Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
608 PM EDT Sun Apr 24 2022
Valid 12Z Thu Apr 28 2022 - 12Z Mon May 02 2022
...Guidance/Predictability Assessment...
Predictability is now bolstered as 12 UTC GFS/ECMWF/UKMET/Canadian
model solutions have significantly converged upon a much more in
common solution days 4-6 (Thursday-Saturday) in stark contrast to
recent higher forecast spreads. Favor a composite that maintains
great WPC product continuity. Model solutions for the evolution of
flow aloft into day 7/8 seems reasonably similar now, but
differences more evident with surface systems seem sufficient
enough to warrant a switch to usage of mainly the still compatible
but less detailed GEFS/ECMWF ensemble means for these longer time
periods to maintain max continuity. The 19 UTC NBM was again not
available for this forecast package via GFE due to lingering AWIPS
issues.
...Overview Weather/Hazard Highlights...
Lead lingering low pressure systems over the northern and eastern
Gulf of Alaska this week will continue some light to modestly
terrain enhanced precipitation from the southern Alaskan coast to
the Southeast Panhandle. Moderate precipitation will progress
across the Aleutians and the Alaskan Peninsula/Kodiak Island with
a couple of frontal systems/main lows through the period and as
amplified upper low/troughing focus gradually transitions from the
southern Bering Sea to the Gulf of Alaska later this week into
early next week. Triple point low re-development next weekend into
next week will transition main low focus downstream over the Gulf
to enhance maritime affect and precipitation there and across the
southern to southeast Alaskan coast. Much of the Mainland inland
should remain dry next week. However, lingering upper
impulse/trough presence and terrain may favor some very localized
enhanced snows for northern Alaska/the Interior.
Schichtel
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