Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
655 PM EST Sat Feb 3 2024
Valid 12Z Wed Feb 7 2024 - 12Z Sun Feb 11 2024
...General Overview...
A deep upper low will initially be in place across much of the
Aleutians and the Bering Sea for the middle of the week with
increased prospects for precipitation and gusty winds for the
Alaska Peninsula. A second storm system is forecast to approach
the southern coastal areas towards the end of the week with
additional snow and rain near the coast, and possibly a third
system trailing behind it towards next Sunday. Temperatures will
continue warming up going into next week with upper level ridging
developing over the mainland.
...Guidance Evaluation/Preferences...
The 12Z model guidance suite has come into better overall
agreement compared to yesterday on the main synoptic scale
features across the Alaska domain, including the North Pacific low
that will likely affect the northern Gulf towards the end of the
week. In terms of differences, the GFS is generally stronger with
the Bering Sea low for mid-week, but generally in good agreement
elsewhere on Wednesday. Overall, there has been a slower trend in
the latest guidance for the late week low over the Gulf, with the
GFS generally on the east side of the model spread, and a rapid
weakening trend is expected once the low reaches the coast. By
Sunday, models vary more on location of the third system to affect
the state, with the ECMWF taking this low closer to the coast
compared to the offshore GFS/CMC. The ensemble means comprised
about half of the model blend by next weekend to account for the
increasing uncertainty, and some previous WPC continuity for the
Wednesday through Saturday time period.
...Weather/Hazards Highlights...
A steady moderating trend is expected to be underway early in the
week as temperatures return to above average across central and
eastern portions of the mainland, which is in stark contrast to
the absolutely frigid conditions that are currently in place
across much of the state. The Yukon Flats will be the slowest to
warm up compared to other parts of the mainland, and the greatest
positive anomalies are expected to be across the southwestern
mainland and the Seward Peninsula going into the middle of the
week with strong warm air advection in place. In terms of
precipitation, periods of onshore flow across the central/eastern
Aleutians and the Alaska Peninsula will keep precipitation chances
in play for much of the week, with generally light to moderate
intensity levels, although locally heavy rain/mountain snow is
possible where orographic forcing is enhanced. There is even the
chance for some sleet and freezing rain across portions of
southwestern Alaska Tuesday night into early Wednesday with
boundary layer temperatures possibly getting above freezing.
Strong southeasterly winds are also likely across portions of the
Alaska Peninsula on Tuesday ahead of a low pressure system
entering the Gulf of Alaska region.
Hamrick
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