879
FXAK67 PAJK 172333
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
333 PM AKDT Wed Jul 17 2024

.SHORT TERM.../Through Friday/ Another wet day across the central
and northern panhandle today as the second atmospheric river in
the last week impacts the area. Heaviest rainfall this morning
ranged from Cape Fairweather to Petersburg. Since then the eastern
edge has moved over to Ketchikan and Wrangell this afternoon.
Rainfall totals so far have been around 0.5 to 2 inches across the
area. The back edge of the precip has reached Sitka, Elfin Cove,
and Pelican as of 1 pm and it should slowly move E through the
evening. It will be where the remains of this moisture plume goes
over the next few days that is the main focus of the short range.
At the moment, it appears that it will weaken as it moves E and
will end up stalling over the southern panhandle by late tonight
while areas north of Petersburg and Kake start to dry out. That is
where it will stick through Thursday in a much weaker state.
Thursday night into Friday sees a much weaker front getting shoved
back to the west as a new low moves NW through the Eastern gulf.
Overall heaviest rainfall will be tonight over the southern
panhandle (up to 1 to 1.5 inches) while the rain ends up north.
Much lesser amounts of rainfall expected after that over any 12
hour period (up to 0.5 inches).

Winds have been rather interesting today. The low that is
generating the winds has tracked a little further east then
expected so the higher winds have mainly impacted Clarence Strait,
Sumner Strait, Frederick Sound, and Stephens Passage. Highest
winds observed have been around 25 kt in these locations. Main
change to the short range forecast for winds was this evening with
a reduction in wind speeds in the northern inner channels as the
low tracks further east. Cross Sound and Northern Lynn could still
see some 20 kt southerly wind conditions this evening though as
the low moves north of the area. After tonight winds mostly
lighten up as there are few strong systems expected after that
point.

.LONG TERM.../Friday through Wednesday/... Overview: A relatively
quiet weather period is likely for SE AK. Friday will see
additional moisture being funnelled up from the south, which will
then be followed by drier air from the south. An easterly, wet
wave is possible late in the weekend and into next week.

With the 500 mb low in place flow pattern will move a low extending
from a deeper system over the far SW Gulf northward into the SE Gulf
by Friday. For now winds around the low expected to be in the 20 kt
range with lighter winds to the north. Light rainfall amounts
move in with the system with most models keeping precip over the
south with diminishing rates as the low moves northward. By late
Saturday this low will have dissipated, but the main low remains
in place into next week and thus can keep pushing precip bands
over the panhandle. The southerly flow and weather breaks will let
day time highs pick back up into the upper 60s to low 70s.

Looking towards late weekend and into next week, there is
increasing confidence of an easterly wave making it over the
mountains. Areas of interest include communities in the northern
panhandle and possibly Juneau at this time.

&&

.AVIATION...Main band of LIFR/IFR in low CIGS and light to
moderate rain extends east of a line from Mt. Fairweather to
Gustavus to about 10 miles offshore of Sitka...with MVFR CIGS and
VSBY Klawock to Ketchikan to Misty Fjords in the south. The
clearing line between LIFR/IFR and MVFR/VFR is slowly working
eastward this afternoon, with the southern Panhandle expected to
get a period of IFR late this afternoon into the evening as the
southern end of the band of rain moves across. We expect clearing
trend to continue central and northern areas of SEAK with the
southern areas with periods of IFR but mostly VFR overnight.
Clearing trend continues tomorrow with small rain chances and
mostly VFR expected after 10Z.

&&

.HYDROLOGY...Rivers across the northern inner channels are still
running high from the second atmospheric river to hit the area in
the last week. As of 1 pm, Chilkat river is the only gage river
above minor flood stage, but several others are at bankfull and
currently showing rises from all the rainfall. Most of these
rivers are expected to rise this evening and crest above minor
flood stage sometime tonight or tomorrow morning after the
rainfall ends up north. Several hydro statements remain in effect.
Hydro issues should improve over the next few days as much less
rainfall is expected over the area.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Flood Watch until 1 AM AKDT Thursday for AKZ325.
MARINE...Small Craft Advisory for PKZ031-034-036-661.

&&

$$

SHORT TERM...EAL
LONG TERM....NC
AVIATION...JG/JLC

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