Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 750 PM EDT Fri May 28 2021 Valid 12Z Tue Jun 1 2021 - 12Z Sat Jun 5 2021 ...Overview and Guidance Evaluation... The weather pattern for the first five days of June will be featured with a pair of upper level lows over the Aleutians and northern Gulf region, and congealing into one main upper level gyre over the Gulf by the end of the week. A narrow upper level ridge axis should extend across the Interior and northwest Canada with a stationary frontal boundary across the north-central portion of the state, and an arctic upper low drifting south toward the northern Bering Sea. In terms of the models, there appears to be better than average deterministic agreement through Wednesday night, mainly owing to the amplified pattern in place. The 12Z CMC is closer to the consensus compared to earlier runs. By the end of next week, the 18Z GFS is stronger with the Aleutian low and this holds true as it tracks eastward near 50 degrees north. The WPC forecast was primarily derived from a blend of the 12Z ECMWF/GFS/CMC/UKMET through Wednesday, and then a slight increase in the ensemble means for Thursday through Saturday with less of the operational GFS. ...Weather/Threats Highlights... The persistent low pressure and onshore flow from the Alaska Peninsula to the southeast panhandle region is expected to produce multiple rounds of moderate rainfall for coastal areas and nearby mountain ranges. Some locations could receive an inch or two of rainfall for the early to middle portion of next week, especially across topographically favored areas, followed by lighter rain and some drier periods by the end of the week. Some showers can also be expected across portions of the Interior, mainly for the middle of the week. Temperatures are expected to reach the 60s and low 70s across much of the Interior for highs, and remaining quite chilly north of the Brooks range where highs should remain in the 30s and 40s. Hamrick 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