535
FXAK67 PAJK 162251
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
251 PM AKDT Mon Sep 16 2024

.SHORT TERM.../through Tuesday night/...
Quick notes:
-Quick moving low south of the gulf will keep rain chances in the
 forecast for the southern panhandle tonight.
-Dry weather and light winds expected for SE AK tomorrow.
-Next front moves in from the west late Tuesday night.

The details:
A quick moving low tracking eastward south of the panhandle will
keep rain in the forecast for areas mainly south of Sumner Strait
tonight. For those to the north of Sumner Strait, a building ridge
will help fade out those rain showers dotting the landscape late
this Monday afternoon. The fading clouds may lead to some fog
developing tonight in the northern half of the panhandle as well.

Brief 500mb ridging will give the area a short break in the rainy
weather, and even some breaks in the clouds, on Tuesday. Light
winds expected as well, so an overall pleasant day.

Tuesday night, the next round of rain and wind approaches from the
west. So expect wind speeds to slowly increase Tuesday night in
the marine areas.

.LONG TERM.../Wednesday through Sunday/...This extended range
forecast period sees Southeast Alaska situated on the north side
of the upper level jet stream with periods of upper level zonal
flow punctuated by pronounced upper level troughs. The single
exception to this will be on Friday when an upper ridge transits
the area from west to east. What this means: No less than three
lows pressure centers will transit across the Gulf of Alaska and
Southeast Alaska over the next five days with the only meaningful
chance of dry weather occurring on Friday when the upper level
ridge passes overhead. Model divergence gets rather large on
Friday going into Saturday with regard to a low over the far
southeast Gulf. Details on how strong and precisely where it will
make its closest approach to the southern outer coast are lacking
big time. Fortunately we have several days to pin down this
potentially storm force low. As is often the case, GFS is offering
the strongest solution. If the worst case GFS solution pans out,
potential exists for the first high wind warning of this Autumn
season for the southern outer coast. Stay tuned.


&&

.AVIATION...Across the panhandle, flying conditions are VFR
except for the far southern panhandle, specifically Ketchikan. A
low is developing south of the panhandle that will move over the
southern area tonight into tomorrow. This will create low enough
ceilings and visibilities for IFR conditions in the far southern
panhandle. These conditions are expected to get better starting
tomorrow morning. For the rest of the panhandle, VFR flying
conditions will prevail for the rest of the day, with times of
MVFR possible. There is potential for fog development early in the
morning, possibly lowering ceilings and visibilities to IFR
conditions. This fog will dissipate Tuesday morning creating good
flying weather once again.


&&

.MARINE...Winds over marine areas should see a decreasing trend
going into tonight. Northern Lynn Canal is flirting with a
marginal Small Craft Advisory wind conditions (winds around 25 kt)
so went ahead and put in Small Craft Advisory for the early
evening. But wind speeds should calm quickly this evening so that
advisory will expire this evening. Late Tuesday night, the next
front will move in from the west, causing wind speeds to increase.
20 to 25 knots in the gulf with 10 to 20 knots in the inner
channels. The exception for the inner channels is Lynn Canal
where wind speeds will increase to 20 to 30 kts by late Tuesday
night with elevated winds lasting into Wednesday.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ641-661-662.

&&

$$

SHORT TERM...GJS
LONG TERM....Fritsch
AVIATION...EAB
MARINE...GJS

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