Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
655 PM EST Fri Feb 2 2024
Valid 12Z Tue Feb 6 2024 - 12Z Sat Feb 10 2024
...General Overview...
A deep upper low will be in place across much of the Aleutians and
the Bering Sea into early next week with increased prospects for
precipitation and gusty winds for portions of the Aleutians and
the Alaska Peninsula. Temperatures are forecast to warm up
considerably going into next week as the deep upper trough departs
and broad upper ridging tries to build northward across the
mainland from the Gulf region. Unsettled conditions may return to
south-central portions of the state by next Friday/Saturday as
another low pressure system becomes better organized.
...Guidance Evaluation/Preferences...
The 12Z model guidance suite, along with the 18Z GFS, continues to
indicate slightly more disagreement than usual for the synoptic
scale pattern, especially by Thursday and beyond. The greatest
differences early on exist across the northern Gulf region
regarding the timing of individual shortwave perturbations, and
also across the Arctic Coast region. Differences become
substantial across the eastern Gulf by midweek regarding a
potential trough/upper low, and then across the entire domain by
the end of the week and into Saturday. There is general agreement
that a broad upper level low will exist across the Bering, but
limited confidence with low pressure systems pivoting around the
main upper low. Therefore, the ensemble means accounted for about
2/3 of the model blend by next Saturday to account for the
uncertainty, and some previous WPC continuity for the Tuesday
through Friday 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. 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. 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