165 FXUS64 KHUN 091743 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1243 PM CDT Tue Oct 9 2018 .UPDATE... For 18Z TAFS. && .NEAR TERM...(Rest of Today) Issued at 1033 AM CDT Tue Oct 9 2018 Somewhat of a cooler change is expected for an abbreviated work week for some after Columbus Day yesterday. In a tropical atmosphere and a southeast lower-level flow, scattered to broken stratus and strata-cumulus clouds continued to work their way further inland, resulting in more clouds than sun across the Tennessee Valley. These clouds of tropical origin, not directly associated with Hurricane Michael will bring slightly cooler conditions and isolated showers this afternoon. Showers as of this writing were mainly to the E-ESE of the Hytop radar. Given trends from the past few days, and given the showers were to our east, raised high temperatures a degree or so for most areas. Also increased winds a tad, especially in the higher elevations. The rest of the forecast is on track for now. .SHORT TERM...(Tonight through Thursday) Issued at 335 AM CDT Tue Oct 9 2018 The synoptic pattern begins to change tonight as a trough across the western US starts to kick east into the Plains. At the same time Hurricane Michael moves closer to the AL/FL Gulf Coasts. We remain in between these two features and the overall forcing would support some subtle subsidence which should keep precip chances limited tonight. However, as Hurricane Michael approaches the coast Wednesday morning we'll see a surge in tropical moisture sending PWATs upwards of 2 inches. As we go through the day Wednesday the trough to our west will send a cold front towards the area. This feature will help to deflect Hurricane Michael to the northeast after it makes landfall. Which models are coming into agreement that landfall will occur near Panama City Wednesday afternoon. Latest hires guidance wants to keep the area on the drier side Wednesday but with good turning of the winds with height and a very saturated airmass think we'll be able to see scattered showers. Any thunderstorms should be limited to the far western half of the area where slightly warmer temps might support a bit more instability. The highest chances for rainfall will occur Wednesday evening into Thursday morning. This is mainly a result of surface convergence between the wind field associated with Michael and the arrival of the front. Models are also suggesting that an axis of deformation could help to enhance vertical motions Wednesday evening and we might see an enhanced band of precip develop along this axis. Hurricane Michael will quickly shift to the NE across central GA early Thursday morning. Drier and cooler air streaming in behind the front will help bring an end to precip chances from west to east Thursday morning. Some lingering cloud cover on Thursday should result in high temps struggling to make it much above the low to mid 70s. .LONG TERM...(Thursday night through Monday) Issued at 335 AM CDT Tue Oct 9 2018 As a surface high builds into the Midwest Thursday night into Friday expect strong CAA to send overnight lows into the 50s. A few locations in TN could see lows dip into the upper 40s Friday morning, which will close to a 30 degree swing in temps from the start of the week to the end of the week. This strong CAA continues into the weekend with highs Friday only around 70 degrees and lows Saturday morning around 50 degrees. This high shifts east to the Atlantic coast by Sunday allowing winds to transition back to the south. More moderate temperatures are expected to close out the weekend and to start next week with highs in the low to mid 70s and lows in the upper 50s. Models are struggling with the overall pattern across the CONUS and this is due in large part to whether or not a cutoff low across the desert SW will phase with Hurricane Sergio in the eastern Pacific and a trough dropping S/SE out of the Pacific NW. In any of these solutions, the trough continues east and will result in showers/storms early next week. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1243 PM CDT Tue Oct 9 2018 Broken lower level stratus (rising to and above MVFR CIG threshold or 3000' AGL) was resulting in VFR conditions for the TAF sites. This trend should continue into the late evening. These clouds from the tropics were not directly associated with Hurricane Michael, which was heading northward across the east/central Gulf. This storm is forecast to make landfall in about a day over the Florida panhandle. At this time, little direct effects are expected to impact the Tennessee Valley during the TAF. MVFR clouds are expected over the area from late tonight and during Wednesday morning. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...RSB SHORT TERM...Stumpf LONG TERM...Stumpf AVIATION...RSB For more information please visit our website at weather.gov/huntsville.