Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
742 PM EDT Sun Jun 30 2024

Valid 12Z Thu Jul 04 2024 - 12Z Mon Jul 08 2024

...Overview and Guidance Evaluation/Preferences...

The latest runs of guidance continue to lock on to the idea of a
deep closed low over the Gulf of Alaska that will move southward
with time as the ridge over the Pacific builds northward all the
while a shortwave trough skirts across the Arctic and northern
parts of the Mainland. The GFS is persistent in lagging/much
further west of the consensus while today the ECWMF began to favor
the right/faster side of the cluster. The CMC has trended back
toward the middle of the pack and presents a fairly deep low
feature. The EC ensemble means and the GEFS means are positioned
closer to the CMC than their parent models but are noted to be
30-40 mb weaker than the deterministic guidance.

An initial starting point of the UKMET,CMC, GFS and ECWMF was used
before dropping the UKMET and leaning a little heavier toward the
CMC solution. The ensemble means were included around day 5 and
continued through the entire extended period. This combination
provided a deeper, slower low feature over the Gulf of Alaska and
provided a more pronounced frontal system across the Arctic region.

...Weather/Hazards Highlights...

Much of the Aleutians and the Southeast will have mostly light or
no precipitation through much of the extended period; however
there will be increases rain for part of the Southern Coast this
coming weekend. Rain/thunderstorms will steadily increase in
coverage and amounts across the western/northwest part of the
state while spreading across the Interior. An increase in wind
speeds and gusts across northern parts of the state could
aggravate the spread of the numerous wildfires that are scattered
across the Interior. Of late, the air quality has been very poor
from the smoke and the increasing wind speeds should help thin
some of the smoke out for a modest improvement of air quality. The
increase in rain potential however will help reduce and contain
the wildfires while providing beneficial moisture to the region.

Daily highs are expected to be mostly in the 60s and 70s across
lower elevations of south-central and portions of Interior Alaska,
50s and 60s in most coastal areas, 50s and 40s across the North
Slope, and mid to upper 40s in the Aleutians.  Higher elevations
in the terrain across south-central and southeast Alaska should
fall below freezing overnight.  

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