Gale Warning 392, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
457 PM AKDT Sun May 29 2022

.ANALYSIS AND UPPER LEVELS...

The upper level ridge remains over Southwest and Southcentral
Alaska this afternoon bringing continued warm temperatures to
the region. That is, if you can stay out of the widespread marine
stratus over the Gulf of Alaska and Bering Sea. This stratus has
been encroaching into the coastal land areas overnight and then
dissipating in the daytime heating.

An upper level short wave is moving northward over Bristol Bay
this afternoon and is the reason for some convection through the
Bristol Bay and Kuskokwim Valley areas this afternoon and evening.

&&

.MODEL DISCUSSION...

Overall model agreement remains high. The biggest question remains
with the areas of convective instability the next few days. As
normal, the NAM indicated a lot more instability than the GFS,
but both are mainly keeping it toward the Alaska Range.

&&

.AVIATION...
PANC...VFR conditions will persist. Southwest winds will switch
to more south-southeast this evening and likely persist through
most of the night.

&&

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

A high pressure ridge located over Southcentral this afternoon
will linger over the region for the next few days while it slowly
builds to the east. As a result, expect continued warm and dry
conditions with generally light winds across most of the mainland
in addition to the typical diurnal sea breezes. The southern
mainland can expect to see mostly clear skies persist into the
middle of the work week, and slightly increased chances for
showers along interior mountains will also continue for a few
more days. Fog and marine stratus over the Gulf and along the
Southcentral coast should stick around through at least Wednesday
afternoon. Southwesterly flow up Cook Inlet (as a result of the
ridge gradually tracking to the east) will diminish Monday
morning. By Monday afternoon, a thermal trough will develop at the
surface across Southcentral and will allow temperatures to warm
once again. A large vertically-stacked low will approach the
southern Gulf by Tuesday, spreading easterly small craft winds
just south of Kodiak Island and northeasterly small crafts through
Shelikof Strait. Winds, clouds, and precipitation chances for
Kodiak Island will start to diminish on Wednesday as the low
exits to the southeast.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Tonight
through Wednesday)...

A weak upper level disturbance has combined with marginal
instability over the interior to bring isolated to scattered
showers to the region. Steering flow is very weak out of the
south-southeast, so the majority of these showers will rain
themselves out before intensifying to thunderstorm strength,
though an isolated lightning strike here or there is possible.
Over coastal areas, weak sea breezes and dissipating fog and
low stratus has led to cooler temperatures than were observed
yesterday. Expect fog to return to the Kuskokwim Delta coast
Monday morning.

On Monday, a north Pacific low will move south of the Akpen,
which will increase easterly winds through Bristol Bay and
Kamishak Gap. For most of the region, expect warm/hot and dry
conditions, though a few more showers are possible over the
Kuskokwim Mountains and Valley Monday afternoon. High clouds
will move over the area as the front approaches, which will
increase morning lows and subsequently highs on Tuesday.
Weather on Wednesday should be mostly calm with dissipating
clouds and warming temperatures as the high over the southern
Mainland becomes the dominant feature once again.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through
3/Tonight through Wednesday)...

Ridging is present over the eastern Bering, separating an occluded
low over the far western Bering and a North Pacific low approaching
the Alaska Peninsula. The western low will merge with a low over
the northwest Pacific, bringing a gale force front to the western
Aleutians on Tuesday. For the eastern low, gales are expected
south of the Alaska Peninsula, albeit well offshore, with rain
and light easterlies over the landmass. The central Bering/Aleutians
will remain fairly calm.

&&

.MARINE (Days 3 through 5: Wednesday through Friday)...

Gulf of Alaska: Expect winds less than 35 kts and seas less than
15 ft for the Day 3 through 5 period.

Bering Sea: A low south of the western Aleutians will produce
Gale force winds across the western and central Bering and
Aleutians through Thursday. The low will slowly track east and
weaken with winds decreasing to small crafts by Friday. Seas
will be 12 to 16 feet near the swath of Gales and then slowly
subside through Friday.

&&

.LONG TERM FORECAST (Days 4 through 7: Thursday through Sunday)...

Looking ahead into the extended forecast, the latest operational
model runs are in good agreement with the evolution and
progression of the synoptic scale features, but diverge in the
specific details towards the end of the period. An upper level
ridge will continue to dominate the southern mainland while low
pressure will be south of the Gulf of Alaska, with a thermal
trough across Interior Alaska. The prevailing weather for much of
southern Alaska will be mostly sunny with above normal temperatures
and dry conditions. The Gulf of Alaska will likely see stratus
and areas of fog and the Bering Sea will see areas of rain and
overcast conditions. Towards Saturday and Sunday the deterministic
models want to introduce more convection south of the Alaska
Range mainly over the higher terrain, but it is too far out to
predict if it will occur with these small scale features.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale Warning 150 155.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...AF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CJ
MARINE/LONG TERM...JW/RC