The Weather Prediction Center
College Park, MD
Alaska Extended Forecast Discussion
Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
657 PM EST Fri Feb 07 2025
Valid 12Z Tue Feb 11 2025 - 12Z Sat Feb 15 2025
...High winds across Aleutians and SW mainland as well as heavy
precipitation over parts of Alaska Peninsula and Kodiak Island
early next week...
...Overview...
The upper-level pattern will feature troughing in the North
Pac/Bering and ridging over the mainland and panhandle at the
beginning of the period. An inverted trough originating over
Canada steadily bisects the mainland ridge before settling over
the interior by the end of the period. Shortwave energy will
likely propagate north across the Bering and western mainland.
Cold front pushes southwest across mainland and into Gulf by
midweek.
...Guidance Evaluation and Preferences...
Reasonably good agreement on depth and placement of Aleutian upper
low feature over the Bering as well as upper ridge over the
mainland on day 4. Shortwave energy digging into western AK on day
5 is captured well by the 12z deterministic GFS/Euro/CMC/UKMET.
The GFS is quicker with the bisection of the mainland ridge,
sending the northern portion well into the Arctic Circle faster
than the rest of the deterministic guidance. The GFS also begins
to over amplify, compared to other guidance, the Aleutian low on
day 5. Notable spread in the 12z GEFS compared to the other means
with respect to timing of the upper trough in the North Pac on day
6.
Decent clustering, for a day 7 forecast, regarding closed upper
low center over the Kamchatka Peninsula. Some differences around
the orientation of the inverted trough protruding into the
mainland from Canada. The deterministic guidance, while varied on
orientation/depth, signals a more amplified pattern over the
mainland by day 8 with agreement on shortwave energy propagating
eastward across the Aleutians. The Euro is notably slower than the
GFS and Canadian with that bit of energy.
...Weather/Hazards Highlights...
Energy associated with a potent mean upper low over the
Bering/western Aleutians will propagate northward through the
Alaskan Panhandle and western mainland through the middle of next
week. The tight pressure gradient between the deep Aleutian
surface low and a strong mainland ridge will result in high winds
across the Alaskan Panhandle and Lower Kuskokwim region on
Tuesday. Heavy rain/snow is likely to continue across the
Peninsula and Kodiak Island throughout the period due to the
persistent troughing and moist southerly flow from the Gulf and
North Pacific into the elevated region. Temperatures should remain
around average for much of the mainland while a warming trend
ensues for the Aleutians and western mainland, except the
Panhandle which should remain cold. An arctic cold front, powered
by a shortwave aloft, will push through the eastern mainland early
next week and arrive along the Gulf/Southeast Coast by the
midweek. This front may focus some precipitation along the coast
mid-to-late next week.
Kebede
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
Last Updated: 657 PM EST Fri Feb 07 2025