Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 321 PM EST Fri Mar 01 2019 Valid 12Z Tue Mar 05 2019 - 12Z Sat Mar 09 2019 A strong upper high in the short term will give way to ridging over northeastern Alaska next week that will only slowly trend weaken by the end of the period. This favors a continued stormy pattern for the Bering Sea/Aleutians and western/southwestern Alaska with only fringe affects farther east. The models/ensembles were fairly well-clustered through the period and the 12Z FV3-GFS/00Z ECMWF were near their means and each other for much of the period. The notable exception was Tue/Wed as the ECMWF was slower than the rest of the guidance but not unreasonable given the ensemble lows spread and low predictability of these sfc waves. Median positioning sufficed. For next Wed-Sat, a lead deep system and trailing perhaps deeper system will traverse the Bering just north of the Aleutians and slide eastward. This will bring strong winds and high waves to the region over more open water than what is typical for this time of year. Precipitation will focus along/ahead of the front into Southcentral with southerly flow Thu/Fri. Incorporated more ensemble weighting (especially ECMWF ensembles) to form a consensus position/track in the Bering with another deep system next Fri/Sat. Fracasso Bullet points from the WPC Days 3-7 Hazards chart: https://www.wpc.ncep.noaa.gov/threats/threats.php - High winds across portions of western Alaska and the Alaskan Peninsula, Mon-Wed, Mar 4-Mar 6. - High winds across portions of the Aleutians, Wed-Fri, Mar 6-Mar 8. - High significant wave heights for coastal portions of mainland Alaska, Mon-Tue, Mar 4-Mar 5. - High significant wave heights for coastal portions of the Aleutians, Wed-Fri, Mar 6-Mar 8. WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can 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