Subj : HVYSNOW: Probabilistic He To : All From : Dumas Walker Date : Sat Feb 07 2026 08:57:36 FOUS11 KWBC 070706 QPFHSD Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 206 AM EST Sat Feb 7 2026 Valid 12Z Sat Feb 07 2026 - 12Z Tue Feb 10 2026 ....Northeast & Mid-Atlantic... Day 1... Extreme cold and dangerous wind chills overspread the Northeast tonight and continue through Sunday with Key Messages in effect and linked below. The combination of an arctic cold front current racing through the Ohio Valley/Interior Mid-Atlantic will combine with a strengthening low pressure well offshore to produce extremely cold temperatures and damaging winds for much of the region, with heavy snow for parts of the area as well. A shortwave driving the cold front southward will help generate widespread light snow across New England and Long Island, but total snowfall amounts are expected to be rather modest. Despite that, briefly heavy snow rates combined with the rapidly increasing winds will still result in impacts, especially to travel due to snow- covered roads and low visibility. The greatest impacts, and likely more substantial snowfall, is expected from far SW Maine, SE New Hampshire, and along the eastern Coast of Massachusetts from Cape Ann to Cape Cod where low-level convergence, onshore flow and resulting ocean effect snow (OES) and an inverted trough will all interact to enhance snowfall. There continues to be uncertainty as to where the heaviest snowfall will occur. However, intense snowfall rates of 1-2"/hr are possible (30-60% chance) thanks to intense ascent into a lowering DGZ within the presence of some instability. WPC probabilities are moderate (50-70%) for 4+ inches from the Seacoast of NH through the Boston metro area, with locally more than 8 inches possible (10-30% chance) and as reflected by significant spread amongst the WSE plumes. ....Pacific Northwest and Northern Rockies... Days 1-3... Mid-level trough positioned off the Pacific coast will slowly track eastward today and Sunday, with the primary trough axis finally pushing onshore Sunday night as a shortwave lifts onshore near the CA/OR coast. This shortwave will then continue to track east while deamplifying, reaching the northern High Plains by the end of the forecast period. This trough evolution will be accompanied by a modest subtropical jet streak arcing meridionally downstream to provide overlapping synoptic ascent. This lift will occur into a moistening column as persistent SW flow ahead of the shortwave/trough axis will provide a long duration of IVT exceeding 250 kg/m/s, with IVT max potentially exceeding 500 kg/m/s (50-60% chance) which will lead to two rounds of heavy precipitation extending from Oregon through the Northern Rockies. Snow levels within the strongest IVT plume will be 6000-7000 ft thanks to pronounced WAA, but will steadily fall to 3000-4000 ft Monday as a cold front, driven by the aforementioned trough, progresses southeast. This will allow for heavier and more impactful snow across the Northern Rockies than what is anticipated in the Cascades due to lower snow levels. 2-day WPC probabilities indicate the heaviest snow is expected in the vicinity of Glacier NP in the Northern Rockies where they exceed 70% for 12+ inches, and locally as much as 2 feet is possible in the highest terrain. Elsewhere, WPC probabilities are high (>70%) for 8+ inches across the Absarokas and Tetons near Yellowstone NP, the Blue Mountains of OR, and across the highest peaks of the WA and OR Cascades. Weiss ....Extreme Cold Key Messages are in effect. Please see current Key Messages below... https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png $$ --- SBBSecho 3.28-Linux * Origin: Capitol City Online (21:1/175) .