260
FXAK67 PAJK 191131
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
331 AM AKDT Wed Jun 19 2024

.SHORT TERM...We are starting off this morning with very similar
conditions to yesterday in that a marine layer has moved in over
significant parts of the panhandle. This marine layer is
preventing temperatures from falling much during the overnight
hours but is also limiting daytime temperatures. Conditions today
are expected to be similar to yesterday with most places warming
up during the day and decreasing cloud cover. The pressure
gradient between Whitehorse and Juneau is expected to tighten
during the day, so winds through Lynn Canal are expected to come
up a little more than the usual sea breezes during the afternoon
and into the evening.

.LONG TERM.../Thursday into the weekend/...A weather pattern
change will bring rain and brief elevated winds back to the
panhandle.

High pressure ridging will slide east into Canada as a trough of
low pressure approaches. This trough could bring some showers or
light rain to the area on Thursday. Low confidence on where the
greatest chances will be, so for now, stuck with 20 to 40% PoPS.

Friday into the weekend is when the greater chance for precip
will move in. This is due to a low tracking east through the gulf
towards Haida Gwaii. The associated front will swing north into
the panhandle. This front will likely (greater than 70% chance)
bring rain to the area, especially in the southern half. Farther
north, confidence is a little lower, so stuck with PoPS around 40
to 60%. This is due to questioning just how far north will the
front track.

In addition to the incoming rain, wind speeds will be elevated
along the front as well. For now, went with marine wind speeds up
to 25 knots along the front in the gulf. Euro ENS and GFS ENS give
greater than 60% chance for wind speeds greater than 20 knots
along the front during this time.

As the front tracks through the inner channels, went with wind
speeds around 15 to 20 knots. This was supported by the latest
NBM, EURO ENS, GFS ENS, and EURO AIFS.

After the frontal passage, 500mb ridge looks to build back up but
surface features generally keep light, leftover rain in the area so
for now, low PoPS and light winds linger.

&&

.AVIATION...
As of 4am AKDT, marine layer and associated cloud
deck is working its way up panhandle this morning leading to a
mixed bag of CIGS ranging from 500ft at Klawock up to 5000ft at
Haines. Lowest CIGS will remain along the southern and coastal
panhandle this morning with gradual improvement to upper MVFR to
low end VFR flight conditions by the afternoon. Winds should
remain 10kts or less expect for PAGY, where an isolated gust up to
25kts will be possible after 00z.


.MARINE...Similar conditions continue this morning across the
water with a marine layer covering significant portions of the
panhandle and all of the gulf. Winds are expected to remain light
with the exception of areas that experience sea breeze
enhancements during the day. This pattern is expected to change
late tonight through Thursday as a low moves into the gulf and
brings south winds to the area. One thing that will need to be
watched will be how much the low disrupts the marine layer that
has developed.

&&

.HYDROLOGY...Minor flooding along the Chilkat due to snow and ice
melt continues. The Flood advisory for this flooding has been
extended through Thursday. Elsewhere, warm temperatures are
allowing for continued runoff from snow and ice melt to bring up
rivers and creeks across the panhandle but remain below bankfull.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012.

&&

$$

SHORT TERM/MARINE/HYDROLOGY...SF
LONG TERM....GJS
AVIATION...NM

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