Extended Forecast Discussion NWS Weather Prediction Center College Park MD 1249 PM EST Fri Jan 01 2021 Valid 12Z Mon Jan 04 2021 - 12Z Fri Jan 08 2021 ...Weather Pattern Overview... Progressive flow of shorter waves is expected next week across the CONUS. Relatively mild Pacific air will dominate, generally keeping colder air contained to Canada at least into the late parts of next week, resulting in near to above normal temperatures for most of the CONUS. The Pacific Northwest will remain in a stormy pattern as successive systems persist. The wave of greatest note arrives at the Pacific Northwest coast Monday and meanders east through the CONUS all week, perhaps amplifying enough to be of winter storm concern in the east-central CONUS by Friday. ...Guidance/Predictability Assessment... Given the shorter wavelength of activity progressive across the CONUS next week, there are notable differences in deterministic guidance even by Day 3. The 00Z ECMWF compared most favorably to their ensembles and was preferred along with an increasing blend of ensembles through the week (with a preference for the 00Z ECENS over the 06Z GEFS). Consensus by later next week generally kept an eastward motion of the system out of the Plains Wednesday toward the VA/NC coast by Friday. ...Weather/Threats Highlights... An area of low pressure lingering near/off New England Monday night through Tuesday night will bring at least modest precipitation to 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 (though not too low) as the systems move through. By later in the week, that Pacific system reaching the coast on Monday will move out of the Plains with an expanding area of at rain and at least some snow on the north side of the system as Canadian air fills in behind the system. Temperatures will be well above normal along the Canadian border by about 10-20 degrees, especially for overnight lows, through next week. Modestly above normal temperatures can be expected for most of the rest of the CONUS east of the Rockies and north of the Southeast. The exception area could be the east-central CONUS depending on the low track and intensity of the main wave of concern crossing the CONUS next week. The interior West should see near normal temperatures in the active pattern. Jackson 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