Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
707 PM EDT Fri Oct 11 2024
Valid 12Z Tue Oct 15 2024 - 12Z Sat Oct 19 2024
...Overview and Guidance Evaluation/Preferences...
The low pressure system over the northern Gulf of Alaska is
expected to steadily weaken going into the middle of the week. A
surface high will be stretched across the central Aleutians and
into the Bering Sea region, although this will give way to more
unsettled conditions across the Aleutians as a second but weaker
low pressure system moves in from the west and likely crosses just
south of the Aleutians. Low pressure will likely linger over the
northern Gulf going into the end of the week, and a surface high
over the Interior.
The 12Z model guidance is in good overall agreement across the
Alaska domain for Tuesday, and a general deterministic model
compromise serves as a good starting point in the forecast
process. Wednesday also features good agreement, with the one
exception across the southern Gulf where the 12Z ECMWF and UKMET
spin up a stronger surface low off the British Columbia Coast, but
the ECMWF is not as strong as yesterday with that low. Looking
ahead to the second half of the week, the CMC remains slower with
the arrival of the next low pressure system crossing south of the
Aleutians. The ensemble means were gradually increased to about
40-50% towards the end of the week and next Saturday.
...Weather/Hazards Highlights...
The strong low pressure system that will be over the Gulf this
weekend will be much weaker by Tuesday, with breezy conditions in
northerly flow across the Alaska Peninsula, and onshore flow
across the southeast Panhandle region. This will fuel additional
rounds of mainly light rainfall across the region, but nothing
expected to reach hazards level criteria. One to two inches of
additional rain is possible through midweek for the southeast
Panhandle, and moderate to heavy snow for the coastal mountain
ranges. Lingering light snow is likely across the Brooks Range
and the eastern North Slope after heavier snow over the weekend.
Temperatures will be trending colder across most of the state as a
cold front crosses and brings more of an arctic air mass to the
region, with highs likely near or below freezing for most inland
areas by the end of the week, and mid 30s to mid 40s near the
southern coast. Some valley locations near the Brooks Range could
have overnight lows near zero by Thursday and Friday.
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