948
FXAK67 PAJK 012310
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
310 PM AKDT Mon Jul 1 2024

.SHORT TERM.../ Through Tuesday night / The ridge of higher
pressure over the central and eastern Gulf of Alaska remains one
the main feature in the forecast area. A lower and mid range deck
of clouds has been pushed into the panhandle. Over the western
portion of the gulf you can see the front with the low near
Bristol Bay.

The flow aloft has a call point near Haines Juction/Whitehorse
area which means the very little movement of items around. The
surface high in the gulf strengthens slightly, but doesn`t make
large changes. The orographic influence has tonight into Tuesday
looking like a high PoP low QPF situation. One thing I did add to
the forecast, large looking fire over NE British Columbia has been
generating a lot of smoke and plume has been moving to the WSW
and the southern panhandle, as a result added general Haze to the
forecast, and as the flow shifts northwards with a minor
repositioning of mid level flow, brought it northwards into the
northern half of the forecast area as well. The main impact will
be reduced clarity of the air, and if visible more stunning
sunrises/ or sunsets.


.LONG TERM.../Wednesday through Monday/...
Overview: Quite weather for the mid range due to semi static mid
level flow pattern through the start of the weekend. Increasing
probability of rain for the end of the weekend into next week.

At 500 mb: Closed low over the Western AK Gulf slowly dropping to
the SE with weak ridging over the Panhandle. The low is expected to
shift back N into next week with uncertainty on how far to the east
it might shift. At the surface the gulf low stays to the west as it
weakens limiting its impacts to the region. The surface ridge keeps
onshore flow for northern half of the panhandle keeping chances of
light precip and mostly cloudy skies in place. Ensembles show high
probability of mostly cloudy skies. Operational models have more of a
spread as NAM showing wide spread low cloud deck while GFS has skies
lifting and more breaks developing by Thursday. Moderated temps
where clouds remain but the southern areas warming into the low 70s
due to solar heating. Warmer 850 mb air mass moves in by next week.
Winds will be generally 10 kt or less initially except for the
northern inner channels where the pressure gradient between the
panhandle ridge and Yukon low will have increased southerly winds.
Gulf winds pick up for the weekend as the surface low moves back
north.

&&

.AVIATION...Ceilings have been on the lower MVFR for most of the
day, but as expected are starting to lift this afternoon with some
sunny breaks forming in ernest. Large scale SW flow will gradually
back to the NW through the evening as a trough moves out and
ridging develops over the Gulf. Think the clouds will stratify
again overnight and lower to MVFR again in most places. Tuesday
afternoon should have more breaks than today and fewer showers,
however some models are delaying the trough moving out till later
Tuesday morning, so lower confidence on timing of improvement.

&&

.HYDROLOGY...
For the TAKU RIVER: Sunday afternoon, the Taku River was steadily
rising beyond predicted snowmelt and rainfall while the water
temperature steadily fell, indicating a glacier dam release. As of
11 AM AKDT Monday, the rate of rise has slowed and it appears the
river is cresting just above the bankful level of 42 feet. Mariners
in the region should watch for additional debris in the water
over the next couple days.

For the CHILKAT RIVER: Warm daytime and overnight temperatures
have continued the melting of high elevation snowpack and glacier
ice to produce minor flooding along the Chilkat River.
Temperatures over the Monday and Tuesday will be slightly cooler,
allowing daily peaks to trend down, but remain above minor flood
levels through Wednesday. If temperatures aloft stay cool, the
river may fall below Minor Flood stage. However, temperatures are
likely to warm back up for the start of next week.

&&

.MARINE...No significant systems in the area with general high
pressure the main feature to the weather maps. Clouds are
restricting sea breeze impacts however lesser versions are
continuing. A westerly push into the Cross Sound area has a minor
speed increase, and Cape Decision area has one as well. There area
also increases up to 15 to 20 kt for (South direction) Lynn Canal
and (NW direction) eastern Icy Strait.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ022-643-644-664.

&&

$$

SHORT TERM...Bezenek
LONG TERM....PRB
AVIATION...Ferrin
MARINE...Bezenek
HYDROLOGY...Ferrin

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