Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 759 PM EDT Wed Mar 29 2023 Valid 12Z Sun Apr 02 2023 - 12Z Thu Apr 06 2023 ...Overview with Guidance Evaluation/Predictability Assessment and Weather/Hazard Highlights... The medium range forecast period for Alaska will begin on Sunday with the threat of strong gap winds diminishing across the favored terrain of the Alaska Peninsula/Kodiak Island/Kenai Peninsula. Farther south across the North Pacific, there has been a decided shift in the forecast pattern from early next week onward--most notably--the 12Z EC mean now agrees much better with the GEFS in bringing a faster-moving shortwave to move up the Aleutian Island chain early next week and eventually push through the ridge axis near/east of the Alaska Peninsula. This is in stark contrast to the 00Z EC mean which favored a much stronger ridge to extend north across the Gulf of Alaska toward the southern mainland, thereby blocking the northeastward progress of the shortwave and surface low tracking near or to the south of the western Aleutians. Given the recent adjustments of the EC mean toward a faster northeastward track of the low through the Aleutians early next week, the medium-range forecasts today call for an increasing chance of precipitation to overspread the southern coastline and down into the Panhandle starting next Tuesday. The precipitation chances are maintained along the southern periphery of Alaska through next Thursday. Farther upstream, additional smaller scale low pressure systems moving into the North Pacific will continue to introduce uncertainty to the pattern affecting the Aleutians in the longer range forecasts. Elsewhere, a period of light snow is forecast for western and northern Alaska with the passage of an upper shortwave and an occluded cyclone tracking north of Alaska. Along the Aleutians, a gradual expansion of precipitation is expected up the island chain Sunday and Monday, with snow likely across southwestern Alaska Monday to Tuesday. Meanwhile, northern Alaska will be milder than normal but well below hazards levels. The WPC Alaskan forecast package begins with 40% from the 12Z EC and EC mean, 40% from the 12Z GFS and GEFS, and 20% CMC and CMC mean, quickly transitioning to mostly a blend of the 12Z EC mean/12Z EC (55%), with the rest of the blend derived from the 12Z CMC mean, and 12Z GEFS. Kong Hazards: - High winds across portions of mainland Alaska, Sat-Sun, Apr 1-Apr 2. 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