Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EDT Wed Mar 25 2020 Valid 12Z Sat Mar 28 2020 - 12Z Wed Apr 01 2020 ...Central Plains/Midwest through Northeast Storm Threat Saturday-Monday... ...Guidance/Predictability Assessment... A deepening area of low pressure from the central Plains to the Midwest/Great Lakes then Northeast includes a threat of heavy rain/snow will highlight the medium range period. There will also be several periods of heavy precipitation for the Pacific Northwest and a less certain potential for organized late period showers/thunderstorms into the Southeast. Leading warmth over the South should have multiple locations see daily records for highs/lows over the weekend prior to frontal passage. The WPC product suite was mainly derived from a composite blend of reasonably compatable 18 UTC GFS/GEFS and ECMWF/ECENS into Saturday. Forecast spread increases uncharacteristically quickly Sunday onward as highly uncertain Northeast Pacific flow works downstream over the lower 48. This leads to overall lower forecast confidence. Most emphasis was applied to the ECENS mean to maintain maximum WPC product continuity and latest trends from 00 UTC model guidance seem relatively favorable. ...Weather/Hazard Highlights... Amplified upper trough ejection should result in a deepening area of low pressure that is expected to track from the Central Plains early Friday to the Midwest/Great Lakes and Northeast Saturday through early next week. In the warm sector, stronger convection is possible while interactions along a stationary/wavy frontal boundary will focus heavier rainfall from the Ohio Valley through portions of the central Appalachians and Mid-Atlantic. The signal remains for a northern tier banded precipitation which could bring a threat for heavier snow/wind from portions of the north-central Plains to the Upper Midwest and Great Lakes, spreading to the Northeast with triple point to coastal low formation. The Northwest will see periods of rain and mountain snow of varying intensity as progressive flow from the northeast Pacific carries along multiple features. Especially by the latter half of the period there is rapidly decreasing confidence in the southern extent of precipitation and system timings. Highest totals for the five-day period should be along favored Olympics/Washington Cascades terrain. 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