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Northern Alaska forecast discussion...updated 
National Weather Service Fairbanks Alaska
204 PM akdt Thursday Jul 31 2014

Synopsis...
aloft...
a strong high over the Bering Sea will persist through the weekend
then slowly weaken. A low aloft north of wrangel island will move
to north of Barrow by 4pm Friday...to Barter Island by 4am Sat and to
inuvik by 4pm Sat. This will keep conditions wet through the
weekend. Weak ridging will develop over the southern interior Monday
and then move north to the North Slope Tuesday. This will make
conditions drier and warmer next week with convective showers as
the ridge builds.

A weak short wave trough from Arctic Village to Denali will move
east of the alcan border tonight. There are isolated showers with
this trough.

A second short wave trough Barrow to McGrath will move to Barter
Island to Denali by 4am Friday...then to Eagle to Denali by 4pm Friday.
Expect scattered showers with this to become more widespread
tonight

850 mb temperatures range from 6c to 12c now through tonight. A
cold front will bring much colder temperatures to the Arctic
slope from Friday through Sat.

Surface...
a 1022 mb high over the Beaufort Sea will weaken through Friday.
A 999 mb low north of wrangel island will move to 300 nm northwest
of Barrow as a 1009 mb low...to 200 nm northeast of Barrow by 4pm
Friday...to 200 nm north of Barter Island by 4am Sat...and then
continue rapidly east. An associated warm front stretching from
the low south to Barrow to the Yukon Delta will move to Prudhoe
Bay to McGrath by 4am Friday...and to Barter Island to Eagle to
McGrath by 4pm Friday...then become stationary. The front will weaken
Sunday and evolve in to a thermal trough.

A cold front trailing the low will move to the western Arctic
coast by 4am Friday...then to Barter Island to Point Lay by 4pm
Friday...then to Arctic Village to Anaktuvuk Pass to Point Lay by 4am
Sat then stationary and weakening. Will see more rain with this
front. Will also see west winds 20 miles per hour along the front turning
northwest north of the front. Should see drying behind the front.

Expect light rain with the front tonight becoming heavier Friday as
west flow increases and increases upslope over the eastern North
Slope and southern interior. Rain will continue among the front
into Sat then become more scattered showers. Expect .50 to 1.50
inches of rain with the front Friday through Sat...heaviest on the
north side of Brooks range and Alaska Range.

High pressure will build over the Chukchi Sea Sat and persist into
sun.

The thermal trough developing from Anvik to Tanana to Eagle on sun
will allow scattered convective showers and possibly some
thunderstorms from sun into next week over the interior.

&&

Discussion...
models initialize well and similar solutions into the weekend.
Slight difference next week but models similar with the broad
scale pattern.

Coastal hazard potential days 3 and 4...none

&&

Fire weather...
relative humidity above 30% today. Friday and Sat will have relative humidity mostly above 40%.

&&

Hydrology...
expect .50 to 1.50 inches of rain across the southern interior and
eastern North Slope Friday through Sat...heaviest on the north side
of Brooks range and Alaska Range. Duration is long enough that no
flooding is expected but it will raise rivers north sides of
Brooks and Alaska ranges.

&&&

Afg watches/warnings/advisories...
none.
&&

$$

Jul 14

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