High Wind in Alaska, September 9, 2016

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
555 AM AKDT FRI SEP 9 2016

.SHORT TERM...Upper level trough moving down from the AK
peninsula will move into the eastern gulf through Friday
afternoon then begin to track into the panhandle through Friday
night. Remnants of Tropical Storm Lester are just ahead of this
trough tracking across the eastern gulf this morning then pushing
across the panhandle in the afternoon. Surface low, seen on water
vapor satellite imagery, have deepened to around 992 mb early this
morning and will track over Cross Sound this afternoon the travel over
the panhandle tonight. Will still have a weak surface wave in the
northern gulf tonight until the upper level trough crosses over
the panhandle.

Occluded frontal band around low has moved strong easterly winds
over the gulf coastal and southern panhandle. Wind gusts upwards
of 30 to 40 kts reported at PAHY and PANT so far. As the low moves
inland winds will subside, then quickly shift west and increase.
Outer coast of Baranof Island will get the brunt of these westerly
winds, so a high wind warning has been issued for AKZ023.
Strongest of the westerlies will occur between 4 and 6 pm tonight.
As the main surface low moves into northern British Columbia
westerlies will subside and shift back to the southeast late this
evening.

Ample tropical moisture from remnants of Lester with precipitable
water standard deviations of 2 to 3 above normal. Moderate to
Heavy rain began this morning over the entire panhandle as the
occluded front advances, 1 hour rain rates upwards of 0.25 to 0.35
inches have been reported. These rain rates will continue through
the morning then begin to taper off by the afternoon. Six hour
rainfall rates for tonight will be less than a quarter of an inch,
heaviest amounts over the central panhandle and at higher
elevations.

Model were still showing slight shifts with each new model runs.
These changes, while not changing magnitude of winds, did changes
position and timing. 00z and then 06Z runs moved the low center
eastward at a faster clip. Used a blend of GFS/NAM and a
combination of the 00z and 06z runs. Forecast confidence is only
average due to timing issues of the winds.

.LONG TERM..Showers will remain over southeast Alaska in the
wake of the storm force low currently affecting the panhandle and
eastern gulf. Heavy precip will have ended by then, but moderate
intensity showers are still possible. Shower activity will end
from north to south Saturday night and Sunday is looking like it
will be a mostly sunny day as well as dry. The break will not last
too long, as another front will move in from the west early next
week with more heavy rain. Whereas the current front in generally
moving from SW to NE, the next one will spread heavy rain from
west to east to Cape Fairweather, and then down the outer coast.
00Z model run of the GFS and Canadian NH are faster to push the
front through than ECMWF. 06Z GFS is slower and looks more like
the EC. Have opted to stay with the slower EC for now and wait for
better agreement before speeding things up. Regardless of the
speed, all are depicting a relatively narrow frontal band with
maximum QPF values over the outer coast and coast mountains. Winds
associated with this front not expected to be nearly as strong as
with the current low. Have up to 30 kts over the central gulf with
a 30 kt easterly barrier jet forming west of Icy Bay overnight
Sunday night.

Used an ensemble approach for pressure updates Sunday and Sunday
night based on good model agreement with NAM as a foundation for
winds. PoP and QPF from SREF and the Canadian NH for Sunday/Sunday
night, but used ECMWF for Tuesday/Tuesday night. No significant
changes to the remainder of the extended range forecast. Overall
forecast confidence is average. .

&&

.AVIATION...Mainly MVFR due to heavy rain so far with IFR
conditions over the southern areas. Improving ceilings and
visibility as the front moves inland. Gusts to 40 mph over the
southern panhandle today will subside. Main impact winds for the
central panhandle will be the developing westerlies this
afternoon. Sitka wind gusts to 50 kt expected mid to late Friday
afternoon. Low level southeasterly wind shear will shift to the
southwest through the day and increase.

&&

.MARINE...Storm force outflow winds on northeast quadrant of the
low this morning will diminish as storm force westerlies develop
south of the low this afternoon. Gulf winds will then become more
uniform westerly gales by tonight. Coastal inner channel easterly gales
will subside then increase as gradient shift west. These stronger
westerly winds will drop off in the early evening.

&&

.HYDROLOGY...Heavy rainfall through the morning already causing
sharp rises in local rivers and streams. At this time only the
Taiya river near Skagway is expected to rise to minor flood
stage, while other only expected to rise to bankfull through this
afternoon and evening. Storm total accumulation around 2 to 5
niches with additional 1 to 3 inches through the day.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...STRONG WIND until 1 PM AKDT this afternoon for AKZ023-026.
     STRONG WIND until 1 PM AKDT this afternoon for AKZ027-028.
     STRONG WIND this evening for AKZ025.
     STRONG WIND through this evening for AKZ022.
     High Wind Warning from 3 PM this afternoon to 7 PM AKDT this
     evening for AKZ023.
     STRONG WIND from this evening through late tonight for AKZ023.
     Areal Flood Advisory until 2 PM AKDT Saturday for AKZ018.
MARINE...Storm Warning for PKZ042-043.
     Gale Warning for PKZ022-033-034-036-041-051-052.
     Small Craft Advisory for PKZ011>013-021-031-032-035-053.
&&

