Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
506 PM EST Sun Jan 09 2022
Valid 12Z Thu Jan 13 2022 - 12Z Mon Jan 17 2022
...Guidance/Uncertainty assessment and Weather Pattern/Hazard
Highlights...
The 12 UTC models have come into better agreement today through
medium range time scales, bolstering forecast confidence given
generally good ensemble support. A composite blend of the
GFS/ECMWF/UKMET/Canadian seems to provide a good forecast starting
point and maintained good WPC product continuity in a pattern with
slightly above normal forecast confidence. The composite tends to
mitigate the less predictable smaller scale differences in
otherwise now reasonably well clustered solutions days 4-8
(Thursday-next Monday).Â
Guidance agrees that an amplified Arctic stream upper trough will
settle over the North Slope/Brooks Range and northern Interior to
offer some cooling and snow potential into mid-late week. A
moderating upper ridge is expected to build northwestward from
western Canada into mainland Alaska well over-top a stormy
maritime pattern held down over the North Pacific/Gulf of Alaska.
Guidance differences have become less problematic with varied
embedded systems within the models, albeit with some pause
considering recent run to run issues with the still complex series
of Gulf of Alaskan lows and interaction with the aforementioned
upper ridge. The preferred composite still maintains a decently
amplified upper ridge that seems most reasonable considering
recent flow nature. While multiple systems are expected to affect
a broad area from the Aleutians through the Southeast this period,
the pattern seems to best favor a south-central AK coastal
precipitation focus whose threat along with enhanced wind flow may
be maximized Thursday/Friday with deepened Gulf low approach.
There is also an increasing guidance signal in support of
additional strong low genesis and track to the Aleutians from next
weekend into early next week.
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