Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
658 PM EDT Wed Jun 15 2022
Valid 12Z Sun Jun 19 2022 - 12Z Thu Jun 23 2022
...Overview and Guidance Evaluation/Predictability Assessment...
Upper pattern will feature a slowly but steadily moving upper low
pushing eastward across the Gulf of Alaska early next week,
eventually into the southern Panhandle and British Columbia by
next Wed/Thu. Troughing initially in northeastern Russia will lift
into the Bering Strait as ridging from the north central Pacific
pokes northeastward across the Aleutians and into southwestern
Alaska. The models and ensembles showed good to
better-than-average agreement, and a blend of the 12Z
GFS/ECMWF/UKMET/Canadian sufficed to start. The 12Z ECMWF became
(again) quite aggressive with height falls into northwestern
Alaska around next Wed, against the majority of ensembles--one
cluster of 4, with 22% of the membership of the GEFS/CMC/ECMWF
ensembles, showed average heights across northern Alaska at the
end of next week (not even below average). Preferred the 00Z ECMWF
ensemble mean by the end of the period, which was a bit more
amplified than the GEFS mean over the North Pacific as another
trough in the northwestern Pacific should help maintain some
amplitude (with agreement from the 12Z Canadian ensembles). This
solution kept reasonable continuity.
...Weather and Hazard Highlights...
Rainfall will focus over Southcentral into the Panhandle ahead of
and north of the upper low/sfc occlusion Sun-Mon, especially over
southeastern-facing areas on the Kenai Peninsula. Showers will
linger over the Panhandle until height start to rise later next
week. A stationary boundary across the North Slope/Brooks Range
will promote another area of rain and some high mountain snow
until the boundary dissipates. Typical surface trough north of the
Alaska Range will spark some showers as well with daytime heating.
Trend will be toward drier conditions by the end of next week with
ridging and high pressure.
Temperatures will be near to below normal over Southcentral into
the Panhandle as well as northeastern Alaska, but near to above
normal over western areas. Trend will be toward milder
temperatures overall through the week.
Fracasso
No significant hazards are expected over Alaska during this
forecast period.
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