Winter Storm Warning 16, NWS Juneau, AK

707 
WWAK47 PAJK 250713
WSWAJK

URGENT - WINTER WEATHER MESSAGE
National Weather Service Juneau AK
1013 PM AKST Fri Nov 24 2017


AKZ022-251500-
/O.CON.PAJK.WS.W.0016.000000T0000Z-171125T1500Z/
Salisbury Sound to Cape Fairweather Coastal Area-
Including the cities of Elfin Cove and Pelican
1013 PM AKST Fri Nov 24 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 AM AKST
SATURDAY...

* WHAT...Snow showers...with 4 to 8 inches expected by early 
  Saturday morning. 

* WHERE...Central Outer Coast including Elfin Cove and Pelican.

* WHEN...Snow showers will decrease Saturday. Some snow showers
  will be heavy tonight. 

* ADDITIONAL DETAILS...Visibility will be reduced below 1/2 mile 
  at times in heavier snow showers. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A warning means that a winter storm is already occurring or
imminent. This storm could pose a threat to life and property.

This statement will be updated by 6 AM AKST Saturday or sooner if
conditions warrant.

&&

$$

AKZ020-021-251500-
/O.CON.PAJK.WW.Y.0030.000000T0000Z-171125T1500Z/
Glacier Bay-Eastern Chichagof Island-
Including the cities of Gustavus and Hoonah
1013 PM AKST Fri Nov 24 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 AM AKST
SATURDAY...

* WHAT...Snow showers...with 2 to 5 inches expected by early 
  Saturday morning. 

* WHERE...Icy strait corridor including Gustavus and Hoonah.

* WHEN...Snow showers will decrease Saturday. 

* ADDITIONAL DETAILS...Visibility will be reduced below 1 mile 
  at times in heavier snow showers. Travel may be hazardous due 
  to snow covered roads and sidewalks. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

An advisory means that a potentially hazardous event is already
occurring or imminent.

This statement will be updated by 6 AM AKST Saturday or sooner if
conditions warrant.

&&

$$

746 
WWAK47 PAJK 251352
WSWAJK

URGENT - WINTER WEATHER MESSAGE
National Weather Service Juneau AK
452 AM AKST Sat Nov 25 2017


AKZ022-251500-
/O.CAN.PAJK.WS.W.0016.000000T0000Z-171125T1500Z/
Salisbury Sound to Cape Fairweather Coastal Area-
Including the cities of Elfin Cove and Pelican
452 AM AKST Sat Nov 25 2017

...WINTER STORM WARNING IS CANCELLED...

Heavy snow showers have ended as of 5 AM. Expect occasional snow
showers through the afternoon with an additional 1 to 3 inches.

$$

AKZ020-021-251500-
/O.CAN.PAJK.WW.Y.0030.000000T0000Z-171125T1500Z/
Glacier Bay-Eastern Chichagof Island-
Including the cities of Gustavus and Hoonah
452 AM AKST Sat Nov 25 2017

...WINTER WEATHER ADVISORY IS CANCELLED...

Snowfall rates tapered off early this morning. Expect occasional 
snow showers to continue through the afternoon with an additional 
1 to 3 inches.


$$

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
605 AM AKST Fri Nov 24 2017

.SHORT TERM...SW jet axis aimed at British Columbia this morning,
but enough warm air is still over-running our area for precip. A
major upper low is over the eastern Gulf with a complex surface
low main center 975 MB right near buoy 46085. There is a full
occluded front around the complex as can be easily seen on
satellite imagery. The main band of the front has gone aloft over
the northern Panhandle almost into the Yukon at 14Z and is also
enhancing over the mountains east of Petersburg and Juneau. Biorka
radar shows lots of showers. At 500 MB the temperature is getting
colder today with a wintry -36C moving over us which makes our
air unstable. Thought better of putting lightning in any of the
forecasts due to cooler temps at the surface. There is a pretty
good low level convergence somewhere between the SE wind at Five
Finger and the N wind in Lynn Canal. Plenty enough wind for a few
mentions of strong wind plus the usual gales and small craft
advisories.

