Graphical Hydro Meteorological Discussion

550
FXAK68 PAFC 240042
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
442 PM AKDT Sun Mar 23 2025

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

Low pressure in the Gulf of Alaska near Kodiak Island slowly
moves northeast of Island through Tuesday afternoon. Rain showers
and southeast winds will persist on the Island through then.
Though a few hundredths of an inch of rain is expected, most of
it will fall from sunrise tomorrow through the mid-afternoon
hours as a stronger wave moves onshore. Its front moves across the
Prince William Sound/ northern Gulf of Alaska area tomorrow. This
will result in a period of widespread precipitation along the
coast. The greatest chance for precipitation will be from the
mid-afternoon through the late evening hours with QPF amounts in
the few hundredths of an inch. Areas along the Eastern Kenai
coastline will also be wet tomorrow and Tuesday from this front
though QPF amounts will be a few hundredths of an inch.

As the front moves through the Gulf, winds will shift from
easterly to southeasterly through the day tomorrow; peaking in
the late evening hours. One notable difference during this time is
the persistent northerly winds through the Kachemak Bay and
Shelikof Strait. These winds will peak early Tuesday morning as
the front moves over the Kenai Peninsula ranging from 20 to 30
knots. Also, northerly winds peak early Tuesday morning in
Thompson Pass though gusts range from 20 to 30 mph.

Elsewhere, dry conditions will continue despite increasing clouds
for Anchorage, Western Kenai and inland area of Prince William
Sound. Mostly clear sky persists from the Mat-Su Valley to
Glen Allen northward including the Copper River Basin through
Tuesday.

&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(Tonight through Tuesday evening)...

An upper level trough axis continues to remain oriented across
Southwest Alaska, while a low across southern Kodiak keep snow
shows across much of southwest Alaska active through the evening.
Winds along the Alaska Peninsula and eastern Aleutians remain
elevated. Gusty northerly winds continue across the Eastern
Bering, crossing the Alaska Peninsula and Eastern Aleutians, and
creating gap winds on the southern side of the Chain. Localized
areas of strong and gusty winds, or squalls, have been observed
and will and continue through Tuesday afternoon.

Snow showers across Southwest Alaska have diminished slightly, but
will continue through Monday afternoon. Some wind may help to loft
some of the snow as well, leading to some blowing snow in wide
open areas. Over the Western and Central Bering, a strong ridge
is building in, promoting drier and calmer conditions across the
area. This ridge is expected to shift slowly toward the Central
Bering, anchoring in place and stabilizing the pattern over the
area. By tomorrow morning, a front is expected to enter the
Western Bering, moving over the Western Aleutians bringing a round
of gusty southerly winds, warmer temperatures and potential for
rain or a rain/snow mix. This front will attempt to progress
eastward toward the Central Bering, but is expected to diminish
greatly and strength and momentum as it pushes against the ridge
in the Central Bering. By Tuesday afternoon, it is possible for
some remnants of the front to persist, pushing into the Central
Aleutians.

&&

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

A broad upper level trough will encompass the Gulf of Alaska and
Central portion of the State with a developing closed low forming
in the Eastern Gulf that will slowly lift to the northwest over
northern Gulf at the start of the weekend. This will bring
scattered rain showers across the coastal regions with snow in the
higher elevations towards the end of the weekend.

A blocking ridge of high pressure will continue to dominate
Western Alaska, Bering Sea and the Central Aleutians. This will
setup a prolonged moderate northerly wind pattern across the
Bearing Sea, Aleutian Islands and the western part of the State,
allowing cooler air to move into this region. Small, fast moving
shortwaves will transit along the northeastern access of the ridge
bringing brief unsettled weather along the eastern ridge axis but
these will be fairly fast moving and have very little impact to
the forecast area.

