Extended Forecast Discussion NWS Weather Prediction Center College Park MD 152 PM EST Sat Mar 05 2022 Valid 12Z Tue Mar 08 2022 - 12Z Sat Mar 12 2022 ...Overview... Strong ridge axes off either coast should keep much of the CONUS within broad and reinforced troughing through this next week. Amplified troughing from a low gyre centered over Baffin Island to begin the week will shift south down the center of the continent, pushing an Arctic cold front down the Great Plains through Friday before shifting to the East Coast through Saturday. A resulting low looks to develop over the Upper Midwest Thursday night before lifting northeast through eastern Canada through Saturday. Ahead of this trough can be expected continued wintry weather across the northern Intermountain West Wednesday into Thursday before it shifts to the Midwest for Thursday/Friday, as well as two rounds of moderate to locally heavy rain for the Southeast/Mid-Atlantic. ...Guidance Evaluation/Predictability Assessment... Good agreement for a slower pattern over the CONUS is seen with the 06Z (and now 12Z) GFS/ and the 00Z ECMWF, particularly by 12Z Thur with the positively tilted trough digging over The West. The 00Z UKMET/CMC are much quicker to shift this trough axis neutral and advance it over the central CONUS. Both the 06Z GEFS and 00Z ECENS means were not as slow/positively tilted with the trough, so the bulk of the model preference were the 06Z GFS/00Z ECENS through Day 5 before shifting toward the GEFS/ECENS by Day 6. Energy diving into The West on Wednesday will reinforce and amplify troughing over Interior West which looks to maintain the positive tilt as it presses south into Mexico and across the northern Plains Friday. Lee cyclogenesis spreads down the High Plains from CO Wednesday/Thursday, with a developing surface low lifting northeast from the central Plains across the Upper Midwest Thursday/Thursday night. ...Weather Highlights/Threats... A shortwave trough over the southern Plains Tuesday evening shifts across the Mid-Atlantic through Wednesday making for widespread rain/thunder chances over the Interior Southeast along a cold front on Day 4 that settles to the Southeast Coast/Florida/eastern Gulf Coast for Days 5/6 and possibly 7. Heavy snow, with snow levels dropping to the valleys before ending, shifts south across the northern Intermountain West through the southern Rockies Tuesday night through Friday. As the lee low shifts down the southern High Plains Wednesday, snow develops over the north-central Plains Wednesday before shifting across the Upper Midwest Wednesday night through Thursday night as noted by the Days 5/6 WPC winter weather outlook. Arctic-sourced air enters the Northern Plains Tuesday night and is reinforced by even colder air Wednesday night shift sends a cold surge behind an Arctic cold front down the Plains to the western Gulf coast through Friday. Min temps of 10 to 15 degrees below normal in MT Wednesday intensify to 20 to 25 degrees below normal (with many areas around zero to minus single digits) and expand across the northern Plains/Rockies to the central High Plains Wednesday night. Some moderation occurs as the cold air mass spills well into the southern Plains Thursday night and into south Texas Friday night though anomalies of 20 to 25 degrees below normal are likely to be maintained. This cold air begins to shift east Friday, reaching the Appalachians Saturday. Above normal temperatures are expected over the eastern CONUS ahead of the cold front except for the coastal Mid-Atlantic/Northeast where cold air damming looks to linger Wednesday into Thursday in the wake of the cold front pushing through on Tuesday. Jackson 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