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
000
FXAK69 PAFG 201225
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
425 AM AKDT Fri Apr 20 2018

.DISCUSSION...

Models...Good run to run, models showing some minor differences
in the precipitation forecast from yesterday, mainly less
precipitation pushing northwest into the Middle Tanana Valley.
They continue to handle the shortwave digging southwest across the
state similarly, and the position differences that where evident
yesterday are not there today. Will use an equal blend of the
solutions today.

Aloft...at 500 hpa...Ridging over the Dateline with a 545 dam
center 150 nm north of Wrangel Island with ridging extending
south over the Chukotsk Peninsula and and Central Bering
Sea, and southeast over the Bering Strait and Southwest mainland.
The center will move south over the Siberian Coast by Saturday
afternoon, then west. Ridging will extend east over the Arctic and
Arctic Coast, and south over the Western Bering Sea. A 500 dam
center over Banks Island will move northeast over the Archipelago.
A 504 dam center over MacKenzie Bay will dig southwest over the
state to be over Allakaket this afternoon, and over Nunivak Island
by Saturday morning with a trough extending northeast to
Demarcation Point. A filling 520 dam low over the Semidi Islands
will continue to fill as it moves to Lower Cook Inlet this
afternoon, then merges tonight with the low digging southwest.
Ridging building over the Southeast Panhandle will build north
over the southeast Interior this evening, then into the Eastern
and Central Interior Saturday with 530 dam heights over the AlCan
Border Saturday morning, and 540 dam heights pushing over the
interior by Sunday afternoon. Weak troughing will persist from the
Seward Peninsula over Demarcation point from Saturday and Sunday. As
the shortwave digs south it will absorb a 514 dam center over the
Alaska Peninsula. The low over Banks Island will move northeast At
850 hpa...The -10C isotherm will be pushed south and west of the
forecast area this morning. The -20C isotherm will pulled
southwest over the area north of the Yukon River and east of the
Dalton Highway today, then slide back to the northeast Saturday.
As the ridging builds in the -10C isotherm will be pushed back
north.

Surface...High pressure remains over the Arctic, with low pressure
to the south. The high pressure to the north consists of a 1025
mb high 100 nm north of Wrangel Island and a 1025 mb high 200 nm
northeast of Wainwright. Ridging extends east over the Arctic
Coast, and south over the Dateline into the Central Bering Sea.
Low pressure to the south consists of a 995 mb low over Upper Cook
Inlet, and a 996 mb low over the Eastern Alaska Range with
troughing extending west over the southern Bering Sea, and east
over the southern Yukon Territory. A 979 mb low has moved to south
of the Central Aleutians this morning and will move east along 50N
through Saturday morning. The troughing over the state will
weaken, and the low over Cook Inlet will move southwest to
Kuskokwim Bay by Saturday morning, then merges with the low south
of the Alaska Peninsula. Weak troughing will spin north in the the
southeast interior this evening and overnight, then dissipate as
the decaying trough spins to the West Coast. By Sunday morning
high pressure will remains north of the Brooks Range and over the
Arctic with a 1025 mb high ear Nuiqsut, and a 1027 mb high 300 nm
north of Wainwright, while low pressure to the south will consist
of a 991 mb low that will develop over outer Bristol Bay, and a
989 mb low 200 nm south of Kodiak Island. Weak leeside troughing
will build north of the Alaska Range Sunday, then weaken with
stronger leeside troughing Monday night and Tuesday.

North Slope and Brooks Range...Stratus is being a pain the
forecast at the moment, and will continue to be today. Earlier
SPoRT satellite products show a band of stratus extending from
Demarcation Point to point Barrow and north into the Arctic. The
stratus was moving southwest, and should be packed up against the
Brooks Range and over the Western Arctic now, and that looks to be
the case on the GOES products. Do expect some clearing as the day
goes on. Some flurries with the stratus, but no significant
accumulation of snow in the Arctic today. Temperatures 5F to 15F
colder today and tonight, then warming slowly Saturday. Northeast
winds 10 to 20 mph for most areas.

West Coast and Western Interior...Pretty quiet today. Some clouds
moving through the area, but mostly high clouds with no
precipitation expected. Winds pick up in the coastal areas to
northeast at 15 to 25 mph for most areas with some gusts to 40 mph
locally. Inland areas will also see fairly strong winds at 10 to
20 mph from the northeast. Temperatures cooling 5F to 15F through
Saturday morning with the colder temperature in the inland areas.
In the Lower Yukon Delta and Upper Kuskokwim Valley snow
developing late this evening and continuing overnight with up to
2 inches of snow.

Eastern and Central Interior...Increasing clouds through the day
with snow and snow showers as the trough sets up southwest to
northeast across the state. Snowfall will be heaviest in the
Alaska Range with potential for 4 to 6 inches by Saturday morning
that may impact travel on the Parks and Richardson Highways. More
than a foot of snow will fall on Denali today and tonight.
Snowfall will taper off from the northeast as the trough weakens
tonight and rotates west. Northeast winds across the area at 5 to
20 mph with local gusts to 30 mph. Temperatures cooling
significantly today with highs only reaching into the 30s in the
Middle Tanana Valley and 20s to the north. Overnight lows could
fall into the single digits tonight in areas that clear out, but
generally should be in the teens.

&&

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

&&

.Fire Weather...Minimum Relative Humidity values above 30 percent
today with much cooler temperatures and snow showers across most
of the area. High temperatures in the lower 30s today. Winds
northeast 5 to 20 mph with local gusts to 30 mph. There is no
threat of thunderstorm activity.

&&

Extended forecast for days 4 to 7...A broad area of low pressure
around a low near the Pribilofs will persist with a trough
extending across the state north of Fairbanks. Showers over the
Lower Yukon Delta mid week, with showers over the Central and
Eastern Interior Late in the week as a low pressure center develop
over the Upper Yukon Flats. Expect temperatures to warm to near
seasonal normals across the forecast area. In the Central Interior
highs will be in the upper 40s to lower 50s, with overnight lows
around 30.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Small Craft Advisory for PKZ200-PKZ210.

Heavy Freezing Spray Warning for PKZ210.

Brisk Wind Advisory for PKZ220-PKZ225.

&&

$$

SDB APR 18



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