Small Craft Advisory 408, NWS Anchorage, AK

101 
FZAK52 PAFC 171147
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
347 AM AKDT TUE MAY 17 2016

COASTAL WATERS FORECAST FOR SOUTHWEST ALASKA+BRISTOL BAY+THE
ALASKA PENINSULA WATERS AND THE ALEUTIAN ISLANDS UP TO 100 NM OUT.

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.

PKZ199-180115-
347 AM AKDT TUE MAY 17 2016
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

HIGH PRESSURE SOUTHWEST OF THE WESTERN ALEUTIANS WILL EXIT TO THE
NORTH PACIFIC AND WEAKEN THROUGH WED NIGHT. A TROUGH OF LOW
PRESSURE WILL DEVELOP OVER THE CENTRAL BERING TONIGHT AND REMAIN
OVER THE BERING THROUGH WED NIGHT. A 1008 MB LOW WILL DEVELOP 500
NM WEST OF SHEMYA WED NIGHT.

$$

PKZ150-180115-
SOUTH OF THE AK PENINSULA SITKINAK TO CASTLE CAPE-
347 AM AKDT TUE MAY 17 2016

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...NW WIND 20 KT. SEAS 8 FT.
.TONIGHT...W WIND 20 KT. SEAS 8 FT.
.WED...W WIND 20 KT. SEAS 7 FT.
.WED NIGHT...SW WIND 20 KT. SEAS 6 FT.
.THU...S WIND 25 KT. SEAS 11 FT.
.FRI...S WIND 30 KT. SEAS 16 FT.
.SAT...SW WIND 25 KT. SEAS 13 FT.

$$

PKZ155-180115-
SOUTH OF THE AK PENINSULA CASTLE CAPE TO CAPE SARICHEF-
347 AM AKDT TUE MAY 17 2016

.TODAY...W WIND 15 KT. SEAS 6 FT. PATCHY FOG.
.TONIGHT...W WIND 20 KT. SEAS 6 FT.
.WED...SW WIND 20 KT. SEAS 6 FT.
.WED NIGHT...S WIND 15 KT. SEAS 5 FT.
.THU...S WIND 20 KT. SEAS 10 FT.
.FRI...SW WIND 30 KT. SEAS 13 FT.
.SAT...SW WIND 25 KT. SEAS 10 FT.

$$

PKZ160-180115-
BRISTOL BAY-
347 AM AKDT TUE MAY 17 2016

...SMALL CRAFT ADVISORY TONIGHT AND WEDNESDAY...

.TODAY...SW WIND 10 KT INCREASING TO 20 KT IN THE AFTERNOON. SEAS
3 FT. PATCHY FOG.
.TONIGHT...W WIND 25 KT. SEAS 6 FT. PATCHY FOG.
.WED...SW WIND 25 KT. SEAS 6 FT. PATCHY FOG.
.WED NIGHT...SW WIND 15 KT. SEAS 4 FT.
.THU THROUGH FRI...SE WIND 20 KT. SEAS 4 FT.
.SAT...SW WIND 15 KT. SEAS 6 FT.

$$

PKZ165-180115-
PORT HEIDEN TO CAPE SARICHEF-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 20 KT. SEAS 4 FT. PATCHY FOG.
.TONIGHT...W WIND 20 KT. SEAS 6 FT. PATCHY FOG.
.WED...SW WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED NIGHT...S WIND 15 KT. SEAS 4 FT.
.THU...S WIND 15 KT. SEAS 4 FT.
.FRI...W WIND 25 KT. SEAS 6 FT.
.SAT...SW WIND 25 KT. SEAS 6 FT.

$$

PKZ170-180115-
CAPE SARICHEF TO NIKOLSKI BERING SIDE-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 4 FT. PATCHY FOG.
.TONIGHT...W WIND 15 KT. SEAS 3 FT.
.WED...SW WIND 15 KT. SEAS 4 FT.
.WED NIGHT...S WIND 15 KT. SEAS 4 FT.
.THU...W WIND 15 KT. SEAS 4 FT.
.FRI...W WIND 25 KT. SEAS 6 FT.
.SAT...SW WIND 25 KT. SEAS 6 FT.

