Extended Forecast Discussion NWS Weather Prediction Center College Park MD 201 AM EST Sat Feb 24 2024 Valid 12Z Tue Feb 27 2024 - 12Z Sat Mar 02 2024 ...Guidance/Predictability Assessment... 12 UTC ECMWF/UKMET and ECMWF ensembles constitute a cluster of guidance that continue to vanguard better separated flow across much of the lower 48 next week than recent runs of the Canadian, and to a lesser extent the GFS/GEFS. The WPC medium range product suite was primarily derived from the ECMWF/UKMET/ECMWF ensembles as recent trends in guidance and machine learning models toward this type of solution continue to better fit known flow biases and WPC continuity over the past day. ...Overview and Weather/Hazards Highlights... An upper ridge traversing the central and eastern U.S. for the first half of next week will spread much above normal temperatures from the Plains through the Midwest and then the East. An emerging precipitation pattern develops into Tuesday/Wednesday from the Midwest/Great Lakes through the East to include some moderately heavy activity. In this precipitation shield, a post-frontal surge of a cold Canadian high pressure in the wake of low system passage offers some wrap-back enhanced snow potential from the eastern Midwest and Great Lakes through the Northeast. Meanwhile, northern and weaker southern-stream troughing from the Pacific look to separately track into the West. The northern stream trough will bring cooler temperatures, elevation-dependent rain/snow, and windy conditions through parts of the Intermountain West/Rockies through Tuesday passage, while southern stream system ejection may bring a moderate precipitation swath over the Southwest, then southern Rockies/Plains into midweek. Downstream translation may then support system genesis, with lead return moisture set to fuel increasing rain/convective chances across the South later next week into next weekend. The central U.S. will see quite warm temperatures early next week underneath an upper ridge. Temperatures of 20-35 degrees above average will expand from the Plains through the Midwest into Tuesday. Widespread well above normal and record-breaking temperatures will spread eastward across the eastern U.S. through midweek. The upper trough and well defined cold front pressing southward and eastward should then cool temperatures down closer to normal or a few degrees below across these broad regions, but unseasonable warmth should rebound later week and the weekend back over the central states. Farther upstream, a growing guidance signal in support of amplifying upper trough development over the east Pacific/West Coast seems to increasingly support chances for some moderate to heavier precipitation focus into the Pacific Northwest mid-later week that may shift down the coast through California later week and next weekend to monitor. A WPC Day 5 Excessive Risk Marginal area was introduced for coastal areas of the Pacific Northwest to usher in this emerging pattern. 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 forecast, excessive rainfall outlook, winter weather outlook probabilities, heat indices and Key Messages 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/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw