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000
FXAK67 PAJK 111351
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
551 AM AKDT Thu Apr 11 2024

.SHORT TERM...
A rinse and repeat of yesterday morning as multiple mesoscale
lows rotate within the Gulf of Alaska under a mid/upper level low
pressure. As of 5am AKDT satellite imagery, a small low center is
moving northeast near Graham Island close to the Dixon Entrance
with recent ASCAT passes showing sustained winds 10-20kts.
Thankfully, not anticipating major marine impacts at this time as
an approaching surface ridge from the west should shunt this
developing low back southeast towards the eastern Pacific, however
winds in the near term will need to monitored. Highest PoP
chances through mid morning expected along the southern portions
of the AOR before a brief precip reprieve through the rest of
today as surface ridging continues to nudge eastward and overhead.
Dry weather doesn`t last as another system approaches from the
west by tomorrow morning. As the system approaches, anticipating
PoPs to overspread the AOR with southerly winds increasing through
the inner channels during the day. Strongest winds could reach
near Small Craft criteria within the Lynn Canal south to Chatham
Strait.

.LONG TERM...
Guidance has been running consistent with the
previous discussions; a 522-decimeter closed low will be
transiting southeast across the Gulf, with a ridge
sliding across the Panhandle into the evening. Simply put,
Thursday is looking like a fantastic spring day. As mentioned
previously, the big unknown is the formation and penetration of a
marine layer, but with respect to winds and swell/seas, not a lot
of concerns.

The main feature focused on the long-range discussion is an
upstream longwave trough lifting through the Bering Strait into
western Alaska Thursday, with the Jetstream moving into the
western Gulf by the afternoon. Increased amounts of IVT near the
Aleutian Islands associated with this Jetstream will shear apart
by Friday, which will help decrease precipitation amounts and
concerns; however, will still see widespread stratiform rain/snow.
Main threat is an increase of southerly winds and seas across our
waters as a surface low lifts into the Kenai Peninsula. For
timing, expect near-gale force winds west of Cape Suckling by
Thursday afternoon, moving east through the night. For the inner
channels, expect southerly winds to ramp up through Thursday
evening, with elevated 20-30 knot winds in the inner channels into
Friday afternoon before dissipating early Saturday. As mentioned
before, guidance consensus is about 25 knots sustained winds, but
if the surface low forming off the Alaskan Peninsula is able to
deepen further than anticipated, we could see closer to 30 knot
winds through some central and northern inner channels. Stay
tuned.

For the weekend, cluster analysis of the various ensembles
indicates a similar theme; the surface low that brought us the
active weather Friday will weaken as it stalls near Prince
Williams, before the parent trough aloft slides across the western
seaboard, bringing the low with it. Guidance struggles with the
timing and location of the eastward movement but the main forecast
notes are the pressure gradient looks weak with breezy, but
lighter winds than Friday in the inner channels, some low clouds,
and stratiform precipitation becoming showery, moving across the
Panhandle through Monday morning.

One note is we will likely see some outflow winds coming out of
Cook Inlet Sunday into Monday bringing some elevated 12-14ft
northwesterly seas in the western gulf. This feature is not fully
captured by wave guidance so something to watch.

&&

.AVIATION...
Area of low pressure south of the panhandle is projected to move
south of the area today. Behind the low, a ridge will build over
SE AK that will last through the evening and most of the
overnight. Next frontal passage will happen tomorrow.

So for today, VFR conditions will be found around the area today,
although brief and isolated MVFR or IFR conditions, due to VIS
and CIG, have been reported this morning and will last for at
least part of the morning.

As the next front moves in late tonight into Friday, clouds and
rain will move in from the west. So expected MVFR conditions to
return as clouds lower and VIS is reduced due to the rain.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale Warning for PKZ652.
     Small Craft Advisory for PKZ012-013-022-032-033-642>644-651-
     661>664-671-672.

&&

$$

SHORT TERM...NM
LONG TERM....AP
AVIATION...GJS

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