$$

PKZ171-180115-
UNALASKA BAY-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 10 KT. SEAS 3 FT. PATCHY FOG.
.TONIGHT...NW WIND 10 KT. SEAS 3 FT.
.WED...SW WIND 10 KT IN THE MORNING BECOMING VARIABLE LESS THAN
10 KT. SEAS 2 FT.
.WED NIGHT...S WIND 10 KT. SEAS 2 FT.
.THU...NW WIND 10 KT. SEAS 3 FT.
.FRI...W WIND 15 KT. SEAS 2 FT.
.SAT...SW WIND 15 KT. SEAS 2 FT.

$$

PKZ172-180115-
CAPE SARICHEF TO NIKOLSKI PACIFIC SIDE-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 6 FT.
.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED...SW WIND 15 KT. SEAS 4 FT.
.WED NIGHT...S WIND 15 KT. SEAS 3 FT.
.THU...NW WIND 15 KT. SEAS 8 FT.
.FRI...W WIND 25 KT. SEAS 9 FT.
.SAT...SW WIND 25 KT. SEAS 9 FT.

$$

PKZ173-180115-
NIKOLSKI TO SEGUAM ISLAND BERING SIDE-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 5 FT.
.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED...SW WIND 20 KT. SEAS 5 FT.
.WED NIGHT...SW WIND 15 KT. SEAS 5 FT.
.THU...W WIND 15 KT. SEAS 4 FT.
.FRI...W WIND 20 KT. SEAS 6 FT.
.SAT...SW WIND 20 KT. SEAS 7 FT.

$$

PKZ174-180115-
NIKOLSKI TO SEGUAM ISLAND PACIFIC SIDE-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 5 FT.
.TONIGHT...W WIND 10 KT. SEAS 4 FT.
.WED...SW WIND 15 KT. SEAS 3 FT.
.WED NIGHT...SW WIND 15 KT. SEAS 4 FT.
.THU...NW WIND 15 KT. SEAS 7 FT.
.FRI...W WIND 25 KT. SEAS 7 FT.
.SAT...SW WIND 25 KT. SEAS 10 FT.

$$

PKZ175-180115-
SEGUAM ISLAND TO ADAK BERING SIDE-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 5 FT.
.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED...W WIND 15 KT. SEAS 5 FT.
.WED NIGHT...W WIND 15 KT. SEAS 4 FT.
.THU THROUGH SAT...SW WIND 15 KT. SEAS 4 FT.

$$

PKZ176-180115-
SEGUAM ISLAND TO ADAK PACIFIC SIDE-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 4 FT.
.TONIGHT...W WIND 10 KT. SEAS 3 FT.
.WED...W WIND 15 KT. SEAS 4 FT.
.WED NIGHT...W WIND 15 KT. SEAS 4 FT.
.THU...NW WIND 15 KT. SEAS 5 FT.
.FRI THROUGH SAT...SW WIND 20 KT. SEAS 9 FT.

$$

PKZ177-180115-
ADAK TO KISKA-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 5 FT.
.TONIGHT...W WIND 20 KT. SEAS 5 FT.
.WED...W WIND 20 KT. SEAS 5 FT.
.WED NIGHT...NW WIND 15 KT. SEAS 5 FT.
.THU...W WIND 15 KT. SEAS 3 FT.
.FRI...S WIND 15 KT. SEAS 6 FT.
.SAT...NW WIND 15 KT. SEAS 6 FT.

$$

PKZ178-180115-
KISKA TO ATTU-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 20 KT. SEAS 5 FT.
.TONIGHT...W WIND 20 KT. SEAS 5 FT.
.WED...NW WIND 20 KT. SEAS 5 FT.
.WED NIGHT...W WIND 15 KT. SEAS 5 FT.
.THU...S WIND 20 KT. SEAS 7 FT.
.FRI...NE WIND 15 KT. SEAS 6 FT.
.SAT...W WIND 20 KT. SEAS 10 FT.

