Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
753 PM EDT Thu Jun 16 2022
Valid 12Z Mon Jun 20 2022 - 12Z Fri Jun 24 2022
...Overview and Guidance Evaluation/Predictability Assessment...
The 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. There was reasonably good model agreement for the closed
upper low trekking east through the Gulf for the first half of
next week along with the ridging behind. The 12Z GFS though ends
up a bit north of consensus across the Panhandle Wed with the
centroid of the upper low and lingers it over the Panhandle Thu
unlike other guidance, so preferred a model blend of the 12Z
ECMWF/CMC/UKMET with some incorporation of the 06Z GFS for this
feature. Upstream, upper troughing and an associated surface low
approaching the Aleutians for the latter part of next week shows
to be faster in the GFS/GEFS than the CMC/EC cluster. Leaned more
toward the latter considering typical model behavior. Meanwhile
farther north of the ridge, there are some rounds of troughing
possible for northwestern Alaska at times, which show some
variability with the details and some phasing differences, but a
deterministic model/ensemble mean blend made for reasonable
compromises there.
...Weather and Hazard Highlights...
Moist inflow associated with the Gulf of Alaska lows will promote
rainy conditions for the Panhandle streaming into eastern parts of
the mainland especially for the first half of next week. There
could be some terrain enhancement of amounts for parts of the
Alaska Range where a typical surface trough should set up, and
across parts of the North Slope/Brooks Range in the vicinity of a
stationary boundary. The trend will be toward drier conditions by
the latter part of the week over the mainland with ridging and
high pressure, though rain chances may increase for the Aleutians
just ahead of a low pressure system.
Temperatures will be near to below normal over southeastern Alaska
into the Panhandle initially, though moderating/warming later next
week. Southwestern to Southcentral Alaska should gradually warm to
above normal through next week as well. Periods of cooler than
normal high temperatures are likely for the Brooks Range into the
North Slope, however.
Tate/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