Small Craft Advisory 84, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
430 AM AKDT THU JUL 21 2016

.DISCUSSION...

Models...Run to run continuity is good, and the 21/00Z solutions
initialized well against the 21/06Z surface analysis. Similar
solutions into the mid range with just minor discrepancies on
locations of the upper level lows over the state. Rainfall amounts
still vary by model with the GFS being the wettest and the NAM the
driest. Will use primarily the NAM for location of the rainfall
and blend the NAM and GFS for rainfall amounts. They are
indicating more precipitation than they were in previous runs with
rainfall the through Sunday morning of 0.50 to 1.50 inches over
most areas south of the Brooks range.

Aloft...At 500 HPA...A 554 dam low has developed over the
northeast mainland and will drift east into the Yukon Territory
this afternoon. Ridging extending out of the north Pacific over
the eastern Bering Sea and Bristol Bay is flattening out as a 551
dam low over the central Bering Sea moves over St Matthew Island
tonight and merges into the developing trough over mainland
Alaska Friday evening. A trough over the high arctic will move
south over the arctic coast by Friday afternoon and a 550 dam low
will develop over Barrow Friday morning. The low over St Matthew
Island will move southeast to be over southern Cook Inlet late
Friday evening, and over Yakutat late Saturday evening. The low
over Barrow will move south over Kotzebue by early Saturday
morning, and over Norton Sound by late Saturday evening with a
second low developing over the northwest coast. Ridging will start
building north over the southeast interior Monday and the eastern
and central interior on Tuesday. At 850 HPA...Not much change in
temperatures over the state through the weekend, then some slight
warming over the eastern interior beginning Monday.

Surface...A broad area of low pressure with several centers over
the state and a trough that will lie east to west across the
state through the weekend, the front will aimlessly drift north
and south. A 1019 mb high will persist over western arctic with
ridging building southeast over MacKenzie Bay by Friday morning. A
996 mb low will persist over northern Cook Inlet and Prince
William Sound through Friday then drift east and northeast to be
over the upper Tanana Valley by Sunday morning.

Arctic Coast and Brooks Range...Northeast flow over the coast will
keep the stratus and areas of fog over areas east of Wainwright.
Northwest coast will be pretty nice today with mostly clear skies.
Temperatures a bit warmer east of Wainwright, and much warmer over
the northwest coast. Winds speeds in the 5 to 20 mph range through
Friday on the coast, with lighter winds inland. Clearing over the
Brooks range today as a upper level disturbance moves out of the
area.

West Coast and Western Interior...A wet remainder of the week and
weekend as the areas sees anywhere from 0.25 to around 1.00 inch
of rain through Sunday morning. The heaviest amounts will be in
the Nulato Hills and western Alaska range. Not much change in
temperatures through the weekend. Winds will generally be light
inland with west winds 5 to 20 mph along the coast.

Central and Eastern Interior...Wet, less wet, then wet again with
storm total rainfall amounts ranging from around 0.25 inch north
of the Yukon River to over 2 inches in the eastern Alaska range.
in the Tanana Valley storm total rainfall amounts will range from
1.00 to around 1.50 inch through Sunday morning. With water
already running high in rivers and streams this rainfall will
increase the potential for more rivers and streams to reach
bankfull, or even minor flood stages, with water inundating low
lying areas near rivers and streams. There will be a few breaks
in the rain as it becomes more showery on Friday but cloudy
conditions will prevail. Wind direction will be dependent on the
location of the frontal boundary lying across the area with wind
speeds generally 5 to 15 mph through Saturday. Temperatures will
remain cool with highs in the 60s and lows in the 50s.

&&

Coastal Hazard Potential Days 3 and 4...None.

&&

.FIRE WEATHER...Not much going on here, high probability of at
least one period of wetting rains through Sunday morning. Relative
Humidity values will continue to be high with minimum Relative
Humidity above 40 percent, and excellent overnight recovery.
Not much potential for Thunderstorm activity as atmospheric
conditions remain stable.

&&

.HYDROLOGY...Flood Advisory continues for the Chena river, see
latest statement for up to date information. Most rivers and
streams were falling, but the current rainfall will bring them
back up to bankfull or minor flood stages by the weekend. Rainfall
amounts across the forecast area will range from 0.25 to around
2.00 inches. The heaviest rainfall with the latest model
solutions is over the eastern Alaska range and Fortymile country,
so will need to keep a close watch on the rivers draining north
into the upper Tanana Valley, the Delta, Nabesna, Johnson,
Robertson, and Gerstile, and the Goodpaster flowing out of the
Fortymile country.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Small Craft Advisory for PKZ210.

