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FXAK67 PAJK 192242
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
242 PM AKDT Fri Jul 19 2024

.SHORT TERM.../Through Saturday night/ The northern panhandle is
dealing with another gray wet day today as the remains of the
atmospheric river/front that affected the area earlier in the
week gets pushed east to west through the area. It is in a much
weaker state then it was earlier in the week with total rainfall
amounts not exceeding much more then a half inch. What is doing
the pushing is a weak low the is passing NW through the Eastern
gulf at the moment. Most of the effects from that feature, except
for the pushing of the front through the northern panhandle, are
staying offshore.

Into the start of the weekend, the general trend is toward drying
conditions especially into Saturday night. Tonight and the first
half of Saturday we will still be dealing with onshore flow and
showers, first from the current low and front that are in the
area, and second from a weaker short wave that will be following
nearly the same track as the low Saturday morning. Total rainfall
will be light with mostly less then a half inch expected through
Saturday night.

Winds will also mostly be light as well. Currently the highest
winds are 20 kt in Cross Sound, Clarence Strait, and the southern
part of Lynn Canal. Those winds will likely gradually diminish
late this afternoon and this evening. After that point most winds
should be 15 kt or less for most areas of the inner channels and
near coast outside water of the gulf through Saturday night.

.LONG TERM...The long range forecast is broken up into two
distinct period, Sunday and Monday, marked by thunderstorms
attempting to cross into SE AK from Canada and largely failing,
and Tuesday, with a potent easterly wave bringing widespread
showers.

Sunday and Monday are expected to be the clearest day, for the
north on Sunday and for the south on Monday. A stacked low feature parked
in the southern gulf will bring in drier air from Canada, while
kicking up some clouds for the southern panhandle. Naturally, due
to the clearing in the north and in Canada, small and large scale
sea breezes will take effect, increasing winds in Icy Straight,
Lynn Canal, and the upper portion of Stephen`s Passage up to 20
knots. During the afternoon period, there is the small possibility
of thunderstorms briefly passing over the White Pass area as storm
direction moves increasingly eastward. Ultimately, any convection
would need to line up with the direction change in order to
actually impact the White Pass area, so naturally, confidence is
lower on this solution.

The interesting situation is on Tuesday, where a rather potent
warm front from a low in British Columbia moves over SE AK from
the northeast. A somewhat unusual situation where a major moisture
source from continental air is overrunning entrenched drier,
cooler air to the south in SE AK. This will lead to light to moderate
rainfall for approximately 24 hours. Unfortunately, for this type
of system, confidence is relatively low. Due to model resolution
in the extended, and NE flow aloft moving over the Coast Mountains
could causing drying from downsloping winds. In addition, dry air
from the south will be drawn in via pressure gradient flow at the
surface. Therefore, actual rainfall is far less confident than any
one model would imply, being anywhere between 0.25 - 2.00 inches.
The EFI tables have tended to assert caution, with a majority of
the shift of tails over the eastern, mountainous portion of SE AK
and much less model consensus over even the far inner channels.


&&

.AVIATION...
Mixed bag of IFR to VFR flight conditions this
afternoon across the panhandle under mostly BKN to OVC skies and
isolated heavy showers as a weak wave pushes up the east Gulf
coast. Conditions will slowly improve through the evening to
predominate MVFR to VFR conditions with CIGS AoB 5000 to 7000ft as
wave pushes into the northern Gulf. Potential again for IFR to
LIFR CIGS and VSBYs for southern panhandle sites overnight with
patchy fog development after 10z. Winds should remain around 10kts
or less through the TAF period.
&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ662-663.

&&

$$

SHORT TERM...EAL
LONG TERM....NC
AVIATION...NM

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