Gale Warning 324, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
416 AM AKDT Wed May 8 2019

.ANALYSIS AND UPPER LEVELS...
The pattern is defined by a broad area of low pressure over the
Bering with ridging off to the east over the panhandle. This
setup allows for southerly flow over most of the southern
mainland. Multiple lows are rotating around the main low with one
of the stronger shortwaves having spun up a low in the Gulf. That
low is pulling a long fetch of moisture to the north Gulf coast
resulting in rain for areas around Southcentral Alaska with the
heaviest rain along the coast.

&&

.MODEL DISCUSSION...
The models are in decent agreement with the main features through
the mid term but there are a few small scale problems. The
biggest concern is with a low tracking toward Kodiak Island on
Thursday from the North Pacific. Guidance is struggling with the
timing of this feature which will play a factor for winds and
precipitation for areas around the Gulf. A middle ground solution
was preferred.

&&

.AVIATION...
PANC...Rain and lower ceilings will continue until late this
morning when winds will pick back up from a southeast direction.
The winds should stay fairly consistent and help to raise
ceilings and diminish the rain through Wednesday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A weather system bringing rain to most of Southcentral this
morning will move north of the area by this afternoon. The rain
will then change to showers and taper off through tonight.
Southerly winds will also sweep across much of the area as the low
level flow becomes strongly onshore with the surface low moving
north. There will be a brief quiet period in the weather tonight
into Thursday morning. Another system will move into the Gulf on
Thursday. The leading front will reach the north Gulf coast by
noon and then push inland. This low will take a more westerly
track than this mornings system, and the flow aloft will become
more easterly. This will limit the precipitation that makes it
inland, with most of the rain falling along and near the coast.
The low will begin to move northward Thursday night, pushing into
the Southcentral mainland on Friday. As this low moves north of
the area Friday afternoon, southerly winds will increase and
become quite gusty.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Moist southerly flow with a few weak shortwaves moving through
will continue to bring showers to Southwest Alaska through
Thursday. A frontal system associated with a low tracking north
through the southwest Gulf will rotate into the area from the
east late Thursday afternoon through Thursday night bringing more
widespread rain with it. The low will track slowly to the
northwest across Southwest Alaska on Friday with rain changing
back over to showers Friday night.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A broad upper level low with multiple fairly weak surface lows
rotating around its periphery will persist over the Bering and
Aleutians through the end of the week. The cool, unstable airmass
associated with the upper low will keep isolated to scattered
showers going over the Bering with more numerous showers
accompanying each of the surface lows and troughs rotating
through.

&&

.MARINE (Days 3 through 5: Friday through Sunday)...

On Friday morning, the low inland over Southwest Alaska will
continue to produce gale force winds through Bristol Bay, Shelikof
Strait, and the Gulf waters east of Kodiak. The winds will subside
from east to west through Friday night. There is some potential
for a low to impact many of the same areas Saturday night into
Sunday with an additional round of gale force winds in Shelikof
Strait and the waters around Kodiak. However, there is substantial
model disagreement about this system and uncertainty is high.
Elsewhere, there is good confidence that no areas of high winds
or waves will occur through Sunday.

&&

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

The long-term forecast remains a quiet one overall across much of
southern mainland Alaska. Two different features: a low moving to
near Kodiak and/or Bristol Bay on Sunday, and a cold front and
associated low moving across the northern Bering into the
Kuskokwim Delta are both depicted by only one forecast model, and
left out by the others. Thus, there is high uncertainty about
whether they will impact the area at all. The low that moves
through Southwest Alaska Friday will slowly depart during the day
Saturday, taking most of its associated precipitation with it by
Saturday night across Southwest Alaska. Disorganized shower
activity will be common across most of southern mainland Alaska on
Saturday and Sunday, with high pressure and quieter weather likely
taking over for Monday and Tuesday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gales...131 138.
FIRE WEATHER...NONE.

&&

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