NWS Fairbanks, AK wrote its last area forecast discussion before the first event at Mar 4, 5:18 AM AKST, 6 hours 42 minutes earlier.
Area forecast discussion, Mar 4, 5:18 AM AKST, 6 hours 42 minutes before
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
518 AM AKST Mon Mar 4 2019
.DISCUSSION...
A weather front is moving onto the West Coast this morning and
will move north and east through the day, bringing gusty winds,
reduced visibility to blowing snow, and heavy snowfall. Another
weather front will slowly north and east across the West Coast and
Western Interior Tuesday and Wednesday, bringing more heavy snow.
A mix of rain, snow, and possibly freezing rain is possible
through Tuesday from the Seward Peninsula south. Snow spreads
eastward across the Interior and North Slope Wednesday and
Thursday.
Aloft, at 500 mb, a high is centered near where the borders of the
Northwest Territories, Yukon Territory, and British Columbia meet,
a low is centered between Yakutat and Cordova, a ridge axis
extends from north from Kodiak to McGrath to Hughes to Prudhoe
Bay, a low is moving onshore the the Kamchatka Peninsula, and
another low is located southwest of Shemya.
As the low along the Gulf of Alaska slides southeast through
midweek, the high over the Northwest Territories, Yukon Territory,
and British Columbia border will elongate and stretch north to
Mackenzie Bay and the ridge axis over northern Alaska will slide
eastward to be centered along the Alcan border by Tuesday evening.
The ridge axis will tap into the elongated high Tuesday night and
Wednesday, resulting in the ridge axis folding over and moving
east across the Yukon Territory.
The low southwest of Shemya this morning will weaken as it moves
into the western Bering Sea this afternoon and carve out a
shortwave as it progresses east northeast across the Bering Sea to
be located just northwest of the Pribilofs Tuesday morning and
west of Nunivak Island Tuesday afternoon. It will continue
northeast Tuesday night to be centered over Norton Sound Wednesday
morning and near Kotzebue Sound Wednesday afternoon, weakening as
it moves over the Brooks Range, with the axis stretching southeast
across the Interior Wednesday, and continuing northeast Thursday.
Ridging will build in briefly behind the shortwave, with the next
low moving into the western Bering Sea Thursday.
Surface...Broad high pressure will persist across the eastern
Interior through midweek, as will a leeside trough north of the
Brooks Range. This will maintain a tight pressure gradient across
the Brooks Range.
A 1004 mb low will develop 75 NM west of Wrangel Island this
afternoon moving northeast to be a 1005 mb low located 150 NM
north of Wrangel Island Tuesday morning, continuing northeast to
be a 1007 mb low 300 NM northeast of Wrangel Island Tuesday
afternoon and into the high Arctic by Wednesday afternoon.
Two lows, a 1006 mb low 75 NM north of Adak and a 1012 mb low 75
NM southwest of Nikolski, will move northeast across the Bering
Sea this morning. The low north of Adak will deepen to be a 1003
mb low located 150 NM west of St Paul Island by this afternoon and
the low southwest of Nikolski will deepen to be a 1005 mb low
located 50 NM northeast of St Paul Island. The low west of St Paul
Island will be absorbed by the deepening eastern low tonight,
resulting in a 999 mb low 100 NM northwest of Nunivak Island. An
elongated trough will develop Tuesday across the Bering Strait,
stretching from near Cape Lisburne south to between St Lawrence
Island and Port Clarence with two low centers developing by
Tuesday afternoon. The trough will stretch northeast along the
Chukchi Sea Coast and Beaufort Sea Coast by Wednesday morning,
with a 1002 mb low emerging 200 NM north of Utqiagvik by Wednesday
afternoon.
The next strong low enters the western Bering Sea Wednesday as a
955 mb low 100 NM west of Shemya, moving northeast to be 300 NM
southwest of the Pribilofs by Thursday morning.
Models...00Z model suite initialized well against the 00Z RAOBS
and the 00Z and 06Z surface obs. Models are in good agreement with
the overall synoptic pattern through Tuesday morning. At the
surface, models are in good agreement with placement and timing
of features through early Wednesday, when differences become
apparent with the handling of the low north of the Arctic Coast,
GFS and ECMWF are slower and keep the low further west, but the
NAM moves it quickly northeast over the Beaufort. QPF values and
placement vary a good deal between models, especially in the
favored southern upslope areas. Opted to go for a model blend
approach to QPF.
North Slope and Brooks Range: A weather front will lift northeast
across the northwest Arctic Coast today, bringing a chance of
light snow from Utqiagvik west. Another weather front will move
north and east across the region late Tuesday and Wednesday,
bringing another chance of snow to the western half of the region
and shifting winds to the southwest. Snowfall accumulations will
generally be in the one and a half to three inch range, with
higher amounts possible from Point Lay west. A tighter pressure
gradient has developed across the Brooks Range, resulting in
southerly winds with gusts to 40 mph in the passes today. This
could cause some areas of blowing snow and a Winter Weather
Advisory for blowing snow remains in effect for the northeastern
Brooks Range. Winds will relax tonight.
West Coast and Western Interior: A weather front is moving onto
the West Coast this morning and will move north and east through
the day, Gusty winds expected with this system, with the strongest
winds occurring north of the Seward Peninsula, along the Chukchi
Sea Coast, with gust to 45 mph possible. Blowing snow will reduce
visibility in some areas to less than half a mile. Periods of
heavy snow are also expected with this front, with the heaviest
snow falling in the upslope areas. The next front will push north
across Y-K Delta tonight and slowly slide north and east Tuesday
and Wednesday. The slow movement of the front will result in more
heavy snow, especially in the upslope areas. Rain may mix with
snow from the Seward Peninsula south at times through Tuesday.
Snowfall totals through Wednesday of 8 to 12 inches, with locally
higher amounts, will be common in the upslope areas of the West
Coast and Western Interior. Winter Storm Warnings and Winter
Weather Advisories remain in effect for much of the region.
Central and Eastern Interior: Patchy stratus lingers across
portions of the Interior this morning but is expected to dissipate
during the day, with mostly clear skies prevailing this afternoon
and tonight. Cloud cover will increase Tuesday and Wednesday, with
snow spreading east Tuesday night and Wednesday. Heaviest snow
will fall west of Bettles. A Tanana Valley Jet will develop today
with gusts to 30 mph and continue through Tuesday as a leeside
trough develops north of the Alaska Range, increasing the gradient
between it and the high centered over the Yukon Territory.
Southerly gap winds develop late this afternoon in the Alaska
Range passes and continue through Wednesday, with the strongest
winds expected Tuesday morning. Gusts up to 40 mph are expected.
Coastal Hazard Potential Days 3 and 4...None.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning for AKZ207-AKZ208-AKZ210-AKZ211-AKZ217.
Winter Weather Advisory for AKZ206-AKZ209-AKZ212-AKZ214-AKZ215-
AKZ216.
Small Craft Advisory for PKZ200-PKZ215.
Gale Warning for PKZ210-PKZ220-PKZ225.
Brisk Wind Advisory for PKZ230.
&&
MAR 19