Extended Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EDT Fri Oct 30 2020 Valid 12Z Mon Nov 02 2020 - 12Z Fri Nov 06 2020 ...Overview... In the wake of an anomalously strong upper trough moving through the northeastern CONUS early in the medium range period, primarily fast zonal flow set ups across the CONUS next week. Aside from a few weather system impacting the Pacific Northwest, much of the lower 48 will see little in the way of precipitation. Temperatures will initially start off below normal for the eastern U.S. then moderate while the western U.S. stays mostly above normal. ...Guidance Evaluation/Preferences... The large scale upper pattern exhibited average to above average forecast confidence and run to run consistency such that high weights of the deterministic runs of the GFS/ECMWF/CMC/UKMET were utilized for day 3-5. Beyond that time frame, the typical fast bias of the GFS was noted and this led to decreasing use of its deterministic run for day 5-7 while the GEFS was supported more. The ECENS was the favored mean late in the forecast period and offered a good blend staying close to continuity. ...Weather/Hazard Highlights... The respectable cold front in the Midwest early Sun will sweep through the East Coast later in the day, ushering in the coldest air of the season to some areas of the Mid-Atlantic as well as some strong/high winds to portions of the Northeast and New England. Morning lows on Monday may flirt with freezing toward the I-95 corridor with highs only in the 40s through Virginia. Temperatures will moderate Tuesday onward as heights rise and NW winds turn to W and SW by mid week. In the West, temperatures will be about 5-15 degrees above normal to start the period, spreading eastward into the Plains by Tuesday and Great Lakes/Northeast Wednesday/Thursday. The greatest precipitation totals across the CONUS will be found across the Pacific NW, particularly Washington State where a series of atmospheric river events will bring unsettled weather. In the wake of the strong cold front early next week, lake effect snows will be possible downwind of Lake Erie and Ontario. Taylor Additional 3-7 Day Hazards information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards: - Flooding possible across portions of the Mid-Atlantic, the Lower Mississippi Valley, and the Southern Plains. - Flooding occurring or imminent across portions of the Southeast, the Mid-Atlantic, and the Southern Appalachians. - Heavy precipitation across portions of the Alaska Panhandle, Mon-Tue, Nov 2-Nov 3. - Much above normal temperatures across portions of mainland Alaska, Mon, Nov 2 and Fri, Nov6. - Much below normal temperatures across portions of mainland Alaska, Mon-Thu, Nov 2-Nov 5. - Much below normal temperatures across portions of the Alaska Panhandle and mainland Alaska, Tue-Fri, Nov 3-Nov 6. WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation, winter weather outlook probabilities and heat indices are at: 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/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml