Area Forecast Discussion
Issued by NWS Anchorage, AK
FXAK68 PAFC 230007
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
407 PM AKDT Sat Apr 22 2017
.ANALYSIS AND UPPER LEVELS...
A highly amplified ridge stretches across much of mainland alaska
southeastward towards the Pacific Northwest. This stubborn ridge
continues to spread a swatch of sunny skies and relatively warm
temperatures across eastern and southcentral portions of Alaska.
South of the Southcentral mainland, conditions are quite
different. Just to the south of this ridge a potent trough
stretches across the Alaska Peninsula and digs southeastward into
the north pacific. An associated surface front is supporting
gusty winds and steady rains across much of Kodiak Island, the
Alaska Peninsula, and Bristol Bay.
Meanwhile, a low spinning south of the Central Aleutian Islands
is supporting gale force winds across the western Bering and
western Aleutian Islands. Its associated front stretches across
the western and central Bering and into the north Pacific, and is
bringing rain to the eastern Aleutian Islands.
Models are in generally good agreement over the short term, as the
front across Kodiak and the Alaska Peninsula slowly weakens but
drifts northward towards the Kenai Peninsula by Sunday. The GFS
model was favored for the Bering Sea and Bristol Bay as the low south
of the Aleutians continues to push eastward over the next few
days. For Southcentral, the NAM was favored to capture local winds
as the front drifts northward.
PANC...VFR conditions and light winds will persist.
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Dry conditions will continue through much of Southcentral Alaska
through Sunday but then the area will see a brief reprieve on
Monday as a wave from the south pushes some moisture into the
area. Most of the rain will stay along the north Gulf coast due to
the flow being east to southeast during this time. However, some
light showers may sneak through the coastal ranges.
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Moist southeast flow on the periphery of the large Bering Sea
trough will keep the southwest mainland in a cloudy and showery
regime through the start of the work week. The most widespread
shower activity will favor upslope areas along the Kilbuck
mountains, while the persistent southeast flow will tend to keep
locations along the western side of the Aleutian and Alaska Ranges
mostly dry due to downsloping. Temperatures will generally
continue to run above seasonal normal values, but will also be
moderated somewhat by the extensive cloud cover over the region.
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Broad cyclonic flow will yield widespread showers across the
Bering Sea through Monday as the sprawling trough and attendant
surface low near the western Aleutians shift eastward, then
gradually weaken in the vicinity of Adak through early next week.
The region will also continue to see the typical widespread
marine stratus, with an easterly component to the winds as the low
fills in over the central part of the chain.
.LONG TERM FORECAST (Days 3 through 7)...
As has been advertised, the days of endless sunshine are coming to
a close. The start of the work week will have an overall increase
in clouds across the mainland. Showers will increase from coastal
locations and some inland areas, but the majority of the Anchorage
Metro should be rain shadowed. A large but weakening low pressure
system currently moving into the central Aleutians will slowly
make its way to Southwest Alaska. Winds should remain relatively
light throughout the state as the overall pressure gradient will
SYNOPSIS AND MODEL DISCUSSION...EN
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB