Gale Warning 405, NWS Anchorage, AK

688 
FZAK62 PAFC 222306
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
306 PM AKDT Wed Jul 22 2020

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-231300-
306 PM AKDT Wed Jul 22 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 1000 mb low at 54N 174E Wed afternoon moves to 55N 177E at 998 
mb by Thu afternoon and continues to 55N 173W at 1003 mb by Fri 
afternoon.

$$

PKZ411-231300-
Bering Sea Offshore West of 180 and East of the International
Dateline-
306 PM AKDT Wed Jul 22 2020

.TONIGHT...NE wind 15 to 30 kt. Seas 7 to 11 ft.
.THU...N wind 15 to 30 kt. Seas 7 to 10 ft.
.THU NIGHT...N wind 10 to 20 kt. Seas 6 to 10 ft.
.FRI...NW wind up to 20 kt. Seas 5 to 8 ft.
.FRI NIGHT...W wind up to 15 kt. Seas 4 ft.
.SAT THROUGH MON...S wind up to 15 kt. Seas 4 ft.

$$

PKZ412-231300-
Bering Sea Offshore 171W to 180 and North of 56N-
306 PM AKDT Wed Jul 22 2020

...GALE WARNING TONIGHT...

.TONIGHT...SE wind 20 to 35 kt. Seas 7 to 10 ft. Patchy fog. Rain.
.THU...SE wind 10 to 25 kt becoming S up to 15 kt in the afternoon. 
Seas 6 to 9 ft.
.THU NIGHT...E wind up to 15 kt. Seas 6 ft.
.FRI...N wind up to 15 kt. Seas 5 ft.
.FRI NIGHT...NW wind up to 15 kt. Seas 5 ft.
.SAT THROUGH MON...S wind up to 15 kt. Seas 4 ft.

$$

PKZ413-231300-
Bering Sea Offshore 171W to 180 and South of 56N-
306 PM AKDT Wed Jul 22 2020

.TONIGHT...S wind 15 to 30 kt. Seas 5 to 9 ft. Rain.
.THU...S wind 10 to 20 kt. Seas 4 to 7 ft.
.THU NIGHT...S wind up to 20 kt becoming NW up to 15 kt after
midnight. Seas 5 ft.
.FRI...NW wind up to 15 kt. Seas 4 to 7 ft.
.FRI NIGHT...NW wind up to 15 kt. Seas 5 ft.
.SAT...W wind up to 15 kt. Seas 4 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 4 ft.

$$

PKZ414-231300-
Bering Sea Offshore East of 171W-
306 PM AKDT Wed Jul 22 2020

.TONIGHT...SE wind 10 to 25 kt. Seas 5 to 8 ft. Patchy fog. Rain.
.THU...S wind 25 kt. Seas 7 ft. Patchy fog.
.THU NIGHT...S wind 10 to 20 kt. Seas 6 ft.
.FRI...SE wind up to 15 kt. Seas 5 ft.
.FRI NIGHT...N wind up to 10 kt. Seas 3 to 6 ft.
.SAT...NW wind up to 15 kt. Seas 3 to 6 ft.
.SUN THROUGH MON...SW wind 15 kt. Seas 5 ft.

$$

582 
FZAK62 PAFC 230517 AAA
OFFALU

Offshore Waters Forecast...UPDATED
National Weather Service Anchorage AK
917 PM AKDT Wed Jul 22 2020

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-231215-
917 PM AKDT Wed Jul 22 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 1000 mb low at 54N 174E Wed afternoon moves to 55N 177E at 998 
mb by Thu afternoon and continues to 55N 173W at 1003 mb by Fri 
afternoon.

$$

PKZ411-231215-
Bering Sea Offshore West of 180 and East of the International
Dateline-
917 PM AKDT Wed Jul 22 2020

.TONIGHT...NE wind 15 to 30 kt. Seas 6 to 11 ft.
.THU...N wind 15 to 30 kt. Seas 5 to 10 ft.
.THU NIGHT...N wind 10 to 20 kt. Seas 6 to 10 ft.
.FRI...NW wind up to 20 kt. Seas 5 to 8 ft.
.FRI NIGHT...W wind up to 15 kt. Seas 4 ft.
.SAT...SW wind up to 15 kt. Seas 3 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 4 ft.

$$

PKZ412-231215-
Bering Sea Offshore 171W to 180 and North of 56N-
917 PM AKDT Wed Jul 22 2020

...GALE WARNING TONIGHT...

