Scientific Forecaster Discussion
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Northern Alaska forecast discussion...corrected
National Weather Service Fairbanks Alaska
240 PM akdt Thu Jun 22 2017
Discussion...high pressure aloft centered over the alcan border
will drift east into the Yukon territory on Friday leaving weak
ridging draped across the southern interior. An upper level low
will move into the Gulf of Alaska on Friday and then into
Southeast Alaska on Sunday before exiting into British Columbia. This system
will spin additional moisture into the southeast interior the
next several days. To the north, a short wave trough over the
Bering Strait will move northeast to Barrow on Friday and then
continue northeast across the Beaufort Sea on Saturday. On
Monday, a long wave upper level trough will develop from the
chukchi to Bering Sea as a large ridge of high pressure builds
over the eastern half of the the state. This pattern will persist
into next week.
Models are in good agreement through the weekend. Some
differences showing up early next week but the general pattern is
for warm and drier conditions over eastern Alaska and cloudy and
wetter over the western half of the state.
At the surface, a weak thermal trough from Arctic Village to
Whitehorse will shift to the eastern Brooks range and along the
alcan border Friday and Saturday. A second thermal trough
extending southwest from Arctic Village to McGrath will be
replaced by surface high pressure on Saturday. Afternoon showers
will develop in these areas with the greatest instability and
isolated thunderstorms along the alcan border today and covering a
broader area across the southeast interior on Friday.
A 1005 mb surface low near wrangel island will continue to move
east across the Beaufort Sea into Saturday. This will bring a
period of strong southwest flow to the Northwest Arctic coast
Friday and Saturday. Small craft advisories and gales will occur
over northern Bering and Chukchi Sea marine waters. In addition,
heavy surf if possible along the Chukchi Sea coast from pt. Hope
to Wainwright Friday night and Saturday.
Coastal hazard potential days 3 and 4...none.
Fire weather...relative humidity value are expected to remain
above 25 percent in the central and eastern interior, except for
the Yukon Flats to the northeast Brooks range where they will dip
into the low 20s. In the western interior and West Coast values
will generally be in the 30s and 40s. A weak pressure gradient
over the interior through Saturday will keep sustained winds below
red flag criteria across the forecast area.
Small Craft Advisory for pkz210-pkz220-pkz225-pkz230.
Gale Warning for pkz230.
Brisk Wind Advisory for pkz235.