334
FXAK68 PAFC 182340
AFDAFC
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
340 PM AKDT Sun Oct 18 2026
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...
Key Messages:
- A large storm system will bring widespread rain and snow to most
of Southcentral tonight through Tuesday night.
Discussion:
Skies have struggled to scatter out throughout the day today as a
persistent stratus deck continues to linger across most of
Southcentral. Similar to the previous night and this morning, the
lingering cloud cover will likely again prevent temperatures from
dropping below the 30s across much of Southcentral overnight
tonight. Looking at satellite and radar imagery this afternoon,
high-level clouds and radar returns are beginning to make their
way into the western Gulf, with rainfall beginning to overspread
Kodiak Island as a front lifts across the AKPen, Kodiak Island,
and the western Gulf this afternoon through this evening.
Widespread precipitation will continue to spread across Kodiak
Island this afternoon before spreading north across the Kenai
Peninsula, Susitna Valley, and Prince William Sound tonight
through Monday morning. Initial downsloping may limit precipitation
for a bit across the western Kenai Peninsula, Anchorage, and Mat
Valley but is expected to fill in by late Monday morning. The
precipitation type continues to be a forecast challenge as it will
be highly dependent on the overnight and early morning temperatures.
Wet snow or a rain/snow mix will be possible at the initial onset
of precipitation across the western Kenai, Anchorage, and the Mat
Valley before quickly changing over to rain as warmer
southeasterly flow erodes the cooler airmass currently in place.
Higher elevations (>2000 ft) will see snow with a possible
changeover to a rain/mix for coastal areas. As temperatures drop
back down toward freezing Monday night, precipitation at higher
elevations will transition back to snow. Snowfall is expected to
be slower to change over to rain in the Susitna Valley Monday
morning through Monday afternoon while the Northern Copper Basin
remains cold enough to see all snow.
By Tuesday morning, an additional, stronger low pressure system
lifts north in the Gulf and tracks toward Prince William Sound by
Tuesday night, leading to an additional round of precipitation
Tuesday night into Wednesday. Snowfall in the Susitna Valley and
Northern Copper Basin can expect to see about 2-4" for lower
elevations to 5-10" for the areas along the Denali Highway and
Richardson Highway corridor near Paxson through Tuesday night.
The Glenn Highway from about Sutton over to Tolsona could also
see snowfall totals of between 2-4". These areas will be the most
likely areas to see temperatures hovering near to below freezing
allowing for snow to accumulate. Thompson Pass will also see
mostly snow, though there is a chance it could swing from snow to
a mix of precipitation at times. However, it should remain cold
enough for modest snowfall rates of 1" to 1.5" per hour with the
potential to see accumulations above 10 inches from Monday through
Tuesday night. The coastal areas along the Gulf and Prince
William Sound will see the bulk of precipitation from the system.
The lower- elevations along the coast could see rainfall amounts
of several inches.
The precipitation forecast across the western Kenai, Anchorage,
and the Mat-Su remains fairly uncertain as model guidance
continues to struggle to come to a consensus on a storm track in
the Gulf. A further west storm track in the Gulf could lead to a
much more substantial second round of precipitation for these
areas for Tuesday and Tuesday night, with temperatures likely
cooling back down enough by this time to see wet snow or a
rain/snow mix near sea level. A more eastward track scenario would
largely clear precipitation out of these areas by Tuesday, with
the Gulf coast, Prince William Sound, and Copper Basin continuing
to see a bulk of the precipitation.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3)...
Rainfall has initiated across Southwest Alaska and the Alaska
Peninsula earlier this afternoon as a front has pushed inland.
A mix of rain and snow has been observed for coastal areas
currently seeing precipitation, with temperatures near or just
above freezing. Precipitation will spread across much of
Southwest Alaska this afternoon. Rain is primarily expected along
the coast as temperatures there are expected to warm quickly as
the front approaches, so areas of rain/snow should transition to
a plain rain by this evening. Further inland may hang onto colder
air a bit longer into this afternoon, allowing for snow initially,
becoming a rain/snow mix. Through Monday, areas such as Sleetmute
and Crooked Creek can expect 1 to 3 inches of snow, however
accumulations at the surface will likely melt during the daytime
hours.
A wave moving across the western Bering Sea will bring the chance
for isolated thunderstorms tonight over Shemya and Attu and over
marine areas. As the wave moves north/west, energy begins to taper
off, however, there remains a slight chance for some isolated
thunderstorms during the early hours on Monday near/over the
Pribilof Islands.
Following the passage of the front, precipitation diminishes
through Monday afternoon. Winds will start to shift northwesterly
across the Bering, primarily across the Alaska Peninsula. As the
pressure gradient grows with a low developing in the northern Gulf
of Alaska, gusty gap winds will develop through favored channels
of the Alaska Peninsula. While there is a fair amount of cooler
air filtering down, the northwesterly flow may limit the upper
limit of gusts as it isn`t quite as favorable of a wind direction
for several of the gaps. Regardless, these fairly gusty winds
should persist through Wednesday morning as a ridge begins to
build in the Central Bering, hinting at a reprieve in the active
weather pattern.
CL
&&
.LONG TERM FORECAST (Days 4 through 7: Thursday through Sunday)...
Key Messages:
* A strong storm moves across the Bering Sea and into Alaska from
Thursday through the weekend, bringing winds as high as 40 to
60 mph.
* Though confidence is low in exact impacts at this time, strong
onshore winds and elevated coastal water levels are a concern
for Southwest Alaska on Friday and Saturday.
Discussion:
The biggest story in the long-term forecast will be a strong low
transiting from the Kamchatka Peninsula to Alaska. Ensembles are
in relatively good agreement with this storm, with seemingly
higher-than-average forecast confidence given that this feature is
4 to 7 days out. Good run-to-run consistency among deterministic
global models is also contributing to higher-than-average forecast
confidence. The areas of highest agreement with this feature are
for gale to storm force sustained winds along the front, including
as it moves across the Alaska Peninsula and Southwest Alaska
coastline. These onshore winds are raising concerns for coastal
impacts (including high surf and perhaps even coastal flooding)
for south-facing portions of the Western coast. It`s too early to
say for now what projected water levels will be, but we will be
closely monitoring this storm. Southcentral should be spared the
worst of the winds with this storm, as the front will very likely
be weakening by the time it exits Southwest Alaska.
In addition to winds, there will also be plenty of moisture advection
along the front, which will bring periods of moderate to heavy
precipitation to the Aleutians, Alaska Peninsula, and Southwest
Alaska. Precipitation amounts are a bit uncertain at this time, as
overall amounts will be dependent on where the front may slow
down and linger as upper waves move through. Given the strong
winds associated with the front, there will likely also be areas
of downsloping that will reduce precipitation totals. While warm
air advection will likely keep precipitation mostly rain for the
majority of Southwest Alaska, colder air lingering in Southcentral
could mean that lower elevation areas may see snow.
-KC
&&
.AVIATION...
PANC...VFR conditions and light north winds will persist through
this evening. Later tonight, a frontal system moving northeast
into Southcentral will bring light precipitation to the terminal.
Low level temperatures could be cold enough for precipitation to
start as a slushy snow or rain-snow mix for a few hours, becoming
all rain by Monday morning as temperatures slowly trend warmer.
MVFR conditions are possible at times during and after the onset
of precipitation starting around 8 to 10z, especially during any
periods of snow reaching down to sea level. Low level wind shear
will also be possible early Monday morning as southeast winds
aloft pick up out ahead of the front. Southeast winds could clip
the terminal for a short time close to midday Monday, but potential
for winds at the surface to turn southeasterly remains highly
questionable at this time.
&&
$$
372
FXAK69 PAFG 182314
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
314 PM AKDT Sun Oct 18 2026
.KEY MESSAGES...
Central and Eastern Interior...
- Colder/drier weather for most of the Interior through Monday.
- Snow moves into the Alaska Range Monday afternoon and persists
through Wednesday. Very heavy snow with rates exceeding 1 inch
per hour at times Monday night through Tuesday night.
* Snowfall totals upwards of 2 to 3 feet in Isabel Pass.