$$

PKZ179-180115-
PRIBILOF ISLANDS NEAR SHORE WATERS-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 3 FT.
.TONIGHT...W WIND 10 KT. SEAS 3 FT.
.WED...SW WIND 15 KT. SEAS 3 FT.
.WED NIGHT...S WIND 15 KT. SEAS 4 FT.
.THU...SW WIND 15 KT. SEAS 4 FT.
.FRI...W WIND 20 KT. SEAS 4 FT.
.SAT...SW WIND 15 KT. SEAS 5 FT.

$$

PKZ180-180115-
KUSKOKWIM DELTA AND ETOLIN STRAIT-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 20 KT. SEAS 3 FT. PATCHY FOG.
.TONIGHT...W WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED...W WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED NIGHT...S WIND 20 KT. SEAS 4 FT.
.THU...S WIND 20 KT. SEAS 4 FT.
.FRI THROUGH SAT...SW WIND 20 KT. SEAS 5 FT.

$$

PKZ181-180115-
NORTH AND WEST OF NUNIVAK ISLAND-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 15 KT. SEAS 2 FT. PATCHY FOG.
.TONIGHT...NW WIND 15 KT. SEAS 3 FT. PATCHY FOG.
.WED...NW WIND 15 KT. SEAS 3 FT. PATCHY FOG.
.WED NIGHT...SW WIND 20 KT. SEAS 3 FT.
.THU...SE WIND 15 KT. SEAS 4 FT.
.FRI...NW WIND 15 KT. SEAS 3 FT.
.SAT...SW WIND 15 KT. SEAS 3 FT.

$$

PKZ185-180115-
SAINT MATTHEW ISLAND WATERS-
347 AM AKDT TUE MAY 17 2016

.TODAY...NW WIND 10 KT. SEAS 2 FT. PATCHY FOG.
.TONIGHT...NW WIND 15 KT. SEAS 2 FT. PATCHY FOG.
.WED...NW WIND 15 KT. SEAS 2 FT. PATCHY FOG.
.WED NIGHT...E WIND 15 KT. SEAS 2 FT.
.THU...NE WIND 15 KT. SEAS 2 FT.
.FRI...NW WIND 15 KT. SEAS 4 FT.
.SAT...SW WIND 15 KT. SEAS 4 FT.

$$

528 
FZAK52 PAFC 172311
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
311 PM AKDT TUE MAY 17 2016

COASTAL WATERS FORECAST FOR SOUTHWEST ALASKA+BRISTOL BAY+THE
ALASKA PENINSULA WATERS AND THE ALEUTIAN ISLANDS UP TO 100 NM OUT.

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.

PKZ199-181200-
311 PM AKDT TUE MAY 17 2016
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A TROUGH OF LOW PRESSURE WILL REMAIN OVER THE BERING THROUGH WED.
A 1007 MB LOW WILL DEVELOP 260 NM NORTHWEST OF SAINT PAUL WED
MORNING AND DRIFTS TO 150 NM NORTHWEST OF SAINT PAUL AT 1005 MB
THU AFTERNOON. A 1008 MB NORTH PACIFIC LOW WED AFTERNOON MOVES TO
380 NM SOUTHWEST OF SHEMYA THU AFTERNOON AND MAINTAINS STRENGTH.

$$

PKZ150-181200-
SOUTH OF THE AK PENINSULA SITKINAK TO CASTLE CAPE-
311 PM AKDT TUE MAY 17 2016

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...W WIND 20 KT. SEAS 8 FT.
.WED...W WIND 20 KT. SEAS 7 FT.
.WED NIGHT...SW WIND 20 KT. SEAS 6 FT.
.THU...SE WIND 25 KT. SEAS 7 FT.
.THU NIGHT...S WIND 25 KT. SEAS 9 FT.
.FRI...S WIND 30 KT. SEAS 15 FT.
.SAT...W WIND 25 KT. SEAS 14 FT.
.SUN...W WIND 25 KT. SEAS 9 FT.