Ramped down the snow amounts a little in the north, and so far all
rain in the south. It's always a little scary when ya have snow
showers as we've all seen one good shower can give a snow dump.
Flakes so far seem to be fine and wet which precludes any one dump.
As the flow aloft becomes more easterly, we should see less snow
and rain. Outflow wind will keep the northern areas below freezing
and expect some strong gusts out of any passes as moderate high
pressure rebuilds into the Yukon. As the main surface low center
backs further west into the Gulf all operations models show some
wave development as a closed low center off Dixon Entrance 18Z on
Saturday. This system will enhance northerlies and reduce precip
in the N while bringing a second shot of showers into the southern
Panhandle and Baranof Island. Confidence is only moderate on this
whole scenario due to the showers being quite tricky to pin down.
Previous forecasts were the main basis for this set and the 24/00Z
operations models supported this persistence.

.LONG TERM.../Sunday through Friday/ Upper level trough over the
eastern AK gulf on Sunday begins to shift to the northeast through
Sunday while a low tracks toward Haida Gwaii from the Pacific.
High pressure ridge replaces the trough over the gulf but that
quickly moves to the east was well by Sunday evening as another
broad upper low moves over the Aleutians and into the western gulf
Monday. Part of this wave follows similar track crossing into the
eastern gulf then into BC followed by another building  ridge.
This active pattern repeats though the rest of the week: low
tracks in from the west, followed by a ridge, followed by another
low.

At the surface Sunday will be a transition as one of the last
with cold air over the central and northern panhandle due to a
shift to more southerly flow and warm air advection. Precip will
be limited to the southern panhandle Sunday due to the low moving
south of Haida Gwaii. The next frontal band advances across the
gulf ahead of the parent low near the Aleutians Monday night
reaching the panhandle early Monday. Points north of Frederick
Sound will still be mostly snow with rain to the south and along
coastal areas. Potential of a developing low moving into the far
SE gulf behind the front but low confidence on this feature.
Parent low will weaken as it moves into the NW gulf Monday night.
Potential break in precip Tuesday into Tuesday night would be
short lived as the next deep low moves over the Aleutians with a
front once again crossing over the gulf. Indications that this low
center will move northward in to the AK interior, which would
push more southerly flow and warmer air over the panhandle.
Starting to see snow levels rising into the 2000 to 3000 ft range
towards the end of the week, so rain is now the likely precip type
for all but the far northern panhandle. Any place staying as
snow, or at least mostly snow could see a few more inches due to
higher QPF amounts from the warmer air mass. Besides then main
change to more southerly flow for most of the panhandle by Monday,
expecting barrier jet formation along frontal boundaries moving
in with small craft winds over most of the coastal waters
extending along the front.

ECMWF/GFS were falling more in line for the mid range. GFS was
showing best run to run consistency lately. Main change from
previous models and forecast was having the low center further
north, which emphasized the warming trend more. Nudge toward
GFS/ECMWf blend then more WPC later in the period. Confident of
the active pattern and warming trend but still uncertainty with
exact track of the mid range features.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Strong Wind through late tonight for AKZ017-018.
MARINE...Gale Warning for PKZ012-013-022-036-041>043-051-053.
     Small Craft Advisory for PKZ011-021-031>035-052.

&&

JC/PRB

Visit us at http://www.weather.gov/Juneau

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1226 PM AKST FRI NOV 24 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     SNOW             HOONAH                  58.11N 135.42W
11/24/2017  M4.0 INCH                           AK   CO-OP OBSERVER

            24 HOUR SNOW TOTAL AS OF 8AM

0900 AM     HEAVY SNOW       MUD BAY                 59.15N 135.37W
11/24/2017  M9.0 INCH                           AK   TRAINED SPOTTER

            24 HOUR SNOWFALL TOTAL AS OF 9 AM.

0900 AM     SNOW             8 N JUNEAU              58.50N 134.13W
11/24/2017  M5.9 INCH                           AK   TRAINED SPOTTER

            FROM 9AM ON 1123 TO 9AM ON 1124

0900 AM     SNOW             2 SSE MENDENHALL GLACIE 58.39N 134.52W
11/24/2017  M6.4 INCH                           AK   NWS EMPLOYEE

            24 HOUR SNOW TOTAL

0900 AM     SNOW             HAINES                  59.24N 135.44W
11/24/2017  M7.2 INCH                           AK   CO-OP OBSERVER

            24 HOUR SNOW TOTAL AS OF 9 AM

1000 AM     SNOW             GUSTAVUS                58.41N 135.80W
11/24/2017  M5.5 INCH                           AK   CO-OP OBSERVER

            24 HR SNOW TOTAL AS OF 10 AM

&&

JBYRD