007
FXAK02 KWNH 072303
PMDAK

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
603 PM EST Thu Nov 07 2024

Valid 12Z Mon Nov 11 2024 - 12Z Fri Nov 15 2024

...Growing signal for Bering Sea storm to bring coastal impacts to
Southwest/Western Alaska later next week...

...Overview...

A couple low pressure systems will pass south of the state during
the first half of next week, and gale force winds accompanying
these storm systems will likely produce hazardous conditions in
the Gulf of Alaska. By mid-next week, a relatively weak arctic low
will move into the Bering Sea, then a more potent Pacific storm
system will move into the Bering Sea later next week. There is a
growing signal in model guidance that this Pacific storm system
could potentially bring coastal hazards to Southwest/Western
Alaska Thursday and Friday.


...Guidance Evaluation/Preferences...

There is very good model agreement on the weather pattern across
the Alaska region early next week, leading to above average
predictability in this time frame. By mid and late next week,
predictability returns to near average as model spread increases.
The most significant uncertainty surrounds the strong low that
will move into the Bering Sea later next week. Models have
consistently shown a strong low in the Bering Sea, but there is
still uncertainty in the timing, location, and strength of this
low. Today`s model runs have been trending more south and slightly
deeper with the low pressure center, and manual adjustments were
made to reflect this in the WPC forecast. The WPC forecast
initially consisted of a blend of the GFS/ECMWF/CMC/UKMET for
Monday, when model agreement is high. The CMC and UKMET held less
weight in the blend because they were depicting a less amplified
pattern, which was a bit of an outlier from the consensus from
other deterministic and ensemble guidance. For Tuesday and
Wednesday, ensemble means from the GFS/ECENS/CMCE were introduced
to the blend, but the majority of the weight was still placed on
the deterministic guidance. By Thursday and Friday, ensemble means
made up the majority of the blend with a small amount of
deterministic guidance still included to retain some details/depth
of the Bering Sea low.


...Weather/Hazards Highlights...

Gale force winds associated with a couple lows passing south of
the state will likely produce hazardous marine conditions in the
Gulf of Alaska during the first half of next week. As these low
pressure systems approach Southeast Alaska, periods of gusty winds
and moderate precipitation will be possible, but conditions are
not expected to be impactful.

Hazardous weather potential will focus over portions of
Southwest/Western Alaska later next week as a strong low moves
into the Bering Sea. Strong onshore winds may create coastal
hazards, especially in areas susceptible to coastal flooding, in
Southwest Alaska Thursday into Friday. This system will also
increase precipitation chances over Western Alaska on Thursday,
and precipitation chances may spread into Interior Alaska on
Friday. There is still uncertainty in the exact location and
timing of impacts associated with this system, which will be
monitored closely in the coming days.

Arctic high pressure north of the state will usher in colder
temperatures next week, with cooling trend expected to persist
through the week. High temperatures will drop 5-10 degrees below
average for most of Alaska by mid-next week, and the coldest
temperatures will focus from the Brooks Range down through
Interior Alaska.


Dolan


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

$$