- Snow, heavy at times moves into the Interior Monday night and
persists through Wednesday. A tight snow gradient sets up from
east to west around Fairbanks. Gusty north/northwest winds
likely, especially in the AK Range and Eastern Interior
Tuesday afternoon with visibility restrictions possible.
* Snowfall totals around 4 to 8 inches around Fairbanks.
* 5 to 10 inches from Harding Lake to Eagle Summit.
* 6 to 12 inches for most of the Eastern Interior with locally
12 to 18 inches between Tanana Cross & Dot Lake. 2 to 5
inches near Northway.
- Most of the snow dissipates by Wednesday afternoon with cold
and dry weather settling in Thursday/Friday. Temperatures may
drop to the single digits/teens Wednesday night and near 0
Thursday night across much of the Interior.
West Coast and Western Interior...
- Rain and snow showers persist through tonight with a period of
snow likely in Southwest Alaska this evening through Monday
afternoon then tapering off.
* Snowfall totals around 1 to 3 inches with locally higher
amounts in the Lower Yukon Valley.
* Rain will mix with snow at times along the YK Delta Coast.
But during periods of snow and gusty wind, visibility
restrictions are expected.
- Moderate snow is likely to continue around Kivalina, Red Dog
Mine and Point Hope. Winds will gust as high as 40 mph making
for poor visibility.
* Snow accumulations around 3 to 6 inches through Monday.
- Temps will range with highs in the 20s/30s for both the West
Coast and Western Interior. The lows along the West Coast will
likely range in the lower 20s, while the Interior will remain
slightly cooler, with lows in upper teens.
- A strong coastal storm is becoming more likely as early as
Thursday. For more details, see the coastal hazard and long
range forecast sections.
North slope and Brooks Range...
- Snow likely in Point Lay and Point Hope through this evening.
* 1 to 3 inches of snow expected.
- Gusty winds up to 40 mph expected along the Chukchi Sea Coast
with 20 to 30 mph along the Beaufort Sea Coast today. It
remains breezy but weaker tomorrow.
- It remains below freezing for most of the North Slope, except
the Chukchi Sea Coast which remains near/above freezing.
&&
.SYNOPSIS...
Active weather continues in Northern Alaska with snow from Point
Lay to Kivalina/Red Dog, heaviest in the Red Dog Mine where
several inches of snow are likely through Monday. Winds will be
gusting upwards of 40 mph in these locations making for minor
blowing snow. Another spot we are monitoring for snow is
Southwest Alaska, especially in the Lower Yukon Valley where
light snow will increase in intensity this evening, then
continue through Monday afternoon. Monday to Wednesday will come
with heavy snow in the Interior, especially the Eastern Alaska
Range and Eastern Interior. The heaviest will be in Isabel Pass
where we might be measuring snow in feet. Otherwise the Central
Interior, such as Fairbanks, will be right in the zone of the
most uncertainty where a 30 mile shift west or east will result
in significant amounts or close to nothing. There will be an in
depth analysis in the short term discussion.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
A lot to get into so we`ll start with 500mb vorticity charts.
The broad view shows troughing from the Arctic to the Bering
with a subtle, transient ridge over the Interior. This is
allowing for breaks in the clouds in the Interior. A
picturesque Arctic low at 497 decameters northwest of Utqiagvik
and a shortwave trough moving north over Western AK is helping
force a narrow band of snow from the Chukchi Sea to the NW
Arctic Coast. A broad, weak, 524 decameter upper low is sitting
south of the Gulf of Anadyr and this is helping provide
rain/snow showers to the West Coast. To the southwest of this
low is a potent piece of vorticity which will be moving towards
SW AK this afternoon/evening allowing for snow to blossom in the
Yukon Valley and along the West Coast from Unalakleet south.
Snow will continue through Monday afternoon before dissipating.
This piece of energy will continue trekking northeast bringing
light snow showers to much of the Interior, especially north and
west of Fairbanks on Monday night into Tuesday. If you`re
wondering why the Tanana Valley/Eastern Interior might not see
snow, it is due to strong downsloping. The Alaska Range will
have southerly winds gusting around 55 to 65 mph, strongest in
Isabel Pass. Meanwhile, the Arctic low will be lifting to the
northeast with a cold front dragging southeast, slowly moving
through the North Slope and Western Interior on Tuesday. This
will play an important role moving forward.
