Areal Flood Warning 2, NWS Juneau, AK

853 
WGAK87 PAJK 130839
FLSAJK

Flood Statement
National Weather Service Juneau AK
1213 AM AKDT Fri Aug 13 2021

AKZ018-142100-
/O.CON.PAJK.FA.W.0002.000000T0000Z-210814T2100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Taiya Inlet and Klondike Highway-
1213 AM AKDT Fri Aug 13 2021

...A FLOOD WARNING FROM RAIN AND SNOWMELT REMAINS IN EFFECT UNTIL 100
PM AKDT SATURDAY FOR THE TAIYA RIVER IN THE NORTHERN INNER 
CHANNELS...

At 1213 AM AKDT, satellite estimates and automated rain gauges 
indicated an area of very heavy rainfall yet to reach the Taiya 
River Basin and the Skagway area but closing in. The heavy rain will
reach the area early Friday morning and will cause more flooding. 
Rapid snowmelt is also occurring and will add to the flooding. 
Rivers and streams are rising rapidly and low lying areas for 
example along the Chilkoot Trail have become inundated.  Around a 
half inch of rain has fallen in the last 24 hours. But since the 
ground has been completely saturated from the rains over the last 
several days, rivers continue to rise in the area. Additional 
rainfall of 1 to 2 inches is expected over the area through the 
next 24 hours, with much of it falling Friday morning.

For the Taiya River: 
At 1213 AM AKDT the stage was 17.5 feet.
Flood stage is 16.5 feet.
Minor flood Forecast: 18.0 feet at 4 PM Friday. 
Impacts: At 19.0 feet the campground three quarters of a mile 
downstream of the bridge starts to flood. There can also be 
considerable bank erosion near the campground. At 17.5 feet the 
National Park Service may close the Chilkoot Trail due to 
flooding impacts associated with high water in the surrounding 
watershed. At 17.0 feet, the National Park Service advises 
against boating and other recreational water-based activities 
on the Taiya River. Trail orientation and navigation begins to 
become difficult and may hinder route-finding for several 
hundred meters. Water will be knee deep or higher in places 
along the lower portions of the trail. 

Please stay tuned to NOAA weather radio or your favorite local
weather news source for updates on this situation.

Mudslides remain possible in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flood Warning means that flooding is imminent or occurring. All
interested parties should take necessary precautions immediately.

&&

LAT...LON 5962 13516 5939 13528 5939 13540 5972 13570
      5977 13547

$$

JWA

199 
WGAK87 PAJK 131743
FLSAJK

Flood Statement
National Weather Service Juneau AK
919 AM AKDT Fri Aug 13 2021

AKZ018-142100-
/O.CON.PAJK.FA.W.0002.000000T0000Z-210814T2100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Taiya Inlet and Klondike Highway-
919 AM AKDT Fri Aug 13 2021

...A FLOOD WARNING FROM RAIN AND SNOWMELT REMAINS IN EFFECT UNTIL 100
PM AKDT SATURDAY FOR TAIYA RIVER IN THE NORTHERN INNER CHANNELS...

At 919 AM AKDT, satellite estimates and automated rain gauges
indicated heavy rain across the warned area causing impacts. Rapid
snow and ice melt is also occurring and will add to the flooding. One
half inch to 1 inch of rain have fallen in the last 12 hours. Additional 
rainfall of 1 to 2 inches with higher amounts in the headwaters is
expected over the area through the next 24 hours. 

For the Taiya River:
At 919 AM AKDT the stage was 18.46 feet.
Moderate flood stage is 17.0 feet.
Forecast: 19 feet. This would be the second highest stage on record.
Impacts:
At 19.0 feet the campground three quarters of a mile 
downstream of the bridge will start to flood. There can also be 
considerable bank erosion near the campground. 
At 17.5 feet the National Park Service may close the Chilkoot Trail due to 
flooding impacts associated with high water in the surrounding 
watershed. 

Mudslides are possible in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flood Warning means that flooding is imminent or occurring. All
interested parties should take necessary precautions immediately.

&&

LAT...LON 5962 13516 5939 13528 5939 13540 5972 13570
      5977 13547

$$
abj

947 
WGAK87 PAJK 140155
FLSAJK

Flood Statement
National Weather Service Juneau AK
543 PM AKDT Fri Aug 13 2021

AKZ018-142100-
/O.CON.PAJK.FA.W.0002.000000T0000Z-210814T2100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Taiya Inlet and Klondike Highway-
543 PM AKDT Fri Aug 13 2021

...A FLOOD WARNING FROM RAIN AND SNOWMELT REMAINS IN EFFECT UNTIL 100
PM AKDT SATURDAY FOR TAIYA RIVER IN THE NORTHERN INNER CHANNELS...

At 543 PM AKDT, satellite estimates and automated rain gauges
indicated heavy rain had fallen across the warned area causing impacts. Rapid
snowmelt was also occurring and will add to the flooding.  1 to 2 inches of 
rain with more at higher levels had fallen in the last 30 hours. Light rain 
amounts are expected though tonight. The Taiya River reached second highest 
recorded stage for the station. Reports of significant flooding of the 
Chilkoot Trail and the campgrounds due to road flooding. 

