Extended Forecast Discussion NWS Weather Prediction Center College Park MD 158 AM EST Sat Dec 05 2020 Valid 12Z Tue Dec 08 2020 - 12Z Sat Dec 12 2020 ...Overview... An closed upper low is forecast to drop south and settle west of Baja California next week, cut off from flow overtop before getting kicked toward the Southwest/Southern Plains Thu-Fri as an uncertain upper trough digs upstream into the West. Troughing over the East is expected to de-amplify quickly early period and lose influence. Fairly quiet weather is expected across the nation overall in terms of precipitation. ...Guidance Evaluation/Preferences... Forecast spread is less than ideal in guidance days 3-7 in a relatively benign but uncertain pattern and embedded system evolution. The WPC medium range product suite was primarily derived from a blend of best clustered guidance from the GEFS/ECMWF ensemble means, with minimal emphasis over time on the much more varied GFS/ECMWF. Also used a heavy dose of WPC continuity and the National Blend of Models. ...Sensible Weather and Hazards... The most notable precipitation is forecast for the Pacific Northwest, with some moderate amounts especially in the Coastal Range and Cascades around Tue, and rounds of light amounts through the week. Snow levels could be relatively high, with light amounts spreading to the Northern Rockies and later next week broadly down across the West with potential system digging. Rain may develop for the Southwest and Southern Plains as the Baja upper low/trough ejects and then emerging/expanding out from the south-central U.S. heading into next weekend if upper troughing/height falls work out from the West to focus a lower atmospheric low/front and return Gulf of Mexico moisture flow response. This scenario remains highly uncertain in guidance. Ridging will promote milder than normal temperatures by 15-25 degrees across the High Plains to the Upper Midwest/Corn Belt. Actual temperature readings could approach 60 degrees as far north as South Dakota on Tuesday. Colder than normal temperatures are favored for much of the East for the early part of the week, before trending back toward more typical values. Schichtel Additional 3-7 Day Hazard 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