Scientific Forecaster Discussion
fxak69 pafg 231236
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
336 am akst Thu Nov 23 2017
models...agreement continues to improve in the short term out to
48 hours or so with the latest solutions. Still quite a bit of
disagreement on what will happen over the Arctic beyond 48 hours.
Will lean on or nudge to an equal blend for the short term. The
23/00z solutions did initialize well against the 23/06z surface
analysis for positions and central pressures.
Aloft...at 500 hpa...a 503 dam low 150 nm north of Point Lay will
move southeast over the Arctic plains and merge with a 502 dam low
over the eastern Brooks range, then moves south over Nenana by
Friday morning with a trough extending northeast over Old Crow yt.
The low continues to move south and merges with a low over the
Gulf of Alaska. A 512 dam low will develop over Demarcation Point
Friday afternoon. A ridge axis lies from Shemya to Huslia this
morning and will move southeast into the North Pacific this
evening. A Second Ridge axis will lie over the western Bering Sea
by late this evening and move east to be over the dateline by
Friday morning extending from the North Pacific to the Gulf of
Anadyr, then northwest. The axis moves east to lie over 170w by
late Friday evening extending north over the Chukchi Sea, then
northwest over wrangel island. The axis will lie from Cold Bay to
Point Hope and northwest by Saturday morning, and by Saturday
afternoon the ridge starts breaking down, and pulling south, and
the low over Demarcation Point moves over Bettles at 517 dam. A
fast moving shortwave will move across the Bering Sea to lie from
the Gulf of Anadyr to Cape Romanzof Saturday afternoon, then
northeast into the central Chukchi Sea. At 850 hpa...temperatures
over the forecast area -12c to -22c.
Surface...983 mb low lingering near the Northwest Arctic coast
will continue to weaken, moving over the Arctic plain south of
Point Barrow this evening, and south of deadhorse by Friday
morning at 1005 mb. It will move east and weak through Friday,
then merge will a trough that extends west out of the Canadian
archipelago. The low that moved over the southwest Mainland coast
is now over Bristol Bay and will move southeast across the Alaska
Peninsula and merge with a 972 mb low over the southern Gulf of
Alaska. Weak high pressure extends east from the chukotsk
peninsula to the central Yukon territory near Mayo yt. Ridging
will continue to strengthen across the area with a 1011 mb center
developing over Lake Minchumina late this evening. As the ridge
build overnight a 1016 mb center will develop near Eagle, a 1014
mb center near Bettles, and a 1024 mb center will move to the
Bering Strait by Friday afternoon as high pressure extends from
the North Pacific to high in the central Arctic. The ridging will
rotate east over the central interior and central Arctic coast by
Saturday morning. As the ridge moves east a weather front will
move to the eastern Bering Sea, Bering Strait, and Chukchi Sea
Arctic coast and Brooks range...low remains in the area, with
trough extending east, so cloudy conditions will prevail with
some light snow or flurries through the day. As the low moves
southeast, then east some enhanced snow on the north side of the
Brooks range with the upslope component. Storm total amounts will
be less than 6 inches as the low moves east. Winds over the Brooks
range will generally be from the southwest at 10 to 20 mph, while
over the coastal areas the winds will be northeast to east at 10
to 20 mph. Temperatures will be falling as the low moves east.
West Coast and western interior...going to be quiet today. Some
clouds, some light snow moving through the area, but nothing like
the last couple weeks. Winds along the coast will swing around to
northwest if they have not already at 10 to 25 mph. Inland winds
generally light and variable. Snowfall amounts will be up to 3
inches. Temperatures will be cooling slowly.
Central and eastern interior...the ridge over the area is pretty
dirty, so clouds will linger around the area with flurries.
Snowfall will generally be less than an inch, with up to 3 inches
in the Alaska Range. A shortwave moving down the back side of the
ridge will spread some light snow to the area tonight, but amounts
will generally be around 1 inch. Temperatures will slowly cool,
areas that do see some clearing will see temperatures drop pretty
dramatically, then warm when clouds return. Winds will generally
be light and variable.
Coastal hazard potential days 3 and 4...none.
Extended forecast days 4 to 7...while model guidance has been
relatively poor, and there is not much agreement, none of the
models are showing any significant weather systems moving to the
area next week. They do agree however that we will see cooler
temperatures through at least Wednesday.
Heavy freezing spray warning for pkz200-pkz220-pkz225-pkz230-
Gale Warning for pkz210-pkz230.
Small Craft Advisory for pkz200-pkz220-pkz225.