053 FXUS02 KWBC 060607 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 107 AM EST Thu Nov 6 2025 Valid 12Z Sun Nov 09 2025 - 12Z Thu Nov 13 2025 ...Overview... An amplified upper level pattern will develop across the nation this weekend into early next week with deep troughing over the Eastern U.S. and eastern Pacific and ridging in between over the West. This will allow several strong cold fronts to push south across the Central and Eastern U.S., ushering in much colder temperatures for these regions. Precipitation, some wintry, will focus under the upper trough over the Midwest, Great Lakes, and Northeast while the West and south-Central U.S. remain dry under the upper ridge. The upper level flow should flatten out some by mid-next week as northern stream energy cuts through the ridge in western Canada and dives into the Midwest/Great Lakes. This will continue precipitation chances in the Great Lakes region, and precipitation chances will likely increase along West Coast as well Wednesday and Thursday as two Pacific frontal systems move onshore. ...Guidance/Predictability Assessment... Model guidance continues to show good agreement on the large scale weather pattern through the medium range period, with an expected amount of uncertainty in the details and timing of individual systems. The highest uncertainty will be near the end of the period when there are some timing and position differences with a couple cutoff lows approaching the West Coast. The upper level pattern over the eastern Pacific looks to become quite complicated as the leading cutoff low interacts and is absorbed into the second deep trough/low moving south out of the northern Pacific. The GFS is a bit more west and south with the second low than other deterministic guidance, which is resulting in lower QPF values over the West Coast, northern Rockies, and Great Basin mid-to-late next week. Since this solution was a bit of an outlier, the WPC forecast favored a more east and north position, with higher QPF over the West Coast. Given good overall agreement, the WPC forecast was composed of a near even blend of the deterministic GFS, ECMWF, and CMC through early next week. By mid-next week, ensemble means were added to the blend in increasing amounts to smooth out timing differences with systems in the eastern Pacific. This approach kept good continuity with the previous forecast. ...Weather/Hazards Highlights... A clipper system is forecast to sweep across the Great Lakes and Northeast on Sunday and Monday, accompanied by gusty winds and wintry precipitation chances for these regions and the central/southern Appalachians. Accumulating snow will be possible in the higher elevations of the Appalachians and downwind of the Great lakes. There will also be chances for isolated showers in the Mid-Atlantic and along the Southeast Coast as a trailing cold front pushes across the region, and a few flurries can't be ruled out for the Mid-Atlantic. Lake effect snow will likely continue through early next week downwind of the Great Lakes as mean upper troughing and west- northwesterly winds persist. Then, another clipper-like system is expected to push across the north-Central U.S. and Northeast mid- next week and renew precipitation chances across the Great Lakes and New England. On the backside of the weekend clipper system, a series of successive cold fronts will push south across the Central and Eastern U.S., ushering in a cold and dry Arctic air mass. Temperatures are forecast to drop to 10-20 degrees below average, with sub-freezing lows forecast as far south as the southern Plains and Southeast Sunday and Monday nights. Freezing temperatures and frost may even be possible down to the Gulf Coast Monday night. The coldest temperatures are forecast to be in the northern Plains and Upper Midwest where highs will struggle to rise above freezing and lows will be in the teens, maybe the single digits, this weekend. Meanwhile, strong ridging will dominate the weather pattern across the West through early next week, which will result in dry weather with above average temperatures. Temperatures will generally be 10-15 degrees above average. Above average temperatures are also expected to spread to the Plains early-to-mid next week as a warm front pushes east across the region. Precipitation chances should increase across the West Coast, northern Rockies, and Great Basin mid-next week as two different upper lows and surface frontal systems push onshore, and there may be chances for locally heavy precipitation in the favored terrain along the coast and in the Sierra Nevada. There is some uncertainty in the timing of these systems, which could affect the onset time of precipitation. Dolan 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 $$