807 FXUS64 KBRO 080522 AAB AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1222 AM CDT Fri Oct 8 2021 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...VFR conditions will prevail through the TAF period. Light and variable winds become E to ESE during the afternoon hours. Patchy shallow fog is possible this morning, generally north of the RGV. && .PREV DISCUSSION... /issued 628 PM CDT Thu Oct 7 2021/ DISCUSSION...Updated for latest aviation discussion below. AVIATION...High pressure over the area will maintain VFR conditions through the forecast period. Light easterly winds early this evening will become nearly calm overnight tonight. As a result of the light winds overnight, light, patchy fog is a possibility just before sunrise Friday. However, probability of fog is too low to include in TAFs. Winds will turn southeasterly and increase on Friday afternoon, but will stay generally light to moderate. PREV DISCUSSION... /issued 239 PM CDT Thu Oct 7 2021/ SHORT TERM (Now through Friday Night): Quiet, beautiful weather is expected to continue through the short term period. Mid level ridging will build overhead this weekend, providing a healthy dose of subsidence to the region. This mid level pattern combined with a deep dry layer in the atmospheric column will leave rain chances out of the picture for this period. At the surface, high pressure will slide off to the east, maintaining an easterly onshore flow. With a weak pressure gradient in place, this flow will remain light through the period and drop off each evening to become light and variable or even calm in some locations. Not expecting any significant fog development with the drier airmass, but cannot completely rule out some patchy shallow fog just before sunrise in some fog-prone locations. Daytime temperatures will be near normal, while overnight lows remain a few degrees below...enjoy these cool mornings while they last because Saturday morning might be the last cool morning for a while...but that's a topic for the long term. LONG TERM (Saturday through Thursday): The long term forecast remains little changed from previously. Ridging above the CWA on Saturday will slowly weaken as the base of a sharp, positively tilted mid level trough digs across the Four Corners and into the southern High Plains. Deepening low pressure over the Texas Panhandle will then help tighten the surface pressure gradient and introduce breezy southeast winds into the forecast through Tuesday. As well, temperatures will trend slightly higher through the weekend, as mentioned above. This will be the focus of the first few days into the long term period. The first mid level trough will lift east and northeast toward the great lakes on Monday, trailing a weak front across Central Texas. Rapidly, another mid level short wave trough will be on the way southeast through the Pacific Northwest on Monday. This trough, too, will move east into the High Plains, with another front slicing toward the Texas Big Bend on Wednesday, and moving closer to the Upper Valley Wednesday night. Though still ill-resolved, both long term models show by mid next week a possible East Pacific tropical feature moving up near Puerto Vallarta which could contribute upper moisture to South Texas. Low level return moisture and some pooling ahead of the approaching front will, in any case, support slightly more unsettle conditions. The model blend introduces isolated to widely scattered rain chances into the region next Wednesday through Thursday. MARINE: Now through Friday Night...Marine conditions will remain favorable as high pressure slowly slides off to the east, which will continue to maintain light easterly to southeasterly winds into the weekend with low seas. Saturday through Tuesday night...Dominating high pressure will support quiet marine weather on Saturday. As the gradient tightens up Saturday night, winds will increase from the southeast, leading to building seas. The latter half of the forecast will see moderate to fresh winds and moderate to moderate-high seas. Small craft should exercise caution conditions will develop at times from Sunday through Tuesday. Wave models are building seas on the Gulf toward seven feet on Tuesday, threatening possible low end small craft advisory conditions. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 69 89 76 91 / 0 10 0 0 BROWNSVILLE 70 91 77 94 / 0 10 0 0 HARLINGEN 66 92 75 94 / 0 10 0 0 MCALLEN 65 95 74 98 / 0 0 0 0 RIO GRANDE CITY 65 97 73 102 / 0 0 0 0 SOUTH PADRE ISLAND 78 84 81 87 / 0 10 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ This product is also available on the web at: https://weather.gov/rgv 56-Hallman...Aviation