Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
628 PM EST Tue Feb 09 2021
Valid 12Z Sat Feb 13 2021 - 12Z Wed Feb 17 2021
...Guidance/Uncertainty and Weather/Hazards Assessments...
An upper ridge building over the mainland through high latitudes
into this weekend will usher in a more moderate pattern across the
region. However, there is a growing guidance signal to dig Arctic
trough energy/height falls down over the North Slope and northwest
Alaska next week in more unsettled but mainly dry flow.
Meanwhile, a stormy weather pattern focus is likely across the
southern Bering Sea and the Aleutians as a series of Pacific storm
systems work through the region, rotating within a broader upper
level trough position. System potential remains heightened for
these deep lows whose wrapping flow will threaten the Aleutians
and the AKPen/Kodiak and Southwest Alaska through the weekend and
into next week. Additional maritime system activity to the east
seems more modest over an unsettled Gulf of Alaska for the next
week, but the flow could eventually bring some organized
precipitation onshore downstream into southern and southeast
Alaska.
The 12 UTC GFS/ECMWF/UKMET are clustered enough (Canadian an
outlier) that a blend seems to offer a decent forecast for day
4-6/Sat-Mon consistent with a pattern with average predictability.
Forecast spread decreases onward when the compatible GEFS/ECMWF
ensemble means seem to provide a more reasonable larger scale flow
evolution.
Schichtel
Hazards:
- No significant hazards are expected for Alaska during this
forecast period.
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