Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
258 PM EDT Sat Jun 09 2018

Valid 12Z Wed Jun 13 2018 - 12Z Sun Jun 17 2018

...Guidance Assessment and Weather Highlights...

Model and ensembles remain decently clustered with a series of
organized maritime lows. A weakening lead system will clip the
southeastern Gulf of Alaska into midweek and produce lingering
modest precipitation for far SE Alaska. Flow amplification then
forces an upstream low/frontal system well south of the Aleutians
midweek to lift northeastward toward the AK peninsula later next
week along with a maritime threat of high winds/waves. Heavy
precipitation works in ernest into the AKpen and
southwest/southern Alaska as deep layered moisture feeds northward
ahead of the deepened low.

Overtop, it remains evident an early-mid next week arctic
trough/low and height falls dig southward over the north slope and
west-central interior. Expect post-frontal cooling and an
unsettled weather pattern with scattered precipitation that could
become more widespread with potential amplification on the deeper
side of the full envelope of model and ensembles solutions.
However, latest guidance is quite varied with the extent of
northern stream amplification and is especially problematic with
potential southern stream phasing issues days 7/8 as the deepened
low lifts through the AKpen. WPC progs show potential for some
phasing and an enhanced interior weather threat, but forecast
predictability seems well below average then at higher latitudes.
The full suite of incoming 12 UTC guidance seems to suggest less
phasing than my WPC progs as per slower lifting of the
aforementioned deepened low heading for the AKpen.

Schichtel

WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can be found at:

http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html