Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 546 PM EDT Sun Jun 20 2021 Valid 12Z Thu Jun 24 2021 - 12Z Mon Jun 28 2021 ...Rainy conditions forecast for Aleutians, Alaskan Peninsula, Kenai Peninsula, and southeast AK/panhandle later this week... ...Guidance/Predictability Evaluation... The models continue to show a mean deep layer trough over the Bering Sea with embedded cyclonic circulations that should bring a few storms to the Aleutians and adjacent Alaska peninsula. Guidance forecast spread continues to indicate above normal predictability on the synoptic scale pattern. Thus, a general model blend was used to produce a consensus-based forecast. The WPC Alaskan medium range product suite was primarily derived from a composite blend of clustered guidance of the 06-12Z GFS/12z GEFS mean/00-12z ECMWF/00Z EC mean. This blend yielded a rather deep cyclone for June to impact the eastern Aleutians to the Alaskan Peninsula late this week before it gradually weakens and meanders gradually west northwest into the southern Bering Sea over the weekend. Strong integrated water vapor transport downstream from this storm supports locally heavy rain from the Kenai peninsula over to southeast AK/panhandle. Farther north in northern Alaska, rain chances should gradually increase later next week in response to a stationary front becomes better defined. The higher precip amounts are forecast on Day 5. Rain chances are expected to linger into the weekend for this region before the front weakens. Early next week, the aforementioned low decays, and a new cyclone develops at the base of the Bering Sea trough in the north Pacific, impacting the adjacent Aleutians, up to and including the AK peninsula next Mon the 28th of June. This would bring the next chance of showery and windy conditions across these regions. Temperatures are expected to be above normal in southeast AK/panhandle as the north Pacific upper ridge persists. Most of the peninsula hovers near normal plus/minus a few degrees, with the clouds and showers leading to slightly cooler than normal conditions across the Aleutians and AK peninsula. Petersen 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