Area Forecast Discussion
Issued by NWS Anchorage, AK

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000
FXAK68 PAFC 110025
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
425 PM AKDT Sun Jun 10 2018

.ANALYSIS AND UPPER LEVELS...
Scattered showers remain over Southcentral and the Copper River
Basin as an upper level trough moves over the region. Gusty
conditions have been seen throughout Prince William Sound
associated with the weak shortwave. IR satellite shows the Arctic
trough starting to drop down further south from the North Slope
increasing cloud cover and northerly flow. Showers and warmer
temperatures remain ahead of the trough for central and eastern
Southcentral, but will result in drier, cooler conditions behind
this trough.

As for out west, high pressure builds over the Bering with
stratus and some fog for the area. Northerly offshore flow over
the mainland is bringing stable conditions. Yesterday`s low that
brought rain to the central and eastern Aleutians is staying south
of the Chain resulting in dry conditions for the Aleutians today.

&&

.MODEL DISCUSSION...
Models are in good consensus with timing and placement of the
Arctic trough as it moves south. The NAM`s previous run was an
outlier, but the most recent run now seems to match up with other
models.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist. Some MVFR
conditions are possible later Monday morning, especially if the
rainfall tonight is fairly significant.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The strong upper level trough that has been pushing through
central Alaska will continue its southerly track across
Southcentral Alaska through the night bringing cooler air with it.
This trough will also bring widespread rain to areas around
Anchorage and the Talkeetna Mountains east through the Copper
River Basin. The heaviest rain will diminish through Monday but
some showers will linger through Tuesday, primarily over higher
elevations.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...

A shift in the weather pattern is underway as a potent and highly
anomalous upper level trough plows south through the Alaska Range.
This will increase northerly winds through late this evening and
then again on Monday. This will allow for clearing skies and dry
weather to continue into the middle of next week. The trough will
eventually weaken and move southeast Tuesday so winds should
diminish from their peak values Monday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

The Bering Sea will continue to remain under the influence of high
pressure with a low pressure to the south over the North Pacific.
This will continue to promote a general east to northeast flow and
areas of sea stratus and some fog. The eastern Bering Sea may
actually clear out some with that clearing making it to the
Pribilof Islands sometime Tuesday as strong offshore flow moves
over the region in response to a digging Arctic trough over the
mainland. Otherwise, the weather will be seasonably normal with
winds less than 30 knots through the middle of the coming week.

&&

.LONG TERM FORECAST (Days 3 through 7)...
By Wednesday, much of southern Alaska will be located in a col
between a large upper level low centered over the Arctic Ocean,
another big upper low well south of the Aleutians and weaker
ridging to the east and west. A trough stretching from the
northern to southeastern Gulf will weaken rapidly and dissipate as
a low to the south swings east and inland into British Columbia.
The Arctic low will dig south into northwestern Alaska Thursday
and Friday, while the North Pacific low lifts up towards the
eastern Aleutians and Alaska Peninsula. In comparison to
yesterday, all the models have shifted further west with the track
of this southern low with the GFS remaining the furthest east
solution. Currently there is a roughly 500 mile surface low
position difference by Saturday morning, but all models are still
in good agreement with regards to a significant pattern shift to
wetter, southerly flow for Friday through Sunday and likely
continuing into next week.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...AH/BL
SOUTHCENTRAL ALASKA...DK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...JR



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