940
FXAK68 PAFC 200040
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
440 PM AKDT Mon May 19 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(Days 1 through 3: This afternoon through Thursday evening)...

Satellite imagery shows cumulus clouds developing along the north
side of the Wrangell Mountains and around the ALCAN border early
this afternoon. Cloud cover from earlier this morning has cleared
out across northern portions of the Copper River Basin. Thus,
temperatures have been able to climb into the middle 50s to around
60 degrees from Mentasta Lake and Chistochina westward to Paxson.
Isolated to widely scattered thunderstorms have developed across
the northeastern Copper Basin and will continue through the
evening. Isolated thunderstorms are possible Tuesday afternoon as
well; although the chance for lightning strikes will be lower
than compared to today.

The forecast continues to be on track with regards to two
shortwaves originating from the Bering Sea affecting Southcentral
Tuesday and Wednesday. The first shortwave and the weaker of the
two will lift up Cook Inlet and bring light rain to the central
Kenai Peninsula, Anchorage, and Mat-Su Valleys Tuesday through
late Tuesday evening.

The second and stronger shortwave will impact Kodiak Island
Tuesday evening into Wednesday as a surface low pressure moves
across the Alaska Peninsula into the North Pacific by then. This
will deliver gusty southeast winds and steady rain to Kodiak
Wednesday through mid-day Thursday before precipitation becomes
more showery and lighter. In addition to Kodiak Island`s southeast
winds, southerly and southeasterly gap winds also pick up through
Turnagain Arm, the Knik River Valley, and the Copper River Valley
Tuesday through Thursday with the highest gusts occurring during
each afternoon. Although the eastern Kenai Peninsula and western
Prince William Sound will see rain Wednesday into Thursday, the
lion`s share of rain looks to remain confined to Kodiak Island due
to the more southern storm track of the low.

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA AND BERING SEA/ALEUTIANS
(Days 1 through 3)...

Weak ridging is present over the East Bering and the Southwest
Alaska mainland, allowing for light winds and low chances for
precipitation. Skies are clearing out over the mainland, but low
stratus is present in the Alaska Peninsula and the Kuskokwim
Delta. Meanwhile, two upper lows between a thin ridge in the
Bering are pushing a "nose" shaped glob of precipitation and small
craft winds eastward. The lows combine forces in the eastern
Bering Tuesday afternoon and reinforce a surface low that
continues moving eastward. The glob of precipitation and winds
will impact the Eastern Aleutians and Alaska Peninsula through
Wednesday. Gale force gap winds will also be present during the
same time period for those regions. The low will drive moisture
into the Southwest mainland, allowing for precipitation for all
regions late Tuesday into Wednesday.

A weak ridge will follow the low, briefly decreasing
precipitation chances and wind speeds first in the Bering
Wednesday afternoon, then in the mainland Wednesday night into
Thursday morning. There will still be enough moisture and lift in
place in the mainland for scattered showers Wednesday afternoon.
This lull will not last long as another low will quickly push in
from the west, driving a front through the Bering and into the
mainland through Thursday afternoon. Once again, the mainland will
see increased precipitation chances and wind speeds everywhere.
Looking a bit ahead shows that the aforementioned pattern may
repeat itself with a ridge, then another low moving into Southwest
Alaska over the weekend.

-JAR

&&



.AVIATION...

PANC...A low stratus deck (mostly in MVFR range) that developed
earlier today appears to finally be eroding this afternoon with
daytime heating, allowing ceilings to predominantly return to VFR
range. Showers along with a gusty Turnagain Arm wind will return
to the terminal by tomorrow afternoon. Cloud bases are expected to
mostly remain in VFR range through tomorrow afternoon, but lower
ceilings/visibilities down to MVFR will be possible at times in
heavier rain showers.

-AS

&&


$$