PRB/Fritsch

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SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JUNEAU AK
751 AM AKDT FRI SEP 9 2016

AKZ019>025-100000-
HAINES BOROUGH AND LYNN CANAL-GLACIER BAY-
EASTERN CHICHAGOF ISLAND-
SALISBURY SOUND TO CAPE FAIRWEATHER COASTAL AREA-
CAPE DECISION TO SALISBURY SOUND COASTAL AREA-
EASTERN BARANOF ISLAND AND SOUTHERN ADMIRALTY ISLAND-
JUNEAU BOROUGH AND NORTHERN ADMIRALTY ISLAND-
INCLUDING THE CITIES OF...HAINES...GUSTAVUS...HOONAH...
ELFIN COVE...PELICAN...SITKA...PORT ALEXANDER...ANGOON...JUNEAU
751 AM AKDT FRI SEP 9 2016

...STEEP RIVER RISES THROUGH TONIGHT...

HEAVY RAIN HAS MOVED OVER THE AREA THIS MORNING WITH MORE ON THE
WAY FROM A STRONG AND MOIST WEATHER SYSTEM. SO FAR THE AREA HAS
SEEN 0.75 TO 1.5 INCHES OF RAINFALL WITH ANOTHER 1 TO 3 INCHES
EXPECTED THROUGH THE REST OF FRIDAY. SMALL STREAMS ARE STARTING TO
RISE RAPIDLY FROM THE HEAVY RAINFALL AND WILL CONTINUE TO RISE THROUGH
TONIGHT. AT THIS TIME THERE IS NO FLOODING EXPECTED BUT SMALL
STREAMS WILL RISE TO NEAR BANKFULL LEVELS.

THE HEAVY RAINFALL WILL DECREASE OVER ANGOON AND SITKA THIS
AFTERNOON BUT AREAS FURTHER NORTH WILL CONTINUE TO SEE HEAVY RAIN
THROUGH TONIGHT.

PEOPLE WHO LIVE OR RECREATE NEAR SMALL STREAMS SHOULD REMAIN
ALERT AND TAKE ACTION IF NEEDED.

THIS STATEMENT WILL BE UPDATED AT 400 PM AKDT FRIDAY OR SOONER IF
CONDITIONS WARRANT.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
100 PM AKDT FRI SEP 09 2016

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

0800 AM     HEAVY RAIN       PELICAN                 57.95N 136.21W
09/09/2016  M1.89 INCH                          AK   CO-OP OBSERVER

            24-HOUR RAINFALL, MAINLY OVERNIGHT AND THIS MORNING.

1200 PM     HEAVY RAIN       ANGOON                  57.50N 134.59W
09/09/2016  M0.83 INCH                          AK   AWOS

            14-HOUR TOTAL

1200 PM     HEAVY RAIN       HOONAH                  58.11N 135.44W
09/09/2016  M2.01 INCH                          AK   ASOS

            14-HOUR RAINFALL TOTAL

1200 PM     HEAVY RAIN       KETCHIKAN               55.34N 131.65W
09/09/2016  M2.13 INCH                          AK   ASOS

            17 HOUR STORM TOTAL

1200 PM     HEAVY RAIN       ANNETTE                 55.04N 131.59W
09/09/2016  M2.18 INCH                          AK   ASOS

            17-HOUR TOTAL

1200 PM     HEAVY RAIN       GUSTAVUS                58.41N 135.80W
09/09/2016  M1.18 INCH                          AK   ASOS

            14-HOUR TOTAL

1200 PM     HEAVY RAIN       JUNEAU                  58.30N 134.41W
09/09/2016  M1.42 INCH                          AK   ASOS

            14-HOUR TOTAL

1200 PM     HEAVY RAIN       SITKA                   57.05N 135.34W
09/09/2016  M1.16 INCH                          AK   ASOS

            17-HOUR TOTAL

1200 PM     HEAVY RAIN       KLAWOCK                 55.55N 133.09W
09/09/2016  M1.29 INCH                          AK   ASOS

            17-HOUR TOTAL

1200 PM     HEAVY RAIN       WRANGELL                56.47N 132.40W
09/09/2016  M1.28 INCH                          AK   AWOS

            14-HOUR TOTAL

1200 PM     HEAVY RAIN       PETERSBURG              56.81N 132.96W
09/09/2016  M1.07 INCH                          AK   AWOS

            14-HOUR TOTAL

1200 PM     HEAVY RAIN       YAKUTAT                 59.54N 139.73W
09/09/2016  M1.30 INCH                          AK   ASOS

            14-HOUR TOTAL

1200 PM     HEAVY RAIN       KAKE                    56.97N 133.93W
09/09/2016  M0.89 INCH                          AK   AWOS

            14-HOUR TOTAL

&&

JWA