Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
627 PM EST Sat Feb 12 2022
Valid 12Z Wed Feb 16 2022 - 12Z Sun Feb 20 2022
...Quite a stormy pattern for Alaska continues through next week...
...Guidance/Predictability Assessment...
Models and ensembles still offer a reasonably similar larger scale
flow evolution through medium range time scales and predictability
is good that the pattern will produce a number of well organized
stormy systems. However, there remain issues with the timing and
focus of embedded systems. Different guidance camp solution
clusters are evident as early as Day4/Wednesday and variance
increases through next weekend. Even so, a composite of the best
clustered 12 UTC GFS/ECMWF/Canadian and GEFS/ECMWF ensemble means
along with some manual edits seems to overall present a reasonable
forecast for days 4-8 with respect to WPC product continuity.
...Weather/Hazard Highlights...
More in a series of highly unsettling storms seem on tap for next
week, both with several deep lows back into the Aleutians and as
ample energies from multiple systems break downstream across
Southwest Alaska, the AKpen/Kodiak Island, south-central Alaska,
the Gulf of Alaska and Southeast Alaska. System timing variance is
not ideally set through medium range time frames, but the overall
stormy pattern seems decently predictable. Expect several more in
a series of deep and relatively slow moving storms for the
Aleutians after an already stormy next few days. These additional
systems are expected Wednesday/Thursday and possibly again into
next weekend, each with the potential for high winds/waves and
wrapping rains. System energies progressing downstream should
spread a focus for deepened moisture fueling heavy precipitation
from a warmed Southwest AK and the AKpen/Kodiak Island through
southern/southeast AK Wednesday/Thursday, and potentially again
across this broad region late next week into next weekend. This
would include a threat for multi-day heavy coastal rains and
inland/terrain enhancing snows.
Meanwhile, expect lingering but generally modest northern stream
upper troughing from the North Slope down into the north-central
Interior, but limited moisture and snow potential outside most
favored terrain in flow dominated by surface high pressure.
Temperatures are expected to be well above normal over a warmed
southern Interior, but still cold enough for a much better chance
for organized snows considering favorable upper support in closer
proximity to each of a main series of aforementioned southern
stream storm track as impulses work through a mean upper ridge
position.
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