Storm Warning 93, NWS Anchorage, AK

364 
FZAK62 PAFC 141159
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT WED APR 14 2010

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.

PKZ499-150200-
400 AM AKDT WED APR 14 2010
.SYNOPSIS FOR CENTRAL BERING SEA...

A WEATHER FRONT WILL MOVE INTO THE WESTERN BERING LATE WED MORNING
AND ADVANCE TO THE PRIBILOFS AND EASTERN ALEUTIANS BY THU MORNING AND
TO BRISTOL BAY THU EVENING. A 974 MB LOW NEAR 50N 148E WILL MOVE TO
59N 177W AT 984 MB BY FRI MORNING.

$$

PKZ411-150200-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 AM AKDT WED APR 14 2010

...GALE WARNING THROUGH THURSDAY...

.TODAY...VARIABLE WIND 10 TO 20 KT INCREASING TO SE WIND 35 TO 45 KT
IN THE AFTERNOON. SEAS BUILDING TO 10 TO 14 FT. SNOW. FREEZING SPRAY.
.TONIGHT...S WIND 40 KT. SEAS 16 FT. PATCHY FOG. SNOW.
.THU...SW WIND 35 KT. SEAS 20 FT. 
.THU NIGHT...W WIND 35 KT. SEAS 22 FT. 
.FRI...NW WIND 35 KT. SEAS 21 FT. 
.SAT...NW WIND 25 KT. SEAS 15 FT. 
.SUN...N WIND 25 KT. SEAS 11 FT.  

$$

PKZ412-150200-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 AM AKDT WED APR 14 2010

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...VARIABLE WIND 10 TO 20 KT. SEAS 10 FT. FREEZING SPRAY. 
.TONIGHT...SE WIND 40 KT. SEAS 12 FT. PATCHY FOG. SNOW. 
.THU...SW WIND 35 KT DIMINISHING TO 25 KT IN THE AFTERNOON. SEAS
13 FT. PATCHY FOG. SNOW.
.THU NIGHT...SW WIND 25 KT. SEAS 15 FT. 
.FRI...W WIND 25 KT. SEAS 18 FT. 
.SAT...NW WIND 25 KT. SEAS 15 FT. 
.SUN...N WIND 20 KT. SEAS 11 FT.  

$$

PKZ413-150200-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 AM AKDT WED APR 14 2010

...GALE WARNING THROUGH THURSDAY...

.TODAY...E OF 177W...W WIND 25 KT. SEAS 11 FT. W OF 177W...W WIND 
20 KT INCREASING TO SE 35 KT IN THE AFTERNOON. SEAS 13 FT. 
.TONIGHT...S WIND 45 KT. SEAS 14 FT. PATCHY FOG. RAIN AND SNOW. 
.THU...SW WIND 35 KT. SEAS 14 FT. 
.THU NIGHT...SW WIND 35 KT. SEAS 21 FT. 
.FRI...W WIND 35 KT. SEAS 22 FT. 
.SAT...NW WIND 30 KT. SEAS 17 FT. 
.SUN...N WIND 20 KT. SEAS 12 FT.  

$$

PKZ414-150200-
BERING SEA OFFSHORE EAST OF 171W
400 AM AKDT WED APR 14 2010

...GALE WARNING TONIGHT AND THURSDAY...

.TODAY...NW WIND 10 TO 20 KT. SEAS IN ICE FREE WATERS 5 TO 8 FT. 
.TONIGHT...S WIND 20 KT INCREASING TO 30 TO 40 KT AFTER MIDNIGHT.
SEAS IN ICE FREE WATERS 9 FT. PATCHY FOG. SNOW.
.THU...S WIND 40 KT. SEAS IN ICE FREE WATERS 14 FT. PATCHY FOG. SNOW
AND RAIN. 
.THU NIGHT...SW WIND 30 KT. SEAS IN ICE FREE WATERS 12 FT. 
.FRI...SW WIND 25 KT. SEAS IN ICE FREE WATERS 16 FT. 
.SAT...W WIND 25 KT. SEAS IN ICE FREE WATERS 14 FT. 
.SUN...NW WIND 20 KT. SEAS IN ICE FREE WATERS 10 FT.  

$$

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKDT TUE APR 13 2010

.ANALYSIS AND UPPER LEVELS...
AMPLIFIED PATTERN CONTINUES TODAY WITH LONG WAVE TROUGH CENTERED
BETWEEN 170W AND 180W AND DOWNSTREAM RIDGE CENTERED NEAR THE ALASKA
PANHANDLE. A 125 KT JET FLOWING AROUND THE BASE OF THE TROUGH
CONTINUES TO TAP THE SUBTROPICAL MOISTURE AND TRANSPORT IT NORTH
TOWARD THE NORTHEASTERN GULF COAST.

VERY FEW SURFACE FEATURES TO SPEAK OF...BROAD SOUTHWESTERLY FLOW
BRINGING GUSTY WINDS TO THE REGION. THE MAIN AREA OF LOW PRESSURE IS
CENTERED NEAR KOTZEBUE SOUND WITH A WEAK FRONTAL BOUNDARY EXTENDING
SOUTH AND WEST THROUGH THE CENTRAL BERING SEA. SATELLITE IMAGERY
INDICATING THE INITIAL SIGNS OF A SHORTWAVE EMBEDDED WITHIN THE
SOUTHWESTERLY JET HELPING TO DEVELOP A WEAK AREA OF LOW PRESSURE THAT
WILL BRING SOUTHCENTRAL ANOTHER CHANCE OF RAIN AND SNOW WEDNESDAY.

