Extended Forecast Discussion NWS Weather Prediction Center College Park MD 259 AM EDT Tue Mar 24 2020 Valid 12Z Fri Mar 27 2020 - 12Z Tue Mar 31 2020 ...Southwest U.S. to North-Central U.S. to Northeast Storm Threat Friday-Monday... ...Guidance/Predictability Assessment... The upcoming medium range period will be highlighted by a deepening storm set to lift northeastward from the Southwest U.S. through the PLains to the Midwest/Great Lakes then Northeast Fri-Mon. The WPC medium range product suite was primarily derived from a blend of the well clustered 12 UTC ECMWF/ECMWF ensembles and the National Blend of Models. The newer 00 UTC ECMWF maintains great run to run and WPC continuity and the 18/00 UTC GFS/GEFS runs seem to be gradually coming into the fold with system intensity/track and potential impact, bolstering forecast confidence. ...Weather/Hazard Highlights... Amplified upper trough passage will support areas of moderate rain and enhanced high elevation snows through the Southwest/Great Basin into the Rockies/High Plains Friday. Deepening lead low pressure tracking northeastward from the Central Plains Fri to the Midwest/Great Lakes/Northeast Sat-Mon should produce a broad area of rain/showers and possibly strong warm sector convection over parts of the central/eastern U.S. The highest rainfall potential/runoff risks may be over the Ohio Valley region as moist flow ahead of the system interacts with a leading wavy front. There is also a growing guidance signal supporting a threat of heavy snow/winds in the northern periphery of the moisture shield from the north-central Plains to the Upper Midwest/Great Lakes and Northeast. 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. Highest totals for the five-day period should be along favored Olympics/Washington Cascades terrain. The West will experience below normal temperatures late this week with moderation over the weekend. Expect decent coverage of minus 10-20F anomalies for highs over central/southern parts of the West into Fri. On the other hand a broad area of above to much above normal temperatures will spread from the Southern Plains and vicinity across much of the East late this week into the weekend. Highest anomalies will likely be for morning lows, up to 15-25F above normal versus 10-20F anomalies being more common for daytime highs. Multiple locations may see daily records for highs and/or warm lows from the Southern Plains eastward. Frontal passage will bring temperatures down to near normal over the eastern half of the country by Sun-Mon. Rausch/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