Before we get there, a strong piece of energy will move into the
Gulf of Alaska on Tuesday and nearly undergo bombogenesis
(strengthening >24mb in <24 hours) before forcing itself into
Prince William Sound and the Interior Tuesday afternoon into
Wednesday. From here, the models do diverge a little bit. Some
take the energy farther east over The Yukon, while others move
it over the AlCan. These differences are very important in
determining where the heaviest snow sets up. 700mb dynamics are
indicating there will be a tremendous amount of lift, both with
frontogenesis and vorticity advection. This is especially true
in the Eastern Interior and Eastern AK Range. Highest confidence
for heavy snow greater than 6 inches exists in the Eastern
Interior, specifically the Upper Tanana Valley, west of
Northway, Fortymile Country and Isabel Pass. Isabel Pass likely
begins snowing as early as Monday and continue through Wednesday
with snowfall rates exceeding 1 inch per hour at times from
Monday night through Tuesday night. There is a potential for
feet of snow around Trims Camp. The tricky spot is directly over
Fairbanks. As the cold front moves in from the northwest, it
will be providing colder and drier air. The low moving northeast
from the Gulf will bring warm, moist air. There will be a
boundary directly over FNSB where these two features meet. One
thing to note is, 700mb vorticity shows a deformation zone
setting up and pivoting from Circle to Isabel Pass (and
continuing southwest). This deformation zone would tend to lean
towards moderate to heavy snow somewhere near FNSB. Based on
current trends, the greatest likelihood for this to set up is
from Eielson to Chena Hot Springs to Circle. Fairbanks may only
end up with light snow accumulations with nearly nothing in
Minto and Tanana. It will be a very tight gradient from
significant snow to no snow at all and a 30 mile shift west or
east will make exceptional differences in the Fairbanks area. To
give another reference on how narrow this is, some guidance
indicates 6 to 8 inches in Eielson with 2 inches in Fairbanks.
It will be difficult to pinpoint the exact location until more
mesoscale models become available.
After this storm moves through it will get quite cold in the
Interior, especially Thursday and Friday mornings where
temperatures may approach or go below zero in some spots. At
this time, there will be a low approaching the Bering Sea which
may bring significant impacts to the West Coast. A more in depth
look is in the long term forecast below.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
On Thursday we should see a brief pause between active weather
as an upper-level ridge moves over Alaska. This ridge will cause
temperatures in parts of the Interior to dip into the single
digits Thursday into Friday as 850 temperatures over the
Interior fall to 10 to 15C below zero and skies clear.
Models are in good agreement on having this ridge stall and
build over eastern Alaska on Friday. This will also put the
brakes on a low arriving in the Bering behind the ridge. The
strengthening of the ridge along with the relatively high
strength of low will work together to produce an impressive
pressure gradient between the two features. As a result, strong
south/southwest winds develop from the Pacific toward the West
Coast, resulting in coastal concerns for the southern West
Coast. This will carry a significant amount of moisture toward
Western Alaska. The bulk of the initial precipitation on Friday
is expected to be wet snow, hitting the southern Seward
Peninsula and southern Brooks Range. When paired with the strong
winds, blizzard conditions may be possible. The band of snow
will advance farther inland on Saturday, but as warmer,
southerly air comes in behind the front, snow will change to
rain along the Coast. It remains uncertain how far into the
Interior precipitation will make it. It will depend heavily on
the strength and orientation of the ridge and the resulting
trajectory of the Bering low. The low may be deflected north, in
which case precipitation remains mostly in Western Alaska.
Otherwise, it may take a more easterly track pushing a band of
rain and snow into the Interior. Winds through the Alaska Range
passes are expected to peak Saturday, likely at hazardous levels
given the strong gradient as the low pushes against the ridge.
After the first Bering Sea low exits, another low looks to take
its place late Sunday potentially extending the duration of
southwest winds into Norton Sound and presenting further coastal
concerns.
Coastal Hazard Potential...
