Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
705 PM EDT Fri Jun 16 2023
Valid 12Z Tue Jun 20 2023 - 12Z Sat Jun 24 2023
...Guidance Evaluation/Preferences...
The 12 UTC GFS/ECMWF/CMC/UKMET and NAEFS/ECMWF ensemble mean
solutions seem reasonably well clustered over the next week
despite some periodic system and stream flow energy phasing
differences. A composite blend with a focus on the higher
resolution models acts to maintain great WPC product continuity
with detail consistent with a pattern with above normal
predictability and longevity. Additional adjustments were manually
applied to offshore low pressure systems to ensure sufficient
depth given favorable upper support.
...Pattern Overview and Weather/Hazards Highlights...
A closed low/amplified trough position aloft and local surface
focus centered over Northwest Alaska should prove slow to vacate,
but may lose influence late next week/weekend. Expect the region
and surrounding areas from western Alaska and the Interior through
the North Slope and into the Arctic Ocean will experience
unsettled conditions next week to include multiple periods with
some locally enhanced winds and precipitation.
Meanwhile farther south out from the westerlies, a leading closed
upper low and associated surface low/frontal system with deepened
moisture will linger mainly over/south of the Aleutians early next
week. The system will gradually work eastward into and then dig
over the Gulf of Alaska mid-later next week. Flow around the
system favors moderate rainfall chances from the Aleutians and
Alaksan Peninsula/Kodiak Island out into South-Central next week,
but may be slow to work further eastward toward Southeast Alaska
as shielded by amplified eastern Gulf of Alaska to Interior to
Southeast Alaska upper ridging.
Upstream, a continued and energetic/active storm flow off eastern
Asia and the western Pacific will continue to churn up additional
low pressure systems to include deepened storm tracks into the
Aleutians/Bering Sea through later next week that would offer
potential for high winds/waves and wrapping rains that may work
steadily eastward toward southwest Alaska and vicinity heading
into next weekend in a pattern to monitor for any emerging
impacts.
Schichtel
Hazards: No significant hazards are expected over Alaska during
this forecast period.
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