872 FXUS63 KIND 101121 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 621 AM EST Wed Feb 10 2021 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 408 AM EST Wed Feb 10 2021 Today will bring chance for snow across the area with total accumulations of 1 to 2 inches possible in northern central Indiana and up to an inch in the south. More chances for snow are possible this weekend and again early to mid next week. Below normal temperatures will continue throughout the forecast period with the start of next week set to be some of the coldest days. && .NEAR TERM /Today/... Issued at 408 AM EST Wed Feb 10 2021 Radar and surface observations show that scattered light precipitation is starting to move into southern Indiana as of the early morning hours. This precip will expand northward through the morning. An upper jet over the Ohio Valley will interact with a baroclinic zone and subtle isentropic lift in the mid to low levels that is bringing in the precipitation today. Warm moist air from the south will overrun cold northerly air at the surface. For most of central Indiana, temperature profiles will remain entirely below freezing but in the south freezing rain may mix in at times where the warm nose aloft has a better chance of getting above freezing. The more significant impacts with this system are slated to stay further south, for our neighbors in Kentucky. While our souther tier of counties could see some ice mix in, we are not expecting much in the way of ice accumulations. Will continue to monitor conditions through the day, keeping an eye on how far north above freezing temperatures reach. If they do push further north than currently forecasted, icing impacts could creep into our forecast area. Later in the day, a deformation band is expected for form north of I- 70. This band will create an area of enhanced lift and higher QPF and snowfall totals, of 1 to 2 inches, for the northern half of the forecast area. At the surface, temperatures today will range from the low 20s in the north to the upper 20s in the south. && .SHORT TERM /Tonight through Thursday Night/... Issued at 408 AM EST Wed Feb 10 2021 The system impacting the region today will start to slowly push out of the area tonight into Thursday. Light snow will continue to be possible into Thursday but with minimal moisture, additional snow accumulation is not really expected beyond tonight. Models show that the band of moisture will stay to the south in Kentucky and Tennessee during the short term period as the surface boundary becomes more stationary across the SE states. Any lingering precipitation should completely move out by tomorrow night as the boundary pushes further SE and surface high pressure to the NW stretches into the area and dries up the atmospheric column. Below normal temperatures will continue through the period with highs in the 20s and lows in the teens. && .LONG TERM /Friday through Tuesday/... Issued at 240 AM EST Wed Feb 10 2021 The main storyline for the extended remains focused on the continued cold and active pattern for much of the eastern part of the country...with another surge of bitterly cold air for the weekend into early next week as a piece of the polar vortex swings across the Great Lakes along with the potential for additional wintry mischief into early next week. A continued blocky and amplified flow pattern aloft will keep the region stuck in a pattern conducive for continued cold and multiple opportunities for snow into early next week. The two lobes of the polar vortex over central Canada late this week will eventually coalesce then swing south and east across the Great Lakes and northeast by early next week...carving out a deeper parent trough across the eastern half of the country and essentially opening the door for a renewed push of bitterly cold air to advect south into the region for this weekend and early next week. At the surface...the Ohio Valley will remain between a large area of strong high pressure dropping down the east side of the Canadian Rockies and a stagnant frontal boundary over the Southeast states early in the period with the high becoming the primary feature influencing our weather by late Saturday into early next week. Extended model guidance continues to struggle with the level of phasing between energy diving south with the PV lobe and just how much it interacts with the leftover boundary extending from the Gulf Coast to the Mid Atlantic region. At this point...think potential certainly exists for some snow at times over the weekend but leaning towards a less phased setup with lighter snows and accumulation. A more interesting setup begins to take shape early next week as the PV lobe kicks out to the northeast and focus turns towards an upper wave amplifying over the Intermountain West this weekend. As this feature traverses east into Monday and Tuesday...there does appear to be a higher ceiling for energy phasing aloft between the polar and subtropical jets and subsequently...a potential for a deeper surface wave over the region. With the strong surface high still present north of the Ohio Valley...there is a threat for a more substantial winter storm to impact the area with snow and/or ice as plenty of the remnant arctic airmass from the weekend remains. Another factor that will likely influence how this plays out is the position of the southeast ridge and whether it flexes enough to draw warmer air aloft into the region above a shallow cold airmass. There are a lot of moving parts here and we remain several days out...but the potential for a higher impact winter storm does appear to be growing for early next week. Temperatures over the weekend will rival the cold blast from this past weekend with highs bottoming out in the single digits and teens on Sunday and subzero lows possible in some parts of the forecast area both Saturday and Sunday nights. Some temperature recovery will develop by early next week but the overall temperature trend will remain well below normal for mid February. && .AVIATION /Discussion for 101200Z TAF Issuance/... Issued at 621 AM EST Wed Feb 10 2021 IMPACTS: MVFR conditions developing with light snow this morning and continuing through this evening. IFR conditions possible this afternoon at KBMG. Snow will diminish in coverage tonight but MVFR ceilings will linger through daybreak Thursday. DISCUSSION: Light precipitation is expanding north early this morning as low pressure tracks into the Tennessee Valley. The precipitation will overspread central Indiana through midday from south to north primarily in the form of light snow. There is a small possibility of freezing rain briefly mixing in at KBMG later this morning...but confidence is far too low to include in the forecast at this time. Snow coverage will peak this afternoon across the region with MVFR conditions. IFR ceilings may develop at KBMG for several hours this afternoon and evening. Snow will diminish in coverage by late evening with just scattered pockets of light snow overnight. Expect visibilities to recover to VFR but ceilings will likely remain in the MVFR category through daybreak Thursday. Northeast winds around 10kts are expected through much of the forecast period. CONFIDENCE: High confidence in light snow impacting the terminals this morning through this evening. High confidence in MVFR conditions with medium confidence in IFR conditions this afternoon and evening at KBMG. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...KH NEAR TERM...KH SHORT TERM...KH LONG TERM....Ryan AVIATION...Ryan