Extended Forecast Discussion NWS Weather Prediction Center College Park MD 1248 AM EST Fri Jan 31 2020 Valid 12Z Mon Feb 03 2020 - 12Z Fri Feb 07 2020 ...Overview and Guidance/Predictability Assessment... The medium range period begins with an amplified shortwave/closed low over the Great Basin early Monday, ejecting into the Central U.S. by later Tuesday. Models indicate this feature splitting into northern/southern stream pieces of energy, with the northern part tracking towards the Great Lakes by early Thursday. Meanwhile, the southern piece of energy should be reinforced by additional western U.S. energy resulting in amplified broad troughing across the Central U.S. by the end of the period. Confidence is above normal in the large scale/synoptic flow pattern, but closer to average on the flow evolution details, especially past day 5. Days 3 and 4 used a majority blend of the latest runs of the well clustered deterministic models (between the GFS/ECMWF/UKMET). After, slowly increased usage of the very agreeable ensemble means (ECENS/GEFS means). This maintains excellent continuity with the previous WPC forecast. ...Weather/Hazard Highlights... Shortwave energy across the Great Basin in day 3 will bring rain and mountain snow, potentially heavy in the favored terrain, to parts of the Central Great Basin into the Central and Northern Rockies. Moisture return ahead of the upper trough and surface cold front will bring showers and thunderstorms from the lower Mississippi Valley to the Southeast and the Mid-Atlantic Tuesday-Thursday. Frontal wave development and leading/increasing Gulf moisture inflow suggest a threat for heavy rainfall especially across the Southeast and into the southern Mid-Atlantic late next week. On the north side of the precipitation shield, sufficient cold air may be in place for wintry precipitation from parts of the Midwest/Mid Mississippi Valley to the Northeast. Meanwhile, persistent onshore flow should bring another round of heavy precipitation to the Pacific Northwest mid next week, with heavy snowfall possible in the mountains. Temperatures to begin next week will be well above average (+15 to +25F) from the south-central Plains to the Mid-Atlantic, with these temps trending back towards normal as the cold front makes its way west to east through the week. Out west, temperatures begin below normal, but should increase back to normal or even slightly above normal by the end of the week as upper level ridging builds in aloft. Santorelli 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