Gale Warning 370, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
449 AM AKDT Tue May 13 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

The widespread light to moderate rain that blanketed the region
yesterday is clearing out from west to east this morning as an
upper level shortwave exits the region near Yakutat. A brief
shortwave ridge will move overhead through Wednesday morning,
allowing for what may be the nicest day of the work week today.
Behind this, another strong low will move south of the Alaska
Peninsula, reintroducing strong winds over the marine areas and
steady light to moderate rain for Kodiak and the western Sound.
Inland areas, while they will be cloudy, should be downsloped, but
afternoon showers are possible over the interior mountain ranges.
Additionally, expect another round of breezy winds through the
southeasterly mountain gaps. Temperatures are likely to remain
slightly below normal from Wednesday onwards.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Today through Friday morning)...

Three storms impact the region through Friday, with the strongest
storm moving over Southwest Alaska from Wednesday through Thursday.
Forecast confidence is moderate to high, and no watches, warnings,
or advisories are currently in effect.

Diving into the details... the low responsible for the past few
days of busy weather continues to weaken over the Central Bering
Sea. Through today, it will phase with and absorb a second low
entering the Bering Sea near the Central Aleutians, then slide
westward across the Bering Sea through Thursday. Winds of 25-30
kt are expected around the two lows, with gusty winds for the
Alaska Peninsula later this afternoon. Though the second low will
bring moisture advection of about 1 inch of precipitable water,
the positioning of the front means that the heaviest and longest
duration rain will remain mostly over water and avoid the biggest
population centers along the Aleutian Islands. Overall, the main
impact will be an uptick in southerly gap winds for the Eastern
Aleutians and southern Alaska Peninsula, along with another round
of rain.

The bigger story will be a North Pacific low that strengthens to
about 982 mb as it approaches Southwest Alaska late tonight
through Wednesday morning. A leading gale force front will lift
northward across the Alaska Peninsula and into Bristol Bay Tuesday
night through Wednesday. This will bring strong and gusty
easterly winds on the order of 40 to 55 mph to much of the Bristol
Bay region on Wednesday, with winds diminishing through Thursday.
The bulk of rain with this system will be confined to upslope
areas, including the south side of the Alaska Peninsula and areas
north and west of Dillingham.

-SEB/KC

&&

.LONG TERM FORECAST (Days 4 through 7: Friday through Monday)...

There is loose agreement with ensemble guidance that an upper
level trough will move from the Bering Sea to the Gulf of Alaska
Friday through Monday. Operational guidance shows variations of
this setup but has poor agreement with regards to timing of
surface features.

Ridging looks to develop behind the Bering trough Friday and move
eastward from the Western Aleutians to the Central Aleutians as
it weakens. Expect quieter weather across these areas while
underneath the ridge. Meanwhile, troughing will linger across the
north Gulf Coast through Sunday with rain continuing along the
coast of Southcentral with diurnal showers developing across
portions of Southwest through Monday. A North Pacific front looks
to lift northward through the Gulf Sunday and Monday with spread
on the track of the low center itself ranging from remaining south
in the North Pacific to a more northerly track into the central
Gulf to near Kodiak Island. Regardless of the low track, the
Alaska Peninsula to Kodiak Island look to be the wettest with more
uncertainty in the precipitation forecast for the Eastern Kenai
Peninsula and north Gulf Coast due to just how far north the front
will end up lifting.

&&

.AVIATION...

PANC...Showers will dissipate and ceilings will continue to lift
early this morning. Light winds and VFR conditions will persist
for the remainder of the day as high pressure nudges in across
Southcentral. Southeasterly winds will increase Wednesday morning
as a strong front pushes north from the Gulf of Alaska.

&&