752 FXUS64 KHUN 080936 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 336 AM CST Sat Feb 8 2020 .NEAR TERM...(Today) Issued at 336 AM CST Sat Feb 8 2020 A potentially messy start to the weekend is unfolding, as an upper level disturbance over the Ozarks region heads eastward. SE of it in an upgliding environment, precipitation was forming over the MS/AL border near the I-22 corridor heading eastward. With air temperatures at or below freezing over our southern middle Tennessee counties, as well as eastern Madison and points east, an accumulation of wintry precipitation is possible this morning. As such, we are continuing the Winter Weather Advisory for Franklin county TN, Jackson, Marshall and DeKalb counties in AL until 11 AM. Locations west of there were generally above freezing, so not expecting as much issues except for short term wet bulbing when the precipitation starts. The shorter term models were in generally good agreement with this next system, quickly moving it and precipitation associated with it east of the area by the early afternoon. Temperatures also will warm as the system exits the region, with highs by the later afternoon ranging from the mid/upper 40s east to lower 50s west. .SHORT TERM...(Tonight through Monday) Issued at 336 AM CST Sat Feb 8 2020 Another chilly night is in store as clouds clear the region and radiational cooling brings low temperatures into the lower 30s. Sunny skies Sunday morning, will become partly cloudy in the afternoon. A return southerly flow will help boost high temperatures from the mid/upper 50s east, to the lower 60s west. Unfortunately, a "dry spell" on Sunday will be a short lived affair, as more wet weather is on the way to start a new week. A strong upper level system now moving over Washington state will move southward along the west coast, producing another amplified pattern over the lower-48. This upper system will send a disturbance eastward, that should form into a surface low over the northern Rockies, which should move towards the Great Lakes region during Mon/Tue. A cold front trailing SW of this low will approach the Tennessee Valley during Monday. A strong moisture return from the Gulf of Mexico, and upglide ahead of the front will bring more showers to the area beginning Sunday night. Widespread to numerous showers and a few thunderstorms are forecast across the area on Monday and Monday night. Forecast soundings from the NAM/GFS both point at 1.3 to over 1.4 inches of precipitable water amounts on Monday, which is nearly wet as it can get this time of year. Given that the area has had very heavy rainfall only a couple of days ago, soil moisture content on Monday will be very wet to saturated. Thus a good chance for more hydrological issues, not limited to more rises in area streams, creeks, and rivers, areal and flash flooding. We send out a Hydrologic Statement this issuance, with Flash Flood or Flood Watches likely in further forecasts. .LONG TERM...(Monday night through Friday) Issued at 336 AM CST Sat Feb 8 2020 A rather soggy pattern will continue into the extended forecast, really the last thing we need at this point. By Tuesday, a frontal boundary is expected to temporarily stall somewhere near or just south of the Tennessee River, and this boundary will provide enough forcing to keep chances for showers going through Wednesday. Given some weak instability, would not rule out a few embedded rumbles of thunder both Tuesday and Wednesday afternoon. Temperatures will be on the mild side, with highs in the upper 50s and lows in the mid to upper 40s. As previously mentioned, models begin to diverge a bit on Thursday. The ECMWF lifts the sfc warm front a bit farther north than the GFS late Wednesday, which would possibly give us a brief break from the rain Wednesday evening. The front then returns to the CWFA by Thursday morning, bringing another round of heavy rain before exiting to the east Thursday afternoon. The GFS holds the stalled sfc boundary along the northern half of AL through Thursday morning, before slowly drifting south and eventually east as an upper lobe of vorticity provides enough forcing to usher this system out. This solution would likely result in periods of heavy rainfall amounting around 2" through Thursday afternoon. Have decided to stick with blended/WPC guidance given the uncertainty, with the highest PoPs and rainfall totals expected late Wednesday through Thursday afternoon. When all is said and done, it looks like we will pick up an additional 4-6" of rain next week, with perhaps some locally higher amounts depending on where the heaviest bands form and the evolution of the sfc boundary. This will only further exacerbate areal and river flooding, and could also lead to some localized flash flooding during periods of heavier rain. Residents in flood prone areas near rivers/creeks need to monitor the forecast for updates as we get closer to next week. The end of the week looks to be a bit more on the dry side, thankfully, with temperatures close to seasonal norms. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1049 PM CST Fri Feb 7 2020 No changes from previous aviation forecast reasoning, as the primary concern overnight remains an upper-lvl disturbance which will dig southeastward into the Mid-South region by 12Z. Strengthening warm/moist air advection ahead of this feature will generate sufficient lift for the development of lgt RA/SN during the early morning hours, and we have included this weather element in the TAFs btwn 08-12Z/MSL and 10-14Z/HSV. Minor vsby reductions to around 5SM and bkn-ovc MVFR cigs in the 1500-2500 ft range will also accompany the precipitation. A cold front will cross the region late Saturday morning, veering sfc flow to WNW by 15Z/MSL and 17Z/HSV. Conditions will improve following fropa, with a return to VFR conditions anticipated btwn 17-19Z. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...Winter Weather Advisory until 11 AM CST this morning for ALZ008>010. TN...Winter Weather Advisory until 11 AM CST this morning for TNZ097. && $$ NEAR TERM...RSB SHORT TERM...RSB LONG TERM...25 AVIATION...70/DD For more information please visit our website at weather.gov/huntsville.