Small Craft Advisory 147, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
204 PM AKDT SUN SEP 11 2016

.DISCUSSION...

Models...Excellent run to run continuity with very little change
in the solutions the last couple runs. Solutions through the
midrange and extended periods continue to be similar enough that a
blend will smooth out the bumps. Will lean toward the NAM
precipitation solution as it handle the rain shadowing better than
the other models with a nudge to the SREF Probabilities.

Aloft...at 500 hpa...A 510 dam closed low over the northeast
arctic will move east tonight to Banks Island and continue into
the Canadian archipelago Monday. A shortwave will swinging south
around the low is moving over the arctic coast and will merge
with a 537 dam low that develops over the Bering Strait. The low
then moves northeast across the interior to the Yukon Territory by
Tuesday evening at 542 dam. A west to east lying trough will
persist over the central arctic through Tuesday, then move south
over the northwest and central arctic coast Wednesday. A ridge
over the north Pacific is pushing 543 dam heights north over the
arctic coast today. The ridge will slide east tonight and heights
will slowly fall over the area through Tuesday. A ridge over the
western Aleutians will move east to the southwest mainland by
Tuesday evening as the low moves across the interior. At 850
hpa...Zero isotherm lies along the crest of the Brooks Range and
north of St Lawrence Island today and will remain stationary into
late Monday before slowly moving south and east to lie from Old
Crow Yukon to Livengood to Holy Cross to St Lawrence Island late
Tuesday.

Surface...A 994 low just south of Nunivak Island will move
northeast to Norton Sound tonight at 986 mb, and to Huslia at 993
mb by Tuesday morning. A 995 mb low will develop over the upper
Yukon Flats early Tuesday and move east into the Yukon Territory.
Ridging will build southeast across the arctic and south over the
Gulf of Anadyr and eastern Bering Sea from a 1030 mb center near
New Siberian Island. Troughing and the associated stationary
weather front will remain across the interior as the low moves
east, and will be enhanced late Wednesday as a 979 mb low over the
Western Aleutians Monday night moves to the Central aleutians
Wednesday morning at 978 mb, and to the western Alaska Peninsula
by Thursday evening at 986 mb. A broad are of low pressure high in
the arctic Wednesday will move south to the central arctic with a
988 mb center 300 nm north of Barrow by Friday morning.
Precipitation will spread over the forecast area today from the
southwest with the exception of the areas in the rain shadow of
the Alaska Range. Snow developing at higher elevations of the
Alaska and Brooks Ranges today and tonight.

Arctic Coast and Brooks Range...SPORT NPP VIIRS 24 hour
Microphysics product at 11/1751Z continues to indicate a band of
stratus a couple hundred miles wide north of the Brooks range.
GOES probability product at 11/19150Z again indicating it is
mostly MVFR sky cover. There are some IFR conditions indicated
around the Chukchi Sea and observations indicate this is mostly
fog. Not much change expected with plenty of cloud cover in the
coastal areas. In the Brooks Range conditions will deteriorate
tonight as the low moves to Norton Sound and spreads precipitation
over the area. Tough call on snow amounts with this being the
transition period and the ground is not frozen, and there will be
some warm air brought north with the system. Expect some heavier
precipitation with the upslope component and a good south feed
into the area, so will maintain the Winter Weather Watch for now
and let the next shift an opportunity to evaluate the latest model
output. Current output indicates anywhere from 4 to 7 inches of
snow is possible above 1500 feet. Some stronger east winds over
most of the area as the low moves north and weak ridging builds
east over the offshore waters.

West Coast and Western Interior...Rain continuing to spread north
overnight, then tapering off from the southwest starting midday
Monday. Rainfall amounts from 0.25 to 0.75 inch will be possible
through Tuesday morning. A few flurries will be possible in the
Kotzebue Sound region Tuesday as cold air starts working its way
southeast. Stronger north to northeast winds over the Chukchi
Sea, Bering Strait, St Lawrence Island, and the coastal areas this
week with the strongest winds near the Bering Strait gusting to
around 40 mph. Temperatures will slowly cool through the week.

Central and Eastern Interior...Rain moving into the area this
evening and the temperatures will continue to slowly cool. Rain
will transition to more showery conditions by late Monday as the
system progresses east. Wednesday will be mostly dry around the
interior as we get a break between weather systems. Patchy fog,
especially along and near the waterways will occur in the
mornings. Strong gusty south winds around 70 mph near the Alaska
Range passes will continue into Monday so have issued High Wind
Warnings for those areas. Gusty winds around Delta Junction to
around 50 mph tonight so will issue a Wind Advisory for Zone 223.
Winds for the remainder of the area will generally be southwest at
5 to 15 mph. Temperatures the remainder of the week will see highs
in the 40 to 50 range and lows in the 30s.

&&

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

&&

.Hydrology...River continue to trend down, but expect them to
start slowly rising as the rainfall Sunday and Monday makes its
way into the mainstem streams and rivers starting Tuesday. No
significant jumps in the river levels are expected with this
event.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

high wind warning for AKZ225-AKZ226.

Wind Advisory for AKZ223.

Winter Storm Watch for AKZ205-AKZ206.

Gale Warning for PKZ225.

Small Craft Advisory for PKZ200-PKZ210-PKZ220-PKZ230-PKZ240-PKZ245.

&&

SDB SEP 16