Area Forecast Discussion
Issued by NWS Anchorage, AK

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000
FXAK68 PAFC 020015
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
415 PM AKDT Sat Oct 1 2022

.ANALYSIS AND UPPER LEVELS...

A broad upper level low situated over the central Bering continues
to gradually dissipate and track into the southeastern Bering.
The associated leading front is spreading inland over Southwest
Alaska bringing abundant cloud cover from the Kuskokwim Delta to
the Alaska Peninsula and Kodiak Island. A triple point low is just
taking shape over Kodiak Island this afternoon.

Meanwhile, a departing upper level trough over the Copper River
Basin has kept a few scattered showers in place this morning,
however conditions have improved. Low level stratus that
blanketed much of Southcentral this morning has lifted, revealing
mostly clear skies over the Kenai Peninsula, Susitna Valley, and
Copper River Basin.

&&

.MODEL DISCUSSION...

Model solutions are in good agreement through the short term.
There is consistency with the progression of the Bering low
(remnants of Kulap) tracking southeastward and gradually weakening
through the next 24 hours. By Sunday afternoon, models show a 996
mb low tracking inland over the Alaska Peninsula and dissipating.
On the heels of this low is another low taking shape over the
western Bering Sunday night. Models have been generally consistent
in showing this low tracking southward over the central Aleutians
and eventually crossing into the North Pacific by early Tuesday.
While the overall track has been consistent, the timing has not
been in agreement. Currently the NAM seems to be the fastest
solution while the GFS/EC/Canadian all show a slower solution.
Will continue to monitor these details with future model runs.

&&

.AVIATION...
PANC...VFR conditions expected through this afternoon. A brief
period of southerly winds to around 10 knots may develop this
afternoon as low pressure over the eastern Copper River Basin
begins to amplify before shifting into Yukon. Conditions may
lower to MVFR after midnight as rain moves in from the south
leading to predominantly MVFR conditions for Sunday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Tonight through Tuesday)...

A trough located over the Bering Sea has reached Kodiak island and the
western Gulf and is now quickly lifting northward to Southcentral
through tonight. A weak triple point low and frontal system will
accompany the aforementioned trough and will push onshore along
the north Gulf coast tonight. As a result, precipitation will be
brought into Southcentral and will continue through Sunday night
as a series of shortwaves traverse through the area behind the
aforementioned frontal passage. As a new Bering low digs into the
North Pacific, the upper-level flow will amplify and will cause
ridging downstream from the Gulf up to Southcentral. This will
result in bringing an end to most of the rainfall over the region.
However, as the trough continues to dig under the aforementioned
ridge, moderate rainfall will track back into Kodiak and the
coastal areas for Tuesday. With the upper-level low weakening in
the Pacific, inland areas could see a longer stretch of dry
weather through the end of the week. Daytime high temperatures
will trend upwards from the low 50s to the mid to upper 50s in
some coastal locations due southerly flow over the region through
the forecast period with night time lows reaching high 30s to low
40s in correspondence to cloud cover likely staying over much of
the domain.


&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...

The King Salmon radar has been active this afternoon as a band of
precipitation from former Typhoon Kulap pushes across the area
bringing .10-.30 inch of new rain to the region.  The
extratropical remnants of Kulap are moving slowly and will
continue to push across the Bering Sea this evening. The surface
low is decaying and filling millibar by millibar. The pressure
gradient field encompasses the much of the Bering Sea with an
estimated surface low of 978 mb. Other impacts include gusty
winds and rain. The potential for coastal erosion is also being
monitored. The surface low will be in Bristol Bay later Sunday.
In the wake of Kulap`s remnant low, expect another storm to push
across the Aleutians. This second low will eventually absorb the
remnants of Kulap on Monday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...

The extratropical remnants of former Typhoon Kulap continue to
push across the Bering Sea this evening. The surface low is
slowly decaying and filling millibar by millibar. The pressure
gradient field encompasses the much of the Bering Sea with an
estimated surface low of 978 mb. Enhanced seas with waves ranging
from 20 to 25 feet will continue tonight and Sunday. Other impacts
include wide spread gusty winds and rain. The potential for
coastal erosion is being monitored. the surface low will be in
Bristol Bay later Sunday. In the wake of Kulap`s remnant low,
expect another storm to push across the Aleutians. This second low
will eventually absorb the remnants of Kulap on Monday. Expect a
wet pattern.


&&

.LONG TERM FORECAST (Days 4 through 7: Wednesday through Saturday)...

The synoptic setup to start off the period begins with an upper
level ridge extending northward from the North Pacific through the
Bering into Southwest Alaska while a strong upper level low moves
northeastward through Siberia. Another upper level ridge is
expected to be present over western North America with the axis of
this ridge bending over much of the Alaska Mainland meeting up
with the aforementioned ridge over Southwest Alaska. Underneath
these upper level ridges just south of the Gulf of Alaska is an
upper level low. Model guidance generally agrees on the movement
of these features for Wednesday and Thursday before beginning to
slightly diverge on Friday with basically very little agreement by
next Saturday.

For the Wednesday and Thursday timeframe, there remains
variability in the exact strength the upper level ridges will be.
There is the potential that much of southern Alaska could endure
two fairly nice fall days with sunshine and mild temperatures for
Wednesday and Thursday with any potential rain remaining to
immediate coastal locations and Kodiak Island. A frontal system
moving west across the northern Bering isn`t expected to move into
Southwest until Thursday night/Friday at this time, though, this
is moderate confidence as one solution moves in this front much
faster bringing unsettled conditions into Southwest during the day
Thursday. In the Bering, expecting small craft winds with the
potential for gales especially in the northwestern Bering
Wednesday. Moderate confidence for the first two days of the
period.

Beyond Thursday night, the forecast gets very fuzzy as each model
is moving along features at varying speeds and strengths. The main
takeaway for Friday and Saturday is expect for an unsettled regime
to return to much of southern Alaska.

&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 165 170 173 174 176 177 178.
 Storm 175.
FIRE WEATHER...NONE.

&&
$$

SYNOPSIS AND MODEL DISCUSSION...KO
SOUTHCENTRAL ALASKA...NS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PJS
LONG TERM...MV


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