271
FXAK67 PAJK 152325
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
325 PM AKDT Mon Jul 15 2024

.SHORT TERM...For the northern inner channels, a last impulse of
heavy precipitation is expected through Monday evening associated
with a short wave feature riding along the boundary. As such, a
flood watch remains in effect for the northern inner channels
through 10 PM Monday night. This feature is expected to lead to a
brief increase in winds for the northern inner channels as the front
pushes in tonight with some gusty winds for land areas as well.
Winds will also pick up in the southern inner channels due to a
pinching of the gradient with a weak ridge that had been helping to
hold the front at bay down there. Northern parts of Clarence
Strait have been reporting around 15 - 20 kt winds through the
early afternoon, and with this front approaching expect winds
overall to pick up to 25 kt or more before settling back down
later on this evening. An inverted trough that is set to bring
more moisture to the southern and central panhandle in mid range
period will begin to build in from the south, which will keep
winds out of the south overall for the southern panhandle leading
up to mid week.

For temperatures, the moderate to heavy rain and associated cloud
cover have offset any significant gains the panhandle would have
gotten from the persistent warm southerly flow in the low to mid
levels, with minimal diurnal surface temperature changes of less
than 10 degrees. While the far northern inner channels and NE gulf
coast may see a brief break from this Tuesday, the majority of the
panhandle will continue to see temperatures hover between 55 and
65 degrees, with the southern panhandle approaching 65. Overall
remaining seasonably cool and wet for the short term period.

.LONG TERM.../Wednesday through Monday/...
To put it simply: with the way the ensembles and operational models
have been shifting surface features from run to run have low
confidence in the mid range and long range forecast. That`s not to
say latest runs aren`t showing good agreement for both ensembles and
some operational models. The main change is the flow pattern now
keeping any of those larger features late in the week further to the
south and thus putting SE AK under just onshore flow with lighter
precip, lower wind speeds, and looking at more breaks in the rain.
However...this was a change in just 24 hours...so...keep that in
mind as we progress.

Anyway, the 500 mb low previously over the AK interior drops
southward over the AK Gulf with lobes extending and continuing to
rotate around it, just further south. To the west a blocking pattern
develops with a ridge over the western gulf and another low past the
Bering. At the surface on Wednesday the remainder of the elongated
low from Tuesday goes northward along the Eastern Gulf. Good
moisture feed from the south producing another round of moderate to
heavy rain fall. BUT, total rainfall not in the realm of what
occurred Sunday and Monday. 24 hours amounts likely only in the 1 to
2 inch range. Thursday into Friday high pressure expands over the
Gulf moving the Wednesday system eastward and possibly dropping rain
chances for portions of the panhandle. Plus the high pressure should
keep the main part of Friday low that was going to hit SE AK to the
south and outside of our area, but still allow some rain bands to
cross over us.

&&

.AVIATION...Rather low aviation weather today with MVFR and some
IFR conditions (ceilings down to 500 ft and vis down to 2 miles in
some cases) widespread across the panhandle due to an atmospheric
river dumping rain. Not a whole lot of wind with this feature
though. Low level wind shear and turbulence reports have been few
and far between today so far. Flying weather is looking to stay
with MVFR or lower ceilings and Vis through tonight at least with
the possibility of improving conditions on Tuesday. Lower
conditions possible for Tue night and Wed as yet another system
moves in from the S.

&&

.HYDROLOGY...Wet conditions continue, but there is a reprieve in
sight. Heavier rain is expected to end Monday evening as the
atmospheric river finally moves off to the east. Area rivers in
the north should crest Monday or Monday night before receding.
Currently only Jordan Creek near Juneau, and Chilkat River near
Haines are above minor flood stage, but Auke Lake near Auke Bay
could join them briefly later this evening. Other rivers and
streams in the north are running high and/or are near bankfull,
but no others that are gaged are expected to start flooding. We
get a brief break on Tuesday before another round of rain comes in
for Tue night and Wed. This one does not look as long of duration
as the last one and it is aimed more at the central and southern
areas rather then the north this time around. Decided to issue a
Hydrologic outlook for it.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Flood Watch until 10 PM AKDT this evening for AKZ318>321-325.
MARINE...Small Craft Advisory for PKZ036-641.

&&

$$

SHORT TERM...STJ
LONG TERM....PRB
AVIATION...EAL

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