.TONIGHT...SE wind 20 to 35 kt. Seas 7 to 10 ft. Patchy fog. Rain.
.THU...SE wind 10 to 25 kt becoming S up to 15 kt in the
afternoon.
Seas 6 to 9 ft.
.THU NIGHT...E wind up to 15 kt. Seas 6 ft.
.FRI...N wind up to 15 kt. Seas 5 ft.
.FRI NIGHT...NW wind up to 15 kt. Seas 5 ft.
.SAT...W wind up to 15 kt. Seas 3 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 3 to 6 ft.

$$

PKZ413-231215-
Bering Sea Offshore 171W to 180 and South of 56N-
917 PM AKDT Wed Jul 22 2020

.TONIGHT...S wind 15 to 30 kt. Seas 5 to 9 ft.
.THU...S wind 10 to 20 kt. Seas 4 to 7 ft.
.THU NIGHT...S wind up to 20 kt becoming NW up to 15 kt after
midnight. Seas 5 ft.
.FRI...NW wind up to 15 kt. Seas 4 to 7 ft.
.FRI NIGHT...NW wind up to 15 kt. Seas 5 ft.
.SAT...W wind up to 15 kt. Seas 3 ft.
.SUN THROUGH MON...S wind 15 kt. Seas 3 ft.

$$

PKZ414-231215-
Bering Sea Offshore East of 171W-
917 PM AKDT Wed Jul 22 2020

.TONIGHT...SE wind 10 to 25 kt. Seas 3 to 8 ft. Patchy fog. Rain.
.THU...S wind 25 kt. Seas 7 ft. Chance of thunderstorms in the
morning. Patchy fog. Rain.
.THU NIGHT...S wind 10 to 20 kt. Seas 6 ft.
.FRI...SE wind up to 15 kt. Seas 5 ft.
.FRI NIGHT...N wind up to 10 kt. Seas 3 to 6 ft.
.SAT...NW wind up to 15 kt. Seas 4 ft.
.SUN THROUGH MON...SW wind 10 to 20 kt. Seas 3 to 6 ft.

$$

775 
FZAK62 PAFC 231140
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
340 AM AKDT Thu Jul 23 2020

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-240145-
340 AM AKDT Thu Jul 23 2020
.SYNOPSIS FOR CENTRAL BERING SEA...

A 996 mb low at 56N 178E moves to 56N 174W at 1003 mb Fri morning
and then moves to 55N 162W at 1005 mb Sat morning.

$$

PKZ411-240145-
Bering Sea Offshore West of 180 and East of the International
Dateline-
340 AM AKDT Thu Jul 23 2020

.TODAY...N wind 15 to 30 kt. Seas 6 to 11 ft.
.TONIGHT...NW wind 15 to 30 kt. Seas 6 to 10 ft.
.FRI...NW wind 10 to 20 kt. Seas 7 ft.
.FRI NIGHT...W wind up to 15 kt. Seas 3 to 6 ft.
.SAT...SW wind up to 15 kt. Seas 3 ft.
.SUN THROUGH MON...S wind up to 15 kt. Seas 4 ft.

$$

PKZ412-240145-
Bering Sea Offshore 171W to 180 and North of 56N-
340 AM AKDT Thu Jul 23 2020

.TODAY...S wind 10 to 25 kt. Seas 6 to 9 ft. Rain.
.TONIGHT...S wind up to 15 kt. Seas 6 ft.
.FRI...N wind up to 15 kt. Seas 3 to 6 ft.
.FRI NIGHT...NW wind up to 15 kt. Seas 4 ft.
.SAT THROUGH MON...S wind up to 15 kt. Seas 3 to 6 ft.