A strong Bering Sea low develops and moves east of the
Kamchatka Peninsula on Thursday. This low will bring a front
with southerly wind gusts potentially over 60 mph to the West
Coast Thursday night into Friday morning. After this, a long
fetch of persistent, southwest flow is expected along most of
the West Coast, especially from the Seward Peninsula southward
Friday into Saturday. This will result in high water and
potential coastal flooding. North of the Seward Peninsula,
from Kivalina to Point Lay, the overall wind direction looks to
be south/southeast. At this point it is too early to give exact
values but significant coastal flooding is not entirely ruled
out next weekend.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Warning until 4 PM AKDT Monday for AKZ814.
Winter Storm Warning from 10 AM Tuesday to 4 PM AKDT Wednesday
for AKZ833-834-838.
Winter Storm Warning from 10 PM Monday to 4 PM AKDT Wednesday
for AKZ835>837.
Winter Storm Watch from Tuesday morning through Wednesday
afternoon for AKZ839>845.
Winter Storm Watch from Monday afternoon through Wednesday
afternoon for AKZ847-848.
Wind Advisory from midnight tonight to 10 PM AKDT Monday for
AKZ849.
Winter Storm Warning from 7 AM Monday to 4 AM AKDT Thursday
for AKZ849-850.
MARINE...Small Craft Advisory until 10 PM AKDT this evening for PKZ801-
806-858.
Small Craft Advisory until 4 PM AKDT this afternoon for PKZ802-
805-811-853-857.
Small Craft Advisory from 4 PM to 6 PM AKDT Monday for PKZ806-
807-854.
Small Craft Advisory until 7 PM AKDT this evening for PKZ810-
812-850.
Small Craft Advisory until 1 AM AKDT Monday for PKZ813-859.
Brisk Wind Advisory until 10 PM AKDT this evening for PKZ858.
Brisk Wind Advisory until 1 AM AKDT Monday for PKZ859.
&&
$$
Bianco
Troyke - Long Term
901
FXAK67 PAJK 190457
AFDAJK
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
857 PM AKDT Sun Oct 18 2026
.UPDATE...update for the long term and 06Z TAF issuance...
Weak onshore flow along with subtle wave will keep mainly cloudy
skies and light showers from Sitka on up through the northern
panhandle tonight. South of there, clearing this evening has
allowed for fog and low stratus to develop at Angoon, Klawock and
Petersburg. Expect the fog/low stratus to expand overnight and
have increased fog coverage overnight from Frederick Sound on
south.
.SYNOPSIS...
Key Messages:
- A brief break in the rain is possible Sunday night into Monday,
however another front and round of heavy rain and strong winds
push across the Gulf of Alaska into the Alaska Panhandle by
Monday night and continues through Tuesday.
- Flood watch issued for Yakutat, Gustavus, Pelican, and Elfin
Cove, and Juneau. Isolated landslides possible along the NE
Gulf Coast, and Glacier Bay, near Steep Terrain.
- Maritime interests need to pay attention to the strong front
projected to move across the Gulf of Alaska by Monday afternoon,
bringing Gale Force to potentially Storm Force winds to the
central and eastern Gulf Tuesday into Wednesday.
&&
.SHORT TERM.../through Tuesday night/...
A strong system is expected to move into the northern central
gulf, reinforcing the existing low pressure system, and drawing a
deeper fetch of moisture from northern Pacific. By Tuesday
morning, this plume of moisture is expected to shift from
southwest to southerly, and is likely to exceed 600 kg/ms IVT for
around a 12-18 hour period for any given location in the Icy
Strait corridor and NE gulf coast. Expecting Yakutat to be the big
winner in terms of rain amounts, with near perfect perpendicular
flow, strong WAA in the low levels increasing lift potential, and
decent divergence aloft. With this, yakutat could see upwards of 6
inches during a 36 hour period, which is a little higher than a 2
year ARI event. There are lower probabilities of around 30% to
see a 5 year event for 36 hours for the NE gulf coast, and even
higher ARIs are possible further into Yakutat Bay. These higher
ARIs look to extend down the coast and into the Glacier Bay area,
with may areas along south facing slopes exceeding 5 year return
intervals and approaching on 10 year over a 36 hour period.
Therefore, added Elfin Cove, specifically for the mountains to the
north, the NE gulf coast, and Glacier Bay to the Flood Watch.
This is mainly for areal flooding of low lying areas and ponding
of water. That being said, the wind component of this system has
wind gusts greater than 40 mph at elevations greater than 500 ft,
and greater than 60 mph at elevations around 2000 ft. Current
thinking is the high rain rates combined with higher return
intervals in the upper rainfall ranges (higher percentiles, lower
probability) leads to an increased risk of isolated landslides in
steep terrain based on historical atmospheric conditions.
.LONG TERM.../Wednesday through Saturday/...
The front that brought heavy rain and strong winds on Tuesday will
have all but cleared the southern panhandle by daybreak
Wednesday. In its wake, persistent onshore flow will continue
through Wednesday and into Thursday as the low lingers and slowly
weakens in the northern Gulf of Alaska. Subtle shortwaves and
upper troughs swinging around this low will keep higher
precipitation chances with moderate to heavy showers and gusty
winds across SEAK through Thursday. Behind the front, snow levels
fall to 1,0002,000 ft on Wednesday over the northern panhandle.
Snow showers will be possible along the Klondike Highway and upper
reaches of the Haines Highway through Thursday, though any
accumulation will remain light. As the low weakens and gradient
relaxes behind the frontal passage, gusty southerly winds will
slowly diminish through Thursday. The northern inner channels and
into Haines and Skagway could still be quite gusty on Wednesday
as the north to south gradient remains a bit tighter, and the High
Wind Watch remains in effect of Skagway. As the Gulf low weakens
further and shifts southeast toward the end of the week, showers
will lighten and end from north to south Thursday night into
Friday across SEAK. Upper-level ridging makes builds east across
Mainland Alaska by late week, with SEAK on the eastern edge of the
ridge. Ensemble and deterministic guidance generally showing high
pressure building in the wake of the departing low, with clearing
skies and drier offshore flow developing Friday and continuing
into the early weekend. Daytime highs will remain in the 40s
throughout the period, with overnight lows in the mid 30s to low
40s.
&&
.AVIATION.../Through 06Z Tuesday/...VFR conditions prevail across
most of the panhandle. A widespread cloud shield has mostly
cleared the southern region, improving cloud decks from OVC/BKN to
SCT/FEW. However, this clearing has brought almost immediate fog
formation, aided by saturated lower levels and calming winds. This
is expected to significantly reduce VSBY to 1-2 SM through the
early morning, impacting sites from Frederick Sound southward,
though also including southern parts of Admiralty Island.
Meanwhile, the northern panhandle will remain in a lighter, showery
regime tonight, ahead of the system tomorrow. Several sites, most
notably PAJN, PAGS, and PAHN, seeing flight categories shift to MVFR
this evening. CIGs expected to sit between 2000-3000ft, then
shifting down to 1500-2500ft by the afternoon.
Finally, LLWS is likely near PAYA starting Monday afternoon into
evening as the next system moves further east into the Gulf. This is
driven by a stout lower level jet of 45-50 kt winds that will push
the system toward the Northern Gulf coast and bring heavy rain and
strong winds across the entire panhandle by Tuesday morning, further
deteriorating conditions.
&&
.MARINE...
Outside (Gulf and Coastal Waters): Lingering westerly moderate to
fresh breezes will continue to push eastward and diminish Sunday
night as a brief area of ridging moves across the Gulf. Conditions
will quickly deteriorate from west to east across the Gulf Monday
morning as a strong system sends a strong gale force front
towards the panhandle into Tuesday. With the initial system on
Monday, southerly winds in the central gulf will increase to gale
force with much of the coast seeing strong breezes to near gale
force winds. A barrier jet also looks to form along the northern
gulf coast from Kayak Island eastward to Icy Bay with this first
system, bringing east to southeasterly strong gale force winds
into Tuesday. Some guidance is indicating potential for this to
reach storm force late Monday night, but current thinking is
capped at 46 kts. Another system looks to race up the western gulf
coast overnight into Tuesday, strengthening the initial system
and sending another strong front into the panhandle Tuesday into
Wednesday. Widespread southerly 35 to 45 kt winds are expected to
take over through the remainder of the gulf and along much of the
coast Tuesday, which should steadily decrease through Wednesday.
Strong southwesterly swell is also expected to increase, with the
first system bringing 10 to 13 ft at a period of 10 to 12 seconds
Monday and the second system quickly increasing to 20 to 25 ft at
a period of 13 to 15 seconds. This will bring accentuated wave
heights of 16 to 19 ft by Monday night and 25 to 28 ft through
Tuesday. This will mainly be an issue for the northern and central
parts of the gulf, with areas near Dixon Entrance staying closer
to 12 to 18 ft at most.
Inside (Inner Channels): Diminishing wind speeds will be the
trend from now through Sunday night before another strong system
moves into the gulf Monday. Northern Lynn Canal and northern
Stephens Passage are the only parts of the channels still seeing
10 to 15 kts of southerly winds, while the rest of the panhandle
is mostly light. Fog development will be possible through early
Monday morning, mainly for the southern panhandle. The northern
inner channels are expected to begin to increase again to 15 to 25
kts overnight into Monday morning as the front approaches, with
Lynn Canal reaching closer to 30 to 35 kts by Monday afternoon.
The strong southerly winds will spread through the rest of the
central inner channels through Monday and into the southern inner
channels by Tuesday morning. Anticipating periods of gale force
winds to spread throughout the inner channels through Tuesday,
bringing 6 to 8 ft wave heights through much of the panhandle.
Winds in the southern and central panhandle should begin to
decrease Tuesday night, while parts of the northern panhandle look
to stay elevated through Wednesday.
&&
.HYDROLOGY...A strong system is expected to move into the
northern central gulf, reinforcing the existing low pressure
system, and drawing a deeper fetch of moisture from northern
Pacific. By Tuesday morning, this plume of moisture is expected to
shift from southwest to southerly, and is likely to exceed 600
kg/ms IVT for around a 12-18 hour period for any given location in
the Icy Strait corridor and NE gulf coast. Expecting Yakutat to
be the big winner in terms of rain amounts, with near perfect
perpendicular flow, strong WAA in the low levels increasing lift
potential, and decent divergence aloft. With this, yakutat could
see upwards of 6 inches during a 36 hour period, which is a little
higher than a 2 year ARI event. There are lower probabilities of
around 30% to see a 5 year event for 36 hours for the NE gulf
coast, and even higher ARIs are possible further into Yakutat Bay.
These higher ARIs look to extend down the coast and into the
Glacier Bay area, with may areas along south facing slopes
exceeding 5 year return intervals and approaching on 10 year over
a 36 hour period. Therefore, added Elfin Cove, specifically for
the mountains to the north, the NE gulf coast, and Glacier Bay to
the Flood Watch. This is mainly for areal flooding of low lying
areas and ponding of water. That being said, the wind component of
this system has wind gusts greater than 40 mph at elevations
greater than 500 ft, and greater than 60 mph at elevations around
2000 ft. Current thinking is the high rain rates combined with
higher return intervals in the upper rainfall ranges (higher
percentiles, lower probability) leads to an increased risk of
isolated landslides in steep terrain based on historical
atmospheric conditions.
&&
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Wind Advisory from 4 PM Monday to 10 PM AKDT Tuesday for AKZ317.
Flood Watch from Monday evening through late Tuesday night for
AKZ317-320-322-325.
High Wind Watch from Monday evening through Wednesday afternoon
for AKZ318.
Wind Advisory from 4 PM Monday to 4 AM AKDT Wednesday for AKZ319.
Wind Advisory from 9 PM Monday to 4 AM AKDT Wednesday for
AKZ320>322-325.
Wind Advisory from 1 AM Tuesday to 4 AM AKDT Wednesday for
AKZ323-324-327.
Wind Advisory from 10 AM Tuesday to 4 AM AKDT Wednesday for
AKZ330-332.
MARINE...Gale Warning for PKZ011>013-021-022-031>036-053-641>644-651-652-
661>664-671-672.
&&
$$
UPDATE...DS
SHORT TERM...NC
LONG TERM...DS
AVIATION...BAS
MARINE...ZTK
HYDROLOGY...NC
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