239
FXAK67 PAJK 222341
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
341 PM AKDT Sun Sep 22 2024

.SHORT TERM...A strong low has entered the eastern gulf and is
brining a plume of moisture toward the panhandle. Main changes
made to the forecast were increased precipitation amounts along
the northern panhandle leaving the southern panhandle. The
heaviest rain will fall tonight into tomorrow totaling up to 1.5
inches for the entire panhandle. Lighter rain will then continue
through the rest of the day Monday. Winds will also be something
to look out for as pressure gradients tighten as the low enters
the gulf and an associated front moves over the panhandle. For the
first time this fall, we will see storm force winds along the far
northern gulf for a short time tonight. Winds will increase
tonight to strong breezes and gale force along the gulf coast and
the inner channels. Winds will continue through out Monday
weakening late Monday/early Tuesday as the pressure gradient
weakens.

In other news, today is the official first day of fall as it is
the Autumn equinox. Temperatures are expected to have highs in the
50s and lows in the high 40s. No frost or freezing temperatures
are currently expected, but we are now officially in that time of
year. For the short term, a non-diurnal temperature trend will
occur tomorrow into Tuesday as the front associated with the low
moves past.

.LONG TERM.../Wednesday Through Sunday/...The mid-range begins
with a rain-filled start as waves of precipitation continue to
rotate in around a decaying low in the Gulf. Periods of rain will
remain throughout most of the area until precip chances diminish
across the northern half of the panhandle on Thursday as a system
approaches from the SW and cuts off the moisture support and
onshore flow to the N. This new low will likely avoid a direct hit
on the panhandle, instead moving from the SW to the NE across the
Haida Gwaii area. Operational guidance has had trouble pinning
down the exact track the system takes thus far, but it is safe to
say that rain and wind are anticipated with this low. Anticipate
that the relative rain amounts and wind speeds will be lower than
the previous system.

Through much of the weekend, chances of rain diminish, though
lingering moisture transport will maintain some chances of precip.
This situation abruptly reverses as a potentially strong Autumn
system arrives Sunday or Monday. Ensemble guidance is broadly
placing the center of the low over the western Gulf, but the
potential for broad areas of storm force winds over the eastern Gulf
and strong or even high winds across parts of the panhandle are
possible if an anticipated frontal bands proves as strong as some
guidance is suggesting. This system will need to be closely
monitored over the next week, as minor changes in timing or track
could have large variations on resulting storm strength and impacts
to SE AK.

&&

.AVIATION...A brief break in weather has allowed for VFR conditions
across the panhandle this afternoon. These conditions will start to
deteriorate this evening as a front moves across the panhandle
bringing rain and lowering ceilings and visibilities. This evening
MVFR is expected to prevail with IFR conditions expected late
tonight into Monday morning. As this front moves over the panhandle
winds will increase creating gusty conditions at many airports and
potential for LLWS and turbulence. Strongest gusts and LLWS are
expected across the gulf coast. Winds and ceilings will start to
improve Monday evening. This allows flying conditions to improve as
well.

&&

.HYDROLOGY...Sunday night into Wednesday will feature a very wet
period of time. 24-hour rain totals for Sunday night are forecast
to be from 1 to 1.5 inches across most of Southeast Alaska.
Changes to the forecast today feature more precipitation spread
out farther north across the panhandle and into the northeast gulf
coast rather than solely focused on the southern inner channels.
Rainfall after Sunday night will continue through at least Tuesday
night but accumulations over any fixed period are expected to
diminish with time. Still, local rivers, creeks, and streams are
fully expected to respond to this rainfall with the more flashy
systems likely approaching bankful by Monday morning.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Storm Warning for PKZ672.
     Gale Warning for PKZ036-644-651-652-661>664-671.
     Small Craft Advisory for PKZ011>013-021-022-031>035-053-641>643.

&&

$$

SHORT TERM...EAB
LONG TERM....GFS
AVIATION...EAB
HYDROLOGY...Fritsch

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