$$

PKZ413-240145-
Bering Sea Offshore 171W to 180 and South of 56N-
340 AM AKDT Thu Jul 23 2020

.TODAY...SW wind 10 to 20 kt. Seas 6 ft.
.TONIGHT...W wind 10 to 20 kt. Seas 5 ft.
.FRI...NW wind 10 to 15 kt. Seas 4 to 7 ft.
.FRI NIGHT...NW wind up to 15 kt. Seas 3 to 6 ft.
.SAT...W wind up to 15 kt. Seas 3 to 5 ft.
.SUN THROUGH MON...S wind up to 15 kt. Seas 3 ft.

$$

PKZ414-240145-
Bering Sea Offshore East of 171W-
340 AM AKDT Thu Jul 23 2020

.TODAY...S wind 15 to 25 kt. Seas 5 to 8 ft. Patchy fog. Chance of thunderstorms 
in the morning. Patchy fog. Rain.
.TONIGHT...S wind 10 to 20 kt. Seas 6 ft.
.FRI...SE wind 10 to 15 kt becoming NE wind in the afternoon. Seas 5
ft.
.FRI NIGHT...N wind up to 15 kt. Seas 4 ft.
.SAT...NW wind up to 15 kt. Seas 4 ft.
.SUN THROUGH MON...SW wind up to 20 kt. Seas 3 to 6 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
526 PM AKDT Tue Jul 21 2020

.ANALYSIS AND UPPER LEVELS...

The southern mainland lies in between systems this afternoon, as
the low that brought rainfall to Southcentral overnight continues
to head eastward across the Gulf towards the Panhandle, and our
next system seen in water vapor imagery heading towards the
southern portions of the state from the northern Bering (currently
the low is just north to northeast of Saint Matthew Island). This
latter feature is helping provide enough ascent (lift) for
showers to develop and move eastward, as seen in the Bethel
Doppler radar imagery loop.

In between these systems, several weak disturbances aloft are
seen in satellite imagery, with small scale associated lows
progressing eastward. Two good examples are a low just south of
Cape Newenham that was observed at 11 am, with a well-defined
cloud band extending southward (frontal-like feature), and a
similar low and associated meso-front south of Nunivak Island.
Both of these systems were completely missed by the numerical
suite. However, they are of little fan fare, aside from a possible
wind shift as they move ashore and some more robust but brief
breaks in the cloud cover as they pass by (likely due to
meso/smaller scale subsidence.

Finally, a low situated near Attu continues to provide sufficient
lift for showery type precipitation to affect the western
portions of the Aleutian chain and Bering Sea. These showers are
getting additional moisture of tropical origin (MIMIC water vapor
imagery shows origins from the northern Micronesia region),
allowing for cooling cloud tops and likely heavier bursts of
precipitation. This is over an unpopulated area though, with it
just affecting maritime interests.

&&

.MODEL DISCUSSION...

The models remain in excellent agreement with their perspective
forecasts at the surface and aloft, with tight clustering seen at
both levels, similar to yesterday. This leads to a higher than
average confidence in the forecast details over the next few days.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist through the
period. Rainfall potential will increase after 22/12z, with at
least brief periods of close to MVFR conditions developing. For
now, opted for a scattered deck at 3000 feet and will await later
numerical guidance.

&&

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

Southcentral is in the middle of two systems today as a low
departs toward the Panhandle and an upper level trough currently
over Southwest Alaska approaches. This transition has increased
the pressure gradient over the Barren Islands and northern Kodiak
Island where gusty northwesterly winds are expected to continue
through Wednesday evening. Isolated thunderstorms are possible
this afternoon and evening over the Copper River Basin and the
western Kenai Peninsula as cloud cover dissipates and daytime
heating aids convection. Cloud cover will increase through the
evening hours into Wednesday morning as the leading edge of the
inbound system arrives from the northwest this evening. Models
have agreed that this low will track rather quickly from the
northwest to the southeast Wednesday morning through Wednesday
evening. The greatest challenge has been the timing of
precipitation as model guidance has not been consistent. Current
thinking is that light rain will begin Wednesday morning over the
foothills of the Alaska Range, Cook Inlet, and the western Kenai
Peninsula. Precipitation will then fill in across much of
Southcentral by midday with the greatest amounts of rain expected
over the Kenai Peninsula and along the northern Gulf coast. Rain
will then taper from west to east beginning late Wednesday
afternoon. Areas across the northern Gulf coast and southern
Copper River Basin should expect rain tapering off by Wednesday
evening. As this low departs late Wednesday, cloud cover may clear
just enough to allow for afternoon and evening thunderstorms over
the Susitna Valley and northern Copper River Basin Wednesday
afternoon and evening. As this low quickly moves toward the
southeast, a beautiful day is in store for Southcentral on
Thursday with clear skies and warm temperatures.

