Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 528 PM EST Mon Jan 31 2022 Valid 12Z Fri Feb 4 2022 - 12Z Tue Feb 8 2022 ...Overview... The large scale pattern over Alaska will be fairly stagnant late this week into early next week, with a col generally in place over Alaska, separating deep layer low pressure west of the Aleutians and an upper high retreating well northwest of the state while an upper low slowly drifts east over far northern Canada. The upper level gyre just west of the Aleutians will produce shortwaves pivoting around it, sending them northeastward along the southern part of the state. These shortwaves and their associated surface lows are expected to track across southern coastal Alaska along with multiple rounds of precipitation, with the heaviest rain/snow from the Kenai Peninsula to the southeast Panhandle. ...Guidance/Uncertainty Assessment... The 12Z model guidance suite is initially in good synoptic scale agreement over the Alaska domain and has a good handle on the storm system over the eastern Gulf and the shortwave approaching the eastern Aleutians for the end of the week, with the exception of the 12Z UKMET that is much stronger and slower with a closed low over the Gulf. For the second system entering the Gulf on Sunday, models are more divergent with the ECMWF farther east than the stronger GFS/CMC solutions. A much stronger storm system approaches the Aleutians by early next week with a decent signal in the CMC/ECMWF/GFS solutions for this, with the ECMWF/GEFS mean offering a reasonable middle ground solutions between the farther west GFS and the southeast CMC solution. The models are also stronger with building an arctic trough across the northern half of Alaska going into the weekend and into Monday, with the GFS among the colder solutions compared to the ensemble means. Therefore, the WPC fronts/pressures forecast was primarily derived from a CMC/ECMWF/some GFS for Friday/Saturday, and then gradually increasing contributions from the ensemble means through the remainder of the forecast period. ...Weather/Hazard Highlights... Three separate pressure/frontal systems tracking northward to coastal southern Alaska and the southeast panhandle region will advect copious moisture into the southern part of the state. These storms will provide forcing for multiple rounds of coastal rain and heavy mountain snow across the Alaska Peninsula, south-central Alaska, and the Panhandle late this week into early next week. Gusty winds and rough seas are also likely from the Aleutians eastward to the Alaska Peninsula. Farther north, arctic high pressure will be in place across northern Alaska, keeping the Interior dry and cold through late week. Some snow showers over the northern mainland may be possible early next week as the surface high retreats. Below normal temperatures across much of the Interior will gradually retreat to the North Slope and the western mainland by early next week, while generally above average temperatures are forecast for southern Alaska owing to the influence of onshore flow and increased cloud cover. Hamrick Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Thu-Sat, Feb 3-Feb 5. - High winds across portions of mainland Alaska, Thu, Feb 3. - Much below normal temperatures across portions of mainland Alaska, Thu-Fri, Feb 3-Feb 4. 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