Graphical Hydro Meteorological Discussion

711
FXAK68 PAFC 240114
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
514 PM AKDT Wed Apr 23 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Wednesday afternoon through Saturday afternoon)...

No major changes to the previous forecast. Unsettled weather will
persist through Thursday as a mature low continues its track
across the southern Gulf of Alaska. By Friday, the low weakens and
moves towards Southeast Alaska, making way for a weak front to
slide northeastwards from Kodiak Island. With both weather systems
looking fairly weak, no hazards are anticipated.

Diving into the details... as seen on satellite, the low in the
Gulf is starting to occlude. Steady precipitation moving into the
north Gulf coast has become much more showery, which can be seen
on radar. Upper level shortwaves moving into Mainland Southcentral
may help spur the development of afternoon convective showers.
Though most of them should stay over the higher elevations, a few
showers may make it off the mountains and over populated areas. In
fact, forecast precipitation chances are likely leaning a bit too
low; the past few afternoons have shown that models are biased
towards keeping showers over the mountains, and therefore
underestimating precipitation chances for Western Kenai Peninsula,
Anchorage, and Mat-Su. Still, any showers that do move over these
areas should be fairly weak, with no lightning or heavy rain
expected. Similar conditions are expected for tomorrow, though the
chance of showers will increase as a much more robust shortwave
moves through.

By late Thursday night, a front moves towards and stalls out near
Kodiak Island, bringing steady light rain through much of Friday.
The front slowly progresses northwards towards Kenai Peninsula on
Saturday, but another front, this time with a higher moisture
stream, will bring another round of rain to Kodiak Island.

-Chen

&&


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

The southwest mainland lies between weather systems in the Gulf of
Alaska and Bering Sea. A weak and decaying upper level low remains
overhead with very little impact on current weather. From the
Kuskokwim Valley through interior Bristol Bay, a nice spring
evening is in store with temperatures in the 50s to upper 40s with
light winds and fair weather cumulus clouds. A stark contrast
exists for the Kuskokwim Delta where snow cover and clouds have
kept temperatures lower. The opportunity for more low clouds and
fog exists overnight for the Delta, especially the Kuskokwim River
Valley.

A front from the Bering Sea moves ashore the mainland late
Thursday evening, bringing snow and rain mainly to the Bristol Bay
area and the Wood River Mountains. Lesser amounts are expected for
the Kuskokwim Delta and Valley, little to no snow accumulation is
expected. The front will keep temperatures lower on Friday,
staying in the low to mid 40s. The responsible low pressure system
will drift toward the area, keeping cooler, cloudier and more rain
the forecast for the weekend.


MTL

&&

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

A frontal boundary is stretched from west to east across the
Bering Sea, turning southward over the eastern Aleutians. The
responsible system has peaked in intensity, and the front is also
weakening and slowing. Expect gale force winds west of the
Pribilofs tonight before diminishing. Along that front, snow
will turn to rain as the front passes, however, along the
Aleutians, temperatures will likely remain high enough to support
rain. Gap winds won`t be very strong across the Alaska Peninsula,
though there will be some enhancement through channeled terrain.
Once the front passes on Thursday, much of the area will remain in
a cloudy and rain/snow showery regime as the low pressure system
decays and shifts eastward.


MTL

&&


.LONG TERM FORECAST (Days 4 through 7/Sunday through Wednesday)...

The long term continues to be characterized by upper level
troughing over the Bering, leading to an active weather pattern
for the Aleutians and southern mainland Alaska. An upper level
shortwave will traverse northwards across Southwest Alaska as a
closed upper low slides eastward towards the eastern Bering by
Monday morning. A surface low lifting from the AKPen into the
eastern Bering looks to bring a wave of precipitation across
Southwest and the AKPen through Monday, likely beginning as rain
for lower elevations before transitioning over to snow as
precipitation from this system tapers off. This low sends its
front across the Gulf and Southcentral bringing rain to Kodiak
Island and the northern Gulf coast and snow to higher elevations
through Tuesday morning as the front pushes inland. Precipitation
associated with this system is expected to be predominantly light,
though locally moderate rainfall is possible along the eastern
Kenai Peninsula and Western Prince William Sound.

