TZUTC: 0000   
   MSGID: 166887.weather@1:2320/105 2d87d433   
   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 210718   
   QPFHSD   
      
   Probabilistic Heavy Snow and Icing Discussion   
   NWS Weather Prediction Center College Park MD   
   218 AM EST Fri Nov 21 2025   
      
   Valid 12Z Fri Nov 21 2025 - 12Z Mon Nov 24 2025   
      
      
   ...California & Southern Rockies...   
   Days 1-3...   
      
   A Pacific upper low near the central CA coast this morning will   
   continue to drop south-southeastward today into a position just   
   west of the northern Baja Peninsula by early Saturday. A   
   combination of healthy PVA, upslope flow, and a modest moisture   
   feed will promote periods of snow for the southern Sierra and SoCal   
   ranges today (San Rafael/San Gabriel/San Bernadino/San Jacinto).   
   Snow levels will continue to tick downward to between 5500-6000ft.   
   With the upper low so far south of the region by tomorrow, the   
   colder temperatures aloft will be displaced southward and   
   diminished upslope flow will reduce precipitation rates. Snow   
   levels will rise and change snow to rain below 7000ft before ending   
   midday Saturday. The upper low will begin to push eastward   
   Saturday night through Sunday and spread moisture across AZ into NM   
   and CO with snow at high elevations (generally above 8000-9000ft).   
   The upper low will pick up speed Sunday evening and lift through   
   CO and weaken into an open wave over the High Plains by early   
   Monday. Along and near its path, modest snow is expected over the   
   San Juans and Sangre de Cristos but snow levels will remain high   
   through the event (no lower than about 7500ft which will be at the   
   end of the event).   
      
   WPC probabilities for an additional 6 inches of snow today are   
   >50% above about 10,000ft over the southern Sierra. Across the   
   SoCal Mountains, with a longer duration of precipitation today, a   
   significant heavy/wet snowfall is likely to continue. WPC   
   probabilities for an additional 6 inches of snow are >50% above   
   8000ft. This could cause locally significant travel disruptions   
   over these higher elevations, along with the potential for some   
   tree damage and infrastructure impacts given the heavy/wet   
   consistency of the snowfall. The WSSI does depict some Moderate to   
   locally Major Impacts in the San Gabriel and San Bernadino   
   Mountains above 8,000ft.   
      
   In the Southern Rockies, WPC probabilities for at least 8 inches   
   of snow primarily on Day 3 (Sunday) are >50% above about 11,000ft   
   in the more remote/higher ridge lines of the San Juans and   
   especially the Sangre De Cristo range.   
      
   ...Pacific Northwest...   
   Day 3...   
      
   Quasi-zonal flow out of the Northern Pacific will bring in a   
   rather strong frontal system to WA/OR/ID and northwestern MT   
   Sunday. Snow levels around 5000-6000ft Sunday afternoon will drop   
   to below 3000ft by early Monday as precipitation lightens. Some   
   significant snow may impact the higher passes where WPC   
   probabilities for at least 6 inches of snow are >50% above about   
   4000-4500ft. Snow will also spread across northern ID into   
   northwestern MT late Sunday/early Monday with snow continuing   
   beyond this forecast period.   
      
   ...Northeast...   
   Day 3...   
      
   A clipper system associated with a shortwave and dip in the jet   
   stream will push quickly through southern Ontario/Quebec and   
   northern NY/New England Sunday afternoon/evening. QPF amounts   
   appear light, and generally only an inch of two of snow is   
   expected. WPC probabilities for at least 4 inches of snow are less   
   than 10 percent, though the NBMexp (v5.0) probabilities max out   
   between 15-25% over the northern Green Mountains of VT.   
      
      
   The probability of significant ice across the CONUS is less than   
   10 percent.   
      
   Fracasso   
      
      
   $$   
      
   = = =   
   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: capitolcityonline.net * Telnet/SSH:2022/HTTP (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: 229/110 206 300 307 317 400 426 428 470 664 700 705 266/512   
   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