935 FXUS64 KBRO 171724 AAB AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1224 PM CDT Sun Apr 17 2022 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...Low clouds continue to plague portions of the Rio Grande Valley with MVFR conditions at MFE and BRO. VFR conditions are expected this afternoon across all aerodromes. Tonight, ceilings and visibilities fall again to MVFR and IFR across all aerodromes as patchy fog and haze develops lingering into early Monday morning. && .PREV DISCUSSION... /issued 614 AM CDT Sun Apr 17 2022/ DISCUSSION...Updated for latest aviation discussion below. AVIATION...Satellite images and surface observations indicate mostly low clouds and patchy fog across portions of the Rio Grande Valley early this morning with some high clouds moving across the area. Ceilings were near 600ft at KHBV to near 1800ft at KTXW. Visibilities were near 3SM with fog at KHBV to near 4SM with fog at KBRO. Expect MVFR conditions to prevail across the Rio Grande Valley through 15Z Sunday before low clouds/fog lift and burn off with diurnal heating allowing mixing to increase. PREV DISCUSSION... /issued 340 AM CDT Sun Apr 17 2022/ SHORT TERM (Today through Monday): A 500mb shortwave trough will be moving eastward across the central and southern plains today. The upper level trough will move eastward across the southeast United States Monday as a 500mb ridge amplifies across the western United States. At the surface...a weak cold front across central Texas will stall today before high pressure across the west- central United States builds southward into south Texas tonight into Monday. This will bring a weak cold front into the Rio Grande Valley Monday. Moisture will pool along and ahead of the frontal boundary providing a slight chance to chance of showers across deep south Texas on Monday. Otherwise...patchy fog and haze will prevail across the lower Texas coast this morning and will return across the coastal sections of deep south Texas late tonight into early Monday morning as the front approaches from the north. Above normal temperatures will continue today through tonight before cooler air filters into the CWA on Monday providing below normal temperatures. LONG TERM (Monday Night through Saturday): Near to slightly above normal temperatures and unsettled weather will prevail through much of the period. Broad 500mb ridge over the Baja Peninsula will maintain a generally northwest flow aloft over Deep South Texas through late week. A weak short wave trough is expected to swing over the area Wednesday into Wednesday night. At the surface, high pressure across the Plains Monday night will gradually move eastward across the Mid-Atlantic coast by Wednesday. The pressure gradient will strengthen Tuesday into the fist half of next weekend. This will result, in breezy conditions across the CWA, especially east of I-69C, Tuesday through Saturday. Unsettled weather is expected to prevail through much of the period with a slight chance to chance pops in the forecast. PWAT values between 1.0 to 1.5 inches, generally below 850mb, will remain in place through the long term. The PWATS jump to around 1.75 inches midweek with the approach of the next short wave. The combination of an upper level disturbance, the lingering frontal boundary, and possible convection developing over Mexican Plateau and drifting across the Rio Grande River, should support an uptick in rain chances across the portions of the area each day. Highs each day will generally be in the 80s to mid to upper 90s through the period. Overnight lows will be in the upper 60s to lower 70 each night. MARINE (Today through Monday): Seas were near 3 feet with southeast winds near 10 knots at buoy020 at 2:10 am Sunday. Moderate southeast winds will prevail across the coastal waters today with SCEC conditions across the Laguna Madre and the nearshore waters this afternoon. Winds will diminish and back to the east as a weak cold front moves into south Texas tonight. Winds will shift to the northeast across the western Gulf of Mexico as the front moves across the lower Texas coast. SCEC conditions will develop across the offshore waters Monday afternoon. Monday Night through Thursday Night...Moderate winds and seas will prevail Monday night into Tuesday with exercise caution likely on the Laguna Madre and the Gulf waters during time. High pressure across the Plains Monday night will slide farther eastward by midweek allowing a long fetch to develop across the Gulf. This will lead to an uptick in seas with low end small craft advisories possible on the Gulf waters Tuesday night into Wednesday. Isolated showers and thunderstorms will be possible through much of the period. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 87 70 81 68 / 0 10 20 20 BROWNSVILLE 90 73 84 71 / 0 0 20 20 HARLINGEN 93 70 86 68 / 0 10 20 20 MCALLEN 96 71 90 69 / 0 10 30 20 RIO GRANDE CITY 100 71 94 69 / 0 10 30 20 SOUTH PADRE ISLAND 77 71 75 71 / 0 10 20 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ This product is also available on the web at: https://weather.gov/rgv 68-McGinnis/Aviation