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FXAK67 PAJK 110536 AAA
AFDAJK

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
935 PM AKDT Thu Jul 10 2025

.SHORT TERM... Not much change to the ongoing forecast for tonight,
only minor changes to the marine forecast and few QPF changes.

Still expecting an unseasonably high amount of moisture to surge
into the panhandle tonight, associated with an atmospheric river
with IVT values around 600 - 700 kg/ms. This combined with
divergence aloft, and a S to SW directing flow of moisture has
allowed much higher rain accumulation than normal for the southern
panhandle. Additionally, while the bulk of the moist will dip
south of the panhandle, not unusual for stronger systems, still
expecting a brief period (around 4-6 hours) for the central and
southern panhandle. For more information, see the hydrology
section.

Beyond the frontal passage, a surge of warm air advection that
looks particularly dry (less than 540% RH) between 700-500 mb
moves in behind. Therefore, drop PoPs down drastically except on
western facing mountains. Boundary layer residual moisture from
heavy rains and westerly flow for orographic lift will keep rain
and clouds present in these locations. Otherwise, the large dry
slot with lack of lift will result in some clearing in the central
and southern panhandle behind the front for Friday. Nothing
widespread, but sun does look to make a brief appearance.

.LONG TERM.../Saturday through Thursday/

Key messages:
- A weak low continues precip for southern panhandle Saturday
- High pushes up from the south, dry but clouds linger next week

Details: Another low moves into the eastern gulf Saturday
morning. The atmospheric river helping to fuel the previous front
will shift south, but not before sending another small plume of
moisture to the southern panhandle Saturday afternoon. A lingering
upper level low and an embedded shortwave trough will help direct
the small front onshore. The front will reach the panhandle by
early Saturday morning, bringing moderate to fresh SE sustained
winds (13 to 24 mph) to the southern coast and channel entrances
with strong southerly gusts midday in Dixon Entrance. Between 0.3
and 0.5 inches of precipitation are expected in 24 hours, with
greatest amounts impacting Ketchikan and higher elevations. Rates
are expected to remain light with ~0.1 inches of rain in 6 hours.
EFIs have indicated a very minor increase in QPF potential in the
12Z run, though the strongest impacts remain south of the
panhandle. Ridging moving north through the gulf will push the low
out of the panhandle and set up for potential drier weather
Sunday afternoon, though clouds are still expected to linger
through the beginning of next week. Another low looks to bring
precipitation back to the panhandle Wednesday. Temperatures are
still slightly below normal, though with the drier weather coming
up next week there is potential for highs in the mid to high 60s.

&&

.AVIATION.../ 06z Friday - 06z Saturday / LLWS with the front is
starting to decrease. The back edge of the initial front moved
through most of the northern 2/3 earlier in the evening based on the
radar near PASI. PAKT and PAWG remain under the front with moderate
to heavy rain, but even PAWG has seen preicp rates drop off in the
last hour. Surface winds have not been as strong, but winds at 2kft
remain 40-50kt over PAKT for a few more hours. Ceilings have also
been elevated with the front, largely MVFR, but starting to see
those trend down through the overnight hours. As the area
transitions to showers on the back side of the front, expect a wind
shift to the W-SW through Friday morning and breaks to develop. West
facing slopes will hold on to the clouds and showers the longest.

&&

.MARINE...

Overall: Not much change in the overall message for the upcoming
system.

Outer: According to the latest ASCAT pass, a swath of gale force
winds are extending from the NE gulf coast down to Cape Edgecombe.
These are being represented well on buoy 48084. Expecting these
winds to enhance as the maximum moves closer to the coastline,
developing as a barrier jet. What is also visible on these ASCAT
winds is the shift to SW winds behind the front, with a fresh
breeze (20 knots) riding directly behind the front. For seas,
expect a maximum significant wave height of 13-16 ft along the
coastline, slowly diminishing as the post frontal winds take over
tonight.

Inside: Similar to the prior forecast, gales are expected to begin
shortly for Clarence Strait and continue through the evening.
Strong breezes to near gales (25-30 knots) are also expected to
kick off across the inner waters for areas exposed to the SE. One
change is changing most of Lynn Canal to lighter winds this
evening. This is due to lack of directing flow aloft along with a
parallel pressure gradient over the channel. With the shift to SW
across much of the inner channels as the front passes, expecting
rapidly rising pressures, which will direct the pressure gradient
to a north south direction. This will increase winds in Lynn Canal
finally late Friday morning.

&&

.HYDROLOGY...

IVT values associated with this system range between 600-700 kg/ms
with freezing levels in excess of 10,000 ft, currently expecting
widespread moderate to heavy precipitation. The peak of these rains
look progressive, moving through the panhandle quickly. Expect heavy
rain to stay in one area for 4 - 6 hours, coinciding with the
frontal passage. S to SW moisture flow aloft means that
corresponding mountains exposed to these directions will receive the
greatest amount of rainfall. Ketchikan and Metlakatla fit the bill
here, with expected rain rates of up to 0.3 inches per hour. A flood
advisory has been issued for the Ward Lake area, but no change to
other rivers. Other rivers are still expected to stay below flood
stage, but can reach bank full.

In addition, a Flood Advisory has been issued for the Salmon
River at Hyder as a trained weather spotter reported that the
river has begun its annual Glacial Outburst event. As of 1045pm
Wednesday, trained spotter reported around mile marker 9 of the
Salmon River highway that the river water is murky and muddy,
flowing quickly, and about 4 ft above its normal level. Spotter
further reported that the water levels had been rising quickly
with the river flow getting rougher,making surf/waves in its flow,
and trees on the edge of the riverbank starting to erode into the
river. However, water is not crossing over the highway. Minor
flooding is ongoing or expected to begin shortly, no major impacts
are expected at this time.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind until 7 PM AKDT this evening for AKZ323.
     Strong Wind from 7 PM to 10 PM AKDT this evening for AKZ327.
     Strong Wind from 10 PM this evening to 1 AM AKDT Friday for
     AKZ330.
     Strong Wind from 7 PM AKDT this evening through late tonight for
     AKZ332.
MARINE...Gale Warning for PKZ036-641>644-651-652-661>664-671-672.
     Small Craft Advisory for PKZ021-022-031>035-053.

&&

$$

SHORT TERM...NC
LONG TERM....ZTK
AVIATION...Bezenek
MARINE...NC
HYDROLOGY...NC

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