Extended Forecast Discussion NWS Weather Prediction Center College Park MD 158 PM EST Tue Feb 01 2022 Valid 12Z Fri Feb 04 2022 - 12Z Tue Feb 08 2022 ...Lingering Snow/Ice Threat exits the Mid-Atlantic/Northeast Friday... ...Overview... A positively tilted and reinforced mean trough aloft should hold strong across much of the CONUS through the medium range period (Friday-Tuesday), as strong upper riding builds over both the western Atlantic and the eastern Pacific (and periodically extending into parts of the west). On Friday, a shortwave moving through the Northeast will drive a potent cold front off the East coast, with potentially heavy wintry precip likely coming to an end on the north side of this system. Into this weekend, uncertainty begins to increase over details of additional shortwaves dropping down the east side of the ridge in the West as well as a series of northern stream shortwaves which should support a train of northern tier waves into early next week. Upper troughing into the East early next week may induce wintry coastal waves, with some signal for additional development of any in a series of lows. ...Guidance Evaluation/Predictability Assessment... Models and ensembles provide a reasonably similar larger scale pattern evolution through medium range time scales, but present significant run to run variance with smaller scale embedded upper impulses and surface wave reflections and local QPF focus. Prefer a composite of the otherwise decently clustered solutions of the GFS/ECMWF/UKMET/Canadian models for days 3/4 (Fri/Sat) before transitioning to the still compatible GEFS/ECMWF ensemble means by days 6/7 to minimize the less predictable forecast components. This provides a good forecast basis along with the 13 UTC National Blend of Models and WPC continuity. ...Weather Highlights/Threats... Troughing into the East on Friday and a leading wavy cold front through the East will continue the threat for lingering significant snow/ice from the Mid-Atlantic to especially southern New England. Lingering moderate to locally heavy showers are still possible across parts of the Southeast along the trailing front Friday with periodic additional activity through the weekend into early next week with additional frontal waves/upper impulses. Elsewhere, northern tier systems may produce secondary shots of cold air into the central U.S.,but only light, scattered snow over the Upper Midwest/Great Lakes. Mostly light rain/mountain snow should accompany a couple systems brushing the Pacific Northwest and northern Rockies. Significant guidance differences with separate streams of energy aloft lead to low confidence in the coverage and amounts of precipitation over the South and East from the weekend into early next week. Ambient cold air offers the potential for some swaths of wintry weather on the northern periphery of these uncertain precipitation areas, with best bet Sunday over the Southeast/southern Mid-Atlantic. Arctic high pressure settling from the central to eastern U.S. behind the front will bring very cold temps later this week into the weekend. Anomalies may be most profound for parts of the southern Plains with values 15-25 degrees below normal possible. Upper ridging trying to build across the northern/central Plains Monday-Tuesday of next week could bring a period of much above normal temperatures to this region. Schichtel/Asherman 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