Severe Thunderstorm Warning 11, NWS Fairbanks, AK

108 
WWAK59 PAFG 140423
SVSAFG

Severe Weather Statement
National Weather Service Fairbanks AK
822 PM AKDT Thu Jul 13 2017

AKZ223-224-140432-
/O.EXP.PAFG.SV.W.0011.000000T0000Z-170714T0430Z/
Upper Tanana Valley and the Fortymile Country-Deltana and Tanana
Flats-
822 PM AKDT Thu Jul 13 2017

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL UPPER TANANA
VALLEY AND THE FORTYMILE COUNTRY AND EAST CENTRAL DELTANA AND TANANA
FLATS WILL EXPIRE AT 830 PM AKDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.

LAT...LON 6442 14494 6417 14488 6402 14569 6419 14590
TIME...MOT...LOC 0422Z 180DEG 0KT 6422 14525 

$$
JK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
242 PM AKDT Thu Jul 13 2017

.DISCUSSION...

Models...Short term solutions in good agreement, but they start
showing differences in day 4 with the handling of the low that
will be moving north through the Bering Strait and over the
northwest coast. There are also some differences in the
positioning of the low that will be moving through the Bering Sea
next week. They did initialize well against the 13/18Z surface
analysis.

Aloft...At 500 HPA...Blocking ridge over the west coast with a
580 dam center over Point Hope this afternoon. The center will be
cutoff from the primary ridge and drift over the central Brooks
Range tonight as heights fall to 575 dam. A shortwave working over
the ridge this evening will swing southwest over the eastern
interior tonight. The center will slowly drift southeast over the
upper Yukon Flats by Saturday afternoon as heights fall to around
568 dam, then to the Copper River Basin by Sunday afternoon as
heights build to 570 dam. A 553 dam low 300 nm southwest of the
Queen Charlotte Island will loop around to the southeast, then
move northeast over the southern Queen Charlotte Islands as if
move inland. A 558 dam low 200 nm north of Adak will move
northeast to to St Matthew Island by Friday morning at 556 dam,
then north over St Lawrence Island by Saturday morning at 552 dam,
and into the Chukchi Sea Sunday morning as it weakens into a wave
and moves over the top of the ridge. Zonal flow will persist over
the Arctic through Saturday as a low north of the Canadian
Archipelago swings a shortwave rapidly east and southeast across
the area from Friday morning through Saturday afternoon. At 850
hpa...Temperatures 12 to 17 Celsius will persist through Saturday
before a cold front pushes east to the Western Interior by Sunday
morning, and the Central Interior Monday pushing temperatures down
to the 7 to 12 Celsius range.

Surface...1024 mb high north of MacKenzie Bay will continue to
slide southeast into Canada. A 996 mb low north of the Canadian
Archipelago will swing a weather front east and southeast across
the arctic tonight through Saturday morning with the front
stalling over the arctic coast. Over the mainland and interior a
thermal trough will persist with a broad area of weak low
pressure persisting. Thermal trough is reorienting and will lie
from the Upper Tanana Valley to Manley Hot Springs with a trough
extending north to the Brooks Range and another extending
southwest to the lower Yukon Delta. A weather front associated
with low pressure in the Bering Sea will move to the coast as it
weakens and eventually dissipate over the coast. The Front over
the Arctic coast will be pushed over the Brooks Range Saturday
night as a 1019 mb high moves to the central Arctic.

Arctic Coast and Brooks Range...Weak ridging over the Arctic coast
tonight will be slowly pushed south as a cold front moves to the
coast early Saturday morning. Expect increasing clouds tonight as
a weak warm front advances to the east. Increasing chance of
showers starting Friday night on the northwest coast and spreading
east Saturday. Some patchy fog, but not much tonight. Winds
5 to 15 mph for most areas. Slight chance of showers and
thunderstorms this evening over the central Brooks Range.

West Coast and Western Interior...High pressure over the coast
will be moving inland as weather front moves to the coast tonight.
Expect showers to develop over St Lawrence island this evening,
then over the lower Yukon Delta tomorrow and spreading north
through the day. Isolated thunderstorms the next couple days in
the Western Interior and Middle Yukon Valley. Light winds less
than 15 mph will swing from south to northeast as the ridge moves
inland. Temperatures slightly warmer.

Central and Eastern Interior...Very isolated thunderstorm and
shower activity across the interior the next couple days. Highest
concentration will be west of Fairbanks and east of Ruby extending
north to Central Brooks Range and south to the Alaska Range. Smoke
will persist over the interior until Saturday when winds turn from
the west and start scouring it out. Locally visibility may be
reduce to around 2 miles at times by the smoke. Temperatures
warmer, but not as warm as they could be because of the smoke.

&&

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

&&

.Fire Weather...No Red Flag conditions developing, though it will
be warm and dry with isolated thunderstorm activity through the
weekend.

&&

.Hydrology...No concerns at this time. Rivers are relatively
steady or trending down.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

None.

&&

SDB JUL 17