Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
616 PM EDT Fri Jun 24 2022
Valid 12Z Tue Jun 28 2022 - 12Z Sat Jul 02 2022
...Pattern Overview and Weather and Hazard Highlights...
It remains the case that strong upper ridge drifting over the
mainland and northwestern Canada should promote a broad area of
above to much above normal temperatures during much of this
period, albeit with the center of an eastern mainland/northwestern
Canada upper ridge gradually drifting more into Canada by the
middle of next week. Expect the most notable/impactful anomalies
to be over the Interior and especially the Panhandle. The
Panhandle may see the greatest departures from normal and best
potential for a few locations to challenge daily records into
early next week. Farther west, an upper trough with embedded low
should persist over the Bering Sea and Aleutians for most of the
period. A main surface low is expected to track into the
Aleutians/Bering Sea by early next week and spread widespread
lead/wrapping moderate precipitation across the Aleutians and into
the AKpen/Kodiak Island/southern AK as well as up into
Southwest/Western then Interior Alaska with approach during the
course of next week while lifting/shearing around the western
periphery of the upper ridge along with increasing moisture.
Upstream, another system emerging from the western Pacific may
start to influence the Aleutians after midweek and with much
uncertainty could then shear northeastward toward the mainland. A
deep upper low over the Arctic Ocean is still likely to remain
well northwest/north of the mainland, but some differences persist
for how surrounding flow could influence the northern mainland.
The North Slope may see episodes of light precipitation if a front
to the north gets close enough to the region.
...Guidance Evaluation/Predictability Assessment...
It was noted that despite good overall guidance clustering
yesterday, the complex nature of systems might still temper
predictability. This is now more evident as model and ensemble
solutions are more diverse today, increasingly from day 5-8. A
model composite blend of the 12 UTC GFS/ECMWF/UKMET/Canadian seems
fine for day4/Tue before opting for a transition day5/Wed to a
composite of just the latest GEFS/NAEFS/ECMWF ensemble means. WPC
product continuity is well maintained in this manner, albeit with
less system detail consistent with uncertainty.
Schichtel
Hazards:
- Much above normal temperatures across portions of the Alaska
Panhandle, Mon-Wed, Jun 27-Jun 29.
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