Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
300 am akdt Wednesday Jul 30 2014
Models...good run to run continuity and initialization. All
showing similar solutions out through at 90 hours...they do
differ slightly in the handling of the low over the northeast
Arctic coast...but not significantly. Will use a blend of the
models through the short term forecast periods.
Aloft...at 500 hpa...538 dam closed low over Banks Island Canada
will drift east through the week. 555 dam closed low over the
southern Gulf of Alaska will drift southwest into the North
Pacific through the week. 587 dam high over the south central
Bering Sea will drift north through the week. Ridge axis lies from
200nm west of the pribilof island to over Norton Sound to just
west of Barrow this morning. Another branch lies from from Norton
Sound over the north slopes of the Alaska Range. As the system
rotates clockwise the branch near Barrow rotates to lies from
Nunivak Island to Anvik to Fairbanks tonight. The ridge continues
to rotate to lie from nunivak to Anchorage to Yakutat by Thursday
morning. A 554 dam low over the siberian coast will move to 76n
180 by Thursday morning with a trough extending south into the
Bering Strait...then continue to 75n 160w by Friday morning with
a trough extending into the central interior. At 850 hpa...models
continue to show temperatures rising 3 to 5 celsius over the next
couple days then begin to slowly fall by late Friday.
Surface...ridging continues over the interior will slowly give
way as surface trough develops over the western interior by
Thursday morning. As ridge axis moves south expect increased
cloudiness. As week progresses trough will slide east to the
central interior with increasing probability of precipitation
across the interior through the weekend. Trough starts out
oriented southwest to northeast and will gradually become more
west to east oriented by the weekend. Precipitation will move to
the Bering Strait tonight and extend from Nunivak Island to
Wainwright by Thursday morning...then continue east to be over
the central interior by Friday morning before becoming stationary
through the weekend.
Arctic coast...dense fog from Barrow east this morning will
dissipate by middle morning...however low ceilings may hang in most
of the day. High pressure remains over the northwest coast and
Brooks range keeping those areas partly cloudy. Area will remain
dry through later tonight before rain starts to move in from the
west. Rain will eventually spread over most of the Arctic zones by
late Thursday as weak surface low develops over the eastern Brooks
range. No significant winds but do expect them to increase to 10
to 20 miles per hour as the main front moves through the area.
West Coast and western interior...nice weather gives way to clouds
and rain that will move in from the west today and tonight. Rain
starts on St Lawrence Island later this morning or early this
afternoon spreads to the Bering Strait by late afternoon...then
into the western interior by late Thursday morning. Cooling
temperatures after today. No significant winds but do expect them
to pick up in the Bering Strait to 20 to 35 miles per hour tonight before
dropping off tomorrow.
Interior...nice today...then increasing clouds as the ridge axis
rotates south of the area. Cloudy conditions will be the rule as
we move into the weekend. Periods of rain beginning Friday and
lasting through the weekend. Rainfall amounts do not look to be
significant...but will be enough to keep things wet. Highs in the
70s for most areas today...then a slow cool down.
Coastal hazard potential days 3 and 4...none.
Fire weather...drier today...but conditions remain marginal in
many areas as far as burnable fuels are concerned.
Small Craft Advisory for pkz220.
Sdb Jul 14