Dense Fog Advisory 21, NWS Juneau, AK

435 
WWAK77 PAJK 011430
NPWAJK

URGENT - WEATHER MESSAGE
National Weather Service Juneau AK
630 AM AKDT Wed Sep 1 2021

AKZ020-021-011700-
/O.EXA.PAJK.FG.Y.0021.000000T0000Z-210901T1700Z/
Glacier Bay-Eastern Chichagof Island-
Including the cities of Gustavus and Hoonah
630 AM AKDT Wed Sep 1 2021

...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM AKDT THIS MORNING...

* WHAT...Visibility one quarter mile or less in dense fog.

* WHERE...Gustavus and Hoonah.

* WHEN...Until 9 AM AKDT this morning.

* IMPACTS...Hazardous travel conditions due to low visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

&&

$$

AKZ026>028-011700-
/O.CON.PAJK.FG.Y.0021.000000T0000Z-210901T1700Z/
Inner Channels from Kupreanof Island to Etolin Island-
Dixon Entrance to Cape Decision Coastal Area-
Southern Inner Channels-
Including the cities of Petersburg, Wrangell, Kake, Craig, 
Klawock, Ketchikan, and Metlakatla
630 AM AKDT Wed Sep 1 2021

...DENSE FOG ADVISORY REMAINS IN EFFECT UNTIL 9 AM AKDT THIS
MORNING...

* WHAT...Visibility one quarter mile or less in dense fog.

* WHERE...Central and southern inner channels including,
  Petersburg, Wrangell, Klawock and Ketchikan.

* WHEN...Until 9 AM AKDT this morning.

* IMPACTS...Hazardous driving conditions due to low visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/ajk

040 
WWAK77 PAJK 011642
NPWAJK

URGENT - WEATHER MESSAGE
National Weather Service Juneau AK
842 AM AKDT Wed Sep 1 2021

AKZ020-021-026>028-011745-
/O.EXP.PAJK.FG.Y.0021.000000T0000Z-210901T1700Z/
Glacier Bay-Eastern Chichagof Island-
Inner Channels from Kupreanof Island to Etolin Island-
Dixon Entrance to Cape Decision Coastal Area-
Southern Inner Channels-
Including the cities of Gustavus, Hoonah, Petersburg, Wrangell, 
Kake, Craig, Klawock, Ketchikan, and Metlakatla
842 AM AKDT Wed Sep 1 2021

...DENSE FOG ADVISORY WILL EXPIRE AT 9 AM AKDT THIS MORNING...

The dense fog has improved in the last few hours. There is still
some isolated dense fog near Wrangell this morning, but that
should burn off in the next hour. 

$$

For more information from the National Weather Service visit
https://weather.gov/ajk

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
233 PM AKDT Tue Aug 31 2021

.SHORT TERM.../Through Thursday/ After some morning fog and low
clouds most of the inner channels has cleared out nicely this
afternoon. The outer coast and the Gulf however continues to see
low marine layer clouds lingering with ceilings as low as 1200
feet. Winds remain rather light with most areas remaining 15 kt or
less.

The short range forecast first features the return of low clouds
and fog to many inner channel areas tonight. The northern inner
channels will likely see low clouds extend all the way over to
Stephens Passage again tonight. The southern panhandle will likely
see a much more extensive area of low clouds and fog late tonight
as overall flow switches from NW to SE late. This should drag the
clouds farther into the southern panhandle early tomorrow morning
before the clouds burn off mid day.

Once the low clouds burn off, Wed looks to be another nice day
with wide spread 60s for highs again. However, change will be
stirring. A new front will be advancing E across the gulf with
increasing winds in the gulf Wed (increasing to gale force for the
N gulf by Wed Evening) and will start to reach the inner channels
by Thu (winds increasing to 15 to 25 kt in those areas). Rain will
also be coming with the N Gulf Coast starting to receive it Wed
night while the rest of the panhandle will have to wait until Thu
or Thu night. Highest rainfall is initially aimed at the northern
panhandle Thu (particularly the outer coast), but that will shift
to more of the southern panhandle Thu night as a new wave rides
north along the front. Overall amounts will be around 1 to 1.5
inches through late Thu night.

Overall changes were minor except for some changes on how far
inland the fog and low clouds will get tonight based on boundary
layer RH guidance.

.LONG TERM.../Thursday through next Tuesday/ Attention remains
focused how far onshore the stalled front advances into the
Panhandle Thursday. Given moist southerly flow pushing across
complex terrain, we decided to go ahead and take likely to
categorical pop east to Juneau and the Inner Channels Thursday,
but clearly the focus of QPF remains over the coast. This change
mandated no need for changes to temperature. Winds still do not
present much of a threat on Thursday as the front weakens in place
positioned along the outer coast. With the parent low stalled
hundreds of miles away, just east of Kodiak Island.

Thursday night, a wave approaches the southern Panhandle from the
southwest. Several iterations of the ECMWF and GFS have now begun
pinpointing this feature as a precipitation enhancer for the
south. For the north though, offshore flow in response help limit
rainfall for Friday. It is still too early to mark a certain
track for any surface reflection, but indications are present,
despite all being fairly weak.

The weekend likely appears showery for much of the area, as
another wave could undercut the Panhandle on its way to Haida
Gwaii. This favors a bit more unstable air across the Panhandle,
and given efficient orographics showers should be a safe bet
through the weekend.

Leading into next week spread rapidly increases. Some ensemble
members lift a jet near the southern Panhandle early next week.
This might suggest the possibility of a period of enhanced heavy
rain with a more robust slug of subtropical moisture. However,
this is by no means certain, but simply non-zero possibility.
Track would favor the southern Panhandle more than the north as
the zone of baroclinicity could grow somewhere across the outer
gulf as a lobe of cooler air funnels southeast into the gulf from
the Bering Strait. Confidence in details are low for next week.
But with a very high chance of onshore flow, we suspect it will be
wet, just probably not very wet.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

EAL/JWA

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