Graphical Hydro Meteorological Discussion

865
FXAK68 PAFC 260012
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
412 PM AKDT Fri Apr 25 2025

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

Uneventful conditions are expected to continue across many of the
inland areas of Southcentral through this weekend, while rain
showers continue across the north Gulf coast and Kodiak Island.
Southeast flow across the Gulf may promote a few showers making
it into the southeast Kenai Peninsula near Homer.

The pattern shifts on Monday as models are pointing towards an
upper-level trough lifting north across Cook Inlet. Rain showers
and/or snow showers (at higher elevations) will spread to the
remaining portions of Southcentral: western Kenai, Anchorage, Mat-
Su Valleys, and the Copper River Basin. There may be a brief lull
in rain/snowfall on Tuesday, though there is decent consensus
that a second trough and associated surface low move across the
Gulf. This solution would result in continued widespread
precipitation across Southcentral and Kodiak Island through
Wednesday afternoon at least.

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA (through Sunday night)...

A broad upper level low pressure over the Bering Sea will keep the
southwest Mainland in an active pattern through the weekend.
Despite both the upper/lower level low pressure being in a
weakening state, an embedded shortwave trough will rotate over the
mainland, keeping rain in the forecast through Sunday. The most
likely places will be windward sides of the Aleutian Range, Alaska
Peninsula, and the Wood River Mountains. Higher elevations could
see light accumulating snow. Otherwise, downslope flow will take
a bite out of rain altogether or reducing it to very light
sprinkles. Southeasterly winds will be relatively benign save for
some enhanced flow through Kamishak Gap into Interior Bristol Bay.

MTL

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (through Sunday night)...

A broad low pressure system over the eastern Bering Sea will
slowly weaken through Sunday night. Winds will be relatively
benign across the Bering Sea. No gales are expected until late
Sunday night when a new north Pacific front moves over the
western/central Aleutians, the strongest winds should remain on
the Pacific side of the Chain. That system looks to ride along and
south of the Aleutians through early next week.


MTL

&&


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

On the Alaska Weather map, an extensive upper level low meanders
around the Eastern half of the Bering through the forecast period.
A number of shortwaves flexes the low`s position from day to day,
and helps maintain the instability across the Aleutians, Alaska
Peninsula and Western Alaska. The low is pinned in place by ridges
over the Arctic and Western Canada into Interior Alaska. the main
storm track remains to the South of the Aleutians through the
week. Forecast guidance anchored by the ECMWF hold the larger
features through the period, even with the GFS a bit fast and the
Canadian model a tad slow. Greatest uncertainty rests in the
smaller details moving through the pattern.

Leading off on surface weather, a closed low over the Southern
AKPEN extends a front along the Pacific side of the AKPEN, over
Kodiak Island and across the Southcentral coast to the Canadian
border with widespread extended period moderate rain for Wednesday
through Friday. Snow is expected over Bristol Bay and Southwest
Alaska, changing to rain on Wednesday. Inland Southcentral will
see a mix of rain and snow as the low tracks along the front in
the Gulf of Alaska through Friday. In the West, a well developed
low and front push into the Western Aleutians late Wednesday with
locally moderate rain. Moderate to locally heavy rain spreads
along the Aleutians to the Southern AKPEN by Friday.

- Kutz

&&

.AVIATION...

PANC...VFR conditions will persist. The southeasterly Turnagain
Arm wind with gusts should keep going through the evening and
diminish some overnight. It is expected to develop again Saturday
afternoon and may be a little stronger than it is today.

&&


$$

067
FXAK69 PAFG 252321
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
321 PM AKDT Fri Apr 25 2025

.SYNOPSIS...East winds and blowing snow have resulted in
visibility below one half mile across parts of the Arctic Coast,
so have gone ahead and issued a Winter Weather Advisory for areas
east of Nuiqsut. Winds will continue through Sunday, though slight
improvement is expected Saturday night. A warm front is moving
north along the West Coast bringing a mix of rain and snow through
Sunday. Southerly gap winds through Alaska Range passes are
likely Saturday and Sunday. Gusts will likely be 30 to 40 mph.

&&

.KEY WEATHER MESSAGES...
Central and Eastern Interior...

-Southerly gap winds through Alaska Range passes are likely
Saturday and Sunday. Gusts will likely be 30 to 40 mph.

-Temperatures warm over the weekend into the low to mid 50s across
the Tanana Valley and into the upper 30s and low 40s north of the
Yukon River under partly to mostly sunny skies.

-A fairly organized shortwave will bring numerous showers across
the area Monday afternoon. Expect most of these showers to fall
as rain, but some snow is possible at higher elevations and
overnight into Tuesday. Any snow accumulations look to be light
at this time, but total precip amounts between a tenth and a
quarter inch are possible.

West Coast and Western Interior...

-A warm front is moving north, bringing a mix of rain and snow to
areas west of Galena. Most areas south of the Seward Peninsula
will see mostly rain, the Seward Peninsula will see mostly mixed
precipitation, and areas north of the Seward Peninsula will see
mostly snow. Accumulations will be mainly light, though Kaltag
and the Nulato Hills will likely see 3 to 5 inches.

-Windy conditions with blowing snow continue at Gambell through
Saturday night. A Winter Weather Advisory is in effect beginning
at 4am as falling snow reaches the island as well, further
reducing visibility.

-High temperatures will be mainly in the 30s.

North Slope and Brooks Range..

-East winds and blowing snow along the Arctic Coast have developed
today as forecasted, though blowing snow appears to be a bit more
widespread than anticipated with numerous sites below 1 mile
visibility. Have gone ahead and issued a Winter Weather Advisory
for areas from Nuiqsut east for visibility of 1/2 mile or less
through tonight, with slight improvement expected Saturday
afternoon and Sunday.

-Lows will be mainly in the single digits with highs in the teens
along the coast and in the 20s in the Brooks Range.

-The Brooks Range will be mainly dry under partly cloudy to
mostly clear skies through the weekend.

&&

.FORECAST ANALYSIS AND DISCUSSION...A vertically stacked low from
the Gulf of Alaska has moved east over the Yukon Territory,
bringing remnant showers east of the Alcan Border with dry
conditions over the Central and Eastern Interior. A warm front is
bringing a mix of rain and snow to the West Coast. As of 2pm AKDT
Friday, precipitation has reached as far north as Shaktoolik to
Galena with northward progression expected through Saturday night.
A trailing shortwave will bring lingering showers to the Yukon
Delta Sunday and Monday as an upper low continues to rotate around
Bristol Bay. South of the Seward Peninsula, mostly rain is
expected. A mix of rain and snow will fall over the Seward
Peninsula and areas north of Selawik will see mostly snow. High
pressure in the Arctic will largely persist in place through
Sunday, bringing continued east winds and blowing snow to the
Arctic Coast. A 2-4 mb gradient across the Alaska Range along with
southerly flow aloft will support south winds through Alaska
Range passes gusting to 35 mph Saturday and Sunday.

For the forecast today, we increased PoPs with the system Monday
into Tuesday across the Interior. More on that below in the
extended section. We maintained the Special Weather Statement for
the Arctic Coast as blowing snow has developed up there, but also
added a Winter Weather Advisory for Nuiqsut east as visibility has
deteriorated in blowing snow to one half miles or less at times.
Also maintained the Winter Weather Advisory for St. Lawrence
Island as falling snow develops over the area with the warm front
while winds remain strong.

&&

.EXTENDED FORECAST DAYS 4-7...A fairly organized shortwave will
continue north through the Interior on Monday night and Tuesday
bringing widespread rain and snow showers. Scattered showers will
persist across the area south of the Brooks Range through the
week. The pattern will be conducive to continued cooler and wetter
than normal conditions across most of the area. On the North
Slope, high pressure over the Arctic will move off to the
northwest, but persist in strength bringing consistent winds 20 to
25 mph to the Arctic Coast through the week. Areas of blowing snow
can be expected, but low visibility is not likely.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Weather Advisory for AKZ827.
Winter Weather Advisory for AKZ804-805.
PK...Small Craft Advisory for PKZ805.
Heavy Freezing Spray Warning for PKZ806.
Brisk Wind Advisory for PKZ807.
Brisk Wind Advisory for PKZ808.
Brisk Wind Advisory for PKZ809-855.
Brisk Wind Advisory for PKZ810.
Gale Warning for PKZ811.
Brisk Wind Advisory for PKZ812>814-817-851-854-858>861.
Gale Warning for PKZ815.
Small Craft Advisory for PKZ816.
Heavy Freezing Spray Warning for PKZ816.
Brisk Wind Advisory for PKZ852.
Brisk Wind Advisory for PKZ856.
Gale Warning for PKZ857.
&&

