FXUS64 KBRO 302338 AAA AFDBRO Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 538 PM CST Mon Jan 30 2023 ...New AVIATION... .SHORT TERM... (Tonight through Tuesday night) Issued at 231 PM CST Mon Jan 30 2023 A strong cold front will finish making its way through the County Warning and Forecast Area this afternoon/evening. I continued to favor the NAM for temps this package. That said, the main impact will be lower temperatures which will drop into the 30s and 40s tonight. High temperatures on Tuesday will be 30 degrees colder than today, settling from the upper 30s across the Northern Ranchlands to the upper 40s for the Lower Valley. Then, low temperatures Tuesday night will be mostly in the 30s across the area except slightly higher for the immediate coast. A few spots across the Ranchlands could see freezing temperatures Tuesday night/Wednesday morning. For now, we are also watching the potential for low wind chill readings. If winds remain strong enough and also maybe back a bit more to northwest (bringing cold overland temps into the picture) and temperatures stay low, a case could be made for a possible wind chill advisory Tuesday night. Yes, there will also be light rain, but precip accumulation in this overrunning scenario will remain meager. That said, a tenth of an inch or two of rain could accumulate Tuesday night. While forecast soundings from the NAM show a nose of below zero colder temperatures just above the deck across the northern sections, freezing rain probability remains low and not enough to justify mention in the deterministic forecast. It is worth noting that the probability is not zero, however. Bottom line for the short term forecast? Look for cold, dreary, gray, and moist (wetting) weather. && .LONG TERM... (Wednesday through next Monday) Issued at 231 PM CST Mon Jan 30 2023 Have gone full NAM even into the start of the long term, as it was the only model with a grip on this arctic air mass. Not too much of a surprise, as the NAM consistently fairs better in these shallow cold air masses through South Texas, and it once again has beat global models or any sort of blended model output. Beyond the NAMs reach, have essentially mixed NBM and NBM10 into Friday to help bring temperatures down. Mid-level flow remains southwesterly into late this week, before the next shortwave runs from Baja CA through northeast Texas into Friday, so until then will lean cooler with persistent northerly flow, low level clouds, and overrunning rain chances. The approaching mid-level trough axis could enhance rain chances late Wednesday through Thursday with more showers than light rain or drizzle, especially along the coast. Total QPF at this time remains generally a tenth to a quarter of an inch. Skies finally clear from west to east into Friday, with radiational cooling bringing another couple cold mornings Friday and Saturday. Highs over the weekend warm back into the 70s. A weak frontal boundary is expected on Sunday with little to no fanfare at this time, potentially even stalling just north of the CWA. Above normal temperatures return Monday, with 80s possible across the brush country and upper valley. && .AVIATION... (00Z TAFS) Issued at 531 PM CST Mon Jan 30 2023 A cold front currently moving through the Lower Valley will back southeast winds to northeast and then north. Low clouds will develop with ceilings lowering from MVFR to IFR this evening, with LIFR ceilings possible late tonight into Tuesday. Isolated to scattered light rain and patchy drizzle are expected through the next 24 hours. && .MARINE... Issued at 231 PM CST Mon Jan 30 2023 Now through Tuesday Night...Opted to hoist a small craft advisory for northeast winds behind a strong cold front edging through the CWA and into the coastal waters this afternoon. The advisory is posted for all waters through midnight, but could be extended. The pressure gradient will remain tight through the remainder of the short term and winds on the Gulf will remain elevated, ranging from small craft exercise caution to low end small craft advisory criteria. Seas will also build through the period. Winds on the Laguna may stay just below advisory criteria after tonight. The chance for rain will remain high on the waters, especially Tuesday night as a coastal trough develops. Wednesday through Monday...Low pressure across the Western Gulf gradually works northeast as high pressure builds over the weekend. Expect showers and light rain or drizzle into Friday before a mostly clear weekend. Moderate to strong northerly flow brings Small Craft Caution to Small Craft Conditions Thursday afternoon into Friday afternoon. Onshore flow returns over the weekend with more favorable marine conditions. A weak frontal boundary approaches on Sunday, but may stall, with moderate southeasterly flow expected on Monday driving potential SCEC to SCA conditions offshore. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 46 48 38 47 / 20 20 60 40 HARLINGEN 43 46 37 46 / 30 30 70 40 MCALLEN 42 44 38 46 / 30 30 70 40 RIO GRANDE CITY 42 43 38 46 / 40 30 80 30 SOUTH PADRE ISLAND 55 55 44 51 / 30 30 70 50 BAYVIEW/PORT ISABEL 49 49 40 48 / 30 30 70 40 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Small Craft Advisory until midnight CST tonight for GMZ130-132- 135-150-155-170-175. && $$ SHORT TERM...54-BHM LONG TERM....56-Hallman AVIATION...63-KC