Area Forecast Discussion
Issued by NWS Fairbanks, AK

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FXAK69 PAFG 172300

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
300 PM AKDT Thu Aug 17 2017

.DISCUSSION...The 17/12Z 500 mb pattern showed long wave troughing
centered over mainland Alaska, consisting mainly of a 531 dm low
located around 150 miles north of Point Hope. Several short waves
are embedded within this trough, the most prominent rounding the
south side of the trough running through the Gulf of Alaska. A
second low/short wave with a 541 dm low center was located over
the far northeast corner of the NW Territories near the Arctic
Coast. A third, weaker one was observed crossing the Alaska Range
into the southeast Interior. At the surface, the main weather
pattern was dominated by broad low pressure centered over mainland
Alaska, with several embedded weaker lows across the state.

The 12Z deterministic models are in good agreement on the overall
pattern through this weekend, but rapidly begin to diverge by next
Monday on the position timing of the upper air features. However,
the guidance does continue to suggest long wave troughing to
persist across the state into next week. The short wave over the
Gulf of Alaska will swing northeastward today, to move into
British Colombia by late tonight. The upper low north of Point
Hope will swing southward through this weekend, to be located over
the AK Peninsula by Sunday evening. The upper low over the
Northwest Territories will move northwest through the Beaufort
Sea, to merge with another shortwave moving east through the
Siberian Arctic by Saturday.

Periods of rain are expected to affect the west Coast Friday into
this weekend as upper low moves south over the coast toward the AK
Peninsula. Snow levels are expected to fall to around 1500 feet
over northwest Alaska and the Seward Peninsula tonight, to persist
through this weekend. Scattered to numerous showers are expected
for Interior Alaska for the next several days, which will be
diurnally enhanced. Isolated thunderstorms will be possible for
the east Interior through Saturday. Weak short wave over the
Interior, which is bringing a round of rainfall to the White
Mountains early this afternoon will lift north to spread rainfall
over the Brooks Range tonight. For the North Slope, periods of
fog, drizzle and stratus will persist there through Saturday
night due to weak onshore flow, before winds turn offshore from
west to east across the Arctic Coast on Sunday in response a
frontal system crossing the Chukchi Sea, which will bring the next
organized chance of rain Sunday night into Monday.

Coastal Hazard Potential Days 3 and 4...None.


.FIRE WEATHER...No issues under cool, wet weather regime.


.HYDROLOGY...Recent cooler temperatures aloft in the eastern
Alaska Range and Wrangels has significantly slowed down glacial
runoff into the Tanana River. The Tanana River near Tok and Tetlin
has dropped considerably during the past 24 hours and overland
flow causing flooding near the Tetlin Village Road and high water
along the Alaska Hwy should begin to recede some during the next
few days.


The Flood Advisory for zone 224 in the Tetlin Village Road areas
through Friday.



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