906
FXAK67 PAJK 302305
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
305 PM AKDT Sun Jun 30 2024

.SHORT TERM...

Key messages:
-No significant marine or land based hazards in the short term
 forecast, isolated to scattered rain chances will continue into
 Monday.

As of 2pm Sunday, no major changes to the short term forecast as
a weakening frontal band pushes into the panhandle, bringing
continuous isolated to scattered rain chances to the area before
eventually dissipating through Monday. As this shortwave pushes
into the N Gulf of Alaska, southerly winds will remain elevated
through this evening ahead of the approaching front, with inner
channel marine winds reaching up to 15-20kt as verified by marine
obs within Clarence Strait and Lynn Canal. Anticipating isolated
and intermittent rain to continue to overspread the panhandle
through Monday. Highest forecast rainfall are around 0.25" across
the SErn and eastern panhandle. Not anticipating a washout, but
just enough wetting rain to ease some fire weather concerns for
the 4th of July week festivities. By the end of the short term,
ridging builds into the Gulf of Alaska with more NWly to Westerly
winds and on- shore Gulf flow by Monday night.


.LONG TERM.../Tuesday through Sunday/ Relatively quiet forecast
for the mid to extended range period today as the upper level
pattern is somewhat static. An upper low will be getting cut off
from the jet stream over the far SW Gulf of Alaska early in the
forecast and will last throughout the period. The main axis of the
jet stream meanwhile is diverted north through the Alaska
interior and Yukon Territory by a ridge upstream of the cut off
low. SE Alaska will be situated in a quiet zone of weak ridging
NE of the cut off low and south of the main jet axis for just
about the entire extended forecast as a result.

At the surface, ridging across the Gulf of Alaska is much more
pronounced then at higher levels resulting in a distinct lack of
any major system affecting the area through next weekend. That
being said the surface ridge axis is rather flat to start off
with, and then starts to situate and strengthen itself more in the
south central gulf by next weekend keeping W to NW flow going
across the gulf and Panhandle through the period. Included in this
is a slight onshore component to the low level flow which will
work to keep at least a chance of showers (highest chances are
early in the forecast due to a weak surface through moving through
the panhandle on Tuesday) across the north and general cloudiness
across most areas through the extended from a combination of
moist marine air interacting with the terrain and marine layer low
clouds invading from the Gulf. I can not rule out some large
holes opening up in the cloud cover from time to time especially
later in the week and during the weekend, allowing the sun to warm
temperatures up move than expected at times, but a general mostly
cloudy forecast with temps in the 60s for highs is the rule of
the extended forecast today.

Little in the way of higher winds expected for the extended with
the lack of any major systems coming through. Winds along the near
coastal waters of the gulf were increased to around 20 kt NW on
Tuesday as a weak trough moves through. Otherwise, highest winds
will mainly be with sea breeze circulations when they do develop
during the afternoons and evenings.

&&

.AVIATION...Passing isolated showers across the north and
scattered to numerous showers across the south today. Some of the
showers are causing periodic MVFR ceilings this afternoon,
however other locations have some low clouds still hanging around
from the morning (PASI, PAYA, PAKT) but are starting to lift.
Over the northern inner channels, large breaks formed this morning
and expect that to last into the early evening, then slowly fill
in as the frontal trough currently over the southern panhandle
tracks northward and weakens tonight. For Monday, likely to see a
similar trend to Sunday, with some patchy fog and low ceilings in
the morning followed by more breaks and fewer showers in the
afternoon.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

SHORT TERM...NM
LONG TERM....EAL
AVIATION...Ferrin

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