Extended Forecast Discussion NWS Weather Prediction Center College Park MD 200 PM EST Sun Feb 02 2020 Valid 12Z Wed Feb 05 2020 - 12Z Sun Feb 09 2020 ...Excessive rainfall threat for the South/Southeast/Mid-Atlantic... ...Heavy snow/ice risk from the south-central U.S. to the Northeast... ...Weather/Hazard Highlight and Guidance/Predictability Assessment... Amplified upper troughing with northern and dynamic southern stream energies will work from the Rockies to the central U.S. Wed/Thu and then cross the eastern U.S. Fri as reinforcing impulses run overtop then dig downstream of a building upper ridge over the West. These impulses and onshore flow will favor a renewed wet pattern from the Pacific Northwest to the Great Basin/Rockies where the threat of heavy snows will again focus into favored terrain/mountains. A feed of mid-higher level eastern tropical Pacific moisture and increasingly deep layered Gulf of Mexico inflow ahead of the approaching upper trough and favorable jet support/instability will fuel an expanding heavy rainfall and local runoff threat from the South/Southeast to the Appalachians/Mid-Atlantic. SPC also still shows a severe weather risk across the South/Southeast. Cold post-frontal high pressure will dig through the south-central U.S./Midwest as lead high pressure dams ahead of the system into the northern Mid-Atlantic/Northeast. Wrapback flow on the northwest periphery of the precipitation shield and thetae advection into the receding cold air over the northern Mid-Atlantic/Northeast will favor a heavy snow/ice swath threat. Activity will be enhanced by deepening frontal waves lifting from the Southern Plains/Gulf Coast to the Appalachians and Northeast Wed-Fri prior to frontal exit into the western Atlantic. Models and ensembles have converged more upon a better clustered forecast with this overall scenario, at least at moderate to larger scales, bolstering forecast confidence in a composite blend along with the National Blend of Models. The next system/shortwave enters the Pacific Northwest next weekend, and models indicate this could drop down the West coast resulting in a possible closed low over central California by day 7. The GFS has been much more consistent with this feature than the ECMWF which has shown wildly different solutions the past few runs, but has now trended toward the GFS. An ensemble blend approach along with some imput from the GFS/ECMWF is preferred given lingering uncertainty. 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