$$

PKZ155-181200-
SOUTH OF THE AK PENINSULA CASTLE CAPE TO CAPE SARICHEF-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 20 KT. SEAS 6 FT.
.WED...W WIND 20 KT. SEAS 6 FT.
.WED NIGHT...SW WIND 15 KT. SEAS 5 FT. RAIN.
.THU...E WIND 20 KT. SEAS 5 FT.
.THU NIGHT...SW WIND 15 KT. SEAS 9 FT.
.FRI...W WIND 30 KT. SEAS 14 FT.
.SAT THROUGH SUN...SW WIND 25 KT. SEAS 9 FT.

$$

PKZ160-181200-
BRISTOL BAY-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 20 KT. SEAS 6 FT. PATCHY FOG.
.WED...SW WIND 20 KT. SEAS 6 FT. PATCHY FOG.
.WED NIGHT...SW WIND 15 KT BECOMING SE AFTER MIDNIGHT. SEAS 4 FT.
.THU AND THU NIGHT...SE WIND 15 KT. SEAS 3 FT.
.FRI...S WIND 20 KT. SEAS 7 FT.
.SAT THROUGH SUN...SW WIND 20 KT. SEAS 7 FT.

$$

PKZ165-181200-
PORT HEIDEN TO CAPE SARICHEF-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED...W WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED NIGHT...S WIND 15 KT. SEAS 5 FT.
.THU...SE WIND 15 KT. SEAS 4 FT.
.THU NIGHT...VARIABLE WIND 10 KT. SEAS 3 FT.
.FRI...NW WIND 25 KT. SEAS 8 FT.
.SAT...SW WIND 25 KT. SEAS 8 FT.
.SUN...SW WIND 20 KT. SEAS 7 FT.

$$

PKZ170-181200-
CAPE SARICHEF TO NIKOLSKI BERING SIDE-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 15 KT. SEAS 3 FT.
.WED AND WED NIGHT...SW WIND 20 KT. SEAS 5 FT.
.THU...VARIABLE WIND 10 KT. SEAS 5 FT.
.THU NIGHT...VARIABLE WIND 10 KT. SEAS 3 FT.
.FRI...W WIND 25 KT. SEAS 7 FT.
.SAT THROUGH SUN...SW WIND 25 KT. SEAS 7 FT.

$$

PKZ171-181200-
UNALASKA BAY-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...NW WIND 10 KT. SEAS 2 FT.
.WED...SW WIND 10 KT. SEAS 2 FT.
.WED NIGHT...SW WIND 10 KT. SEAS 2 FT.
.THU AND THU NIGHT...VARIABLE WIND LESS THAN 10 KT. SEAS 3 FT.
.FRI...W WIND 20 KT. SEAS 3 FT.
.SAT THROUGH SUN...SW WIND 15 KT. SEAS 2 FT.

$$

PKZ172-181200-
CAPE SARICHEF TO NIKOLSKI PACIFIC SIDE-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 10 KT. SEAS 4 FT.
.WED...SW WIND 15 KT. SEAS 4 FT.
.WED NIGHT...S WIND 15 KT. SEAS 4 FT.
.THU...VARIABLE WIND 10 KT. SEAS 3 FT.
.THU NIGHT...NW WIND 15 KT. SEAS 7 FT.
.FRI...W WIND 25 KT. SEAS 9 FT.
.SAT THROUGH SUN...SW WIND 25 KT. SEAS 9 FT.

$$

PKZ173-181200-
NIKOLSKI TO SEGUAM ISLAND BERING SIDE-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED...SW WIND 20 KT. SEAS 6 FT.
.WED NIGHT...SW WIND 15 KT. SEAS 5 FT.
.THU...VARIABLE WIND 10 KT. SEAS 4 FT.
.THU NIGHT...W WIND 15 KT. SEAS 4 FT.
.FRI...W WIND 20 KT. SEAS 7 FT.
.SAT...SW WIND 20 KT. SEAS 7 FT.
.SUN...SW WIND 25 KT. SEAS 7 FT.

