Extended Forecast Discussion NWS Weather Prediction Center College Park MD 128 PM EST Sat Feb 22 2020 Valid 12Z Tue Feb 25 2020 - 12Z Sat Feb 29 2020 ...Dynamic storm system to bring active few days to the eastern half of the CONUS next week... ...Overview and Guidance/Predictability Assessment... The synoptic pattern through the medium range period (Tues Feb 25 - Sat Feb 29) is expected to generally favor western U.S. ridging and central/eastern U.S. troughing. Overall, model agreement was average to above average, with reasonable consensus on the developing storm system poised to affect the central/eastern U.S. next week. Initially, the 06Z GFS, 00Z ECMWF/UKMET/CMC were well clustered on day 3/4 and were primarily used for the model blend preference. Northern/southern stream interaction late Wednesday into Thu is expected to lead to strong cyclogenesis over the Mid-Atlantic into the Northeast as has been seen for several runs and remains constant in the last several ensemble runs. By the end of the week, uncertainty increases along/off the West Coast where a digging trough near 140W early Fri may either close off west of 130W (Canadian) or simply continue eastward (GFS/ECMWF). Ensembles favor the most progressive GFS/ECMWF approach with less trends toward a closed low forming off the western US. ...Weather/Hazard Highlights... Some modest to locally heavy rain is expected across the Southeast (Fl/GA border) as the front moves through on Tue-Wed. Precipitation on the northwest side of the organizing fronts will support a swath of snow from the Corn Belt to the Great Lakes/Midwest. Once the system starts to deepen over the Mid-Atlantic, snow will expand across much of New York away from the coast and through northern New England. Temperatures will trend cooler with time as the system moves through, with the coldest readings (10-20 deg below average) progressing to the Appalachians and even down into Florida by Friday. By contrast, the West will see generally dry conditions next week. Temperatures about 10-20 deg above average (and even some record highs) can be expected. Light rain/snow will be confined to the coastal areas of WA/OR. Fracasso/Taylor 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