-DD

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

&&

$$

294
FXAK69 PAFG 232038
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
1238 PM AKDT Sun Mar 23 2025

.SYNOPSIS...
The band of snow over the West Coast will taper off tonight into
Monday as pressure builds east and west of it. Weather remains
warm, calm, and clear over the Interior. Easterly winds continue
for the North Slope with low clouds and fog remaining for the
eastern Arctic Coast.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...
-Warm and dry weather continues for the Interior with highs
ranging from the upper 20s in the northern Interior to around 40
just north of the Alaska Range and around Fairbanks.
-Slight downward temperature trend through the week although
temperatures remain above their normal.
-Pressure continues to build across the mainland helping to
maintain clear skies and generally calm winds in the valleys.
-Some moderate Northeast winds around 20mph expected along ridge
lines and the Dalton Highway Summits.

West Coast and Western Interior...
-The band of snow over the West Coast and Western Interior is
shifting further inland today and will taper off Monday. The
heaviest snowfall has already passed with remaining accumulations
of 1 to 3 inches expected from the Upper Kuskokwim Valley
through the Chukchi Sea Coast.
-Winds shift more northwesterly tonight and gradually diminish
through Tuesday.

North Slope and Brooks Range..
-Easterly winds peak today with gusts up to 30 mph along the
eastern Arctic Coast. Easterly winds continue through the week
with sustained speeds of 15-25 mph.
-An area of open water east of Kaktovik is producing a large area
of stratus and fog with some snow showers from Kaktovik to
Atqasuk.
-Light snowfall continues through tonight for the Western Arctic
near Point Hope with near 2 inches additional accumulation
expected.

&&

.FORECAST ANALYSIS AND DISCUSSION...
A 503 dam upper level low in eastern Siberia extends a trough
into the Bristol Bay region today as surface pressure builds
slowly in the Interior. Strong ridging develops tonight in the
Bering Sea and will disrupt this trough and force the Siberian low
further to the north and west. This will cause the eventual
breakdown of the snow band along the West Coast and Western
Interior Monday. With the breakdown of the trough, surface
pressure over the mainland can build faster reaching into the 1030
mb range by Wednesday. A 1030mb high over the high Arctic will
strengthen to the 1040s by midweek. This is fueling easterly winds
across the North Slope which will decrease in strength as pressure
increases over the mainland reducing the relative pressure
gradient despite the increasing pressure in the high Arctic.
Higher pressure across the Interior will keep conditions stable
and clear. The North Slope can expect to see continued low clouds
and fog due to openings in the ice allowing additional low level
moisture despite the increasing pressure. The ridge over the
Bering continues to strengthen through the week.

&&

.EXTENDED FORECAST DAYS 4-7...
A strong ~580 dam subtropical high is poised to form over the Bering
Sea late week, which will usher in a pattern change aloft for the
Mainland of AK. Model agreement begins to differ greatly mid-weekend
as the EC and CAN progress the ridge into the state much quicker
than the GFS. This eventually results in very different breakdown
patterns of the ridge at the beginning of next week and any
shortwaves that form along the downstream side of the ridge.

With this ridge, the EC and CAN show a widespread areas of
precipitation with the associated front that extends down toward
lower portions of the state. Which eventually come across the
interior. To add on, both of the models have been consistent with
this feature in model runs. Coastal areas will continue to see
sustained winds around 15 to 25 mph, with a chance of stronger winds
for the NW Arctic at the end of the weekend with the ridge
progression.

Coastal Hazard Potential Days 3 and 4...None


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ805.
PK...Brisk Wind Advisory for PKZ802.
Brisk Wind Advisory for PKZ805-852-853-861.
Brisk Wind Advisory for PKZ806.
Brisk Wind Advisory for PKZ812-814-858.
Brisk Wind Advisory for PKZ813-815-859-860.
Brisk Wind Advisory for PKZ854.
Brisk Wind Advisory for PKZ856.
Brisk Wind Advisory for PKZ857.
&&