&&

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

The upper level low that moved into the Kuskokwim Delta earlier
today will continue to spread eastward over the Southwest mainland
through the overnight hours. Showers associated with this upper
level feature will begin to taper off Wednesday morning, allowing
for a break in the active weather pattern as this system moves
out of the region for the afternoon and evening hours.

On Thursday, a front associated with a Bering low will approach
the Southwest coast, stretching across the Alaska Peninsula. This
will bring the next chance of widespread rainfall for the coastal
areas on Thursday, which will then move farther inland through
the end of the week.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

A low centered just west of Shemya continues to be the driver over
the western Aleutians and Bering as the associated front pushes
eastward. Small craft advisory winds and widespread rain remain in
the forecast through the next few days as the front moves over the
Pribilofs by Wednesday afternoon and then pushes into the
Southwest coast by Thursday. However, expect the strong, small
craft winds to continue on the backside of this low system over
the western Bering on Thursday as a tight gradients remains in
place.

&&

.MARINE (Days 3 through 5)...

...Bering Sea and the Aleutian Coastal Waters...

An area of low pressure will meander across the central Bering.
Sustained small craft criteria winds (23 knots or more) will
develop south of the Aleutian Chain from the Rat Islands eastward
to south of Nikolski for Friday into Saturday morning. Here,
waves will build to near 10 feet given good fetch length. These
winds and waves will weaken for the remainder of the weekend as
the low itself fills/weakens some.

...Gulf of Alaska...

A front will swing eastward across the Gulf on Friday, ahead of a
deepening area of low pressure that reaches the western Gulf
Friday night, and then moves slowly northeast to near the
coastline by Sunday. It's possible some sustained small craft
strength winds will develop across the northern Gulf on Saturday
ahead of the low. Otherwise, winds and waves will remain below
headline criteria.

&&

.LONG TERM FORECAST (Days 3 through 7: Friday through Tuesday)...

A cooler than normal and unsettled pattern is expected for Friday
through Tuesday as broad upper level troughing extends across
Southcentral and Southwest Alaska. This troughing will be driven
by global weather patterns, reaching as far away as the Indian
Ocean. This is significant as upper level troughing over Alaska
is enhanced by upper level ridging over the Indian subcontinent.
Furthermore, ECMWF/GFS/GEM ensembles are showing easterly 200mb
zonal winds in the polar-jet region. This dynamic will help weaken
the polar-jet and increase the likelihood in a meridional pattern
setting up across Alaska.

Ensembles show positive precipitation anomalies along the coast
for Southcentral Alaska for this period, meaning there will be
more rainfall than normal during the period. Deterministic models
are showing a broad low pressure system over the Bering/Aleutians
on Friday. This low is projected to move east-northeastward
across the Gulf of Alaska. There is a moderate degree of
uncertainty in the exact track of this low as the GFS and GEM
bring this low northeastward into Yukon Territory while the ECMWF
keeps the low stalled off the coast of Southeast Alaska. Due to
this, there is low to moderate confidence in the precipitation
forecast as precipitation amounts are highly dependent on the low
track.

In summary, days 3-7 is expected to have cool temperatures and
above average precipitation. However, there is a high degree of
uncertainty in projected rainfall amounts in Southcentral Alaska.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES: 130, 131
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...KO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...AH
MARINE/LONG TERM...PD/ED