Extended Forecast Discussion NWS Weather Prediction Center College Park MD 144 PM EST Fri Feb 04 2022 Valid 12Z Mon Feb 07 2022 - 12Z Fri Feb 11 2022 ...Overview... The overall theme for this forecast period remains a West Coast ridge and broad cyclonic flow aloft over the eastern half of the nation, with multiple northern stream shortwaves/clipper systems reinforcing the trough for much of next week, and a surface low developing off the East Coast through Tuesday. An anomalous closed upper high evolves just off the West Coast for the second half of next week as part of a +PNA pattern, and this favors a broad trough east of the Rockies with mainly dry conditions for most locations. ...Guidance Evaluation/Predictability Assessment... The latest deterministic model guidance and ensemble means are generally in reasonable agreement with the upper-pattern through the first half of the medium range forecast period, with some minor timing differences noted with the individual shortwaves east of the Rockies. The biggest differences involve the evolution of East coast low pressure Monday onward. The 0Z ECMWF presents a slower, more northerly surface track to the initial Southeast surface wave, while the GFS is quicker to push the low out to sea (with a slightly deeper system noted on the 12z run). Meanwhile, the 12Z CMC and UKMET have a similar low track to the ECMWF, but are more bullish with the system strength. To resolve this uncertainty, used a deterministic blend to obtain a middle ground solution for the between the various model camps for days 3-5. Beyond Tuesday, growing spread with the depth and subsequent evolution of upstream Great Lakes frontal systems supported an ensemble blend slightly weighted toward the 0Z ECMWF and 6Z GEFS ensemble means for days 6-7. In general, this blending approach yielded good continuity with the overnight WPC forecast. ...Weather Highlights/Threats... A developing low pressure system off the North Carolina coast early in the week is likely to be close enough to produce a cold rain across eastern portions of the Mid-Atlantic region through early Tuesday, with the potential for snow on the northwestern edge of this precipitation. This threat may also affect eastern New England depending on the eventual track of the surface low, so this event will continued to be monitored for future trends. Elsewhere across the nation, mainly dry conditions are expected for most areas, with the exception of some rain/mountain snow for western Washington early in the week, and patchy areas of light snow across portions of the north-central U.S. and the Great Lakes region in association with the clipper systems. Temperatures are expected to generally remain below normal across much of the south-central U.S. for the beginning of the week, albeit on a moderating trend compared to the well below average readings expected this weekend. Readings across the central and northern Plains are likely to become 10-20 degrees above average, and near average for most of the East Coast region through the middle of next week. Above average temperatures can be expected for the entire week for the West Coast region owing to the large upper ridge encroaching from the eastern Pacific. Asherman/Hamrick 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