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FXAK67 PAJK 102348
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
348 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.../ through Friday afternoon / Front making landfall
this afternoon and evening across the panhandle. For most part
afternoon locations are still Visibility greater than 5 miles and
ceilings above 3000 feet. Will those lower though the even as the
main band move inland. Pilots reporting light to Moderate
Turbulence in the low to mid range...expect that to lower and as
the front gets closer the lower level Jet will have band of LLWS
spread through majority of sites. Band at three to five thousand
are 40 to 55 kt in the models. Terrain induced Turbulence also
expected to pick through the evening. Early morning time frame
could see central and northern panhandle with lowers ceilings
below 1000 feet post frontal with wind shift to more of an onshore
pattern. Morning may not be best to trying to fly around as well.

&&

.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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