By Monday morning, an upper level low lifting out of the North
Pacific supports a deepening surface low south of the western and
central Aleutians. This low is expected to continue to track
eastward south of the Aleutians and AKPen through the remainder of
the forecast period. Some light precipitation is possible for the
Aleutians as the system skirts to the south of the island chain
through the early part of next week, though even a slight shift in
the track to the south may limit precipitation. As the low nears
the Gulf, the focus for Tuesday into Wednesday shifts towards
another round of potentially heavier precipitation for the AKPen,
Kodiak Island, and northern Gulf coast. The greatest chance for
heavy rain and snow at elevation will likely again be along the
eastern Kenai Peninsula and Western Prince William Sound given the
southeasterly flow in the Gulf. Northwesterly flow and cold air
advection on the back side of the low may enhance northwesterly
gap winds through the eastern Aleutians and AKPen Tuesday into
Wednesday.

-JH

&&

.AVIATION...

PANC...VFR conditions expected to prevail through the TAF period;
however, given the chance of scattered showers developing later
this afternoon and evening there is a possibility that ceilings
could briefly drop to MVFR if a shower moves over the terminal.
Light winds will become more southerly later this afternoon into
the evening hours before becoming light and variable again by
early Thursday morning.

&&


$$

168
FXAK69 PAFG 232256
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
256 PM AKDT Wed Apr 23 2025

.SYNOPSIS...Very quiet weather across northern Alaska will
continue through Thursday before winds increase across the Arctic
Coast, bringing blowing snow. Northeast winds will be breezy
across the Interior through Friday. Showers in the Interior will
be mostly isolated and light through Friday before conditions
completely dry out Friday night. A warm front will bring a mix of
rain and snow the the West Coast Friday through Sunday.

&&

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

-Northeast winds peak Wednesday evening with gusts up to 30 mph
along highway summits. Winds may mix down into the valleys with
gusts 20 to 25 mph possible Wednesday evening. NE winds remain
elevated through the end of the week.

-Temperatures remain steady through the end of the week with highs
in the 40s to near 50 and lows dipping down below freezing in
most places.

-Isolated rain showers possible in the afternoons. Showers will
fall as snow in elevated terrain with low to no accumulations.
Showers become more numerous Thursday in the eastern Interior.

-Southerly gap winds through Alaska Range passes are likely
beginning Sunday.

West Coast and Western Interior...

-North and Northeasterly winds increase along the West Coast
Wednesday and Thursday to sustained speeds of 10 to 20 mph.
Kivalina and Red Dog Dock may see stronger winds with gusts up to
35 mph possible. Sustained northerly winds through the Bering
Strait and across western St. Lawrence Island will be stronger
with sustained speeds of 20 to 25 mph peaking Friday evening with
gusts up to 35 mph.

-Showers remain isolated along the West Coast and Western Interior
through Thursday before a front brings a band of rain and snow
to the YK Delta and lower Yukon Valley Friday and moving up the
coast through the weekend.

North Slope and Brooks Range..

-Northeasterly winds 15 to 20 mph across the Arctic Coast today
will increase to 20 to 25 mph Friday with gusts 40 to 45 mph by
Friday afternoon. These decrease slightly to gusts up to 35 mph
on Saturday. Blowing snow is likely, but blizzard conditions are
not anticipated at this time.

-High temperatures will be mainly in the teens on the North Slope
with 20s in the Brooks Range.

&&

.FORECAST ANALYSIS AND DISCUSSION...Most of northern Alaska
currently lies in a col between a vertically stacked low pressure
system in the Gulf of Alaska and a high to the north of Wrangel
Island. There is weak ridging over the far eastern interior.
Surface high pressure in the Arctic has a NE gradient draped
across the central and eastern Interior. Otherwise, the pattern is
weak with weak flow and non impactful amounts of moisture. The low
in the Gulf of Alaska will bring a backdoor warm front to the
eastern Interior late tonight through Thursday before weakening
near Yakutat on Friday. A weak low pressure system will move into
the southern Bering Sea Thursday night, bringing another warm
front to the west coast. This front will arrive at the Yukon Delta
coast Friday morning and continue to push north, bringing a mix of
rain and snow. Impacts will be limited and no products are
currently planned. Models are in poor agreement on the timing and
how far east precipitation will reach. At this time, prefer the
NAM for limiting the easterly extent, but the ECMWF for faster
northward progression of the front. High pressure in the Arctic
will increase easterly winds across the Arctic Coast beginning
Friday morning. Blowing snow is likely but at the time do not
expect blizzard conditions. Winds will diminish Monday.

