Extended Forecast Discussion NWS Weather Prediction Center College Park MD 201 AM EDT Sat Apr 25 2020 Valid 12Z Tue Apr 28 2020 - 12Z Sat May 02 2020 ...Extended Period of Much Above Normal Temperatures Across the West... ...Stormy Weather to Affect the Central and Eastern States... ...Guidance/Predictability Assessment... The WPC medium range product suite was primarily derived from a blend of reasonably well clustered guidance of the 18 UTC GFS/GEFS, 12 UTC ECMWF/ECMWF ensembles and the 01 UTC National Blend of Models days 3-7 in a pattern with above average predictability. This composite solution maintains great WPC continuity and acts to mitigate the less certain smaller scale weather features and interactions. ...Weather/Hazard Highlights... A building western U.S. upper ridge Tue into Thu will shift eastward over the central U.S. later next week. This amplified ridge will support much above normal temperatures to include a risk of record maximum/minimum temperature values from CA and the Southwest to south-central portions of the Great Basin/Rockies/Plains. Temperatures should moderate in the wake of the exiting upper ridge as Pacific system moisture/height falls work inland and promote some moderate precipitation mainly into the Northwest into later next week. Lead shortwave trough energies will meanwhile significantly dig over the central to eastern U.S. downstream of the amplifying western U.S. ridge. This will carve out an amplified mid-upper level trough/closed low and generate a deep surface low/frontal system that will rejuvenate as it tracks from the Plains/Midwest through the East Coast mid-later next week. This developing system will increasingly tap Gulf moisture and instability to fuel an expanding area of rainfall/strong to severe thunderstorms. Enhanced precipitation will spread from the MS Valley/Midwest Tue through the Appalachians/Northeast Wed into Thu. Locally heavy rainfall/runoff issues are possible, mainly in recently saturated areas near the lower MS Valley/Mid-South Tue. 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