$$

PKZ174-181200-
NIKOLSKI TO SEGUAM ISLAND PACIFIC SIDE-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED...SW WIND 15 KT. SEAS 4 FT.
.WED NIGHT...SW WIND 15 KT. SEAS 4 FT.
.THU...VARIABLE WIND 10 KT. SEAS 4 FT.
.THU NIGHT...NW WIND 15 KT. SEAS 6 FT.
.FRI...W WIND 25 KT. SEAS 7 FT.
.SAT THROUGH SUN...SW WIND 25 KT. SEAS 9 FT.

$$

PKZ175-181200-
SEGUAM ISLAND TO ADAK BERING SIDE-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 15 KT. SEAS 5 FT.
.WED...W WIND 20 KT. SEAS 5 FT.
.WED NIGHT...W WIND 15 KT. SEAS 5 FT.
.THU...VARIABLE WIND 10 KT. SEAS 4 FT.
.THU NIGHT...W WIND 15 KT. SEAS 4 FT.
.FRI THROUGH SAT...SW WIND 15 KT. SEAS 5 FT.
.SUN...SW WIND 20 KT. SEAS 5 FT.

$$

PKZ176-181200-
SEGUAM ISLAND TO ADAK PACIFIC SIDE-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED AND WED NIGHT...W WIND 15 KT. SEAS 4 FT.
.THU...VARIABLE WIND 10 KT. SEAS 3 FT.
.THU NIGHT...NW WIND 15 KT. SEAS 5 FT.
.FRI THROUGH SUN...SW WIND 20 KT. SEAS 8 FT.

$$

PKZ177-181200-
ADAK TO KISKA-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 20 KT. SEAS 5 FT.
.WED...W WIND 20 KT. SEAS 5 FT.
.WED NIGHT...NW WIND 15 KT. SEAS 5 FT.
.THU AND THU NIGHT...W WIND 15 KT. SEAS 4 FT.
.FRI...S WIND 15 KT. SEAS 6 FT.
.SAT...W WIND 15 KT. SEAS 9 FT.
.SUN...SW WIND 25 KT. SEAS 9 FT.

$$

PKZ178-181200-
KISKA TO ATTU-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 20 KT. SEAS 6 FT.
.WED...NW WIND 20 KT. SEAS 6 FT.
.WED NIGHT...W WIND 15 KT. SEAS 5 FT.
.THU...SW WIND 15 KT. SEAS 7 FT.
.THU NIGHT...SE WIND 20 KT. SEAS 7 FT.
.FRI...NE WIND 15 KT. SEAS 7 FT.
.SAT THROUGH SUN...SW WIND 25 KT. SEAS 8 FT.

$$

PKZ179-181200-
PRIBILOF ISLANDS NEAR SHORE WATERS-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...VARIABLE WIND 10 KT. SEAS 3 FT.
.WED...SW WIND 15 KT. SEAS 4 FT.
.WED NIGHT...SW WIND 15 KT. SEAS 4 FT.
.THU AND THU NIGHT...SW WIND 15 KT. SEAS 4 FT.
.FRI...W WIND 20 KT. SEAS 4 FT.
.SAT...SW WIND 15 KT. SEAS 6 FT.
.SUN...SW WIND 20 KT. SEAS 6 FT.

$$

PKZ180-181200-
KUSKOKWIM DELTA AND ETOLIN STRAIT-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...W WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED...W WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.WED NIGHT...S WIND 20 KT. SEAS 4 FT.
.THU...SE WIND 20 KT. SEAS 5 FT.
.THU NIGHT...S WIND 15 KT. SEAS 4 FT.
.FRI THROUGH SAT...SW WIND 20 KT. SEAS 6 FT.
.SUN...SW WIND 15 KT. SEAS 6 FT.

