Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
719 PM EDT Tue Jul 02 2024

Valid 12Z Sat Jul 06 2024 - 12Z Wed Jul 10 2024

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

The guidance continues to show fairly good agreement on the large
scale pattern featuring an upper low initially drifting westward
north of Alaska and eventually stalling/meandering near the
Chukchi Sea into mid-next week. The CMC and ECMWF actually bring
the low back East again early next week, which seems to be related
to interactions with another potential upper low towards the
northern edge of the AK domain (well north of the northern coast).
The GFS seemed more in line with the ensemble means in suggesting
a much slower progression, and fit better with previous WPC
continuity. Meanwhile, a deep upper low will meander south of the
Gulf of Alaska this weekend before slowly drifting north towards
the southern coast. Latest guidance shows good overall agreement
with this system.

The WPC blend for today favored the ECMWF, GFS, and CMC for the
first few days of the period, significantly increasing the
ensemble means days 6 and beyond to help mitigate the noise
especially with the northern system.


...Weather/Hazards Highlights...

A weakening surface front tracking west to east across Mainland
Alaska should provide focus for moderate to locally heavy
precipitation, with higher totals likely associated with higher
terrain. Alaska remains generally wet and unsettled the entire
period, which should help bring some relief to the spreading
wildfires across the state currently. By this weekend, rain and
storms will increase in coverage and intensity from the Alaska
Peninsula to Southern Coast as Gulf moisture gets pulled northward
ahead of the troughing over the mainland. As the Gulf low gets
pulled closer to the coast, precipitation is expected to increase
for Southeast Alaska too. Given overall upper troughing over the
state much of the period, daytime highs across nearly all of
Mainland Alaska and into the Southeast will be well below normal,
with the greatest anomalies across western and northern parts of
the state. Temperatures may begin to moderate again by mid next
week.


Santorelli


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