Gale Warning 311, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
315 AM AKDT Mon Apr 27 2020

.ANALYSIS AND UPPER LEVELS...

A quiet weather pattern persists across Southcentral this morning
leading to leading to another day of sunshine and dry conditions.
Water vapor imagery shows a low spinning over the southeast Gulf,
but any precipitation or significant cloud cover is staying south
of mainland Alaska. A few rain showers persist across the central
Bering and Aleutians this morning as a decaying surface low
continues to move south of the Aleutian Chain. To the west, weak
upper level ridging is building over the western Aleutians,
resulting in a brief break in precipitation before the next front
moves in associated with a low positioned west of Shemya.

&&

.MODEL DISCUSSION...

Models continue to be in good agreement for the next few days,
thus forecast confidence is above average. Models are in better
agreement today with keeping precipitation south of the forecast
area with the low spinning in the southeast Gulf. There is
agreement in timing and strength of the low moving into the
western Bering starting this afternoon.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

&&

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

The general pattern of high pressure over the mainland and low
pressure over the Gulf will continue through Tuesday night. Sunny
and dry conditions are expected for the next couple of days over
most of Southcentral as a result of the high pressure. Some clouds
are expected to push into the area from Prince William Sound
eastward at times due to the low in the Gulf. A stray shower in
that area is even possible, with the best chance Tuesday
afternoon and evening.

&&

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

Mostly clear skies will persist in a weak, northeasterly flow.
Ample sunshine will keep temperatures above average except for much
cooler temperatures along the Kuskokwim Delta coast.

&&

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

Scattered showers will continue west of Unalaska through Monday
afternoon under a weak front. A stronger, more defined front will
track across the western and central Aleutians beginning Monday
afternoon. This front will bring moderate rain and gusty
southerly winds through Wednesday. Besides this, a weak,
northeasterly flow is expected for the central and eastern
Aleutians resulting in more benign conditions for the forecast
period.

&&

.MARINE (Days 3 through 5/Wednesday through Friday)...

Generally quiet conditions are expected over the Gulf of Alaska
through Thursday. By Friday morning, a North Pacific low moves
into the Gulf, however there is low confidence in the track of the
low at this time. Small craft winds are likely over the Gulf
waters late Friday with a potential for gale force gusts.
Meanwhile over the Bering, there is high confidence a low enters
the western Bering on Wednesday. Westerly gale-force winds are
expected across the western Aleutians Wednesday morning through
Thursday morning. By Thursday afternoon, the low weakens and
moves southward, keeping small craft winds in place across much of
the western Bering.

&&

.LONG TERM FORECAST (Days 4 through 8/Thursday through Monday)...

Looking ahead to next weekend, two key features that model
solutions seem to be locking onto are an upper level low in place
over the Bering and an upper level ridge in place over the
Mainland. Models are also hinting at a trough axis in place over
the Yukon Thursday and Friday with a NE-SW orientation. It's hard
to say what type of interaction this trough will have with the
ridge set up over the Interior, but it may be strong enough to
allow for unsettled weather over Southcentral toward the end of
the workweek. However by the weekend, the ridge looks to regain
control with midlevel offshore flow in place by Saturday and
Sunday. Meanwhile farther west, a nearly stationary low in place
over the western Bering looks to finally move south of the Chain
by Saturday night. By Sunday night, another upper level trough
drops southward over the western Aleutians, bringing a fast moving
surface low that eventually moves into the North Pacific by
Monday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gales 177 178 411.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...ALH
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CK
MARINE/LONG TERM...KO