214 FXUS64 KLCH 221847 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA Issued by National Weather Service Houston/Galveston TX 147 PM CDT Thu Oct 22 2020 .DISCUSSION... For the 10/22/20 1800 UTC TAF package. && .AVIATION... Early morning fog and stratus has cleared out and mostly MVFR to VFR conditions will continue through the day. Easterly flow will continue through the day with some isolated late afternoon showers and thunderstorms possible. Overnight, some lower stratus will form again and patchy fog in the early morning hours will bring IFR to LIFR conditions due to the lower ceilings and low visibility. Like today, conditions are expected to improve mid to late morning across the area. 35 && PREV DISCUSSION... /issued 452 AM CDT Thu Oct 22 2020/ SYNOPSIS... Latest UA analysis and WV imagery shows a weak shortwave trough over TX, with another shortwave further upstream along the AZ/NM border. Relatively dry air persists in the mid levels with mean RH values between 45 and 50 percent per KLCH 00Z sounding. Meanwhile, east-southeasterly low level flow continues to bring Gulf moisture into the region, resulting in abnormally warm and muggy conditions for mid to late October, along with the typical late night/early morning patchy low clouds and fog developing in a few locations. 24 DISCUSSION... Fog is expected to dissipate by mid-morning, giving way to partly cloudy skies. Another day of unseasonably warm and humid conditions can be expected with aftn highs into the middle 80s. An increase in moisture over the region, combined with sufficient instability provided by the weak shortwave aloft and daytime heating, will result in some widely sctd showers or an isolated tstm or two, with the best potential for convection acrs S Cntl LA. Any showers that develop will dissipate this evening, with muggy conditions and patchy fog again possible acrs the area overnight. A weak cold front will progress southeastward into the region on Friday, with widely sctd to sctd showers or tstms possible. The highest chcs are again expected acrs S Cntl LA where deepest moisture will reside. Frontal convergence will weaken through the day as pre-frontal wind fields attain a northeasterly component in response to broad low pres developing in the NW Caribbean and Yucatan region. This will result in decreasing convective coverage by late Friday into Friday night. The front will slip through the area Friday night into Saturday morning, weakening further and gradually washing out as it moves into the northern Gulf. Weak high pres will bring slightly drier air into the region, with dry weather expected through the weekend. A very modest cooldown can be expected in the wake of the front, with temperatures only a few degrees cooler than what they've been this past week. Daytime highs Saturday will be closer to seasonal normals, while overnight temperatures are expected to remain abv normal, with lows Sunday morning in the lower 60s north to middle 60s south. Southeasterly winds will return during the day Sunday, ushering a return of warm and moist gulf air back over the region. A more significant cold front will approach the region Monday, with southwesterly flow developing aloft as shortwave energy cuts off over the SW states. Beyond Monday, discrepancies in global model solutions continue to impact placement of sfc low development and overall timing of when the front finally gets a decent push through area. The GFS remains the faster and more progressive solution, with FROPA occurring on Wednesday, while the ECMWF is about 18 to 24 hours slower. Maintained a preference toward National Blends at this time, with 20 to 30 percent PoPs Tuesday through Thursday and a gradual cooldown toward the end of the week. 24 MARINE... Light to modt east to southeast flow will continue through Friday as high pres remains centered over the southeast US. A weak front will slide south into the area Friday and stall over the coastal waters by Saturday morning, providing a brief period of offshore flow. Onshore winds will resume by Sunday, with another cold front forecast to move into the area early next week. 24 && .PRELIMINARY POINT TEMPS/POPS... AEX 86 67 84 64 / 20 10 30 10 LCH 84 70 83 67 / 20 10 30 10 LFT 86 71 84 68 / 40 10 40 10 BPT 84 71 85 65 / 20 10 20 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$ AVIATION...HGX (35)