Area Forecast Discussion
Issued by NWS Fairbanks, AK

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
000
FXAK69 PAFG 231412
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
612 AM AKDT Fri Aug 23 2019

.DISCUSSION...

Synopsis...Some isolated showers in the Interior today, otherwise
pretty quiet. Most activity will be focused on the Arctic as a
couple of weather fronts work their way east across the area.
Snowfall in the Eastern Brooks Range, mainly above 2000 feet will
bring up to 4 inches of new snow. Less than 2 inches of snow in
Atigun Pass. Periods of rain on the Arctic Coast as the fronts
move through. Some very isolated showers on the West Coast today.
Persistent north winds will produce some elevated surf on the
north facing coastlines today.

Models...23/00Z Solutions are in good agreement for the short
term and even into the midrange. Broad cyclonic flow over the area
will persist with it becoming more zonal as it extends south over
the Alaska Range later in the solutions. It is going to be a
pretty active pattern for the Arctic, but not too active south of
the Brooks Range. Will lean quite a bit on the current forecast
database nudging it to the NAM solutions that seems to be
providing better coverage for precipitation than the ECMWF or the
GFS which have been much too aggressive with coverage. Will be
using the NAMDNG for winds again today, but will kick the winds up
a bit in a few locations as they are a bit stronger than solutions
suggest.

Aloft...At 500 hpa...Broad cyclonic pattern will persist. Low
remains near the North Pole and has deepened to 516 dam. A second
low with a 522 dam center has developed along the trough 400 nm
north of Demarcation Point. Troughing extends from the 522 dam low
southwest over Kaktovik to Tanana to Bethel to a 548 dam low over
the Pribilof Islands. By Saturday morning the trough will lie
from the low near Banks Island southwest to Eagle to Anchorage to
549 dam low that has moved just south of the Pribilof Islands. The
low near the North Pole will move to 600 nm north of Point Barrow
with cyclonic flow persisting over the Arctic. Weak ridging over
the Chukchi Sea today will slide south and push east over the West
Coast, and the Lower Yukon Delta. The ridging will slide east
over Southcentral Alaska Sunday with weak trough developing north
of the Alaska Range as a decaying front push south. At 850
hpa...0C isotherm lies from Old Crow YT to Ambler, then northwest
this morning and will persist in the same area through Saturday
morning. By Sunday morning it will lie along the crest of the
Brooks Range and persists there through Monday morning.

Surface...Benign pattern remains over the area with a broad area
of low pressure extending from the Arctic to the Northeast
Pacific. High pressure persists over Siberia and the Bering Sea.
The combination of low pressure over the Arctic, and high pressure
in Siberia is producing a tightened pressure gradient over the
Western Arctic, Chukchi Sea, and Bering Strait. A 993 mb low 250
nm N of Kaktovik with a front extending S is moving SE and will
move E of the area this afternoon. Weak high pressure behind the
front will move across the area today. A 987 mb low will move to
500 nm N of Point Barrow by Sat morning as a weather front over
the Western Bering Sea moves E to lie along 160W this afternoon,
then along 150W by Sat morning. The front will move into the
Beaufort Sea late Sat morning. Another front will sweep SE around
the low as it moves E and will lie from the low to the Chukchi Sea
Sat afternoon. By Sun morning the low will be in the Northern
Beaufort Sea with a 982 mb center and the front will lie along 72N
as it drags E. A 987 mb low in the southern Gulf of Alaska will
move east and weaken, but will continue to spin moisture north
into the Interior. A 1001 mb low in the Upper Tanana Valley will
move southeast and deepen to 999 mb as it moves into the Copper
River Basin, then over Prince William Sound by Saturday morning.
High pressure associated with a 1025 mb center in the Western
Bering Sea will push northeast over St Lawrence Island, the
Seward Peninsula, and the Western Brooks Range Saturday morning,
then slowly rotates south over the Lower Yukon Delta Saturday
evening, and over the southwest mainland by Sunday morning.

Arctic Coast and Brooks Range...A couple weather fronts will move
across the area spreading periods of rain to most of the Arctic
Coast and Plains. The Western Brooks Range will stay relatively
dry, while the Eastern Brooks Range will see another round of snow
above 2000 feet. Snow accumulation up to 4 inches east of the
Dalton Highway, with less than 2 inches in Atigun Pass. Winds are
a bit stronger than model solutions suggested and will be gusting
to around 25 mph today and up to 35 mph Saturday. More snow in the
mountains Saturday night.

West Coast and Western Interior...Fairly quiet. Winds north 20 to
25 mph in the Chukchi Sea and through the Bering Strait today
diminishing tonight. West winds developing Saturday night will
increase to 15 to 25 mph on the coast south of the Bering Strait.
Some isolated showers today, but nothing significant. Elevated
surf on north facing coastlines west of Cape Espenberg today.

Central and Eastern Interior...A few showers around the area
today, but nothing really organized. Will remain mostly cloudy
through the day, but expect some breaks in the afternoon. No
significant winds are expected. No significant change in
temperatures the next couple days.

&&

Coastal Hazard Potential Days 3 and 4...None. A long westerly
fetch will develop over the Bering Sea Sunday night bringing
elevated water levels to West Coast locations south of the Bering
Strait. Water levels are currently expected to be slightly above
the Normal High Tide Line. Wave action will wash above the Normal
High Tide Line and may cause some minor erosion.

&&

.Fire Weather...Relative Humidity Values generally above 40
percent with excellent overnight recovery. No significant winds
through the weekend. No thunderstorm activity expected. Go to
www.weather.gov/arh/fire for details.

&&

.Hydrology...River levels continue to slowly fall, but ground
water levels remain high. No significant additional rainfall is
expected through the weekend. Extreme caution should be used
around all waterways in the interior as trees and other debris
will continue to move downstream while the levels fall. For the
latest forecasts go to www.weather.gov/aprfc.

&&

Extended forecast for days 4 to 7...Not much change in the
solutions as they keep the upper level low over the Arctic with
zonal flow over the forecast area to start, then move the low east
and dig a trough south over and across the state late next week.
Still looks like an active pattern with periods of rain and snow
in the Arctic, dependent on elevation and periods of rain south of
the Brooks Range. Most likely period for the showers will be
Tuesday/Wednesday. Long wave trough digging south late in the week
will bring some much cooler temperatures to the area.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Small Craft Advisory for PKZ210-PKZ220-PKZ245.

&&

$$

SDB AUG 19


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.