Area Forecast Discussion
Issued by NWS Fairbanks, AK
FXAK69 PAFG 022302
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
202 PM AKST Fri Dec 2 2016
The 12z model suite initialized well against the 12z analysis
and verified reasonably well against the 18z analysis which is a
marked contrast to how previous model runs initializated. Model
spread continues to be minimal through the weekend but increases
considerably by the middle of next week.
Aloft, at 500 hpa a 476 DAM low near 85N and 170W with a long wave
trough extending southward to Utqiagvik and southward from there
to Galena and then soutwestward to Bristol Bay will slowly nudge
to the east to be along a Prudhoe Bay to Bettles to McGrath line
Saturday and along a Demarcation Point to Fairbanks line Sunday. A
high amplitude ridge continues to build in the Bering Sea while a
secondary upper level low develops along the southern end of the
long wave trough over the northern Gulf of Alaska saturday night.
This upper level low will move southeast to be over the panhandle
Sunday and over British Columbia Monday while the high amplitude
upper level ridge previousy over the central Bering Sea moves east
to be over the west coast of Alaska Monday.
On the surface a 977 mb low in the northeast Gulf of Alaska will
continue to move inland near Yakutat this evening. A lee side low
over the southern Yukon develops out of the sharp lee side trough
currently over the southwest Yukon. Moisture moving to the west
around the trough and low continues to overrun a cold and deep
airmass over the central and eastern interior and continues to
generate snow over much of the central and eastern interior to the
east of Manley Hot Springs. 4 to 6 inches of snow have fallen over
these areas since Thursday. Another shortwave moves over the same
areas tonight and tomorrow and will deposit an additional 2 to 4
inches. Winter weather adivisories remain in effect in these areas
through mid day tomorrow.
Temperatures have modified considerably over the central and
eastern interior from earlier this week with clouds and snow but
remain cold in the western interior where temperatures again
dropped into the 30s and 40s below. Expect the cold temperatures
to return to the central interior Sunday and eastern interior
Monday as clouds and snow move north and east and skies scatter
out. 30s and 40s below still on track for these areas begining
late Sunday or Monday depending on how quickly the clouds depart.
Model guidance continues to present a split decision on how long
the cold temperatures will remain over the central and eastern
interrior with the ECMWF bringing in warmer temperatures by mid
week and the Canadian, and GFS models keeping the cold temperatures
in play for the central and eastern interior through the end of
next week. This is however a flip flop from previous model runs
so forecast confidence remains low beyond the middle of next week.
By Sunday night as a 1050 MB or stronger high pressure system
builds over the Yukon, altimeter settings could rise to above
31.00 inches to the east of Fairbanks and continue into Tuesday.
This may present problems for aircraft with altimeters limited to
Surface pressures are forecast to exceed 1050
Coastal Hazard Potential Days 3 and 4...None.
Winter Weather Advisory for AKZ220-AKZ221-AKZ222-AKZ223-AKZ224-
Heavy Freezing Spray Warning for PKZ210-PKZ220-PKZ225-PKZ230.
CCC DEC 16