Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 650 PM EST Sat Jan 06 2024 Valid 12Z Wed Jan 10 2024 - 12Z Sun Jan 14 2024 ...Stormy conditions for the Aleutians and western Alaska... ...Overview... An upper ridge axis stretching from the east Pacific northward into the eastern Interior will cause the main storm track to focus across the Bering Sea and western Alaska, leading to an active and windy pattern as multiple low pressure systems move through the region. Another low may also sneak across the Alaska Peninsula to Kodiak Island for some enhanced winds and precipitation there late week. The upper ridge will promote milder than normal temperatures across most areas, with the exception of Southeast Alaska where continental flow ahead of the trough will bring in cold air. ...Guidance Evaluation/Preferences... Model agreement is good regarding the larger scale ridge setting up and amplifying across eastern parts of the Mainland, but guidance struggles relatively more with the details of shortwaves and surface lows within the mean trough across the Bering/Aleutians. On Wednesday-Thursday, one shortwave will support a low moving northeast across the eastern Bering while tending to weaken, with some typical variations in the low position and strength. A multi-model deterministic blend could be used for the WPC forecast early in the forecast timeframe. By Friday, a surface low from the north Pacific looks to track north toward the Alaska Peninsula/Kodiak Island with reasonable model agreement, while a deep surface low tracks quickly eastward near the Aleutians. With the latter, in general the deterministic guidance has this low south of the Aleutians on Friday while the ensemble means show the low center to the north. The CMC was on the slower side with the shortwave and the resultant low track compared to other guidance. This is still generally better agreement than models showed a day ago though. Regardless, the large and deep low is likely to affect the Aleutians late week with windy conditions, but the wind direction will depend on the track. The low is likely to pivot into the eastern Bering over the weekend. The WPC forecast transitioned to a model blend of half ensemble means by Day 7 and more Day 8, though maintaining some GFS and ECMWF components. ...Weather/Hazards Highlights... High winds are possible through midweek across the Aleutians with the initial surface low pressure system, and these winds could spread into southwestern portions of the Mainland for Wednesday and Thursday, particularly the Seward Peninsula and Lower Yukon/Lower Kuskokwim regions, possibly helping to create blizzard conditions. Then the Pacific surface low looks to focus potentially heavy precipitation across the Alaska Peninsula into Kodiak Island and the southern Kenai Peninsula Thursday-Friday. Precipitation totals have trended up there in today's forecast given better model agreement for the low, and winds may be a threat in favored areas as well. It is uncertain how much precipitation could spread into Southeast by late week into next weekend, but amounts should not be heavy. Fairly dry conditions should prevail over the Interior and North Slope. Also by late week into next weekend, another surface low could be deep when it comes near/across the Aleutians, and high winds may be expected once again. As the period begins Wednesday, the western half of the state should see milder than average temperatures, which will spread east through late week as the upper ridge builds. The highest anomalies are likely to remain over northern and western parts of the Mainland. Meanwhile, Southeast Alaska will see cold/below normal temperatures with northeasterly flow ahead of the ridge axis, but temperatures may moderate closer to normal there by next weekend. Tate 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