$$

Chriest

576
FXAK67 PAJK 252238
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
238 PM AKDT Fri Apr 25 2025

.SHORT TERM...

Key Points:
- Showers continue tonight with breaks between precipitation
before diminishing Saturday.
- A weak trough across the gulf will increase marine winds along
the coast Saturday.

Details: Showers diminish tonight as a low weakens over the far
northern panhandle. There will be breaks in between these showers. A
weak trough will then begin to move across the gulf late tonight
into tomorrow continuing rain for the southern panhandle. This
precipitation will be light with little to no precipitation
accumulation expected.

Winds for northern land areas will be the strongest tonight around
15 to 20 kts before diminishing this evening. The same story is
expected for the inside waters as the gradient weakens with the low.
Winds along inside waters and over land will then become light and
variable around 10 kts or less through Saturday. The outside waters
will increase tonight into tomorrow reaching moderate to fresh
breezes. Gusts of 25 to 30 kts along the coast and northern gulf
will occur as the trough mover over the area.

.LONG TERM.../Sunday through Friday/...Continued wet weather pattern
for the mid and long range forecast over SE AK. Advancing low/front
Sunday into Monday now tracking further north. Overland winds
increasing by early Monday. Moderate to heavy rain should be more
widespread but with heaviest amounts aimed at the southern areas
with totals of an inch to two inches. The next system coming in late
next week is a low pressure system that all ensembles show coming in
along the western Gulf from the Aleutian Islands, bringing
precipitation to the panhandle around Wednesday into Thursday night.
All ensemble guidance at this time points towards an upper level
ridge over B.C. and a low cutting into the western Gulf. Southerly
winds for northern areas increase as the pressure gradients tighten.
EFI showing QPF for this time of year across parts of the panhandle
Thursday.

&&

.AVIATION.../Through Saturday afternoon/...Widespread marginal
visual conditions with the occasional drop to instrument
conditions in heavier showers this afternoon and into the evening.
As precip diminishes and finally ends, overnight breaks in the
clouds will likely result in low scud and possibly even bona fide
fog in the usual fog magnets: Juneau, Petersburg, Klawock,
Gustavus. Generally dry conditions expected on Saturday with cloud
bases lifting slowly through the day. Light winds across SEAK - 10
kts or less. Freezing levels still lower than normal for this time
of the year, so departing and arriving instrument flights will
have to pay attention to airframe icing while in cloud. No
turbulence or LLWS concerns for the short term due to a weak
surface ridge situated over the Panhandle and northeast Gulf
coast.

&&

.MARINE...Outside: A weak trough moving over the Eastern Gulf with
narrow band of increasing winds reaching strong breeze (22 to 27
kt). The advancing low Sunday night into Monday now tracking further
north bringing more defined SE max small craft low end gale force
winds overnight. As parent low moves into NE Gulf small craft
westerlies develop then diminish Monday into early Tuesday. Next
small craft front tracks in Wednesday. Eastern gulf seas building to
12 ft from swell and wind waves by Monday.

Inside: Saturday, most of the inner channels will be experiencing
light breezes (7 to 10 kt), though some areas could at times go
calm. Winds will begin to strengthen again during the latter half of
Sunday with advancing front. Stronger winds near Clarence Strait/
Dixon Entrance early Monday. Northerly shift with passing front but
then return to southerlies. Ridging over the panhandle Tuesday
picking up pressure gradient with south winds of 15 to 20 kt, mainly
for NS channels such as Lynn Canal.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ662>664-672.

&&

$$

SHORT TERM...EAB
LONG TERM....PRB
AVIATION...Fritsch
MARINE...PRB

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