Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 751 PM EDT Tue Apr 19 2022 Valid 12Z Sat Apr 23 2022 - 12Z Wed Apr 27 2022 ...Guidance/Predictability Assessment... Extended range period over Alaska begins with a deep surface low moving into the Gulf, and weakening with time. The latest models are showing some timing/placement differences on this low (the GFS is quicker to weaken/shift into western Canada late period), but a general model blend seems to give a good middle ground for now on this feature. Farther upstream, a surface low will cross the Kamchatka Peninsula next weekend, moving into the western Bering Sea by late Monday. After this, models show uncertainty on the eventual track of this feature. The 12z GFS weakens this low over the northern Bering Sea, while the 12z CMC and ECMWF break a new low off this parent low and move it over the Aleutians and into the Gulf of Alaska by the middle of next week. The ensembles are varied on this feature resulting in a rather washed out mean solution, but at least would suggest low pressure in the Gulf around Tues-Wed next week, rather than ridging like the 12z GFS is showing. By next Wednesday, another low looks to enter the Bering but the models show quite a bit of uncertainty on timing and strength of this. For the later periods, the WPC blend incorporated more of the ensemble means to help mitigate the differences, with some contribution from the deterministic CMC and ECMWF for added system definition. Despite increasing uncertainty in the guidance compared to yesterday, todays forecast remained fairly consistent with yesterdays WPC forecast. ...Overview Weather/Hazard Highlights... Moisture will direct northward along the attendant cold front of the low pressure system into the Gulf this weekend to support enhanced and locally heavy precipitation (lower elevation rain/mountain snow) across parts of the Southern Coast and eventually eastward into the Panhandle this weekend and early next week as the system weakens. Parts of the Aleutians may also see precipitation associated with uncertain low and cold front progressions. Precipitation could return across the Southern Coast/Panhandle region by mid next week, but depending on the next low pressure system into the Gulf. Elsewhere, much of the Interior and North Slope regions should remain dry, with temperatures mostly above normal and trending warmer through the period. Southern regions, from the Aleutians to the Panhandle, should remain near or below average owing to increased clouds and precipitation. Santorelli Hazards: - Heavy precipitation across portions of the Alaska and Kenai Peninsulas, Sat, Apr 23. 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