies across the CWA. Light to variable winds will dominate through the TAF period with mostly VFR conditions. Patchy fog is expected across portions of the Rio Grande Valley starting as early as 08z Monday. This fog will provide brief MVFR conditions before 15z Monday. && .PREV DISCUSSION... /issued 526 AM CST Sun Nov 7 2021/ DISCUSSION...Updated for latest aviation discussion below. AVIATION...Satellite images and surface observations indicate mostly clear skies across the CWA early this morning. Visibilities were near 4SM with fog at KTXW. Patchy ground fog across portions of the Rio Grande Valley will provide brief MVFR conditions before 15Z Sunday. Otherwise...VFR conditions will prevail the rest of the morning through the afternoon as the 500mb ridge across northeast Mexico and south Texas continues to provide subsidence across deep south Texas today. PREV DISCUSSION... /issued 309 AM CST Sun Nov 7 2021/ SHORT TERM (Today through Monday): 500mb ridge across east Texas and northern Mexico will continue to provide subsidence across south Texas today through Monday. At the surface...a weak onshore flow will continue across the lower Texas coast today through Monday with surface high pressure across east Texas and Louisiana shifting slowly eastward through the short term forecast period. Below normal to near normal temperatures will prevail today through Monday. No rain chances are expected. Patchy fog will develop across portions of the CWA late tonight into early Mon morning. Tides were running just below minor flood category along the lower Texas coast last night and with high tide tonight at 8:20 pm...will likely see water levels approach minor flood category so will issue a coastal flood statement for minor tidal overflow for this evening. LONG TERM (Monday Night through Saturday):H5 ridge begins to flatten Monday night ahead of a shortwave forecast to move through northern Texas Tuesday. Not a whole lot of fanfare expected with this shortwave as it only helps to increase mid to high level cloudiness Tuesday night into Wednesday. A longwave trough begins moving into the High Plains Wednesday afternoon and will push a cold front into northern Texas Wednesday night. A secondary vort max on the backside of the longwave trough causes it to dig farther south Thursday night into Friday and will help push the cold front through Deep South Texas sometime Friday. Rain chances remain highest over the Gulf waters as the cold front pushes south, but the 0Z EURO did show slightly better rain chances across Deep South Texas, so this trend will continue to be monitored in future forecasts. As far as temperatures are concerned, a southeast to southerly breeze will continue to cause both overnight and daytime temps to moderate through Thursday afternoon. Friday’s temperatures are highly dependent on the timing of the cold front, so continued with the NBM for temperatures Thursday night into Friday. As the cold front clears by Friday afternoon, cooler, drier weather moves in thanks to a surface high oozing down from the Central Plains. As a result, decided to trend a bit cooler than the NBM and mixed it with the NBM 25 percent for lows, especially in the Northern Ranchlands, Friday night and Saturday night. Below normal daytime highs are anticipated Friday and Saturday. Dew points and relative humidity values are forecast to drop quite a bit behind the cold front Friday. Will continue to monitor any trends for fire weather concerns due to the possibility of areas west of I-69C having RH values less than 25 percent Friday and/or Saturday afternoons. MARINE (Today through Monday): Seas were near 4 feet with east to southeast winds near 4 knots at buoy020 at 2:10 am this morning. Light east winds will prevail across the coastal waters today with surface high pressure across the northwest Gulf coast. The pressure gradient will remain weak across the lower Texas coast tonight into Monday. Light southeast winds will prevail across the coastal waters tonight into Monday. Monday night through Friday: Light to moderate southeast to south winds and low to moderate seas prevail through Wednesday morning. Winds pick up Wednesday afternoon, and could reach SCEC criteria, due to a developing low in the middle of the country and a tightening pressure gradient over our coastal waters. After a brief relaxation of the winds Thursday afternoon into Thursday night, they’ll begin to pick up to near SCA criteria Friday morning as the cold front nears and clears the lower Texas coast Friday afternoon. The cold front will also bring a chance for scattered showers and storms to our coastal waters Thursday night through Friday afternoon. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 64 81 64 83 / 0 0 0 0 BROWNSVILLE 63 83 65 86 / 0 0 0 0 HARLINGEN 59 82 62 85 / 0 0 0 0 MCALLEN 59 84 63 87 / 0 0 0 0 RIO GRANDE CITY 58 85 61 88 / 0 0 0 0 SOUTH PADRE ISLAND 72 78 73 80 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ This product is also available on the web at: https://weather.gov/rgv 65-Soria/Aviation