Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
101 am akst Friday Dec 13 2013
very windy conditions are continuing over much of the interior
south of the Brooks range. Current GFS/NAM runs indicating a
gradual decrease in wind speeds aloft along with a relaxation of
the sea level pressure gradient later this morning. Current
advisories in zones 216-219-220-221-222 are scheduled to expire at
6 am this morning. Will wait until just before forecast issue time
to decide whether or not to extend the advisories for a few
additional hours. Temperatures at higher elevation sites in zone
222 have cooled off a few degrees...some sites continue to report
wind gusts over 30 miles per hour and wind chill near -30f.
Elongated upper low extends from southwest Alaska northeastward
across the interior with the main center over the lower Kuskokwim
valley. By Sat afternoon the main low center will move to just
east or northeast of Kodiak Island with the upper trough axis
extending northward to the Prudhoe Bay area. The trough will
open up some as it moves to the eastern interior by Sun afternoon
with low center moving to near or southeast of Prince William
Sound. A moderately cold air mass will remain over much of
northern Alaska through the weekend...850 mb temperatures near
or below -20c.
975 mb low near 52n/153w in the Gulf of Alaska is prognosticated to
deepen to around 970 mb over the northern Gulf of Alaska by this
afternoon...filling to near 980 mb over the Kenai Peninsula by Sat
afternoon. This low will pump moisture across the Alaska Range and
into the eastern interior. Snow is expected to begin over the
southeastern Alaska Range late this afternoon or this evening...
spreading northward and westward across the central and eastern
interior through Sat afternoon and continuing through Sat night...
and continuing over the Alaska Range and southeast interior into
Extended forecasts indicate a quiet weather pattern over the forecast
area Monday through Wednesday...increasing winds and a chance of snow
over the northern Bering Sea...southern West Coast areas and
southwest interior Thursday as a weather front pushes northward.
GFS/European model (ecmwf) 1000-850 mb mean temperatures prognosticated to climb to
near or a little above 0c in zone 214 Thursday night and Friday...indicating
a possibility of rain or mixed rain/snow.
Coastal hazard potential days 3 and 4...none
Winter Weather Advisory...akz219-akz220-akz221-akz222.
Heavy freezing spray warning...pkz210-pkz220-pkz225.
Brisk Wind Advisory...pkz200.
Small Craft Advisory...pkz220-pkz225.
Rf Dec 13