Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 528 PM EST Mon Feb 14 2022 Valid 12Z Fri Feb 18 2022 - 12Z Tue Feb 22 2022 ...Stormy pattern continues for Alaska... ...Guidance/Predictability Assessment... Models and ensembles offer reasonably similar larger scale flow evolution through medium range time scales. However, there remain issues with the timing and focus of embedded systems as day4/Friday. A composite of the "best" clustered 12 UTC GFS/ECMWF and GEFS/ECMWF ensemble means seems to present a reasonable forecast days 4-6 (Friday-Sunday) with respect to WPC product continuity. Prefer just the ensemble means days 7/8 (next Monday/Tuesday) amid normal forecast spread growth. ...Pattern and Weather/Hazard Highlights... It remains generally the case that more in a series of highly unsettling storms seem on tap over the next week, both with several deep lows near the western Aleutians and as ample energies from multiple systems again break downstream across Southwest Alaska, the AKpen/Kodiak Island, south-central Alaska, the Gulf of Alaska and Southeast Alaska. System timing variance is not ideally set through medium range time frames, but has marginally improved within an overall stormy pattern that offers above normal larger scale predictability. While the short range also remains very active, expect an additional series of deep and relatively slow moving storms for the western Aleutians through medium range time scales into the weekend and early next week. Each with presenting a maritime and Aleutians threat with potential for high winds/waves and wrapping rains. System energies progressing downstream should spread a focus for deepened moisture fueling heavy precipitation from a warmed Southwest AK and the AKpen/Kodiak Island through southern/southeast Alaska. While active in the short range, expect additional focus especially this Friday and the weekend, then again early next week. This includes threats of multi-day heavy coastal rains and inland/terrain enhancing snows. Meanwhile, expect overall Arctic stream upper troughing from the North Slope down into the northern Interior, but generally modest moisture and snow potential outside of favored terrain in lower atmospheric flow dominated by cooled surface high pressure. Temperatures are expected to be well above normal over a warmed southern Interior, but cold enough for periods with enhanced snows considering ample support with approach and passage of a series of moistened southern stream systems slamming inland through a mean upper ridge position combined with a lingering and wavy surface frontal system focus. The best bet for organized snows may be Friday, then possibly again early next week. Schichtel Hazards: - Heavy precipitation across portions of the Alaska Panhandle, Thu-Fri, Feb 17-Feb 18. 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 Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html