Extended Forecast Discussion NWS Weather Prediction Center College Park MD 211 PM EST Sat Feb 01 2020 Valid 12Z Tue Feb 04 2020 - 12Z Sat Feb 08 2020 ...Excessive Rainfall Threat for the South/Southeast/Appalachians... ...Heavy Snow/Ice Risk from the Mid-Mississippi Valley northeastward to the Northeast... ...Weather/Hazard Highlights and Guidance/Predictability Assessment... Medium range forecast confidence remains above normal in the synoptic flow pattern evolution Tue-Thu, but decreases next Fri-Sat amid growing forecast spread. The WPC medium range product suite was primarily derived from the reasonably compatable GFS/ECMWF days 3-5, then the more consistent GEFS/ECMWF ensemble means days 6/7. This maintains good WPC continuity. Onshore flow/impulses running overtop a buidling western upper ridge will bring rounds of heavy precipitation to the Pacific Northwest next week that work inland across the northern Great Basin to the north-central Rockies. Locally heavy mountain snows are likely in this pattern. The impulses subsequently dig to the lee of the ridge to maintain/reinforce an ampified lead mid-upper level trough. This active trough will work through from West/Rockies Tue/Wed and Central U.S. Wed/Thu before ejecting over the East late week. Frontal wave developments and leading/increasing Gulf moisture inflow and instability in advance of amplified upper troughing and favorable upper jet flow favor an emerging threat for excessive rainfall, especially across the Southt/Southeast and into the southern Appalachians/southern Mid-Atlantic Tue-Thu. SPC also highlights a risk for severe weather shifting from the Lower Mississippi Valley to the Southeast during this period. On the north side of the precipitation shield, there is an increasing signal indicating that sufficient cold air will settle in place for a swath of heavy snow/wintry precipitation from the Mid-MS Valley to the Northeast. Temperatures from the Southern Plains to the Mid-Atlantic will average 15 to 20 degrees above normal early-mid week, trending back towards normal following wavy cold frontal passage later week. Widespread record minimum temperatures are especially possible in this pattern. Temperatures in the west-central states will be much below normal Tue/Wed, but warm back to normal or slightly above normal by the end of the week as upper level ridging builds aloft. Schichtel Additional 3-7 Day Hazards information can be found on the WPC medium range hazards 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