Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 721 PM EDT Tue May 24 2022 Valid 12Z Sat May 28 2022 - 12Z Wed Jun 01 2022 ...Overview... A blocky upper high centered over the Bering Sea late this week is forecast to slowly weaken as it shifts east, with leftover ridging holding strong over the Mainland into the middle of next week. This will separate an upper low well north of Alaska (which may send some troughing into the North Slope region) from a train of upper level/surface lows in the North Pacific. As the blocky high breaks down early next week, this should allow for one such low to lift farther north and into the Gulf around next Tuesday-Wednesday increasing precipitation chances from the eastern Aleutians to the Southern Coast and Panhandle. Much of interior Alaska should remain mostly dry and warm through the period. ...Guidance/Predictability Assessment... The latest model guidance remains in generally good agreement through at least the first half of the period and a general model blend between the 12z GFS, ECMWF, and UKMET was preferred. By about early next week, uncertainty increases surrounding an upper low lifting towards the Gulf. The 12z ECMWF (and the ECENS mean) strayed from consensus in showing this low moving more north/north-westerly across the Alaska Peninsula and into the Bering Sea, whereas the other guidance (including the GFS and CMC) show this low staying out in the Gulf. The differences seen in the ECMWF seem to stem from interactions with a weaker low along the western Aleutians pulling the system towards the west. The GFS and CMC (and respective ensemble means) suggest more separation from this low allowing the low to drift more towards the Gulf. The WPC forecast preferred to stick close to continuity and leaned more towards the GFS/CMC and 00z ECENS mean/12z GEFS mean rather than the 12z ECMWF which has only showed this evolution for one run now (the 00z run was much more consistent with the GFS and CMC). ...Weather and Hazard Highlights... Precipitation across most of Alaska should be generally light, and tending to focus along/near frontal boundary across the northern portion of the state this weekend. By early next week, some increasing precipitation chances could move in towards the eastern Aleutians/Southern Coast/Panhandle associated with a surface low in the Gulf. Much of interior Alaska will remain dry and quite warm with daytime highs averaging 10 to 15 degrees above normal for some areas. Initial troughing may bring temperatures below normal across the North Slope region this weekend but moderate back towards normal as the upper ridge edges into the region by next week. 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 outlook 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