Extended Forecast Discussion NWS Weather Prediction Center College Park MD 141 AM EST Wed Jan 5 2022 Valid 12Z Sat Jan 8 2022 - 12Z Wed Jan 12 2022 ...General Pattern Overview... An amplified but progressive upper level pattern is expected to be in place through early next week with a deep trough tracking from the Rockies to the East Coast, and a ridge axis moving into the western U.S. from the eastern Pacific. By next Wednesday a second trough moves across the Plains and a storm system begins approaching the Pacific Northwest, with more of a quasi-zonal flow pattern over the eastern U.S. as the earlier trough departs. ...Guidance/Predictability Assessment... The 00Z model guidance suite and ensembles continue to agree quite well on the overall synoptic scale pattern, particularly through the upcoming weekend. Going in early next week, the models still have a good handle on the deep trough over the East Coast region and the timing of the cold front passage. However, model differences are more apparent for the western U.S. as a split flow aloft likely develops. Timing differences exist among the CMC/ECMWF/GFS with northern stream energy approaching the Pacific Northwest, and latitudinal differences with a potential closed low near southern California. By Wednesday, the GFS is faster with this shortwave energy in the northern stream across the Great Lakes and Ohio Valley, compared to the slower CMC/ECMWF guidance. The WPC forecast was based primarily on a multi-deterministic model blend through Sunday, and then gradually increasing use of the ECENS and GEFS means through early next week while still keeping about 50 percent of a CMC/ECMWF/GFS blend.. ...Hazards/Sensible Weather Highlights... Gulf moisture advecting northward ahead of a developing Plains/Midwest cold front is expected to result in increasing coverage of showers and thunderstorms from eastern Texas and the central Gulf Coast, to the Ohio Valley and Mid-Atlantic region this weekend, with lighter rainfall expected farther north. There will likely be some embedded heavier rainfall across portions of the Deep South where convection is persistent. Areas from the upper Great Lakes to the Northeast could see wintry weather, with the best snowfall prospects over northern New England and northern New York. Parts of the Great Lakes may see lake effect snow behind the passing front. Going into next week, dry conditions are expected across most of the nation except for some showers and mountain snow over western Washington and Oregon associated with the next storm system. Some moderation of the severe cold over the Plains/Midwest is expected on Saturday ahead of the next arctic surge that reaches into the northern tier states by Sunday and into Monday. The second surge may not be quite as intense as what is expected for the end of this week, but temperatures could still be 10-25F below normal from eastern Montana to Wisconsin. From Saturday into Sunday, above normal temperatures will progress from the southern Plains to the Deep South and Southeast U.S., with overnight lows on the order of 15-25 degrees above normal across the central Gulf Coast region Sunday morning. Seasonably cold conditions are likely west of the Continental Divide with readings generally within 10 degrees of climatological averages, and 10-20 degrees below normal for the East Coast by next Tuesday. 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