Uitleg wetenschappelijke weersvoorspelling
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
317 am akst Friday Jan 30 2015
Models...good initialization of the 00z model run. There continues
to be good agreement on the major features in the forecast area in
the short term with only minor departures as we get into the
midrange. Models all agree on the temperature warming trend for
the next 24 hours so will use a blend and nudge the current short
term forecasts. Will use a blend of the models...leaning on the
NAM and sref for precipitation.
Aloft...at 500 hpa...ridge building northeast across the state
from a 561 dam center over the Bering Sea will flatten out with
zonal flow across the top of the ridge. The fast flow will allow a
499 dam low to zip east over the Arctic with the associated
shortwave moving over Banks Island Saturday morning. The high
center will move from the central Bering Sea over Norton Sound by
Saturday morning...then the upper Kuskokwim valley at 555 dam by
Sunday morning...and over Cook Inlet by Monday morning at 548 dam.
A shortwave will develop on the back side of the ridge and move to
the Bering Strait early Monday morning. At 850 hpa...temperatures
currently 8 to 18 below celsius below will continue on the rise
and be in the zero to 16 below celsius range by Saturday morning
with the coldest temperatures north of the Brooks range.
Surface...1045mb high has settled in over the upper Yukon Flats
with a 1040mb high over the eastern Bering Sea. A 997mb low 250nm
northwest of wrangel island will move northeast to be near 77n
150w by Saturday morning. A warm front extending southwest from
the low is on the northwest coast this morning and will move east
through the day reaching the Barrow area late this morning...the
Prudhoe Bay area by late this afternoon...and exiting the state
overnight. A cold front will drag in behind the low and hang up
in the Brooks range. A strong pressure gradient with the warm
front is currently bringing 30 to 50 miles per hour winds to the northwest
coast...winds are expected to be weaker as the front moves
east...but still be in the 20 to 35 miles per hour range. The strongest
winds associated with the front will be tapering down Friday
Arctic coast and Brooks range...blizzard conditions on the
northwest coast this morning will taper off as the front pushes
to the east. Expect some blowing snow issues to the east so the
winter weather advisories posted look good. Winds come up sharply
in zone 204 later tonight so will issue Winter Weather Advisory
for tonight through Saturday for that area. Snow amounts will be
light...northwest facing upslope areas of the eastern Brooks range
will see snowfall amounts of 3 to 5 inches with snow tapering off
Saturday afternoon. Temperatures will continue to rise along the
Arctic coast into Saturday before beginning a slow cooling trend.
West Coast and western interior...from Kivalina north and through
the Bering Strait winds will continue to be quite strong today
with gusts around 55 miles per hour. Winds tapering down later this evening
and conditions improving. Snow on the south slopes of the Brooks
range in the upslope areas today into middle day Saturday will taper
off Saturday night expect 2 to 6 inches of snow in zone 208 and 2
to 4 inches in zone 217. There will also be a few flurries in the
Bering Strait. Warming temperatures and mostly clear skies from
the Seward Peninsula south through the weekend.
Central and eastern interior...snow south of Chicken in the upper
Tanana Valley and eastern Alaska Range will taper off by early
afternoon. Mostly clear conditions will persist over much of the
area through the weekend. Cold will hang on through today then
warming temperatures through the weekend. Light winds.
4 to 7 day extended...continued warmer through Tuesday...then
another cold spell on the way for Wednesday and beyond. Models
have changed things up a bit and it is looking more like the cold
will hang on into next weekend.
Satellite...a lot of high clouds accompanying the weather systems
in the area so the GOES MVFR/IFR/LIFR probability products at
30/1000z and modis 24 hour microphysics at 30/0950z not much
help...but some of the stratus in the upper Tanana Valley can be
seen as far west as the DOT Lake area using the products in
Blizzard Warning for akz201-akz205.
Winter Weather Advisory for akz202-akz203-akz204-akz206-akz207-
Gale Warning for pkz225-pkz230.
Brisk Wind Advisory for pkz220-pkz235-pkz240-pkz245.
Sdb Jan 15