Extended Forecast Discussion NWS Weather Prediction Center College Park MD 128 AM EST Fri Mar 11 2022 Valid 12Z Mon Mar 14 2022 - 12Z Fri Mar 18 2022 ...Overview... In a progressive flow pattern, a couple notable weather systems will move through the Lower 48 next week. The firs system dives southeast through the northern Rockies toward the Gulf Coast and Southeast through the middle of next week while a compact and moderately strong atmospheric river impacts the Pacific Northwest. Temperatures will trend above normal for much of the central to eastern U.S. mid to late week, offering spring-like temperatures reaching 10-20 above normal. ...Guidance Evaluation/Predictability Assessment... In general, the synoptic pattern for the CONUS offered very good agreement in the main surface features and evolution in the 500 mb pattern for next week. Some notable differences were associated with the closed mid-level low over the Southeast Tues-Wed, where some north-south waffling between the various deterministic models continues. The GFS has been a northern and faster solution while the CMC was a southern outlier. The ECMWF/UKMET offered a good consensus and was heavily included in the forecast blend along with the 18Z GFS and 12Z CMC. Toward days 6-7, as the next shortwave energy emerges into the central U.S., there are some timing and strength differences where the GFS shows its fast bias compared to the ECMWF. Given the increasing spread, heavier weights of the ECENS/GEFS were included to maintain continuity while adjusting for the latest trends. For the Pacific Northwest, there was above agreement with the deterministic guidance in the amplitude and progression of the shortwave trough moving through Monday-Tuesday. ...Weather Highlights/Threats... Much below normal temperatures can be expected Monday morning across the Southeast where readings well into the 30s are forecast as far south as northern Florida, which would be 10 to 15 degrees below normal. The aforementioned low pressure over the Plains then drops toward the lower MS Valley Monday-Tuesday then the Gulf Coast/Southeast mid-week. This system may draw up modest amounts of Gulf moisture ahead of it and could combine with sufficient instability to bring widespread thunderstorms capable of producing heavy rainfall, especially along/near the Gulf Coast region. For the Pacific Northwest, the bulk of the atmospheric river aims on the region Monday into Tuesday where widespread precipitation of several inches is possible. This rainfall is expected to be mostly beneficial but localized flooding issues could develop for some of the more sensitive locations. With snow levels generally 5000-6000 ft, the higher peaks of the Olympics and Cascades could see another round of heavy elevation snowfall. A taste of spring-like temperatures is also generally expected for much of the central to eastern U.S. next week. Daytime highs reaching 10 to 20 degrees above normal, especially for portions of the Midwest to Great Lakes. Taylor 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 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