TZUTC: 0000   
   MSGID: 168562.weather@1:2320/105 2dcfb979   
   PID: Synchronet 3.21a-Linux master/123f2d28a Jul 12 2025 GCC 12.2.0   
   TID: SBBSecho 3.28-Linux master/123f2d28a Jul 12 2025 GCC 12.2.0   
   BBSID: CAPCITY2   
   CHRS: ASCII 1   
   FORMAT: flowed   
   FOUS11 KWBC 141935   
   QPFHSD   
      
   Probabilistic Heavy Snow and Icing Discussion   
   NWS Weather Prediction Center College Park MD   
   235 PM EST Wed Jan 14 2026   
      
   Valid 00Z Thu Jan 15 2026 - 00Z Sun Jan 18 2026   
      
      
   ...Upper Midwest through Northeast, and the Appalachians...   
   Days 1-3...   
      
   The longwave trough in place across the eastern CONUS will   
   repeatedly reload into the weekend, becoming increasingly amplified   
   as shortwaves periodically drop south out of Canada and rotate   
   through the trough and then off the east coast. The core of this   
   trough will deepen most impressively over the Gulf Coast Thursday   
   aftn (ECMWF 500mb heights as low as the 0.5 climatological   
   percentile). Within this progressive flow, even as these lead   
   impulses rotate away on Friday, the next shortwave trough will   
   follow immediately in its wake, moving from the Northern Plains to   
   the Mid-Mississippi Valley Friday night. Similar to the Southeast   
   on Thursday afternoon, 500mb heights over the Missouri River Valley   
   are likely to be as low as the 0.5 climatological percentile.   
      
   In addition to producing true winter cold air across much of the   
   eastern 1/3 of the CONUS, and potentially some of the coldest wind   
   chills of the season, widespread snow is likely from the Upper   
   Midwest through the Tennessee Valley and back northeast through the   
   Central Appalachians and into the Northeast. While most of this   
   snow will be more "conversational" and light than impactful, there   
   are a few areas that will experience more significant snowfall.   
      
   Great Lakes: Periods of lake effect snow (LES) are likely each day   
   as persistent cyclonic flow and periodic shortwaves/fronts renew   
   CAA across the lakes. The heaviest LES is likely D1, especially   
   downwind of Lake Michigan into northern Indiana where, despite some   
   modest longitudinal fluctuations in the axis from the most recent   
   model runs, a long fetch north-south across Lake Michigan should   
   result in a narrow and intense single band of snow into far SW MI   
   and northern IN. Here, HREF probabilities for 1+"/hr snowfall peaks   
   above 60% for much of D1, and with locally 2-3"/hr snowfall rates   
   possible, WPC probabilities support a high risk (>70%) for more   
   than 12", and locally up to 20 inches is possible. Elsewhere, heavy   
   snowfall is likely south of Lake Erie along the Chautauqua Ridge   
   where WPC probabilities indicate a moderate risk (30-50%) for more   
   than 12 inches. Otherwise, while LES will be periodic and briefly   
   intense at times all 3 days, additional snowfall in other areas   
   should generally be around 6 inches or less, especially southeast   
   of Lake Ontario and across portions of the U.P. of MI.   
      
   Central Appalachians: The passage of an arctic front associated   
   with the lead shortwave will quickly cool the column to change   
   precipitation from rain to snow, with post-frontal gusty westerly   
   winds leading to pronounced upslope flow. Regional soundings   
   suggest favorable ascent into steepening lapse rates and elevated   
   low-level moisture to support heavy snow rates from the higher   
   elevations of NC near the Smoky Mountains northward through the   
   Central Appalachians of WV and into the Laurel Highlands. Guidance   
   has trended a little wetter and more intense with this event, and   
   WPC probabilities now reflect a high chance (>70%) for more than 6   
   inches in the higher terrain, generally above 3000 ft, across this   
   region on D1. Light snow showers will likely continue, although   
   with minimal additional accumulations on D2, but renewed upslope   
   flow with a secondary front D3 could again result in a few inches   
   of snow (WPC probabilities above 30% for 4+ inches) across the   
   higher elevations from NC to WV once again.   
      