$$

PKZ181-181200-
NORTH AND WEST OF NUNIVAK ISLAND-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...NW WIND 15 KT. SEAS 3 FT. PATCHY FOG.
.WED...W WIND 15 KT. SEAS 3 FT. PATCHY FOG.
.WED NIGHT...S WIND 15 KT. SEAS 3 FT.
.THU...SE WIND 20 KT. SEAS 4 FT.
.THU NIGHT...SE WIND 15 KT. SEAS 4 FT.
.FRI THROUGH SAT...SW WIND 15 KT. SEAS 4 FT.
.SUN...S WIND 20 KT. SEAS 5 FT.

$$

PKZ185-181200-
SAINT MATTHEW ISLAND WATERS-
311 PM AKDT TUE MAY 17 2016

.TONIGHT...NW WIND 15 KT. SEAS 2 FT. PATCHY FOG.
.WED...NW WIND 15 KT. SEAS 3 FT. PATCHY FOG.
.WED NIGHT...E WIND 15 KT. SEAS 3 FT.
.THU...NE WIND 15 KT. SEAS 2 FT.
.THU NIGHT...VARIABLE WIND 10 KT. SEAS 2 FT.
.FRI...NW WIND 15 KT. SEAS 3 FT.
.SAT...SW WIND 20 KT. SEAS 4 FT.
.SUN...S WIND 20 KT. SEAS 7 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
459 AM AKDT MON MAY 16 2016

.ANALYSIS AND UPPER LEVELS...

The atmosphere has stabilized quite a bit this morning after
scattered showers and thunderstorms were observed Saturday
afternoon and evening. A few lingering showers continue across
portions of Southcentral and Southwest Alaska but these showers
should continue to gradually taper off as the upper level
disturbance that helped create these showers shifts west into the
Bering Sea. One cool feature of note this morning is the
impressive number of outflow boundaries seen on the Bethel (PABC)
WSR-88D from the showers and thunderstorms observed on Saturday.
These outflow boundaries don't appear as if they will be any
triggers for showers or thunderstorms this afternoon with lower
instability and copious amounts of dry air aloft.

Looking back at the grand scheme of things, two major surface
features pretty much dominate the weather pattern this morning.
The first being high pressure over the western half of the Bering
Sea that continues to slowly drift westward. The second is an area
of low pressure in the Northern Pacific that is moving quickly
north into the Gulf of Alaska. The high over the Bering Sea has
trapped moisture in the lowest levels in what we call a marine
layer. This marine layer is characterized by fog and low stratus
which can be seen on several channels of IR imagery as well as
visible (during the daytime) satellite. Areas from Adak across
Dutch Harbor and Cold Bay have seen several rounds of this marine
layer with low ceilings and fog. This will continue into the late
morning hours when diurnal heating helps to mix the lower levels
of the atmosphere and conditions improve.

The low moving into the northern gulf if pushing a weak front
towards the northern gulf coast. This will bring in another marine
layer from the south which has already moved across Middleton
Island and is beginning to impact Cordova and parts of the Kenai
Peninsula.

&&

.MODEL DISCUSSION...

No significant models discrepancies are observed this morning. It
will be important to watch the timing and strength of a coastal
ridge developing ahead of the front moving through the northern
Gulf of Alaska as it will impact wind speeds through gaps and
passes throughout Southcentral Alaska. Overall, forecast
confidence remains above normal due to the excellent model
agreement. A blend of high resolution data (the NAM and GEM
Regional) was used with the forecast package.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A pattern change is underway which will bring an end to the very
warm and dry conditions which have dominated Southcentral for the
past few days. The Gulf Coast and Prince William Sound will see
the change first as a marine air mass surges onshore today
bringing significantly cooler temperatures. An upper level trough
swinging across the Gulf will also lead to increasing showers.

Meanwhile, an upper level ridge and surface thermal trough will
persist over interior Southcentral for one more day with enough
instability to produce isolated to scattered convection, mainly
along the eastern Alaska Range and Wrangell Mountains. Much of
inland Southcentral will start out with sunshine, but the
approaching short-wave will lead to increasing clouds this
afternoon through evening. In addition, a surface ridge will
build along the north Gulf coast in response to a low over the
northeast pacific heading toward the Gulf. This will lead to gusty
gap winds through Turnagain Arm, the Knik River Valley, and along
the Copper River. Good vertical mixing in a still unstable
atmosphere will help these winds spread inland to portions of
Anchorage and the Mat-Su. The combination of increased clouds and
winds will lead to marginally cooler temperatures, though still
above normal.

