955 FXUS64 KHUN 111549 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1049 AM CDT Thu Oct 11 2018 .NEAR TERM...(Rest of Today) Issued at 1049 AM CDT Thu Oct 11 2018 Shower activity associated with Tropical Storm Michael has moved well east of the region. Other lighter areas of light rain showers not directly associated with the storm were moving southward along the AL/GA border, north of and in the vicinity of I-20. The TS otherwise was located about 35 miles SSE of Charlotte NC heading to the NE around 23 mph. A cold front also moved across the region during the overnight and early morning, and was also east of the region, extending roughly from near Chattanooga to Gadsden and Troy. Colder surface high pressure ridging southward from southern Canada to the High Plains was building to the east. Drier air associated with the high was gradually causing stratus (in a cloud-street like manner) to thin over and near this region. With a return of more solar insolation plus cold air advection occurring, will result in temperatures generally remaining steady from the mid 60s to around 70 into the mid afternoon, before notably cooling towards the early evening. Night time lows into the mid/upper 40s look to be on track for late tonight. The abnormally warm conditions the area has experienced over the past couple of weeks or so is pretty much over for the foreseeable future, with a return of more seasonable conditions. .SHORT TERM...(Tonight through Saturday) Issued at 218 AM CDT Thu Oct 11 2018 A more or less zonal 5h flow pattern will develop over the southern U.S. while a vigorous shortwave drops southeast through the upper Midwest on Friday, and through the OH valley Friday night into Saturday. Another cold front will drop southeast bringing light showers just to our north and northwest Friday night into Saturday. However, strong subsidence behind the shortwave will likely dry the atmosphere sufficiently eroding clouds and rain chances this far southeast. The 5h pattern rapidly becomes zonal again by afternoon. After chilly lows in the m40s-a50 Saturday morning, afternoon highs will only reach the m60s atop the Cumberland Plateau with l70s in valley locations. .LONG TERM...(Saturday night through Wednesday) Issued at 218 AM CDT Thu Oct 11 2018 The brisk zonal 5h flow across the southern U.S. will result in rapid progression of minor shortwaves that eject from the cutoff low that develops over So Cal. This results in moderate overrunning/isentropic ascent across the mid South Saturday night into Sunday. Elevated instability, LLJ of 40-50kt at 850 mb and resulting moisture transport will likely help to form one or more MCS clusters across AR moving into western TN and north MS. Instability and drier air to the east and the best convergence located just northwest of our forecast area brings some uncertainty to how far southeast precipitation will occur. Will go with likely PoPs north and northwest to lower chance southeast from Sunday into Sunday night. On Monday, a shallow cold air mass will drop southeast into the area. With the low level jet weakening, and lack of upper QG forcing, PoPs will go down Monday into Monday night. The shallow nature of the cold air and it's progression will certainly make temperature forecasting difficult for highs Monday. For now, will side above the suggested blend with midday max temps likely to occur. Will go with lower 70s north and west areas with u70s to near 80 likely further southeast before the front arrives. In fact, raw EC and GFS values indicate l80s in our central and southeast areas, so future updates may be needed depending on the speed of the shallow cold layer moving in. Will carry just a slight chance of light showers through Tue morning before drying the forecast out. Lows Tuesday and Wednesday morning will be back down into the 40s to a50 as high pressure at the surface shifts east from the Plains into the OH/TN valleys. Afternoon highs will only recover into the 60s. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 557 AM CDT Thu Oct 11 2018 A cold front moving southeast through middle Tennessee into northwest Alabama will exit by midday. Ceilings of 015-030agl (MVFR) will clear behind the front by midday if not sooner. Northerly sustained flow of 10-12kt is expected and will gust at times to 17-21kt through this afternoon. VFR flight weather conditions are expected this afternoon and tonight. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...RSB SHORT TERM...17 LONG TERM...17 AVIATION...17 For more information please visit our website at weather.gov/huntsville.