Flood Watch 4, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
526 AM AKDT Sun May 31 2026

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

Isolated showers remain in the forecast over the northern Susitna
Valley, along the Alaska Range, Copper River Basin, and south to
Valdez through the rest of this morning then become confined
toward the Alaska Range this afternoon. Otherwise, many locations
away from the Gulf coast can expect some peeks of sunshine this
afternoon and evening.

The larger weather story shifts to the Gulf as a strong low
pressure system lifts into the southwestern Gulf later tonight
into Monday. At the same time, strong high pressure building along
the northern Gulf Coast will tighten the pressure gradient across
coastal Southcentral. Easterly to southeasterly winds will
increase Sunday and persist into Monday, especially favored
terrain gaps. Gap winds through Turnagain Arm, the Knik River
Valley, and Copper River will pick back up both Sunday and Monday
afternoons, while Kodiak Island can expect increasing winds and
periods of moderate rain as the Gulf system approaches. The
strongest winds are expected across marine areas, including
portions of Shelikof Strait and the Barren Islands vicinity, where
gale-force winds appear likely tonight through Tuesday morning.

Looking towards mid week, a building ridge over mainland Alaska
continues to support a warming and drying trend for much of
Southcentral. After what has felt like endless days of clouds,
showers and cooler temperatures, the forecast will finally see
increasing sunshine and temperatures gradually climbing.

-LM/AS/Rux

&&

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

As of this morning, the synoptic setup at the surface shows
strong vertically stacked high pressure encompassing the central
Bering, which has in effect stalled a Kamchatka front across the
Western Aleutians. The other big feature to note is a front
lifting northward from the North Pacific. Aloft, as the upper
level ridge begins to slowly nudge eastward through this
afternoon, an arctic trough digs southward towards Southwest
Alaska, which will add upper level support to diurnally driven
showers and isolated thunderstorms with a few lightning strikes.
The focus for today will likely be along a corridor from Aniak and
southwestward along the Kuskokwim and Kilbuck Mountains. With a
west to southwest storm motion in place, an isolated storm cannot
be ruled out as far southwest as just east of Quinhagak. With the
loss of daytime heating this evening, generally expect convective
activity to decrease.

As a front from a North Pacific low lifts northward Sunday
evening, rainfall and northeasterly small craft winds will be on
the increase south of the Alaska Peninsula. By Monday morning
through the afternoon, sustained winds increase to gales with wind
gusts nearing storm force as rainfall moves northward across the
Alaska Peninsula. The front likely reaches peak intensity Monday
morning with sustained winds approaching storm force for our
coastal marine zones south of the Alaska Peninsula with wind gusts
topping out in the 50 to 55 kt range. From here, the front begins
a weakening trend as the parent area of low pressure remains
quasi-stationary and fills across the North Pacific and southwest
Gulf. Total rainfall amounts have trended up with this system,
and totals generally around a half inch to three-quarters of an
inch now seeming likely through Tuesday afternoon. The one
exception here will be Chignik, where upslope enhancement could
lead to up to 2 inches of rainfall.

A warming trend is on the way for Southwest Alaska for the first
part of the week with high temperatures climbing to near 70
degrees from Bethel to Lime Village. One area to watch for
possible fire weather concerns will be the Crooked Creek and
Sleetmute area on Tuesday as a stout northerly flow advects in
warmer and drier air from the Interior. Daytime highs on Tuesday
for these two locations could very well warm into the low to mid
70s.

-AM

&&

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

Monday's Gulf low should be drifting southwestward back into the
North Pacific by Tuesday. A remnant front from the low is forecast
to slide westward across the Alaska Peninsula while steadily
deteriorating. High pressure then builds over the Bering and
interior Alaska for Wednesday and Thursday, with warmer
temperatures and daily shower and thunderstorm chances from strong
daytime heating. A new North Pacific frontal system tracks into
the Aleutians by early Friday with renewed showers and the
potential for gusty southeasterly winds from Adak into Cold Bay as
the front progresses quickly eastward into Friday night.

-BL

&&

.AVIATION...

PANC...VFR conditions persist. Southeasterly winds are expected
to increase by late morning. Gusts up to 30 is likely with brief
gusts to 35 mph possible late this afternoon after 00Z through
08Z/midnight. By Monday morning, winds become light as they shift
northerly.

&&