The more significant change in weather for inland areas will
occur tonight through Tuesday as a cold upper level low digs
southward from the Beaufort Sea to interior Alaska and
Southcentral gets squeezed between this trough and the trough
crossing the Gulf. This will lead to rapid cooling of low level
temperatures (with complete dissipation of the thermal trough),
widespread cloud cover, and development of areas of steady rain.
The dynamic nature of this scenario of being caught between two
troughs leads to some uncertainty in where rain will set up.
Based on latest guidance rain looks most likely across the Copper
River basin and Susitna Valley tonight through Tuesday night.
However, there is a good chance the Matanuska Valley and Anchorage
will also see rain at some point in this time period. Bottom line,
expect Tuesday to be very noticeably cooler and cloudier.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Diurnally driven convective activity will continue to be the
primary forecast concern across the southwest mainland today as
the thermal trough extending into the southwest interior once
again provides the focus for afternoon and evening thunderstorms
centered over the Lower Kuskokwim Valley. Thunderstorm potential
will also extend south and westward towards the Ahklun Mountains
and eastern portions of the Kuskokwim Delta, where numerous
remnant outflow boundaries from last evening's convection may help
to initiate new activity today. Areal thunderstorm coverage is
expected to be slightly diminished from yesterday as temperatures
will run a few degrees cooler and stability indices are not
expected to be be quite as impressive. Convection will continue to
trend downward on Tuesday as a closed upper low passes north of
the area and temperatures continue to fall, however increasing
cyclonic flow will still help to maintain a chance for showers
into Tuesday evening.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Relatively weak surface and upper level flow will continue to
promote benign conditions across the Bering Sea, with extensive
low stratus and fog dominating much of the region through the
early part of the weak before an upper low drops into the central
Bering from the north.

&&

.LONG TERM FORECAST (Days 3 through 7)...

An amplification of the longwave pattern will commence by the
middle of the week. The extended models are slowly coming into
some better agreement as another fairly impressive ridge of high
pressure builds northward from the Pacific and into southern
Alaska. The exact position of the ridge axis will be critical to
the positioning of clouds and rainfall (to the west of the ridge
axis), and the ridge axis position is largely a function of how
far east in the Bering Sea the stationary upper low sets up shop
early in the week. It looks increasingly likely that this ridge
axis will be located in the vicinity of the Copper River Basin and
ALCAN border. This means that cloud-cover will be on the increase
across Southwest and Southcentral Alaska on Thursday, with two
rounds of fast-moving but widespread rain likely in the Thursday
night/Friday morning time-frame and again during the day
Saturday. Temperatures will moderate from recent record highs, but
the bigger driver of possibly significant cooling will be the
increasing influence of a low-level maritime air mass working
into upper Cook Inlet and the Mat-Su Valleys.

Meanwhile, the Bering Sea and Aleutians will stay clear of
significant large-scale weather systems for the next week. The
only exception will be the eastern Bering/Aleutians that will
receive a glancing blow from a northward-moving low and weather
front on Thursday. In general, this means the area will experience
typical warm-seasons conditions such as calm winds, widespread
low-clouds, and areas of fog.

&&

.HYDROLOGY...

Many of the rivers and streams around Southcentral Alaska have
seen water levels rise significantly as the recent heatwave
kicked snow-melt in the mountains into high gear. In fact, based
on available observed snow pack data, most of the mountain ranges
in the area have lost about 5 inches of snow-water equivalent in
the past 6 days. The rivers are responding as if we were receiving
the better part of an inch of rain each day for 6 straight days!
With lowering freezing levels and cooler temperatures expected to
begin moving into the area for the start of the week, these
elevated river levels will begin to moderate back to typical
spring levels. No flooding is anticipated.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

SYNOPSIS AND MODEL DISCUSSION...MMC
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
LONG TERM...AD