Extended Forecast Discussion NWS Weather Prediction Center College Park MD 102 AM EST Mon Feb 24 2020 Valid 12Z Thu Feb 27 2020 - 12Z Mon Mar 02 2020 ...Overview and Guidance/Predictability Assessment... The western ridge and eastern trough will shift eastward over the weekend in a rather quiet pattern. Exiting system at the short range/medium range interface (Thu) will continue to slowly move into Quebec and Atlantic Canada Fri-Sat. A Pacific system will move into WA/OR early this weekend and continue southeastward and eastward, perhaps in two pieces, to then re-emerge over the Plains by the start of next week. The models generally clustered well with the ensemble means, but favored the 18Z/12Z GFS and 12Z ECMWF with minority weighting of the Canadian for the first few days. Trended toward about a 50% ensemble weighting by next Sun/Mon with continued uncertainty in the speed/depth of the incoming Pacific upper trough and surface front(s) and how they evolve. ...Weather/Hazard Highlights... Wrap-around flow over the Great Lakes will support a several day period of snow focused downwind of Lakes Ontario and Erie. Accumulations could be significant for the Tug Hill Plateau. Temperatures will trend cooler behind the system, generally for a couple days, before rebounding back toward average by next Sun/Mon. Some record lows (or low maxes) may be approached on Saturday as the core of the cold slides into the East Coast. By contrast, the West will see generally mild/warm days Thu-Sat with some potential record highs in California. Dry conditions on Thursday and into Friday will be replaced by increasing coverage of generally light rain/snow. Temperatures will trend cooler as the system moves in, pushing the milder air east of the Rockies next week. Fracasso 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