Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
454 PM EST Wed Mar 02 2022
Valid 12Z Sun Mar 06 2022 - 12Z Thu Mar 10 2022
...Pattern Overview...
A very warm weather pattern remains on tap for much of Alaska
under amplified upper ridging as multiple but modest systems
traverse the North Pacific to impact the Aleutians as well as the
southern coast and Southeast Panhandle...
...Guidance/Predictability Assessment...
The 12 UTC GFS/ECMWF/Canadian solutions seem best clustered and
reasonable valid Day 4/Sunday into early Monday and a blend seems
to have good ensemble support. Models solutions quickly become
much less clustered through the rest of the forecast period
increasingly into a pattern with less than average
predictability.ÂI'd suggest a blend of the more run to run
compatible 12 UTC GEFS/ECMWF/NAEFS means to maintain as much
product continuity as feasible. This solution holds onto more
mainland upper ridging next week than the GFS/Canadian and less
than the amplified ECMWF. This seems reasonable at this point
given increasing uncertainties with embedded impulses at these
time frames and persistence.
...Weather/Hazard Highlights...
Modest low energies will work over the Gulf of Alaska into
Sunday/Monday to focus some moderate to heavy precipitation from
the southern Alaskan coast through the Southeast Panhandle with
northern stream upper trough passage. Meanwhile, a series of lows
with uncertain intensities will rotate through a mean western
Aleutians upper trough position to likely keep conditions
unsettled next week to include periods of enhanced rains/winds for
the Aleutians and the Alaskan Peninsula. Elsewhere, the Interior
and North Slope should be mostly dry into early next week in the
wake of weekend system passage. Much above average temperatures,
especially overnight lows, will focus over the Interior and
especially northern Alaska. Warmest anomalies are expected to
generally range from 20-30 degrees above normal, but locally
higher values may produce record values into early next week.
There is some model signal for unsettling and moderating Bering
Sea sourced upper troughing and associated downstream system
digging/passage across this region into the Tuesday-next Thursday
time frame, but considerable flow uncertainty exists at these time
frames, so prefer at this point a favored composite of ensemble
means to maintain max product and pattern continuity.
Schichtel
Hazards:
- Heavy precipitation across portions of the Alaska Panhandle and
southeast mainland Alaska, Sat-Mon, Mar 5-Mar 7.
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