Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 440 PM EDT Mon Jul 29 2019 Valid 12Z Fri Aug 02 2019 - 12Z Tue Aug 06 2019 The flow pattern over Alaska during the medium range (late Thursday into late next Monday) changes with time, as a trough across Alaska gets replaced with an Omega Block extending across much of the eastern Pacific downstream of a significant upper trough across northeast Asia. The guidance showed good agreement early on before discrepancies increased in and near the Bering Sea with time. To account for this, the pressures, 500 hPa heights, and winds started a blend of the 00z Canadian, 00z ECMWF, 06z GFS, and 00z UKMET early before making the blend more evenly split with the 00z NAEFS mean and 00z ECMWF ensemble mean by early next week, with some tweaks made thereafter to better define features. The remainder of the grids were evenly split between the ensemble means (half of the blend) and the 06z-12z GFS, 00z Canadian, and 00z ECMWF guidance (composing the second half of the blend). Eastern and southeastern Alaska are expected to be the sunnier areas this period, with highs in the 60s near the coast and 70s inland. To the west and north, cloudy skies should prevail as disturbances ride around the eastern side of the northeast Asia trough bring the promise of skirmishes of heavy rainfall (1-3" with locally higher amounts) from the Aleutians into northwest Alaska. Roth Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php - High significant wave heights for portions of the Arctic Coast of Alaska, Thu-Fri, Aug 1-Aug 2. - High winds across portions of the Arctic Coast of Alaska, Fri, Aug 2. - High winds across portions of western Alaska, Sat, Aug 3. - Heavy rain across portions of northwestern Alaska, Sat-Sun, Aug 3-Aug 4. 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