Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 140 PM EST Mon Nov 15 2021 Valid 00Z Tue Nov 16 2021 - 00Z Thu Nov 18 2021 ...Heavy rain and mountain snow culminate today over the Pacific Northwest before tapering off tonight... ...A rapidly intensifying low pressure system will bring very high winds across the northern Rockies today and through the northern Plains on Tuesday into early Wednesday... ...Areas of Lake Effect enhanced snow downstream of the Great Lakes will gradually taper off as low pressure system exits New England... The tail end of prolonged Atmospheric River event into Washington is coming with one last strong push as strengthening surface low across British Columbia helps to accelerate a cold front through the Pacific Northwest through the early overnight hours tonight into Tuesday morning. Due to saturated grounds much of the rainfall is running off adding to swollen rivers across much of Western Washington and the Northern Washington Cascades. Given the rapid deepening of the low, strong cold winds will support rapidly reducing freezing levels across the Olympic, northern Cascade and northern Rockies of ID/MT through tonight supporting heavy snowfall with 4-8+" in the highest elevations of the Washington Ranges, with 1-4" across the Northern Rockies. The storm continues to deepen extreme downslope winds are expected along the northern MT frontal range with 50-70 mph sustained winds with gusts of 80-100 mph possible today into tomorrow. While off the range into north-central MT, winds of 30-50 gusts to 70 mph will expand eastward into western ND by Tuesday, resulting in High Wind Warnings and Red Flag fire concerns. Winds will remain elevated as the very strong low pressure center tracks across southern Canada, through Wednesday, reducing to 15-30 mph. The only positive is the strong down sloping will expand well above average temperatures across the Rockies, High Plains and into the Plains today and Tuesday with high temperatures 20-40 degrees above normal. By late Tuesday into Wednesday, the associated cold front will emerge across the northern high plains and bring temperatures to slightly below average (10-15 degrees) for Wednesday's highs. Still, the warm up will slide eastward across the Mississippi, Ohio Valleys into the Great Lakes, head of the front though upper 60-70s are expected, about 10-15 degrees above average. Rainfall is expected to be very light along the front by Wednesday but this system is otherwise bone dry until then, with only precipiation generally across Canada. Along the eastern U.S., cooler air is in place as the cold front has crossed off the East Coast as the low deepens across the Canadian Maritime. Today's and tomorrow morning's temperatures will be below normal (10-20 degrees) behind the front. Lingering Lake Effect plumes downstream of Lake Erie and Ontario are likely to produce a few inches of snow, but will taper off by late Tuesday. A steady warm up is expected by late Tuesday into Wednesday from the Ohio Valley to New England respectively. Gallina Graphics are available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php