&&

.EXTENDED FORECAST DAYS 4-7...Broad troughing will persist over
Alaska through next week with periods of weak southerly flow
possible as the storm track continues to bring low pressure
systems across the Aleutians and into the Gulf of Alaska. This
will bring continued quiet weather to most of northern Alaska with
temperatures near seasonal norms. Showers across the Interior will
be very limited with most precipitation along the west coast and
in the southwest Interior, though amounts there look to be light
as well.

Coastal Hazard Potential Days 3 and 4...None

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...None.
PK...Heavy Freezing Spray Warning for PKZ806.
Brisk Wind Advisory for PKZ811-812-857-858.
Heavy Freezing Spray Warning for PKZ816.
Small Craft Advisory for PKZ816.
Brisk Wind Advisory for PKZ817.
Brisk Wind Advisory for PKZ851-854.
&&

$$

Chriest

381
FXAK67 PAJK 232330
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
Issued by National Weather Service Anchorage AK
330 PM AKDT Wed Apr 23 2025

SHORT TERM...A low continues to track into the central Gulf
this afternoon, extending a warm front over the panhandle.
Currently, light precipitation has been observed over a majority
of the panhandle as of this discussion, having spread from south
to north with the approaching system. Precipitation is keeping as
rainfall near sea level, with some light snow at higher
elevations. Area roadways, such as the Klondike Highway near White
Pass, may see low accumulations of wet snow. The front is
expected to stall and train over the area, which will continue to
overspread light to moderate precipitation over the panhandle
through the remainder of the work week. A weak barrier jet has
formed along the eastern Gulf coast, promoting near gale-force
winds along the Gulf coast waters. For the inside waters,
particularly east west oriented channels will see fresh to
moderate breezes with gusts to strong breeze as the front lifts
inland this evening.

LONG TERM.../Friday through Wednesday/...The low currently in the
Gulf is expected to continue tracking northeast in the Gulf by
Friday. Showers will diminish into the evening Friday as the low
center moves inland and weakens. Relatively drier conditions are
expected for Southeast Alaska into the weekend given the exiting
low pressure system. Light rainfall may persist as the axis of
moisture shifts increasingly over the southern portion of the
region, including Sitka and Prince of Wales Island. Ensembles
trend towards the open wave trough solution. From there
operational models diverge. Another surface low and associated
front is expected in the western gulf and impacting SE AK early
Monday into Tuesday. Model agreement is increasing towards a
elongated northwest oriented trough to push over much of SE AK,
bringing a return to widespread rainfall and near gale-force winds
along the Gulf coast waters.

&&

AVIATION...A warm front settled over the panhandle has
deteriorated conditions, with widespread MVFR conditions
predominant. Conditions will occasionally dip to IFR for a few
locations, particularly for places like Haines and Yakutat, as
moderate bands of rain move through. Expect SE-ly LLWS near 30kts
around 2000ft and turbulence associated with the approaching front
over the outer coast through the remainder of this afternoon.

Conditions will largely remain similar tonight into Thursday for
the outer coastal areas and the northern half of the panhandle,
though the southern panhandle will see some improvement during
this time frame.

&&

MARINE...Near gales along the N and NE gulf coast have developed
this afternoon as a low takes up station in the central gulf and
pushes a warm front into the panhandle. Winds to gradually
diminish as the low shifts north and inland out of the area. Fresh
breezes will extend SE along the gulf coastal waters and continue
into Thursday. Seas 8 to 10 ft for coastal waters by this
afternoon to maintain this evening, with increasing SSW swell
tonight into Thursday as follow on cold front impacts the
panhandle.

Inside waters will largely see fresh breezes develop,
with moderate breezes limited to east west oriented channels as
the front approaches. Slight slackening of winds this evening
before picking up once more with the approaching cold front.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036-641>644-651-652-661>664-671-672.

&&

$$

SHORT TERM...CL
LONG TERM....CL
AVIATION.....CL
MARINE.......CL

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