Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
653 PM EST Thu Mar 07 2024
Valid 12Z Mon Mar 11 2024 - 12Z Fri Mar 15 2024
...General Overview...
Much colder temperatures will already be in place across parts of
northern and west/southwest Mainland/Interior and will begin to
slowly moderate by the later part of the period. Multiple low
pressure systems will track south of the Aleutians and into the
northern Gulf keeping precipitation focused across the Southern
Coast, Southeast Alaska, and adjacent mountain ranges.
...Guidance Evaluation and Preferences...
In general, the synoptic pattern of mean trough/upper low setting
up over western Alaska and Gulf of Alaska with multiple lows
tracking through the flow remains consistent. Forecast confidence
continues to be about average given model differences on timing,
location and depth for each individual feature - particularly with
those tracking across the Gulf.
The WPC preferred approach started with the 12Z/06Z GFS and 12Z
CMC/UKMET/ECWMF and then included the GEFS mean and EC ensemble
means by the middle period while dropping the UKMET. This approach
stayed near continuity with the previous WPC Alaska forecast.
...Weather/Hazards Highlights...
Most of Southeast Alaska and portions of the southern coast will
be in an active wet pattern through the extended period as a few
surface lows and frontal systems affect the region. Precipitation
(rain and mountain snow) should extend back into the Southeast
Coast/AK Peninsula and portions of the mainland under general
unsettled flow/troughing, but not as heavy. Multiple systems
maintaining rain across this part of the region coinciding with a
warm up in temperatures across the Southeast that may lead to snow
melt increasing the potential for runoff across the Panhandle. The
period with the best potential for moderate/heavy rain will be
Wednesday into Thursday.The Aleutians should stay wet and
unsettled for much of the forecast period as several systems move
through the region.
Temperatures for a vast portion of western Alaska will be quite
cold into the first half of the week which will be much below
average for early/mid March. Widespread subzero lows are expected
for western and northern portions of the mainland, with perhaps
some -30s across the normally colder locations of the North Slope
Campbell
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