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FXAK67 PAJK 110738 CCA
AFDAJK

Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
1138 PM AKDT Wed Jul 10 2024

.SHORT TERM.../Through Thursday/...The story of the next 36 hours
is the tale of two fronts. The first of which is currently over
the panhandle with light to moderate rainfall hitting most areas.
Area of highest rainfall totals continues to be the Juneau area as
southerly winds continue to pump more moisture northward. In
particular, Mendenhall Valley and Douglas are taking the brunt of
the heaviest rainfall due to the southerly winds and topographic
forcing. Additionally, Montana Creek has responded and will
continue to respond to heavier rainfall within its basin. Upper
level support looks to briefly subside for Wednesday night,
mildly increasing ridging around the 700 mb level and shift the
moisture transport. Expect over the next few hours for the bulk of
the moisture transport to pivot from mainly southerly to
southwesterly in nature, with additional rainfall moving towards
the Mendenhall basin and Jordan Creek basin. At this time, no
flooding is expected as both flashy river are well below action
stage.

The second front looks relatively similar to the current front,
moving into the area mid Thursday morning from the decaying parent
low in the gulf. Similar to the southerly moisture transport, this
front will again see heavier rainfall in the same areas. While
upper level support does return, significant widespread upward
motion from vorticity advection is not expected to be as substantial,
which will lead to lesser rain totals. Regardless, expecting
another day of rainfall for the panhandle.



.LONG TERM.../Friday through Wednesday/...
Overview: Dissipating low over the NE Gulf keeps band of showers over
the northern portions of the AK Panhandle Friday with some breaks
developing Saturday. A stronger system and associated front move in
Sunday into Monday with more moderate to heavy rainfall. As the
low weakens by mid week, rain rates and coverage diminish.

A low moving into the NE Gulf will weaken to an open wave trough
Friday into Saturday. On shore flow will keep post frontal shower
activity going for most of the panhandle with the far south
getting more breaks in showers than the north. Another stronger
system moves in Sunday into Monday dropping down over the
Aleutians. This front keeps upper level support so stays intact as
it moves over the panhandle. While winds will pick up main impact
from this front will be the moderate to heavy rainfall. GFS IVT
has the wide swath of moisture crossing the gulf under the main
low and being directed directly at SE AK. As of now rainfall
totals will be highest over the NE Gulf Coast with higher
probability of 1 to 2 inches of rain over 24 hours with 0.5 to 1.5
inches elsewhere. Have below 30% chance of totals higher than 2
inches. Expect river rises and some ponding of water in culverts
and roadways but still nothing significant. Post frontal showers
will continue Monday into Tuesday with possible breaks by
Wednesday. Ensembles still show the active pattern continues into
late next week.

&&

AVIATION.../through Thursday afternoon/...Wednesday has been a day
of ups and downs in the world of aviation. As the main band of
rain passed through, CIGs dropped to as low as a 400 to 600 feet
with VIS dropping to near 1 mile. These were the worst conditions
that only lasted a short time. Conditions today can be averaged
out to low-end MVFR to IFR.

And going forward into tonight, mostly low-end MVFR to IFR
conditions will continue. Since the main band of rain has passed
through, the rain will be the on/off and showery type. So as the
brief heavier rain passes through, conditions will lower to IFR.
But as the heavier rain lets up, conditions will raise back to
MVFR.

The main cause will be the CIGs. VIS doesn`t look like it will
drop too much, to around 3 to 5 miles at worst. But the CIGs could
get as low as 1000 feet at times. But 1500 to 2500 feet is mostly
expected.

Tomorrow afternoon into tomorrow night, just beyond the TAF
issuance, the next wave of precip is expected with higher
probabilities of aviation conditions lowering to low-end IFR to
even LIFR.

&&

.MARINE...The current front moving through the panhandle is
increasing winds in the inner channels at the time of writing,
with many north-south channels experiencing 15-20 kt winds and 4
ft seas. Expect brief periods of 25 kt winds as the front
progresses northward, particularly from around Grave Point and
northward. Beyond this front, expect a brief, mild lull in winds
in between fronts, around 10-15 knots. Then swiftly behind the
current front is another front of winds up to 20 knots beginning
Thursday morning. Expect this front to be slightly more easterly
in nature, with Peril Strait, Icy Strait and Fredrick Sound near
Farragut Bay seeing an increase of winds to around 20 knots.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ643-644-651-652-663-664-671-672.

&&

$$

SHORT TERM...NC
LONG TERM....PRB
AVIATION...GJS

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