Extended Forecast Discussion NWS Weather Prediction Center College Park MD 212 AM EST Fri Feb 18 2022 Valid 12Z Mon Feb 21 2022 - 12Z Fri Feb 25 2022 ...Early-mid next week heavy snow threat from the central Great Basin/Rockies to the northern plains/Upper Midwest and northern Northeast... ...Heavy rain/runoff threat from the Lower Mississippi/Tennessee Valleys to the Mid-Atlantic Monday-Friday, with a heavy snow/ice threat from the southern plains and Mid-Mississippi/Ohio Valleys to the Northeast Wednesday-Friday as an early week central U.S. Arctic surge spreads eastward... ...Pattern Overview... An active weather pattern will develop next week as upper troughs dig over a cooling West and as ejecting energies and induced frontal waves progress downstream over a Canadian high pressure cooled central to eastern U.S. and a warming Southeast/East upper ridge. ...Guidance Evaluation/Predictability Assessment... Models and ensembles offer a quite similar mid-larger scale flow evolution next week in a pattern with above normal predictability. A composite of overall well clustered guidance from the GFS/ECMWF/UKMET/Canadian and GEFS/ECMWF ensemble means along with the National Blend of Models provides a seemingly good forecast basis that tends to mitigate lingering smaller scale system variances while maintaining good WPC product continuity. ...Weather Highlights/Threats... Moderate to heavy mountain snows are likely to focus early to mid next week across the Great Basin and Rockies as ample trough energies dig into a amplified western U.S. trough position. A wavy front on the leading edge of an Arctic surge set to dig through the Northern Rockies and central U.S. early next week with have upper support to favor a swath of heavy snow from the northern plains/Upper Midwest to the northern Northeast. Meanwhile, ample upper energies working downstream from the West next week will also act to induce waves along a lead front and tap deepening moisture from the Gulf of Mexico moisture. This is expected to fuel a heavy rain and runoff threat from the Lower Mississippi/Tennessee Valleys to the Mid-Atlantic starting early next week along with potential for re-development along the wavy/slowed trailing front later next week. This may also support a heavy snow/ice threat from the southern plains and Mid-Mississippi/Ohio Valleys to the Northeast Wednesday-Friday as the early week central U.S. Arctic blast spreads eastward. Expect a few record cold temps over the northern Rockies/plains to starkly contrast a few record warm pre-frontal temperatures under the Southeast/East upper ridge. Schichtel Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook 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