Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 707 PM EDT Fri Oct 8 2021 Valid 12Z Tue Oct 12 2021 - 12Z Sat Oct 16 2021 ...Active pattern continues with periods of gusty winds and precipitation across southern Alaska... ...Pattern Overview and Model Guidance... Progressive and energetic flow aloft will lead to multiple surface low pressure systems affecting portions of Alaska through the period. A strong low pressure system is expected to affect the northern Gulf region on Tuesday and then rapidly weaken on Wednesday. Another low should move across the Bering Sea and then cross into the Gulf over the Alaska Peninsula by midweek, and this low pressure in the Gulf is likely to linger through the end of the workweek. Areas of enhanced precipitation and/or strong winds are likely with each system. In terms of the models, there is good overall synoptic scale agreement through midweek regarding the evolution of the main low pressure systems. By Thursday, the CMC becomes more amplified than the model consensus with the upper level trough over the Gulf and thus a stronger cold front, and this becomes even more pronounced by next Friday, and the CMC also has a stronger downstream ridge over the Aleutians. There was enough agreement among the 12Z UKMET/ECMWF/GFS to merit a blend of those models through Thursday morning, before transitioning to mainly GFS/ECMWF and their respective ensemble means for the remainder of the forecast period. ...Weather/Hazard Highlights... The strong surface low development in the Gulf of Alaska is expected to result in enhanced precipitation early in the week across coastal portions of southern Alaska and the southeast panhandle, with the potential for a few inches of rain near the coast and heavy mountain snow, along with strong winds. The next low pressure system should bring precipitation and windy conditions to the Aleutians and the western mainland through midweek, while persistent low pressure in the Gulf keeps the moist inflow into the Panhandle and thus precipitation chances there through late week with additional heavy totals possible where orographic enhancement is maximized. Temperatures should generally be cooler than normal through next week for much of the southern part of the mainland and the Panhandle, particularly in terms of highs. For the northern two-thirds of the state, near average highs are forecast with a mixture of slightly below and slightly above normal readings. Hamrick Hazards: - Heavy precipitation across portions of mainland Alaska, Mon-Tue, Oct 11-Oct 12. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Thu, Oct 11-Oct 14. - Heavy rain across portions of the Alaska Panhandle, Mon-Thu, Oct 11-Oct 14. - High winds across portions of mainland Alaska and the Aleutians, Mon-Tue, Oct 11-Oct 12. 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