.MODEL DISCUSSION...
MODELS IN EXCELLENT AGREEMENT THIS MORNING. THE MOST SIGNIFICANT
FEATURE IS THE LOW DEVELOPING ALONG THE FRONTAL BOUNDARY IN THE NORTH
PACIFIC. MODELS HAVE FINALLY COME INTO AGREEMENT ON THE TIME AND NOW
THE ECMWF...WHICH WAS THE OUTLIER...IS ALSO ADVERTISING A SIMILAR
TRACK OF THE LOW WHICH IS JUST EAST OF KODIAK ISLAND BEFORE MOVING
INLAND NEAR SEWARD. THE OTHER FEATURE OF INTEREST IS A STRONG GALE
FORCE FRONT MARCHING ACROSS THE ALEUTIANS AND BERING SEA WEDNESDAY
THROUGH THURSDAY. MODELS ARE VERY CONSISTENT WITH THE TIMING AND
STRENGTH OF THIS FEATURE. ONLY MINOR CHANGES ARE EXPECTED WITH THIS
FORECAST PACKAGE.

.SHORT TERM FORECAST...
.SOUTH CENTRAL ALASKA...PARTLY CLOUDY TO MOSTLY SUNNY SKIES
PREVAILING THIS AFTERNOON OVER MUCH OF SOUTHCENTRAL ALASKA. SHOWERS
DEVELOPING ALONG THE EASTERN PRINCE WILLIAM SOUND COAST THANKS TO THE
MOIST SOUTHWESTERLY FLOW BUTTING UP AGAINST THE MOUNTAINS. SHOWERS
WILL TURN INTO STEADY RAIN AND SNOW LATE TONIGHT INTO WEDNESDAY
MORNING AS THE WAVE APPROACHES THE REGION. THE WESTERN EXTENT OF THE
PRECIPITATION IS STILL UP IN THE AIR AS THE LAST TWO MODEL RUNS HAVE
BACKED OFF SIGNIFICANTLY ON PRECIPITATION FOR THE ANCHORAGE BOWL.
THERE IS A LACK OF SOUTHEASTERLY FLOW ALOFT AT ANY LEVEL TO THROW THE
PRECIPITATION OVER THE MOUNTAINS BACK TOWARD ANCHORAGE. TEMPERATURE
ADVECTION IS NEUTRAL WHILE THERE IS MOISTURE AVAILABLE. BY THE TIME
COOLER AIR ARRIVE...IT IS AFTER THE MOISTURE HAS EXITED THE REGION.
STILL...THE POSITION OF THE LOW NEAR SEWARD AND WESTERN PRINCE
WILLIAM SOUND COUPLED WITH THE SOUTHWESTERLY SUBTROPICAL FETCH OF
MOISTURE ALOFT IS HISTORICALLY A FAVORABLE SCENARIO FOR PRECIPITATION
IN ANCHORAGE. AGAIN...TEMPERATURES WILL BE AT OR ABOVE FREEZING AT
SEA LEVEL WHICH WILL EITHER LIMIT ACCUMULATION OR RESULT IN A MIX OF
RAIN AND FALL. THE HILLSIDE HAS THE BEST CHANCE AT ACCUMULATING
SNOWFALL WHERE TEMPERATURES WILL BE NEAR FREEZING. THE SPEED OF THE
SYSTEM WILL LIMIT ACCUMULATION TO A FEW INCHES.

ANOTHER AREA OF CONCERN WITH THIS SYSTEM IS THE COPPER RIVER BASIN
WHERE A BOUNDARY BETWEEN THE WARMER AIR TO THE SOUTH AND EAST AND THE
COLDER AIR OVER THE NORTHWESTERN HALF OF THE ZONE WILL SET UP. THE
PRESSURE GRADIENT WILL RELAX OVERNIGHT AS THE LOW APPROACHES AND
MOISTURE AND WARMER AIR BEGINS TO OVERRUN THE COLDER AIR TO THE
NORTH. THE RESULT WILL BE LIGHT TO MODERATE SNOW THROUGHOUT THE
BASIN. WILL FINE TUNE SNOW AMOUNTS BUT EXPECTING RESPECTABLE
TOTALS...JUST BELOW ADVISORY CRITERIA.

.SOUTHWEST ALASKA...SOUTHWESTERLY ONSHORE FLOW CONTINUES WITH
SCATTERED SHOWERS AND NEAR NORMAL TEMPERATURES EXPECTED THROUGH MID
WEEK. A SURFACE TROUGH AXIS ROTATES INLAND WEDNESDAY AFTERNOON
ENHANCING THE SHOWER ACTIVITY ACROSS THE LOWER KUSKOKWIM VALLEY.
BEHIND THAT TROUGH...HIGH PRESSURE BUILDS BRIEFLY AHEAD OF THE NEXT
FRONTAL BOUNDARY THAT WILL AFFECT THE COAST THURSDAY AND MOVE INLAND
THURSDAY NIGHT.

.ALEUTIANS AND BERING SEA...SHOWER ACTIVITY WILL SLOWLY DISSIPATE AS
MINIMUM GALES GIVE WAY TO SMALL CRAFT ADVISORY WINDS. THIS IS ALL
RELATED TO AN AREA OF HIGH PRESSURE BUILDING BUILDING BRIEFLY TONIGHT
AND TOMORROW AHEAD OF THE APPROACHING FRONTAL BOUNDARY. THE FRONT
WILL AFFECT THE WESTERN ALEUTIANS EARLY WEDNESDAY MORNING BRINGING
STRONG GALE FORCE WINDS AND ABUNDANT MOISTURE TO THE REGION. BY THE
WEEKEND...THE FRONT WILL HAVE WEAKENED AS IT MOVES INLAND AND INTO
THE NORTHERN GULF AND THE PARENT LOW POSITIONS ITSELF IN THE CENTRAL
GULF.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...170 172 175 176 179 185
FIRE WEATHER...NONE.

AB APR 10