469
FXAK67 PAJK 151242
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
442 AM AKDT Sun Sep 15 2024

.SHORT TERM...The brief lull in the active pattern will draw to a
close through Sunday as a gale force front advances into the
panhandle.

Satellite and radar imagery show an organized frontal band
advancing across the Gulf and into the panhandle as of the time of
writing. Already, rain has started to fall across much of the
northern half of the panhandle. Fog which formed during the
overnight hours across parts of the southern panhandle will
dissipate through the morning as cloud cover increases ahead of
the approaching system.

As the system arrives, wind speeds will rapidly increase through
the morning hours, with elevated winds across the panhandle -
though the strongest winds will be for the northern half of the
area. Winds will intensify to small craft conditions across most
of the inner channels with small craft conditions also expected
across many of the outer coastal waters, and gales for parts of
the northern gulf.

Rain may be heavy at times, with moderate to heavy precip
arriving through the morning hours for the northern panhandle, and
during the afternoon hours for the southern half of the area. By
Sunday night, the heaviest rain will have largely departed the
area, though onshore flow and continuing moisture support will
lead to chances of precip remaining across SE AK. Another low may
manage to impact the southern panhandle on Monday, depending on
how far N it reaches, for additional details, see the long term
forecast discussion.

Primary changes to the forecast were to increase wind speeds
across a few of the land-based areas, along with some minor
increases in wind speeds across the inner channels and some of the
outer coastal waters. Given onshore flow and still respectable
moisture transport after the initial system has begun to depart,
also increased PoP chances across the area on Sunday night.


.LONG TERM...An active pattern will continue across the panhandle
through next week. To start off, a weakening front will move over
the panhandle Monday morning before a low affects the southern
panhandle Monday night into Tuesday morning. This low will start to
move across the far southern panhandle Monday evening bringing
precipitation and increasing winds. Winds are expected to be around
15 kts on land and in the inner channels, and be around 25kts along
the coast. Confidence is high on the timing of this low as it tracks
across the panhandle, but confidence is low on the location of this
low. Guidance has a range of locations, some bringing the low
directly over the southern panhandle, and some tracking the low
south of the panhandle. The location of the low will determine where
the strongest winds and heaviest rain occurs.

A short break is then expected as a low makes its way into the
northern gulf Wednesday morning. There will be both wind and rain,
but no impressive values are expected. The largest impact seems to
be the chance of strong breezes along the gulf coast and northern
inner channels.

Ultimately, what is currently on the radar as the next impactful
rain event could possibly be next weekend. There are early
indications of a long duration rain event. At this time, there is 40-
60% chance of IVT values exceeding 250 kg/m/s for three days.
Unfortunately, details are scarce, but it will be monitored
closely.

&&

.AVIATION.../until 12z Monday/
Another morning of near calm winds and saturated low levels have
created isolated LIFR to VFR CIGS and VSBY flight conditions
across the southern panhandle. Rest of today, a low in the gulf
and its associated front will deteriorate conditions and
overspread rain showers across the panhandle through Sunday
afternoon. Anticipate prevailing MVFR or worse flight conditions
with CIGS AoB 3000ft and vsbys dropping to 4SM or less within
heaviest showers. Winds increase from west to east across the
panhandle through mid morning as pressure gradient tightens with
sustained winds up to 15-20kts and gusts up to 30kts through the
afternoon, lasting into the late evening for Skagway and Haines.
Mechanical turbulence and LLWS increase through early morning on
the northeast Gulf Coast, spreading southeast through Sunday
afternoon before decreasing by 03z post- front.

//Aviation Forecast Confidence...
-High confidence on precipitation, winds, and coastal LLWS
-Medium confidence on visibilities, ceilings, and interior LLWS

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind from 10 AM AKDT this morning through late tonight
     for AKZ318.
     Strong Wind from 10 AM AKDT this morning through this afternoon
     for AKZ324.
     Dense Fog Advisory until 10 AM AKDT this morning for AKZ326-332.
MARINE...Gale Warning for PKZ652-672.
     Small Craft Advisory for PKZ011>013-021-022-031>034-036-053-
     641>644-651-661>664-671.

&&

$$

SHORT TERM...GFS
LONG TERM....EAB
AVIATION...NM

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