$$

Stokes
Extended...Twombly

961
FXAK67 PAJK 232244
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
244 PM AKDT Sun Mar 23 2025

.SHORT TERM...
Main threat over the next 24 hours is a low moving ashore,
bringing gusty post frontal southerly winds, impacting the coast
and inner channels into Monday. See marine section for further
wind information. Onshore flow continues through Monday and
Tuesday, driving multiple rounds of moderate precipitation.
Freezing levels continue to hold near 1000 to 2000ft in the north,
and increasing to 3000ft in the south, so expecting all rain for
our communities outside the highways. A Winter Weather Advisory is
still in place for the Klondike Highway overnight Sunday into
Monday as the front moves over, driving 3 to 5 inches of snow,
most concern for White Pass. Still keeping a close eye on Haines
Highway west of Klukwan for snow impacts, but for now, the current
forecast reflects about 1 to 2 inches overnight into Monday.

.LONG TERM...
For the start of the long term, the remnants of a low over the
Gulf of Alaska are expected to be bringing continued active to the
area. Showers are expected to remain over the panhandle Tuesday
before starting to dissipate Tuesday evening into Wednesday
morning. Heading into Wednesday morning, high pressure is expected
to build over the Arctic Ocean and stretch down into the
Northwest Territories. Meanwhile, a low off the coast of the
Pacific Northwest is expected to move northward. With this low
moving northward, the pressure gradient is expected to tighten
along the Coast Mountains for the middle to the end of the week.
With this gradient developing, outflow and gap winds are expected
to develop for most of the panhandle. The southern panhandle is
expected to see precipitation though as a front with the
associated low wraps around and moves northward into the area.
Most of this precipitation is expected to stay south of Sitka and
Angoon at this time. As we head into the weekend, ensembles
continue to keep the weather active with either a low in the Gulf
of Alaska before giving way to a low moving up from the Northern
Pacific. Right now, nothing stands out as being problematic but
guidance will still need to be watched in case this changes going
forward.

&&

.AVIATION...
No major changes to current aviation weather forecasts. A low in
the eastern Gulf off the coast of Baranof Island and its
associated front will continue to overspread isolated showers
across the panhandle as it moves northward through Sunday night,
dissipating in the NE Gulf coast by Monday morning.

Outside of Yakutat, anticipating low VFR to predominate MVFR
flight conditions to prevail through the TAF period for the rest
of the panhandle with CIGS AoB 5000ft and visibilities 3SM to
P6SM. Expect elevated sustained winds between up to 15kts to
continue with likely gusts up to 25kts, decreasing to 10kts or
less through Sunday night. Southwesterly LLWS continues through
late tonight across southern panhandle TAF sites on the backside
of the coastal low moving north, near 2000ft up to 30kts max,
decreasing through 12z Monday.

Flight conditions on Monday will improve with more widespread VFR
conditions down to upper end MVFR expected for majority of TAF
sites, with isolated to scattered rain showers continuing with
CIGS AoB 7000ft and visbys 4 to 6SM, lowered in isolated heavier
showers.

&&

.MARINE...
Gulf: Fresh seas are currently turning southwest, peaking near 13
to 16ft with a focus of wave energy from Dall Island north to
Cape Edgecumbe. Seas diminish later Monday, with significant wave
heights dropping below 13ft as southwest swell starts to dominate
the overall wave spectrum. With that said, expect fresh to
moderate breezes out of the southeast to continue driving some
wind waves on top of the southwest swell along the coast.

Inner channels: Gusty southerly winds continue to fill in across
the central and northern inner channels as a front moves across
the Panhandle. Buy-and-large expecting southerly strong breezes
into Monday prompting some Small Craft Advisories. Gusty winds
subside Monday afternoon with southerly onshore flow continuing
and winds settling in to moderate to fresh breezes.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory from 1 AM to 1 PM AKDT Monday for AKZ318.
MARINE...Small Craft Advisory for PKZ022-031>035-641>644-651-652-661>664-
671-672.

&&

$$

SHORT TERM...AP
LONG TERM....SF
AVIATION...NM
MARINE...AP

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