Extended Forecast Discussion NWS Weather Prediction Center College Park MD 158 AM EDT Wed Apr 17 2019 Valid 12Z Sat Apr 20 2019 - 12Z Wed Apr 24 2019 ...Overview and Guidance Preferences... Upper pattern will transition toward much more zonal flow next week after a vigorous system exits out of the Northeast this weekend. Models and ensembles show decreasing agreement on the flow, which is expected given the short wavelengths. As such, trended from a multi-deterministic model blend to start the forecast (Sat/Sun) to a 50/50 deterministic/ensemble blend of the latest guidance for next week. Relatively weak systems will rule the pattern next week focused from the southern Plains northeastward/eastward and also in the Pacific Northwest with another front moving into WA/OR around Tuesday. ...Weather Highlights/Threats... Wrapped-up system in the east will be on the way out with a focus for modest rain into primarily Maine on Saturday before moving into Canada. This may linger into Sunday depending on how long it takes the upper trough to actually clear the area. Western front will spur some light rain over the Plains Sun/Mon and slowly push southward and eastward, gradually increasing in amounts as Gulf moisture continues to lift into the region. Temperatures will generally trend milder than average for most of the lower 48 given the quasi-zonal flow 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