Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 233 PM EST Tue Feb 12 2019 Valid 12Z Sat Feb 16 2019 - 12Z Wed Feb 20 2019 Upper ridging along and east of 150W (through interior eastern Alaska) will give way to wavy zonal flow by next week atop ridging just south of the Aleutians. The 12Z GFS and 00Z ECMWF clustered fairly well with the 06Z GEFS mean and 00Z ECMWF ensemble mean through about next Mon/Tue with the lead system into western/southwestern Alaska this weekend and then a significant system crossing the western Aleutians late Sunday and moving into the Bering Sea Monday. Timing differences were the main point of contention rather than track or intensity, so a majority deterministic blend worked well to start. This still yielded 40+ kts wind along/ahead of the front across the Aleutians into the Bering late Sun into Mon with 30-35 kts behind the surface low. For next Tue/Wed, Bering system will translate eastward as the flow becomes quasi-zonal. Next system will perhaps approach the western Aleutians at the end of the period but the ensembles differ on that timing/track. Otherwise, the longwave pattern was in good or very good agreement as the bigger differences existed south of the area in the mid-latitudes and toward Hawai'i. Fracasso WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can be found at: http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif http://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html