Extended Forecast Discussion NWS Weather Prediction Center College Park MD 244 AM EST Fri Feb 14 2025 Valid 12Z Mon Feb 17 2025 - 12Z Fri Feb 21 2025 ...Arctic Blast for the Central to Eastern U.S. next week... ...Emerging Precipitation Threat from the South-Central U.S. to The South then up the East Coast mid-later next week... ...Guidance/Predictability Assessment... Model and ensemble solutions are unusually well clustered for next week, bolstering forcast confidence through medium-range time scales. A favored composite of the latest GFS/ECMWF/Canadian/UKMET and inclusion over time of the GEFS/ECMWF/Canadian ensemble means offers good system detail, albeit with the blend smoothing less predictable smaller scale features. This solution seems reasonably aligned with the National Blend of Models. WPC product continuity is good for much of next week. However, latest 00 UTC model guidance has pivoted more inland with East Coast coastal low precipitation for later next week to monitor over the coming days. ...Weather/Hazards Highlights... A closed upper low/trough and deep surface low will work into the Canadian Maritimes by early next week. Trailing upper energies and very cold lower atmospheric flow will combine with lingering wrap- back moisture to fuel Great Lake effect to northern New England snows. The tight pressure gradient may result in a period of strong, gusty winds. Behind this system, elongated upper troughing will linger across the northern tier and an impressive Arctic airmass takes hold over the central and eastern U.S. next week. Entrenched cold air will maintain lake effect snows and also offer a widespread threat of record cold temperatures with focus over especially the central U.S. in this pattern. Upstream, several organized shortwaves/frontal systems will dig southeastard through the West. These systems will bring rounds of low elevation rain and mountain snow to the Pacific Northwest, Northern California, and the Northern/Central Intermountain West/Rockies through the period. A main focus for precipitation will spread to the Central/Southern Plains early next week as a low pressure system moves south across the region towards the Gulf Coast. A WPC Day5/Tuesday Excessive Rainfall Outlook (ERO) Marginal Threat area has been introduced. Precipitation will expand across the South and Southeast heading through next midweek as wavy frontal lows develop and swing along the Gulf Coast to the Southeast. Impactful wintry weather is expected on the northern side of this system from the Central/Southern Plains through the Mid-Mississippi and Tennessee Valleys. The WPC Winter Weather Outlook outlines the snow/ice threat that may continue into later next week with possible coastal low/storm development to threaten up the East Coast from the Mid-Atlantic to eastern New England. 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 (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: 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