Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 622 PM EDT Tue Mar 22 2022 Valid 12Z Sat Mar 26 2022 - 12Z Wed Mar 30 2022 ...Pattern Overview and Weather/Hazard Highlights... An amplifying upper trough south of the Aleutians and then entering the Gulf by early next week will sustain the development of a well organized surface low. This will approach the southeast Alaska mainland and then the eastern panhandle region with the potential for heavy precipitation. A ridge axis builds northward across western Alaska and adjacent portions of the Bering and the Aleutians ahead of the next storm system approaching the Aleutians by the middle of next week, with more rain and windy conditions likely. The developing Gulf low for early next week will likely have gusty winds, moderate to heavy rain, mountain snow, and even high waves across the southeast panhandle region for next Monday and into Tuesday. Strong onshore flow that is orthogonal to the terrain will enhance precipitation totals for the windward areas. In terms of temperatures, most of the mainland should enjoy readings above average through the weekend, followed by a return to seasonal to below average readings for some areas through next Wednesday. ...Guidance/Predictability Assessment... The 12Z model guidance suite is in very good agreement on the overall synoptic scale pattern through the upcoming weekend. The main differences by Sunday include a stronger and farther south solution with the 12Z GFS regarding the maritime low entering the Gulf of Alaska, and this trend is even more pronounced by Tuesday, whilst the GFS/ECMWF and the ensemble means all suggest a solution closer to the south-central Alaska coast and a little weaker. The UKMET is likely a bit progressive with the next major storm system approaching the Aleutians/Bering Sea region by late Sunday/Monday, and by the middle of next week, the CMC is broader with the ridge axis that is downstream of the Bering low, and it is also south of the model consensus with an upper low over northern Alaska by this time. Taking these factors into account, the WPC forecast is primarily based on a multi-deterministic blend for Saturday, and then slightly less weighting on the GFS for Sunday and beyond, and mainly a ECMWF/CMC/ensemble blend with minimal use of the GFS for early-middle next week. Hamrick Hazards: - Heavy precipitation across portions of southern mainland Alaska, Fri, Mar 25. - Heavy precipitation across portions of the Alaska Panhandle, Mon-Tue, Mar 28-Mar 29. 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