Extended Forecast Discussion NWS Weather Prediction Center College Park MD 154 AM EST Tue Jan 4 2022 Valid 12Z Fri Jan 7 2022 - 12Z Tue Jan 11 2022 ...General Pattern Overview... The upper level pattern over the continental U.S. through the beginning of next week should remain fairly amplified but also progressive. A strong shortwave trough and associated Nor'easter will exit the East Coast Friday, and this should give way to a Canadian surface high and cold weather settling across the east-central U.S. in the wake of the strong cold front. By the weekend, another cold front crosses the Plains with a renewed surge of arctic air for the north-central U.S., and a surge of moisture ahead of it across the Gulf Coast region. Upper level ridging sets in across the West by early next week. ...Guidance assessment and uncertainty... The 00Z model guidance suite is in very good synoptic scale agreement through the weekend with some mesoscale timing and amplitude differences with the individual shortwave passages. The GFS is slightly more amplified with the trough originating from the West Coast Saturday as it tracks eastward across the Plains Sunday, and also a bit more potent with a northern stream shortwave dropping south from the Hudson Bay region late on Monday, although excellent agreement with the large scale trough expected to be over the East by that time. There are also some modest differences with a southern stream closed low near southern California, but close enough to support a general model blend. The WPC forecast was based primarily on a multi-deterministic model blend through Saturday, and then gradually increasing use of the ECENS and GEFS means through early next week. ...Sensible Weather... After an active period of weather during the short range period across the Pacific Northwest, some lingering rain and mountain snow is still likely from northern California to western Washington, and snow for the Northern Rockies, on Friday. A drying trend should commence in time for the weekend across much of the West as high pressure builds back into the region. Meanwhile, an intensifying nor'easter off the New England Coast may still produce some lingering snow showers for much of the Northeast states, with the heaviest QPF likely offshore by Friday morning. More showers and storms are likely to make a return to the Gulf Coast region and into the Tennessee Valley by Sunday ahead of the next front. Temperatures are expected to be quite cold across the central/northern Plains to the Upper Midwest through the end of the week with a large surface high of arctic origin governing the weather pattern for this region. Highs in the teens settling as far south as central Indiana and Illinois are likely on Friday. Some moderation of the severe cold may come across this region on Saturday ahead of the next arctic surge into the northern tier states on Sunday, which is not expected to be quite as intense as the earlier arctic blast. Elsewhere, seasonably cold conditions are expected west of the Continental Divide with readings generally within 10 degrees of climatological averages, and mild across the southern Plains and Deep South with highs running 5 to 15 degrees above average this weekend. Hamrick 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