Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
752 PM EDT Sun Jun 16 2024

Valid 12Z Thu Jun 20 2024 - 12Z Mon Jun 24 2024

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

Most of mainland Alaska will be situated under a narrow upper
level ridge axis extending from northwestern Canada going into the
middle to end of the week.  A compact upper level polar is
forecast to be just south of Bering Strait for the end of the
week, with gradual weakening going into next weekend.  Meanwhile,
the main storm track across the North Pacific is expected to
feature two low pressure systems, with the lead system approaching
the southeast Panhandle going into Saturday, and the second one
passing south of the Alaska Peninsula Sunday/Monday.

Overall, the latest model guidance is in above average agreement
across the Alaska domain to close out the week, and even
reasonable agreement for next weekend with the main synoptic scale
features.  The CMC is on the northwestern edge of the guidance
with the polar low over the Bering Sea, compared to the more
clustered GFS/ECMWF/UKMET solutions, and weaker with the second
North Pacific shortwave later in the forecast period.  Going into
Sunday, the GFS is over the southwestern mainland coast with the
polar low and well southeast of the GEFS mean.  There is better
agreement among the ECMWF/ECENS.  The ensemble means accounted for
about 40-50% of the forecast blend going into next Monday.


...Weather/Hazards Highlights...

Isolated to scattered showers and thundershowers can be expected
most days across the Interior during the afternoons and early
evenings, and some generally light onshore flow induced showers
for the southern coastal areas. The greatest QPF is expected
across the Alaska Range and portions of the Brooks Range, along
with southeastern mainland Alaska. 
Depending on the evolution and track of a surface low over the
eastern Gulf by next weekend, a more organized round of rain could
approach the southeast Panhandle, although it's not expected to be
a major event.  Areas north of the Brooks Range should generally
remain dry with the Arctic high exerting its influence across the
North Slope and Arctic Coast.

In terms of temperatures, afternoon highs are expected to reach
well into the 70s for many areas across the Interior, perhaps
reaching 80 degrees for the Yukon Flats, and also just north of
the Alaska Range over the weekend.  Overnight lows here should
also be rather mild with readings bottoming out from the upper 40s
to middle 50s.  The Arctic Coast will likely remain chilly with
onshore flow from the Arctic Ocean, with highs generally from the
middle 30s to middle 40s. 

Hamrick


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