Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
442 FXUS02 KWBC 080600 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 100 AM EST Mon Dec 8 2025 Valid 12Z Thu Dec 11 2025 - 12Z Mon Dec 15 2025 ...A shot of quite cold air has been saved for portions of the Northern Plains, Midwest, and Ohio Valley this weekend... ...Overview... A broad upper level trough with reinforcing shortwaves will continue to dominate areas east of the Rockies with broad ridging persisting along the West Coast through this weekend, though the amplitude of both appears to be weakening. While the heavy precipitation and high wind threat fades in the Northwest, cold weather and clipper systems will be favored in this pattern east of the Rockies with enhanced northern tier wind/snow chances and following lake effect snow in the lee of the Great Lakes. ...Guidance/Predictability Assessment... While detail issues remain with shortwaves and resultant ridge/trough strength, the guidance is in much better agreement than last night. A general model compromise worked out well for the pressures/fronts/500 hPa heights. This led to the 01z NBM being more useful, though its struggle with reasonable QPF magnitude near the Great Lakes and wind (in general) remains real. ...Weather/Hazards Highlights... As the heavy precipitation/wind threat across the Northwest slowly fades, the Marginal Risk across western WA remains to account for saturated soils from heavy rains that have shifted into the short range period for day 4/Thursday. To the east, clipper systems/disturbances rounding the base of the trough will bring rounds of precipitation, mainly snow, over a cold northern Plains and Midwest, Great Lakes/Appalachians, and the Northeast next week. Reinforcing fronts slow as they approach Florida and help solidify the polar front across the Caribbean Sea, but each leads to a threat rain near the Gulf Coast/Florida. A strong temperature gradient is forecast across the High Plains Thursday into early next week with 15-25F above average temperatures across the West and 20-30F below average temperatures Friday through this weekend from the Northern Plains across the Great Lakes, Midwest, and Ohio Valley. Roth Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw $$