528
FXAK67 PAJK 031253
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
453 AM AKDT Mon Jun 3 2024

.SHORT TERM.../ Through Monday night / A strong spring to summer
storm developing will move into the southern gulf with a center in
the upper 970 mb range. The system has also absorbed remains of a
former tropical system (Tropical Storm Ewiniar) into so will add
a heftier punch of moisture to the system that will catch just the
southern portion of the panhandle a good portion seems to headed
in British Columbia. Do not expect the main push of the front
until the tonight period and into Tuesday.

The winds ahead of the front will bring in gusty southeast wind to
the southern panhandle so could see gusts to 25 to 35 mph with
portions Clarence Strait with gust up to 45 mph. A strong wind
headline has been posed for the Ketchikan area and along Clarence
strait.

Will be watching stream levels for the southern panhandle and with
the larger rainfall amounts there ( 24 sea level estimate is 1 to
2 inches ) solid rises should be seen. The present thinking is
that flooding is not anticipated.

.LONG TERM.../ Tuesday through Saturday/ Continuing from the
short term discussion, the the big story is the unseasonably strong
low that enters the Gulf and begins impacting the southern panhandle
late Monday into Tuesday. Model guidance remains on track for
the system to recurve northward and northwestward on Tuesday.
Unlike the previous system, this one will likely bring moderate
rain to a majority of the panhandle in the form of convective
showers as it transits the gulf, with the heaviest rain still
expected for the southern panhandle. The storm itself is expected
to have substantial embedded moisture, while a significant plume
of moisture will be primarily aimed further south toward the
Pacific Northwest and British Columbia. Models continue to trend
towards having this system weaken as it makes its turn north and
west into the central gulf. Despite this, sustained winds of 25+
kt are expected for Clarence Strait and northward towards Sumner
through Tuesday afternoon before starting a downward trend as the
storm continues tracking NW. Similarly, NE gulf coast will see
widespread small craft conditions due to rising seas ranging from
17 ft SW of Prince of Wales Island to 12 ft near the Fairweather
grounds. As the storm progresses into the north central gulf there
is a chance for a barrier jet to develop along the NE gulf coast
from Cape Fairweather towards Cape Suckling. Either way, seas of
9+ ft are expected for the majority of gulf waters before the
storm finally exits the region Thursday morning and seas begin to
subside.

While the storm continues marching westward during the day Thursday,
southerly flow and remnant moisture will mean lingering showers for
most of the panhandle. The model turbulence towards the end of
the week has cleared up a bit, with a ridge setting up over SE AK
and potentially building up towards the interior. This will lead
to clearing conditions and therefore maximized daytime heating, as
well as warm flow in the low to mid levels with snow levels set
to reach upwards of 6000 ft in the southern panhandle by the
second half of the day Friday and continue increasing into the
weekend. This will be driven by overall increased southerly flow
due to the developing gradient between the above mentioned ridge
as well as another strong low that is set to spin up in the west
central gulf. Overall forecaster confidence is moderate for this
period due to relative agreement between models in the mid range
and lower model divergence in the long range compared to previous
runs.

&&

.AVIATION...
Fog development overnight has resulted in isolated LIFR to IFR
CIGS and VSBYs for portions of the southern panhandle, but
expecting conditions to improve through mid-morning. Isolated to
scattered rain chances will continue through today for much of the
area, with highest precip chances across the southern panhandle.
For the southern panhandle TAF sites, expect low-end VFR to upper
MVFR flight conditions through tonight with CIGs bouncing between
2500 and 5000 ft. For the northern TAF sites, expect primarily VFR
flight conditions under BKN to OVC skies with low-end precip
chances increasing after 06z. Widespread sustained winds should
remain less than 15kts with potential for a sporadic gust up to
25kts for southern panhandle TAF sites this afternoon.

&&

.MARINE...Marine forecast is mainly focused on the storm for Mon
night into Tuesday. Winds in the extreme SE Gulf and over the
southern inner channels, especially Clarence Strait, have been
increased to min gale force for Monday night as the initial
frontal band moves in late. Those winds are expected to diminish a
little down to 25 to 30 kt by Tuesday but will remain at that
level through Tuesday night at least in the south. Central inner
channels and NE gulf likely will not see elevated winds from this
system until during the day on Tuesday, and even then it will only
be around 25 kt at max. 30 kt winds will then transition to the
northern gulf Wed with diminishing winds for the rest of the area
by that point. Seas will be elevated with this storm possibly
reaching 15 ft for the SE gulf and up to 9 ft or 10 ft for
southern Clarence Strait on Tuesday before slowly diminishing.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind late tonight for AKZ330.
MARINE...Gale Warning for PKZ036-641-661.
     Small Craft Advisory for PKZ035-642-662-663-671-672.

&&

$$

SHORT TERM...Bezenek
LONG TERM....STJ
AVIATION...NM
MARINE...Bezenek

Visit us at http://www.weather.gov/Juneau