Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 521 PM EST Thu Dec 26 2024 Valid 12Z Mon Dec 30 2024 - 12Z Fri Jan 03 2025 ...Arctic cold over much of the Mainland this weekend should moderate with time next week... ...Gusty winds possible for parts of the Aleutians and AK Peninsula region this weekend into early next week... ...Overview with Guidance Evaluation and Preferences... The extended range period over Alaska begins with ridging across the Mainland and an elongated trough, anchored by a closed low, over the Bering Sea/Aleutians. An initial quick shortwave/surface low will shift across the eastern Aleutians this weekend, while a shortwave/deeper low pressure system tracks south of the Aleutians into the Gulf by next week. A series of shortwaves to follow will help reinforce low pressure over the Gulf as the troughing over the Bering Sea gradually weakens. Another possibly deeper system will move in to the western Aleutians by the end of the period. The models generally have a good handle on the overall pattern evolution, but a lot of uncertainty still in the details, strength, and placement of individual systems. Outside of the UKMET, the rest of the deterministic guidance was reasonable enough for a general model blend for the first few days of the forecast period (Monday-Tuesday). After this, models had trouble resolving the details of shortwaves into the Gulf as well as with the timing and evolution of the next deeper low towards the Aleutians late period. The WPC forecast for the latter half of the period trended quickly towards the ensemble means to help mitigate and smooth out the differences. In general though, this maintains good continuity with the previous WPC forecast. ...Weather/Hazards Highlights... A train of low pressure systems into the Gulf will keep the Aleutians to Southern Coast to Southeast generally unsettled and wet, though rainfall should be mostly light to moderate in nature. An initial low pressure area near the eastern Aleutians on Sunday and weakening as it lifts into the Bering Sea on Monday may produce a brief time of gusty to hazardous winds for parts of the Aleutians into the far western Alaska Peninsula region. A stronger low pressure system into the Gulf Tuesday into Wednesday may provide some additional precipitation enhancement and the possibility for some gusty winds, from the AK Peninsula eastward to Cook Inlet and Kenai Peninsula. High waves may present maritime hazards as well. Interior to northern Alaska should be dry most of the period. As for temperatures, a surge of arctic air is expected to be in place over much of mainland/interior Alaska associated with troughing over the Arctic this weekend. Temperatures could be 20-30+ degrees below average, with actual temperatures closer to -20 to -30 degrees, or more, in some locations and especially the North Slope this weekend. This air mass should moderate gradually from west to east into next week but still remain close to or below normal. Meanwhile, mild and near to above normal temperatures should prevail across the Aleutians, southwest Alaska, and the Southern Coast/Southeast. Santorelli 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