Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
454 PM EDT Wed Jun 05 2024
Valid 12Z Sun Jun 09 2024 - 12Z Thu Jun 13 2024
...Guidance Evaluation and Preferences...
There is better agreement in the 12z guidance today, though the
12z ECMWF has some detail issues that appear unrealistic. Later
on, the 12z Canadian is the best match to the ensemble mean
solutions near the Bering Sea/Aleutians. Early on, a blend of the
12z Canadian/ECMWF/GFS/UKMET was used, before inclusion up to 50%
of the 12z NAEFS/00z ECMWF and lower weights of the 12z ECMWF, and
to some degree the 12z GFS, were employed to deal with the detail
issues. Most grids used a 19z NBM starting point, with the most
deviation within the wind and QPF grids, to increase magnitude.
...Weather/Hazards Highlights...
One system is expected to fade/become absorbed into a larger
cyclone south of AK early on (Saturday night). The combination of
these systems should allow for gales well out at sea, and possibly
coastal locations more prone to wind funneling, with rain general
expected in the south. Pressure gradient in the North Slope could
bring coastal winds towards gale force as well. Rainfall is heavy
enough in and near south-central AK for a hazard to be placed in
the outlook. Moderate to occasionally heavy rain then shifts east
around the increasingly barotropic low from south-central AK into
the AK Panhandle by early next week, which could lead to a burst
of moderate to heavy rains as an occluded front and increased
onshore flow in its wake occur. Interior shower chances exist due
to daytime heating at the periphery of the nearly cold low. High
temperatures range from the mid to upper 30s along the North
Slope, to generally 50s along the southern coast, to near 80F
inland. Subfreezing low temperatures appear confined to the North
Slope and higher elevations in south-central and southeast AK
between this weekend and mid next week.
Roth
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