Extended Forecast Discussion NWS Weather Prediction Center College Park MD 148 AM EST Fri Jan 01 2021 Valid 12Z Mon Jan 04 2021 - 12Z Fri Jan 08 2021 ...Weather Pattern Overview... Quasi-amplified but progressive flow will continue next week over much of the lower 48. Relatively mild Pacific air will keep colder Canadian air to the north, resulting in near to above normal temperatures for most of the CONUS. The Pacific Northwest will see a stormy pattern as successive systems move inland, moving across the central/eastern states with light to modest precipitation. ...Guidance/Predictability Assessment... Aside from near New England early in the week, the progressive flow favors a blended solution owing to timing differences that expand in time. The 12Z ECMWF compared most favorably to the ensembles (along with the parallel GFS), with differences still between the 18Z GEFS mean and 12Z ECMWF ensemble mean. Consensus by later next week generally kept an eastward motion of the system out of the Plains Wednesday toward the VA/NC coast around next Friday. Back to New England for early in the week, preferred a middle ground solution between the GFS/ECMWF as the evolution is rather complex and tied to smaller-scale shortwaves with limited predictability. ...Weather/Threats Highlights... Area of low pressure just off New England Mon-Tue may bring modest precipitation to at least eastern New England depending on its proximity to the coast and structure. A slow exodus could prolong oceanic affects at the least, but perhaps remain a coastal threat as well. The Pacific Northwest will see the brunt of the precipitation next week with a string of systems, about one every other day, coming ashore. Multi-day precipitation totals could exceed several inches in many areas (even lower elevations west of the Cascades) with considerable snowfall in the Cascades. Expect windy conditions and variable snow levels as the systems move through. By later in the week, the lead Pacific system will move out of the Plains with an expanding area of at least light rain and some northern snow. Temperatures will be well above normal along the Canadian border by about 10-20 degrees, especially for overnight lows, and modestly above normal for most of the rest of the CONUS east of the Rockies and north of the Southeast. The interior West will see near to below normal temperatures in the active pattern. Fracasso 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, 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