Weather Service Report


342 
FXAK69 PAFG 241320
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
420 AM AKST Sat Feb 24 2018

.DISCUSSION...

Models...24/00Z solutions continue the trend of better agreement
into the midrange and building a high amplitude ridge that will
extend from the NE Pacific over the state and high Arctic. Solutions
are also very agreeable on a cooling trend that looks like it will
extend through next week. Will be leaning on a blend of the NAM 
and Canadian guidance for snowfall and precipitation amounts.

Aloft...At 500 hpa...Broad area of lower heights persists over 
the Canadian Archipelago, and the trough that extended west over 
the central Arctic yesterday has moved south over the Brooks Range
this morning, and extends west to a 514 dam low over the Chukotsk
Peninsula. A 517 dam low will move southeast from the Lower Yukon
Delta to the northern Gulf of Alaska this morning, and continue 
over the southeast Panhandle by late this evening. A ridge will 
move over the Central Aleutians and Western Bering Sea this 
morning and rotate east to lie from Sand Point to Cape Romanzof 
and northwest over the Gulf of Anadyr by Sunday morning. A 484 dam
low 700 nm northeast of Demarcation Point will move to 300 nm 
north of Demarcation Point by Sunday morning, and then east over 
Banks Island by Monday morning at 469 dam. A strong shortwave will
swing around the low to be over 80N by this afternoon, and moves 
to the Eastern Arctic Coast by Sunday morning. A second strong 
shortwave will develop near 80N and the Dateline Sunday evening 
and move south over the Chukchi Sea Monday morning. Ridging over 
the West Coast Sunday will shear off with the portion south of the
Bering Strait moving southeast as a 508 dam low that is moving 
east across the Central Bering Sea moves to Cape Romanzof by 
Sunday night, then into the interior as it merges into the broad 
area of lower heights over the state. At 850 hpa...-10 isotherm 
remains south of the forecast area, and the airmass will generally
continue to slowly cool through the week. There will be a weak 
warming period over the Lower Yukon Delta and Alaska Range Monday 
morning, but it starts cooling by afternoon.

Surface...A broad area of low pressure extends W across the 
Arctic. A 982 mb low 700 nm northeast of Demarcation Point will 
move to 300 nm north of Demarcation Point by Sun morning as a 
weather front along 80N moves S to the Arctic Coast. A 982 mb low 
in the high Arctic will move into the Western Arctic Sun night, 
and to the Northwest Arctic Coast Mon afternoon. A 996 mb low in 
the northern Gulf of Alaska will continue to move southeast. 
Leeside troughing north of the Alaska Range will weaken today. A 
1006 mb low near St Matthew Island this morning will move east 
over mainland Alaska. Weak high pressure will move over the 
Eastern Bering Sea and Chukotsk Peninsula this evening as a 983 mb
low moves into the Western Bering Sea. The high pressure will 
continue moving southeast into mainland Alaska with weak high 
pressure remaining over the Bering Strait and Chukotsk Peninsula. 
The low moves east across the Central Bering Sea to Nunivak Island
at 982 mb by Sunday evening, and will continue inland Monday as 
weak high pressure rebuilds over the Eastern Bering Sea.

Arctic Coast and Brooks Range...Blizzard conditions redeveloping
from Nuiqsut east today as the stronger winds have backed further
west than previously thought. Will also issue a Winter Weather
Advisory for Point Barrow east for later today and tonight.
Another strong weather system will move to the Northwest Arctic
Coast monday. Strongest winds will be around Kaktovik with wind
gusts to 65 mph expected. There is some potential for even
stronger gusts to around 70 mph late tonight. Winds west of Point
Barrow will increase tonight with some areas gusting to around 40
mph. Visibility will be reduced to 1/2 mile or less from Point 
Barrow east today and tonight, and west of Point Barrow tonight
and Sunday it will be reduced to less than 1 mile. Cloudy 
conditions will prevail with flurries or light snow over most of 
the area as weather front makes its way onshore. Temperatures will
continue the cooling trend.

West Coast and Western Interior...Snow in the lower Yukon Delta,
and a few flurries north into the Middle Yukon River Valley, but
expect it to stay south of the Seward Peninsula, and snow will be
ending as the low moves southeast to the Gulf of Alaska. Weak
high pressure moving over the Eastern Bering Sea tonight and will
linger over the Bering Strait Monday. A low moving east across the
Central Bering Sea will bring another round of gusty winds to St
Lawrence Island, and snow to St Lawrence Island and the Lower
Yukon Delta Sunday afternoon and night. Heavy snow will be
possible in the southern Nulato Hills Monday. Winds northeast to
north at 5 to 20 mph today and tonight becoming north to northwest
at 5 to 20 mph except north of the Bering Strait winds will be 15
to 30 mph. Temperatures north of Norton Sound will continue the 
cooling trend, to the south there will be a short lived warming
trend Monday, the cooling the remainder of the week.

Central and Eastern Interior...Increasing clouds as a low moves to
the south of the Alaska Range and moisture sneaks north into the
area. Chance of light snow mainly from Fairbanks south and east 
over the hills later today and tonight, but not expecting any 
significant accumulation around Fairbanks. Around 1 inch of snow 
will be possible east of Fairbanks. Clearing Sunday with cooler
temperatures. Increasing clouds early Monday morning with another
round of light snow possible from Livengood south with potential
for a couple inches of snowfall Monday. Temperatures will be  
cooling through the week. Winds generally light, except for some
stronger Gap winds in the Alaska Range to 45 mph at times.

&&

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

&&

Extended forecast for days 4 to 7...Solutions continue to show
better agreement, but will most likely use a blend of the 
Ensemble means. High amplitude ridge continues to develop in the
solutions bringing the potential for a blocking pattern to
develop, and for much cooler temperatures over the Central and
Eastern Interior. 

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Blizzard Warning for AKZ203-AKZ204.

Winter Weather Advisory for AKZ202.

Heavy Freezing Spray Warning for PKZ210.

Gale Warning for PKZ240-PKZ245.

Brisk Wind Advisory for PKZ210-PKZ230-PKZ235.

&&

$$

SDB FEB 18

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Western Regional Climate Center, wrcc@dri.edu