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fxak69 pafg 242316 

Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
216 PM akst Sat Feb 24 2018

the 12z model suite initialized well against the 12z surface
analysis and verified well against the 18z surface analysis.
Model spread is minimal in the short range as well as mid range.
Model spread is remarkably low in the extended range as a high
amplitude ridge builds over the Bering Sea through the middle of
next week.

Aloft at 500 mb a cold upper level low 150 nm north of Banks
Island will move south and west to be located just west of Banks
Island Sunday morning as an upper level low pushes east out of the
Bering Sea near Nunivak Island Sunday evening. The upper level
low over Nunivak Island continues to move east and then northeast
and is absorbed by the strong upper level low over Banks Island as
it also flattens the upper level ridge over south central Alaska
Monday morning. A cold airmass flows into a trough rotating south
and southeastward over central and eastern interior of Alaska
Monday and Tuesday with 850 mb temperatures dropping into the 20s
below over northeastern Alaska and into the 15 to 20 below range
over central and eastern interior. A strong ridge builds over
eastern Siberia and the western Bering Sea Tuesday and Wednesday
which slowly drifts to the east with the ridge axis moving over
the western CAPES Wednesday and western Alaska Thursday. The
ridge axis continues to drift to the east and will be centered
over central Alaska Friday. As the upper level high pressure ridge
moves slowly over the West Coast and central Alaska cold and
relatively dry conditions will prevail over northern Alaska.

On the surface a 976 mb low pressure system currently 150 nm
northwest of Banks Island will continue to drop south and
southwest toward the McKenzie Delta and will continue to increase
winds and snow along the eastern North Slope. On going blizzard
warnings on track with blizzard conditions reported at many sites
east of the Dalton Highway. Winds are expected to gust to 65 mph
tonight as the low approaches and a barrier jet develops along the
eastern Brooks range. Winds will also increase tonight and
tomorrow along the central and western North Slope where winter
weather advisories for blowing snow have been issued.

Mostly clear conditions are found over the northern interior
under weak high pressures while clouds and light snowfall over the
lower yk Delta push north and east into the southern interior
tonight. Clouds and generally less than an inch of snow is
expected in these areas as a weak low pressure system moves east
from near Nunivak Island to near Kodiak Island where the low is
absorbed by a deeper low pressure system over the Panhandle.

A second low pressure system a 986 mb low currently 150 nm south
of sheyma will move north into the southwest Bering Sea tonight
and then move northeast to be located over Nunivak Island as a 981
mb low Monday morning. The low will bring another round of
precipitation over the lower yk Delta late Sunday night and the
southwestern interior Monday morning. Snow will move into the
souther portions of the central interior Monday afternoon.
Generally 2 to 4 inches of snow is expected over the lower yk
Delta and 1 to 3 inches expected over the southern interior
Monday. This low rapidly moves south and east over the northern
Gulf of Alaska Tuesday.

Will need to monitor a 966 mb low that is forecast to move rapidly
south over the high Arctic to be located 350 nm northwest of
Point Barrow Monday evening and is forecast to weaken to 974 mb as
it moves on shore near Point Barrow Tuesday morning. Will need to
monitor for strong winds, snow and blowing snow developing along
the western North Slope Monday night and Tuesday. As this storm
pulls east along the North Slope Tuesday and Wednesday a
reinforcing shot of cold air moves south and southeast into
northern Alaska.

Coastal hazard potential days 3 and 4...none.


Afg watches/warnings/advisories...
Blizzard Warning for akz203-akz204.

Winter Weather Advisory for akz201-akz202-akz205-akz206.

Heavy freezing spray warning for pkz210.

Gale Warning for pkz240-pkz245.

Small Craft Advisory for pkz210.

Brisk Wind Advisory for pkz230-pkz235.

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