Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
538 PM EST Thu Jan 21 2021
Valid 12Z Mon Jan 25 2021 - 12Z Fri Jan 29 2021
...Deep lows to Threaten Alaska next week...
...Overview and Guidance/Uncertainty Assessment...
A series of potent closed low/trough will track into the Bering
Sea next week and downstream energy transfers into the Gulf of
Alaska still offer less than stellar models depictions of
potentially deep systems, but the overall upper flow evolution now
seems better represented in some guidance. The WPC Alaskan medium
range progs were primarily derived from a blend of the 12 UTC
ECMWF and 12 UTC GEFS ensemble mean. The older 00 UTC ECMWF
ensemble mean and other 12 UTC model solutions were not as well
clustered with our preferred solution, but the newer 12 UTC ECMWF
ensemble mean seems to be more in line now. This collaborated
forecast strategy maintains reasonably good WPC product continuity
and seems to highlight the most predictable low systems showing
deeper development and threat potentials.
...Weather/Hazards Highlights...
There remains a good guidance signal showing that a reasonably
deep Aleutian/Bering system Sun/Mon and lead triple point low will
bring high winds/waves and precipitation to the unsettled region.
This should spread along the western coast of Alaska as the front
pivots and redevelops to the southeast across the AKPen into Tue.
An upstream and potentially much deeper system would spread heavy
wrapping precipitation and a threat of high winds/waves to the
Bering Sea and Aleutians by Tue-Wed. This system may offer
substantial effects to monitor both into western Alaska, but
especially across the AKPen/Southwest AK then a stormy northern
Gulf of Alaska into southern/southeastern Ak mid-later next week.
Schichtel
Hazards:
- High winds across portions of the Aleutians, Tue-Wed, Jan 26-Jan
27.
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