Extended Forecast Discussion NWS Weather Prediction Center College Park MD 200 AM EST Sun Nov 22 2020 Valid 12Z Wed Nov 25 2020 - 12Z Sun Nov 29 2020 ...Overview and Guidance Evaluation... The WPC medium range product suite was mainly derived from a blend of best clustered guidance and continuity as per the 12 UTC ECMWF/UKMET, but did include a touch of the 12 UTC Canadian/ECMWF ensemble mean and 18 UTC GFS to smooth less predictable smaller scale details. This yielded a solution in line with recent guidance trends and maintains good WPC continuity in a pattern with near average predictability. The ECMWF/UKMET show ample system amplitudes and stream separations while the ECMWF ensemble mean is the most amplified of the ensemble means. Recent GFS runs have been on the more progressive side of the full forecast envelope and recent Canadian runs have showed poor run-run continuity. ...Sensible Weather and Hazards... A separated southern stream shortwave trough/low aloft and well organized surface low pressure/frontal system will produce a progressive swath of moderate rainfall over the eastern third of the nation Wed, lingering into New England into Thu before exiting with approach of an amplified northern stream trough. Upstream, progressive but energetic flow aloft will deliver another round of unsettled weather through midweek over the Northwest to include rain and higher elevation snows with highest totals over the Cascades and a secondary maximum into the Northern Rockies. Trough/closing low energies aloft in an emerging and separated southern stream are slated to dig down through the West later week along with potential some organized precipitation. System ejection and downstream cyclo/frontogenesis along with increasingly deep return moisture from the Gulf of Mexico should then promote enhanced to locally heavy rainfall next Fri/Sat with a focus across the Deep South. Schichtel 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 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