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   FOUS11 KWBC 181939   
   QPFHSD   
      
   Probabilistic Heavy Snow and Icing Discussion   
   NWS Weather Prediction Center College Park MD   
   239 PM EST Wed Feb 18 2026   
      
   Valid 00Z Thu Feb 19 2026 - 00Z Sun Feb 22 2026   
      
      
   ...Pacific Northwest...   
   Day 1...   
      
   The longwave trough responsible for the recent mountain snowfall   
   will continue to influence the the region through tomorrow morning.   
   Following this, an upper-level ridge is expected to build late   
   Thursday and persist into Saturday, bringing a pause to the active   
   pattern. Snow levels along the I-5 corridor will dip toward 500ft   
   again tomorrow morning, though the most impactful moderate-to-   
   locally heavy accumulations will remain confined to higher elevations   
   of the southern Washington, Oregon Cascades, and the southern   
   Oregon coastal ranges.   
      
   ...California...   
   Days 1-2...   
      
   ...Heavy, disruptive snowfall for the California ranges to persist   
   through tomorrow...   
      
   A pair of phasing shortwaves diving southeast from the Pacific   
   Northwest coast will support intensifying snowfall across the   
   California ranges tonight into tomorrow. The heavy snowfall threat   
   will begin to wane late tomorrow as upper-level ridging begins to   
   build and remains in place into the weekend.   
      
   Additional snowfall of 1-2 feet is likely for the northern Sierra   
   Nevada above 3,000ft, while the southern Sierra could see several   
   more feet above 4,000ft. The WSSI continues to indicate Major   
   Impacts for nearly all of the Sierra Nevada above 4,000ft through   
   Thursday, including Donner Pass. In the Shasta/Siskiyou region,   
   Moderate to locally Major impacts are possible along the I-5   
   passes. For Southern California, additional accumulations of a foot   
   or more are possible for the higher elevations of the Transverse   
   and northern Peninsular ranges.   
      
      
   ...Intermountain West/Southwest to the Rockies...   
   Days 1-2...   
      
   Pacific moisture spilling over the Cascades and Sierra Nevada will   
   contribute to the Intermountain and Rocky Mountain snowpack. While   
   a brief lull is expected tomorrow for some areas, Nevada and the   
   Four Corners region will see a continued snow threat into Friday   
   as the next shortwave arrives. WPC Probabilities indicate that   
   additional snow accumulations exceeding 8in are likely (greater   
   than 50 percent) for the high elevations of the Nevada and   
   southern Utah mountains, the northern to central Arizona plateaus   
   (including the Mogollon Rim), the Arizona White Mountains, and the   
   central Rockies - specifically the northern Utah and western   
   Colorado ranges.   
      
      
   ...Northern Plains & Upper Great Lakes...   
   Day 1...   
      
   Potent winter storm ongoing today will gradually spin eastward and   
   weaken by Friday morning. Around this system, heavy snow   
   will continue in response to impressive WAA beneath a TROWAL   
   across the U.P. of MI and the Arrowhead of MN, with additional   
   light snow persisting within an elongated inverted trough extending   
   into North Dakota. While additional snowfall across ND/western MN   
   should be light (WPC probabilities less than 10% for 4+ inches),   
   heavy snow will continue into the Arrowhead through Thursday   
   morning. This will be the axis of heaviest snow thanks to its   
   position beneath the TROWAL, aided by lake moisture and persistent   
   upslope flow into the Iron Ranges. Here, WPC probabilities are high   
   (>70%) for an additional 6 inches after 00Z this evening, bringing   
   storm total snowfall to more than 2 feet in some areas.   
      
      
   ...Northeast...   
   Days 2-3...   
      
   A strengthening surface low moving across the Great Lakes Friday   
   will slow as it becomes vertically stacked beneath its associated   
   closed mid-level low. Downstream warm advection emerging from the   
   Gulf will surge a warm front northeast into the Mid-Atlantic, with   
   the subsequent occlusion and triple point resulting in secondary   
   low development near the eastern Ohio Valley/eastern Great Lakes   
   Friday evening. This secondary low will track only very slowly   
   eastward as the parent shortwave gets sheared into the more   
   confluent westerlies, but this mid-level westerly flow will help   
   translate an expanding precipitation shield eastward across the   
   Northeast through Saturday.   
      
   During this evolution, WAA on 850mb SW flow emerging from the Mid-   
   Atlantic and overrunning the surface warm front will expand the   
   aforementioned precipitation shield northeastward Friday and Friday   
   night. As this occurs, a weak high pressure will retreat, and the   
   antecedent airmass is marginally conducive for winter   
   precipitation, so precipitation may initially be rainfall,   
   especially for the Mid-Atlantic and into southern New England,   
   before transitioning to mixed and then snow, especially farther   
   north and east. The key thermal evolution will occur as yet a third   
   surface low develops well offshore New England along the warm   
   front/stationary front, which will help manifest a switch in wind   
   direction to the N/NW and subsequent cold advection to cool the   
   column. This will help transition precipitation to all snow from   
   Upstate NY through New England, and although there is some concern   
   about dry air near the top of the DGZ limiting snow growth, there   
   is expected to be sufficient ascent for moderate snowfall (briefly   
   heavy during the greatest fgen during the early stages of this   
   event Friday evening).   
      
   The heaviest snowfall is expected between 18Z Friday and 12Z   
   Saturday, with light snow continuing in some areas through Sunday   
   morning as a secondary vorticity impulse swings southward across   
   the area. While this will lengthen the duration of snowfall,   
   additional accumulations after 12Z Saturday should be relatively   
   light which is reflected by modest growth of the WSE plumes. While   
   the duration of the most intense forcing will be limited, WPC   
   probabilities indicate a moderate risk (50-70% chance) of at least   
   6 inches in the higher terrain of the Adirondacks, Greens,   
   Whites, and Monadnock region of NH, with widespread 4+ inches   
   likely (70-90%) across much of central New England and northern   
   Upstate NY. Locally as much as 10 inches is possible in the highest   
   elevations before precipitation ends by the end of the forecast   
   period.   
      
      
   ...Central Plains into the Great Lakes...   
   Days 1-3...   
      
   A shortwave emerging from the Great Basin will amplify into a   
   negative tilt as it crosses the Central Rockies and into the   
   Central Plains late tonight into Thursday morning. This feature may   
   continue to deepen into a closed low as it moves over the Corn Belt   
   Thursday night, with the overlap of these height falls/PVA and the   
   LFQ of a strengthening subtropical jet streak leading to surface   
   cyclogenesis in the lee of the Rockies. This low will then track   
   E/NE towards the Great Lakes by Friday morning, with substantial   
   deepening possible in the favorable synoptic setup.   
      
   The guidance has trended slightly deeper with this low, with a   
   subtle NW jog in the track from IA to MI, but the ensembles are   
   very well aligned leading to high confidence in this development.   
   Downstream of this low, moisture will stream northward from the   
   Gulf, and although the highest PW anomalies (above the 90th   
   percentile according to NAEFS) will remain east of the region, the   
   accompanying theta-e ridge will rotate cyclonically back into the   
   system as a modest TROWAL on Thursday. At the same time, increasing   
   850-600mb fgen behind a cold front, and overlaid with an   
   impressive deformation axis NW of the surface low in response to   
   the deepening mid-level wave will drive ascent into the TROWAL,   
   suggesting an increasing potential for a band of heavy snow from   
   western Nebraska into the western U.P. of MI. While there is still   
   uncertainty into the exact placement of this narrow corridor of   
   heavy snowfall, this band will likely (>60% chance) contain at   
   least 1"/hr snowfall thanks to CSI noted in regional cross-   
   sections, so should accumulate rapidly despite the transient nature   
   of the system.   
      
   This is reflected by WPC probabilities that range from 50-90% for   
   4+ inches from the Pine Ridge of NE through western IA, with   
   locally as much as 8 inches possible (30-50%). Lighter snowfall   
   (10-30% chance for 4+ inches) is possible from northern IA through   
   the western U.P. of MI, but if the deeper trends continue these   
   probabilities could also shift upward, and there are already a few   
   WSE members showing much higher snowfall potential.   
      
   As this low pressure fills and then redevelops along an   
   occlusion/triple point farther east, a lingering inverted trough is   
   progged to drape from the center of the low back to the NW into the   
   U.P. of MI and Arrowhead of MN. This will drive locally enhanced   
   ascent into Saturday, with N/NW flow in the vicinity creating some   
   lake enhancement along the south shore of Lake Superior in the   
   U.P. of MI. Forcing for ascent generally wanes with time on D3, so   
   despite the cold column and deep DGZ leading to fluffy SLRs, WPC   
   probabilities suggest only a modest potential (30-50%) of 4+ inches   
   of snowfall, highest across the western U.P. of MI.   
      
      
   Weiss/Pereira   
      
      
   $$   
      
   = = =   
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