For the Taiya River:
At 500 PM AKDT the stage was 18.88 feet.
Flood stage is 16.5 feet.
Forecast:Taiya River crested at 19.19 feet at 2 pm AKDT 13 August.
Impacts:The river levels are falling and may take a day or two for water 
levels to fall below flood stage. 

Mudslides remain possible in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flood Warning means that flooding is imminent or occurring. All
interested parties should take necessary precautions immediately.

&&

LAT...LON 5962 13516 5939 13528 5939 13540 5972 13570
      5977 13547

$$

!Bezenek

374 
WGAK87 PAJK 141435
FLSAJK

Flood Statement
National Weather Service Juneau AK
611 AM AKDT Sat Aug 14 2021

AKZ018-142100-
/O.CON.PAJK.FA.W.0002.000000T0000Z-210814T2100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Taiya Inlet and Klondike Highway-
611 AM AKDT Sat Aug 14 2021

...A FLOOD WARNING FROM RAIN AND SNOWMELT REMAINS IN EFFECT UNTIL 100
PM AKDT SATURDAY FOR THE TAIYA RIVER IN THE NORTHERN INNER 
CHANNELS...

At 611 AM AKDT, rivers in the Taiya Basin continued to decline. . 
But significant flooding is still occuring.   One to two inches of 
rain have fallen in the last 24 hours. Additional rainfall of less 
than 0.5 inch is expected over the area through the next 24 hours. 
Portions of the Chilkoot Trail are inundated, and the Chilkoot Trail 
has been closed. 

For the Taiya River: 
At 611 AM AKDT the stage was 17.1 feet.
Flood stage is 15.0 feet.
Forecast:  After a crest of 19.2 feet at 215 PM Friday, the river 
has been falling.  
Impacts: At 17.0 feet, the National Park Service advises against 
boating and other recreational water-based activities on the 
Taiya River. Trail orientation and navigation begins to become 
difficult and may hinder route-finding for several hundred meters. 
Water will be knee deep or higher in places along the lower 
portions of the trail. The river is expected to continue receding. 

Please stay tuned to NOAA weather radio or your favorite local
weather news source for updates on this situation.

Mudslides remain possible in areas of steep terrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flood Warning means that flooding is imminent or occurring. All
interested parties should take necessary precautions immediately.

&&

LAT...LON 5962 13516 5939 13528 5939 13540 5972 13570
      5977 13547

$$

JWA

013 
WGAK87 PAJK 142059
FLSAJK

Flood Statement
National Weather Service Juneau AK
1254 PM AKDT Sat Aug 14 2021

AKZ018-142104-
/O.EXP.PAJK.FA.W.0002.000000T0000Z-210814T2100Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Taiya Inlet and Klondike Highway-
1254 PM AKDT Sat Aug 14 2021

...THE FLOOD WARNING FROM RAIN AND SNOWMELT WILL EXPIRE AT 100 PM
AKDT FOR THE TAIYA RIVER IN THE NORTHERN INNER CHANNELS...

The heavy rain ended on Friday afternoon, temperatures at elevation 
have cooled, and flood waters are restudying. Please continue to 
heed any road or park closures.

The Taiya River crested at 19.19 feet at 215 pm Friday, this is the 
second highest crest on record. As of 12 pm Saturday, the river 
level is at 16.54 feet and falling steadily. Minor flood stage is 
16.5 feet.

LAT...LON 5962 13516 5939 13528 5939 13540 5972 13570
      5977 13547

$$

FERRIN

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
304 PM AKDT Thu Aug 12 2021

.SHORT TERM...A robust atmospheric river (AR) directs an
incredible amount of moisture towards the Northern half of
Southeast Alaska over the next 24 to 36 hours. Rainfall began
falling over Yakutat Wednesday morning and has since greatly
increased in intensity with 4 to 6 inches having already fallen
in that area. The 12Z PAYA raob shows a top ten PW value with an
IVT of 2nd all- time (734 kg/m/s). Farther east, rain is falling
across the northern Panhandle, but at much more manageable rates.
All of this changes tonight, as a shortwave lunges into the
Bristol Bay region and begins to shove the AR eastward into the
northern Panhandle later this evening and tonight. Heavy rain
rates reach the eastern gulf coast and Icy Strait corridor later
this evening and then Juneau by tonight. Heaviest rain is expected
between 10 pm Thursday and 10 am Friday for much of the Northern
Panhandle.