&&

SDB JUL 16

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1002 AM AKDT THU JUL 21 2016

AKZ225-220800-
DENALI-
INCLUDING...HEALY...DENALI NATIONAL PARK...CARLO CREEK...
KANTISHNA
1002 AM AKDT THU JUL 21 2016

...HIGH WATER ON STREAMS AND RIVERS IN WESTERN DENALI NATIONAL PARK...

HEAVY RAINFALL THE PAST FEW DAYS IN WESTERN DENALI NATIONAL PARK
IS RESULTING IN SIGNIFICANT RUNOFF INTO SMALL STREAMS AND RIVERS.
OVER THREE QUARTERS OF AN INCH OF RAIN FELL AT EIELSON VISITOR
CENTER SINCE WEDNESDAY MORNING AND UP TO ANOTHER HALF INCH OF
RAIN IS POSSIBLE TODAY. THIS RAINFALL IS ON TOP OF GROUND THAT IS
ALREADY SATURATED FROM RAINFALL EARLIER IN THE WEEK. RIVERS AND
STREAMS WEST OF TOKLAT WILL BE NEAR BANKFULL BUT ARE EXPECTED TO
REMAIN BELOW FLOOD STAGE. BACKCOUNTRY TRAVELERS IN THIS AREA
SHOULD BE PREPARED FOR RAPID CHANGES IN WATER LEVELS TODAY THROUGH
FRIDAY. WATER LEVELS ARE EXPECTED TO BEGIN FALLING SATURDAY.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1007 AM AKDT THU JUL 21 2016

AKZ221>223-222000-
CENTRAL INTERIOR-MIDDLE TANANA VALLEY-DELTANA AND TANANA FLATS-
INCLUDING...NENANA...ANDERSON...TANANA...MINTO...
MANLEY HOT SPRINGS...RAMPART...LAKE MINCHUMINA...LIVENGOOD...
FAIRBANKS...FORT WAINWRIGHT...EIELSON AFB...ESTER...NORTH POLE...
MOOSE CREEK...TWO RIVERS...FOX...CHATANIKA...CHENA HOT SPRINGS...
SOURDOUGH CAMP...SALCHA...DELTA JUNCTION...FORT GREELY...
HARDING/BIRCH LAKE...DRY CREEK...DOT LAKE...HEALY LAKE
1007 AM AKDT THU JUL 21 2016

...HIGH WATER ON RIVERS IN THE CENTRAL INTERIOR INTO THE
WEEKEND...

HIGH WATER AND BANKFULL CONDITIONS ARE OCCURRING ON MANY RIVERS
IN THE CENTRAL INTERIOR. THIS INCLUDES THE CHENA...LITTLE
CHENA...SALCHA...AND TANANA RIVERS. HEAVY RAINFALL EARLIER THIS
WEEK FOLLOWED BY AN ADDITIONAL 0.5 TO OVER 1 INCH OF RAIN SINCE
WEDNESDAY WILL KEEP THE RIVERS BANKFULL INTO THE WEEKEND. IN
ADDITION TO THE HIGH WATER...THERE IS INCREASED DEBRIS AND
EROSION ON AREA RIVERS.

ON THE CHENA RIVER IN FAIRBANKS...SOME PATHS NEAR THE RIVER ARE
INUNDATED AND THERE IS LIMITED CLEARANCE FOR BOAT TRAFFIC UNDER
SOME BRIDGES THROUGH TOWN. THE U.S ARMY CORPS OF ENGINEERS ALASKA
DISTRICT IS CURRENTLY OPERATING THE MOOSE CREEK DAM AND REGULATING
FLOW OF THE CHENA RIVER INTO FAIRBANKS. THE CHENA RIVER IN
FAIRBANKS WILL REMAIN NEAR ITS CURRENT LEVEL WHILE THE FLOW IS
BEING CONTROLLED.

MINOR FLOODING IS OCCURRING FROM NORTH POLE UPRIVER INTO THE
CHENA RECREATION AREA. PLEASE SEE THE FLOOD ADVISORY STATEMENT FOR
MORE INFORMATION.

EWP