Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
750 PM EDT Fri May 28 2021
Valid 12Z Tue Jun 1 2021 - 12Z Sat Jun 5 2021
...Overview and Guidance Evaluation...
The weather pattern for the first five days of June will be
featured with a pair of upper level lows over the Aleutians and
northern Gulf region, and congealing into one main upper level
gyre over the Gulf by the end of the week. A narrow upper level
ridge axis should extend across the Interior and northwest Canada
with a stationary frontal boundary across the north-central
portion of the state, and an arctic upper low drifting south
toward the northern Bering Sea.
In terms of the models, there appears to be better than average
deterministic agreement through Wednesday night, mainly owing to
the amplified pattern in place. The 12Z CMC is closer to the
consensus compared to earlier runs. By the end of next week, the
18Z GFS is stronger with the Aleutian low and this holds true as
it tracks eastward near 50 degrees north. The WPC forecast was
primarily derived from a blend of the 12Z ECMWF/GFS/CMC/UKMET
through Wednesday, and then a slight increase in the ensemble
means for Thursday through Saturday with less of the operational
GFS.
...Weather/Threats Highlights...
The persistent low pressure and onshore flow from the Alaska
Peninsula to the southeast panhandle region is expected to produce
multiple rounds of moderate rainfall for coastal areas and nearby
mountain ranges. Some locations could receive an inch or two of
rainfall for the early to middle portion of next week, especially
across topographically favored areas, followed by lighter rain and
some drier periods by the end of the week. Some showers can also
be expected across portions of the Interior, mainly for the middle
of the week. Temperatures are expected to reach the 60s and low
70s across much of the Interior for highs, and remaining quite
chilly north of the Brooks range where highs should remain in the
30s and 40s.
Hamrick
Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards 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