Area Forecast Discussion
Issued by NWS Anchorage, AK

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000
FXAK68 PAFC 130103
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
503 PM AKDT Wed Jun 12 2019

.ANALYSIS AND UPPER LEVELS...
Extensive cloud cover and some light rain left over from last
nights convection has slowed the development of convection this
afternoon. As of early afternoon, thunderstorms were firing along
the thermal trough north of the Alaska Range. Conditions however
are becoming more unstable across Southcentral as clouds were
clearing and allowing surface heating. Low clouds and some fog
are evident across the western Gulf/Kodiak Island with weak
northeasterly flow. A weak trough with showers is drifting west
across the western Bristol Bay and southwest corner of the
Kuskokwim Valley zone. Abundant sunshine across the Southwest
interior are allowing showers and thunderstorms to rapidly
develop, especially across the Kuskokwim Valley. Broad cyclonic
flow across the Bering Sea/Aleutians continue generally cloudy
conditions with areas of light rain/drizzle with a little fog.

&&

.MODEL DISCUSSION...
Models are in generally good agreement through the short term.
Forecast confidence is high. Favored guidance were the hi-res
models and the new FV3-GFS model.

&&

.AVIATION...
PANC...Generally VFR conditions conditions are expected through
Thursday afternoon. Gusty southeast which develop late this
afternoon/evening will slowly diminish overnight and should become
light by the mid-morning hours on Thursday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through
3/Wednesday night through Saturday)...

Low pressure continues to spin in the Gulf of Alaska, however it
has weakened to the point where it is only producing isolated
showers. Convection is firing as expected, mainly over the
Talkeetnas and norther Copper River Basin. Over the next day, the
low will continue to weaken and high pressure aloft will move in,
which will quiet weather in general. The high aloft will also cap
convection, reducing thunderstorm activity for southcentral AK.

Friday into Saturday another round of low pressure is expected to
move into the Gulf of Alaska from the southwest. Right now it
looks pretty similar to the low that has just moved in, meaning
just some showery activity to start the weekend. Overall, confidence
is high in the forecast that we will have generally quiet weather
in the short term.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA...
The unchanging pattern of afternoon showers and thunderstorms
across the region will finally start to wane in the coming days.
High pressure will begin to nose in from the southeast, keeping
the area warmer and drier. The main axis of instability and
thermal trough will shift north over the coming days, but ridging
will help to keep any significant chances for showers and
thunderstorms at bay. By Saturday a front will move in from the
north Pacific and across the AKPEN. Showers from this front will
mainly impact the southern aspect of the Alaska Range. Areas in
Bristol Bay through the Kusko Delta should stay downsloped and
dry, but the occasional shower making it over the range cannot be
ruled out. Increased cloud cover from the approaching front will
keep daytime temperatures into the upper 60s as we work into the
weekend.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS...
Low pressure south of the central Aleutians will dominate the
weather picture into the weekend. Easterly winds with scattered
showers will dominate the Bering Sea, while steady rains will
accompany low pressure lifting out of the Pacific. By the weekend,
the low will slide east leaving most areas along the chain dry,
but summertime stratus will continue as winds turn northerly.

&&

.MARINE (Days 3 through 5)...

On Friday...a surface low slowly tracks eastward just south of the
Alaska Peninsula and then becomes stationary on Saturday. Another
surface low quickly develops across the North Pacific on Saturday
night and take a northward track to the Gulf. This second low will
be the system to watch for gale strength winds as it takes a track
somewhere between the AKPEN and Kodiak Island. The model guidance
are not in good agreement on the track or strength of this system
which could bring gusty winds as far west as the Alaska Peninsula
and across much of the Gulf. For now a more conservative approach
was taken with this forecast.

&&

.LONG TERM FORECAST (Days 3 through 7)...

The long range forecast starting on Sunday continues to advertise
higher rain chances across the Gulf as an upper low pressure
system continues to spin near the western gulf. A few showers are
expected to push inland across the southern mainland with upper
level shortwaves rotating around the parent low. To the west...a
ridge builds across the Bering bringing low clouds and fog for the
start of the new week. A front moves toward the western Aleutian
Chain Tuesday into Wednesday, but there is still a bit of
uncertainty on how quickly the Bering ridge breaks down. Overall,
there is high uncertainty between the operational models and the
ensembles next Monday through Wednesday. The forecast was updated
toward the new blends which keeps a clouds and scattered showers
across the southern mainland and surrounding waters.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...RMC
SOUTHCENTRAL ALASKA...BB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SS
MARINE/LONG TERM...KH


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