Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 730 PM EDT Sat Jun 19 2021 Valid 12Z Wed Jun 23 2021 - 12Z Sun Jun 27 2021 ...Heavy rain and wind threaten eastern Aleutians and Alaskan Peninsula later next week as enhanced rainfall expands east into the Alaska Panhandle... ...Guidance/Predictability Evaluation... The WPC Alaskan medium range product suite was primarily derived from a composite blend of relatively well clustered guidance of the 12Z GFS/GEFS mean/ECMWF/00Z EC mean, along with some 12Z CMC and CMC mean. Guidance forecast spread continues to indicate above normal predictability on the synoptic scale pattern. Thus, a general model blend trending toward the ensemble means for Days 6-8 should work fine as a starting point. This blend yielded a rather deep cyclone for June to impact the eastern Aleutians to the Alaskan Peninsula late next week before it gradually weakens and meanders in the same vicinity by the weekend. More of the 06Z GFS rather than the 12Z run was used in the blend since the 06Z GFS was more compatible with the ensemble mean position of the Aleutians low. This blend provided results that stayed pretty close to WPC continuity. ...Weather/Threats Highlights... A rather deep cyclone for this time of the year is forecast to impact eastern Aleutians and the Alaskan Peninsula with gale-force winds and a few inches of heavy rain possible later next week. The moisture is expected to quickly expand eastward through the southern coastal sections and into the Alaska Panhandle where moderate to heavy rain is possible. A slow drying trend should then work its way from west to east across the Aleutians as the cyclone weakens while meandering over the eastern Aleutians. Farther north across the rest of Alaska, rain chances should gradually increase later next week across the northern portion of the state where a stationary front becomes better defined. Rain chances are expected to linger into the weekend for this region. The gradual trend toward damp and cloudy conditions later next week area wide will keep low temperatures warmer than average for much of Alaska while high temperatures are expected to be slightly above normal for the latter half of next week, cooling to near normal by the weekend. Kong 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