Small Craft Advisory 149, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
135 PM AKDT MON SEP 12 2016

.DISCUSSION...

Models...Short term continuity continues to be excellent. They
diverge quite a bit in the extended periods so will need to pick a
model and go with it for now. Will again lean toward the NAM
precipitation solution as it handles the rain shadowing, and is
not so generous with the precipitation coverage and amounts as
well as snow amounts. Will nudge to the SREF Probabilities to
kick them up a bit.

Aloft...At 500 hpa...A 507 dam closed low has moves northeast of
Banks Island with a trough extending southwest to a developing low
over the Chukchi Sea. The trough and low will weak and dissipate
Tuesday morning. The primary low of concern has moved over Norton
Sound at 534 dam and will move east tonight to be over Tanana
Tuesday morning at 535 dam, and over Chalkyitsik late Tuesday
night at 539 dam, then dissipates over the Yukon Territory
Wednesday morning. Ridging over the eastern interior will continue
to weaken today as it pulls back south over the northeast Pacific.
A ridge over the central Aleutians and Central Bering Sea will
continue to slide east tonight and lie from The Gulf of Anadyr to
Kodiak Island by Tuesday afternoon, then stalls and weakens as a
strong shortwave that develops over the central arctic moves south
over the northwest coast by Wednesday morning and lies over
Deadhorse to St Lawrence Island by Wednesday afternoon. This will
produce a persistent southwest to west flow over most of the
forecast area into next week. At 850 hpa...Zero isotherm lies
along the crest of the Brooks Range and over St Lawrence Island
today and will slowly move south and east to lie from Old Crow
Yukon to Livengood to Sleetmute to St Lawrence Island by late
Tuesday. It then starts slowly moving back to the north and will
lie from Old Crow to Ruby to Mekoryok by Thursday morning, and
Old Crow to Huslia to Marshall and south by Saturday morning.

Surface...The primary low has moved over Norton sound at 992 mb
today while a 998 mb low has developed along the front over the
upper Yukon flats at 998 mb. The front will remain quasi
stationary across the area through the short term and into the mid
range. Position of the front will be difficult to as it shifts
north and south as minor shortwaves move through the area and the
ridge transitions to lie to the south. A 980 mb low near the Rat
Islands will continue its trek east to the central Aleutians by
Tuesday evening at 978 mb, then to Dutch Harbor by Thursday
morning at 983 mb. The associated weather front will swing north
to Bristol Bay and the Gulf of Alaska by early Wednesday morning
and merge with the trough over the interior late Thursday night or
early Friday morning. The low will continue into Bristol Bay by
Friday evening and into the Gulf of Alaska Saturday. A secondary
low will develop over the the middle Yukon Valley near Anvik
Saturday morning at 989 mb and move east through the weekend. A
low over the North Pole Wednesday morning will move south to be
300 nm north of Barrow by Friday morning with a front extending
southwest into the Chukchi Sea. Bands of precipitation around the
low out west will continue to move through the forecast area into
Wednesday, then a short break before more showers move across the
area late Thursday

Arctic Coast and Brooks Range...SPORT NPP VIIRS 24 hour
Microphysics product at 12/1734Z showing a lot of high cloud
coverage over the mainland obscuring the MVFR/IFR conditions that
the GOES probability product at 12/1800Z is indicating over most
of the arctic. Observation confirm it is mainly low cloud
coverage. Heavy Snow warning remains in effect with no changes to
the amounts or timing. WebCams are not showing a lot of
accumulation currently but it is snowing at Anaktuvuk Pass and the
temperatures will continue to slowly fall. As the low settles in
near Huslia expect heavier precipitation with the upslope
component and a good southerly feed of moisture into the area.
East winds over most of the area as the low settles in and weak
ridging continues to build east over the offshore waters.

West Coast and Western Interior...Rain or showers over most of the
area this evening with it tapering off over the lower Yukon Delta
later this evening and tapering over over the Norton Sound region
tonight. Showers will continue in the middle Yukon and Upper
Kobuk regions into early Wednesday before ending. North winds over
the coastal areas have picked up and will diminish in the near
shore areas as the low moves further inland tonight and tomorrow.
Offshore around St Lawrence Island winds will remain relatively
strong and gusty through the week. Additional rainfall amounts up
to 0.50 inch for most of the area through Wednesday morning. A few
flurries will be possible in the Kotzebue Sound region Tuesday as
cold air starts working its way south and east. With the
persistent north flow temperatures will slowly cool through the
week.

Central and Eastern Interior...periods of Rain or showers will be
moving through the area until early Wednesday then a short break
before the next system bring some bands of precipitation across
the area Thursday and Friday. Patchy fog, especially along and
near the waterways, can be expected in the mornings. South winds
in the Alaska range will continue to taper off through tonight.
West to southwest winds to 10 mph will continue over the remainder
of the area. Gusty south winds will return to the Alaska range
Thursday but they will only be in the 35 to 45 mph range.
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...Rivers have leveled off with the recent rain and will
start slowly rising tonight as the rainfall makes its way into
the mainstem streams and rivers. No significant jumps in the
river levels are expected.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Wind Advisory FOR AKZ223-AKZ226.

Winter Storm Warning FOR AKZ205-AKZ206.

Small Craft Advisory FOR PKZ200-PKZ210-PKZ230-PKZ235-PKZ240-
PKZ245.

Gale Warning FOR PKZ220-PKZ225.

&&

SDB Sep 16

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1247 PM AKDT MON SEP 12 2016

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

0240 AM     NON-TSTM WND GST 33 SW ALCAN             62.36N 141.88W
09/12/2016  M75 MPH          SOUTHEAST FAIRBANKSAK   MESONET

            MESONET STATION 33 WSW ALCAN /M27KX/.

&&

NWS FAIRBANKS AK
IRIS SYSTEM