Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
651 PM EST Sun Feb 23 2025
Valid 12Z Thu Feb 27 2025 - 12Z Mon Mar 3 2025
...General Overview...
A strong storm system develops over the north Pacific, potentially
under 960 mb, and tracks in a general northeasterly direction to
the south of the Aleutians through the end of the week, and likely
reaching a location a couple hundred miles southeast of Kodiak
Island by Friday night. This will also increase chances for
moderate to heavy precipitation near the southern coastal areas
along with windy conditions. Meanwhile, an upper ridge axis is
expected to extend from western Canada into the Interior through
most of the forecast period, with gradually warming conditions for
central and southern Alaska, and continued cold north of the
Brooks Range where an arctic surface high will govern the overall
weather pattern.
...Guidance Evaluation and Preferences...
The big low pressure system south of the Aleutians late in the
week has good overall model agreement, but there is still some
uncertainty going into Saturday as the low potentially splits into
two smaller lows, as suggested by the CMC and ECMWF. The GFS
takes the low farther west across Bristol Bay, but all bring
impacts with enhanced onshore flow and heavy precipitation/wind.
Heading into next weekend, the models generally agree that a broad
upper ridge will extend across the eastern mainland and western
Canada, but vary more across the North Pacific with the next
potential storm system to develop south of the Aleutians and a
separate arctic upper low near eastern Siberia. The ensemble
means were gradually increased to about half of the forecast blend
by next Monday.
...Weather/Hazards Highlights...
In terms of precipitation, multiple rounds of coastal rain and
mountain snow can be expected for the southeast Panhandle region,
and another surge of moisture in association with the big Pacific
low late in the week will likely result in 1-3 inches of rainfall
for parts of the Kenai Peninsula, Kodiak Island, and near the
Prince William Sound, and heavy snow for the higher elevations.
Widespread gale to strong force winds are likely across the open
waters of the Gulf and potentially reaching some of the coastal
zones, so this would create hazardous boating conditions.
Temperatures are generally expected to be near to slightly above
average across most of central mainland Alaska through the
forecast period south of the Brooks Range, with gradually warmer
temperatures expected each day. It should remain the case that
the coldest conditions will continue to be across the North Slope
and northward to the Arctic Coast where readings should remain
slightly below seasonal averages with the Arctic high in place.
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