Model indicated recurrence intervals have not been hugely
impressive, expecting rainfall totals for this AR to be around a
10 year recurrence interval. But what gives us pause is the
performance of some of the higher res models, notably the ARW over
Yakutat and the under forecasting of global and regional models
like the GFS/ECMWF/Canadian and NAM. If one examines the QPF
forecast related to the ten year return interval levels, then the
high res models collectively pick out much of the Icy Strait
Corridor including Juneau as an area to watch tonight into Friday
for potential flooding issues. Did not make big changes to the
overall QPF forecast with today's forecast package. Nudged the QPF
forecast with some of the higher res models to increase totals
slightly along western and SW facing slopes and decrease QPF
slightly across the rain shadowed areas in Upper Lynn Canal. Still
expecting many daily rainfall records to be broken for today and
tomorrow. Through Saturday morning, expect an additional 3 to 6
inches of rain to fall across the Northern Panhandle with the
highest amounts in upslope favored areas (Downtown Juneau,
Douglas, Pelican, Mendenhall Valley, along the mountains in
Sitka). Slightly lower totals in Upper Lynn Canal around 1 to 3
inches due to rain shadowing from SW flow aloft.

After coordinating with the RFC, A Flood Advisory has been issued
for Taiya River and Mendenhall River through Saturday afternoon
and the Situk River through Friday morning for rising river levels
reaching Minor Flood Stage. The threat for flooding continues
across much of the Northern Panhandle through Friday evening. The
risk for landslides still exists, especially during the peak
period of heavy rain from 10 pm Thursday through 10 am Friday.

Regarding winds, breezy conditions will continue for much of the
northern Panhandle with lighter winds dominating the south. Given
anticipated strengthening of gradients through Lynn Canal, kept wind
speeds to gale force through this evening. This goes well with
the strong wind gusts in Skagway and Haines through tonight. Gusts
of 50+ mph have already been observed in Skagway this afternoon
and should continue through the overnight hours. Expect another
enhancement of both land and marine winds early Friday morning as
another wave of low pressure pushes into the NE gulf Coast. Expect
small craft conditions to develop in much of the Central and
Northern Inner Channels, peaking late Friday morning then
diminishing Friday night. Due to such a stable atmosphere and WAA
aloft, it will be difficult for strong low level jet winds (45
kt) to mix down to the surface. Kept strong wind gusts of 40 mph
in Skagway as the gradient will remain tight up there; however do
not think other areas across the Northern Panhandle will see
winds that high Friday. Expect a wind shift from SE flow to SW
flow Friday evening as the main front pushes SE through the
region. A brief burst of stronger winds is likely for both land
and marine areas as the front passes through and winds shift
Friday evening. Expect winds to dramatically decrease late Friday
night through Saturday as the gradient and flow aloft weakens.

Overall confidence is high through the period.

.LONG TERM.../ Saturday to Thursday, as of 9 PM Wednesday /
A short wave aloft from the northern stream moves from western
Russia into the Yukon Delta and then into the northwest Gulf of
Alaska Saturday morning. This merges with the southern stream south
of the Aleutians, and the entire moderate long wave trough will
move across the panhandle Saturday evening.

There is a trailing low over the north Pacific that chases after
the out-going frontal band and moves into the British Columbia
coast. The northern edge of the moisture on this wave will be far
enough north to impact the weather of at least the southern
portion of the panhandle Saturday. Depending on any shifts in
tracks it could reach the south central panhandle.

A flat ridge over the western gulf will move slowly east across
the gulf followed by a short wave from a trough over the central
Aleutians. The trough exiting and the start of the ridge should
limit amount of shower activity for maybe 24 hours late Sunday to
Monday. The westerly flow that follows over the flat ridge into
southeast Alaska Panhandle will have rain spreading back in by
Tuesday.

Overall a continued damp weather pattern for SE Alaska, with no
large significant storms anticipated for the week.

&&

.HYDROLOGY...With around 4.5 inches of rainfall forecasted today
in Yakutat, we will have to watch the Situk. There are signs that
our forecasted amounts are lower than what will fall today (see
above), so flooding is still a risk here. Further east, Taiya has
fallen below action stage, but we fully expect its waters to rise
past flood stage sometime tonight or Friday. Should confidence
rise, a flood advisory or warning will be issued. Juneau area
rivers, while somewhat high, have not responded as much to light
rains lately. But again, given saturated conditions, and expected
heavy rainfall rates tonight, especially in the higher elevations,
we do expect Jordan, Montana, Mendenhall Lake among others to rise
quickly toward Friday. The Salmon at Gustavus needs to be watched
tonight as well. We have less concern for the Chilkat in Haines
and rivers around Sitka, as recurrence intervals are not as
impressive in these locations. But for now, the flood watch is
justified.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Areal Flood Advisory until 4 PM AKDT Saturday for AKZ018-025.
     Flood Watch through Friday evening for AKZ019>023.
     Strong Wind until 7 PM AKDT this evening for AKZ019.
     Strong Wind until 1 AM AKDT Friday for AKZ018.
     Strong Wind from Friday afternoon through late Friday night for
     AKZ018.
     Areal Flood Advisory until 10 AM AKDT Friday for AKZ017.
MARINE...Gale Warning for PKZ012.
     Small Craft Advisory for PKZ013-022-031>035-041>043-051>053.

&&

CM/Bezenek

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