   Interior Northeast: A surface low pressure moving across PA tonight   
   will continue to push northeast, reaching Atlantic Canada by   
   Friday morning. This low will be accompanied by modest warm/moist   
   advection to spread precipitation across Upstate New York and   
   northern New England. While the guidance has trended north to focus   
   the heaviest snowfall across Canada, a modest TROWAL pivoting   
   westward behind this low and interacting with an inverted surface   
   trough elongated from the primary low will pivot some heavier   
   snowfall tonight through Thursday aftn. Brief snowfall rates in   
   excess of 1"/hr are possible (10-30%) across the Adirondacks,   
   northern VT, and near Lake Ontario tonight before lifting northeast   
   through Thursday. As the low pulls away, some upslope snow on   
   increasing NW winds may also lead to heavier rates across the   
   Adirondacks and Greens. WPC probabilities across this area are   
   moderate (30-70%) for 8+ inches of snow through Friday, with the   
   greatest accumulations likely near the St. Lawrence Valley, the   
   Adirondacks, and the northern Greens.   
      
      
   ...Northern/Central Plains...   
   Day 2...   
      
   A potent shortwave and accompanying vorticity lobe will drop   
   rapidly southward out of Saskatchewan/Manitoba into the Dakotas and   
   then continue to dig southeast reaching the Mid-Mississippi Valley   
   by 00Z Saturday /end of D2/. This feature will drive an arctic cold   
   front southward, and the overlap of modest, but transient, height   
   falls, PVA, and low-level convergence along the front will   
   manifest as periods of snow showers, with coverage and snowfall   
   amounts limited by below-normal PWs and ongoing CAA. However,   
   impressively strong winds within the PBL and exceptionally steep   
   low-level lapse rates will encourage any snow showers to be   
   accompanied by gusty winds, and where low-level fgen combines with   
   modest 0-2km CAPE of 100-200 J/kg, convective snow showers may   
   result. While the duration and coverage of these may be limited, as   
   reflected by most simulated reflectivity, any of these snow   
   showers will likely include limited visibility and brief heavy snow   
   rates. This could produce hazardous travel as reflected by 30-50%   
   chance for moderate impacts from the WSSI-P despite snowfall   
   amounts that will likely (>70% chance) be less than 2 inches from   
   the Dakotas into western Minnesota and down into Nebraska/Iowa.   
      
      
   The probability for significant ice across the CONUS is less than   
   10%.   
      
      
   Weiss   
      
      
   $$   
      
   = = =   
   To unsubscribe from WX-STORM and you already have a login, go to   
   https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email   
   Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.   
      
   --- SBBSecho 3.28-Linux   
    * Origin: Capitol City Online (1:2320/105)   
   SEEN-BY: 4/0 19/10 88/0 90/0 93/1 104/119 105/81 106/201 114/10 120/302   
   SEEN-BY: 128/187 129/14 153/757 7715 154/10 30 50 110 700 218/700   
   SEEN-BY: 218/840 220/10 20 30 90 221/1 6 360 226/18 30 44 50 227/114   
   SEEN-BY: 229/110 134 206 300 307 317 400 426 428 470 664 700 705 266/512   
   SEEN-BY: 291/111 301/1 320/219 322/757 335/364 341/66 200 342/200   
   SEEN-BY: 396/45 460/58 633/280 712/848 880/1 900/0 102 106 902/0 19   
   SEEN-BY: 902/26 904/0 13 905/0 2320/0 105 304 3634/12 5019/40 5020/400   
   SEEN-BY: 5075/35   
   PATH: 2320/105 154/10 221/6 341/66 902/26 229/426