Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 649 PM EDT Thu Apr 15 2021 Valid 12Z Mon Apr 19 2021 - 12Z Fri Apr 23 2021 ...Overview and Guidance/Uncertainty Assessment... Latest guidance continues to depict a blocky regime during the period. This pattern will be highlighted by upper ridging that covers the mainland and western Canada and eventually joined by another ridge that builds over the western Bering Sea/eastern Siberia, while a consolidating Pacific mean low aloft should settle into a position south of the eastern Aleutians and Alaska Peninsula. Shortwave energy within progressive flow around the north side of the upper ridge may push a cold front into the northern/eastern mainland by Tuesday-Thursday. Most of the state should be fairly dry for most of next week, with the best potential for precipitation along coastal locations shifting west to east from the Aleutians to Southern Coast to Panhandle. Overall, the guidance shows fairly good agreement through much of the period and continues to trend towards a stronger ridge aloft. For days 4-6, the WPC blend favors a majority deterministic guidance (GFS/ECMWF/CMC). After this, the ECMWF (and to some degree the ECENS mean) want to break down the ridge a little too fast, thus the forecast leans more heavily towards the GFS/GEFS solutions which hold onto the ridge/blockiness a little longer. This approach fits well with yesterdays WPC continuity as well for days 4-7. ...Weather/Hazards Highlights... Most precipitation should be confined to the Aleutians/Alaska Peninsula and vicinity, with a fairly persistent flow of moisture carried in the gradient between one or more Pacific lows and high pressure well to the north. Light to moderate amounts are most likely but some locally higher totals could be possible depending on exact strength and track of Pacific systems. By the end of the week, lighter precip may begin shifting east towards the Southern Coast region and the Panhandle. The rest of the mainland should remain dry throughout the entire week. Most of the state should see above normal temperatures at the start of the period Sunday, with the warmest anomalies over the North Slope and for morning lows. A gradual cooling trend with time will tone down the warm anomalies somewhat while possibly bringing at least high temperatures to near or below normal first over parts of the southeastern quadrant of the mainland and the Panhandle an then eventually much of the eastern half of the mainland by next Wednesday-Friday. Santorelli No significant hazards are expected over Alaska during this forecast period. 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 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