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000
FXAK69 PAFG 042013
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1213 PM AKDT FRI SEP 4 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 12Z
ANALYSIS. MODELS CONTINUE TO PERFORM WELL IN THE THE SHORT RANGE
BUT CONTINUE TO DISPLAY LARGE SPREAD BOTH BETWEEN MODEL FAMILIES
AND FROM RUN TO RUN IN BOTH THE MID RANGE AND IN THE LONG RANGE.

ALOFT AT 500 HPA...A 543 DAM LOW CURRENTLY OVER THE WESTERN
BERING SEA WILL MOVES SOUTH AND EAST TO BE LOCATED OVER THE
CENTRAL BERING SEA AS A 548 DAM LOW SATURDAY MORNING AND THEN AS A
552 DAM LOW OVER BRISTOL BAY SUNDAY MORNING. THE UPPER LEVEL LOW
CONTINUES TO MOVE SOUTH AND EAST OVER KODIAK ISLAND SUNDAY
EVENING AND INTO THE EASTERN GULF OF ALASKA MONDAY MORNING.
ANOTHER 543 DAM LOW MOVES INTO THE WESTERN BERING SEA AS A DEEP
TROUGH DIVES SOUTH AND EAST TOWARD THE NORTHWEST COAST MONDAY
MORNING. THESE TWO FEATURES PHASE WELL TUESDAY CREATING A DEEP
COLD LONG WAVE TROUGH ALONG A BARROW TO ST PAUL ISLAND AXIS.

ON THE SURFACE A 1009 MB LOW OVER THE CENTRAL BERING CONTINUES TO
WEAKEN AND WILL MOVE ON SHORE SATURDAY MORNING NEAR UNALAKLEET
AND MERGE WITH THE REMNANTS OF A WEAK FRONT OVER THE YK DELTA WHICH
IS CURRENTLY PRODUCING LIGHT RAIN OVER SOUTHWEST ALASKA. SCATTERED
SHOWERS ARE EXPECTED BOTH SATURDAY AND SUNDAY OVER THE SOUTHERN
WESTERN INTERIOR AND WEST COAST AS THIS FRONT CONTINUES TO
DISSIPATE. DRY AND SEASONABLE TEMPERATURES ARE EXPECTED OVER THE
CENTRAL AND EASTERN INTERIOR THROUGH THE WEEKEND NORTH OF A LINE
FROM TOK TO FAIRBANKS TO NOME.

FOCUS CONTINUES TO CENTER ON STRONG COLD FRONT MOVING SOUTHEAST
OUT OF THE HIGH ARCTIC AND ONTO THE NORTH SLOPE MONDAY AND
TUESDAY ACROSS THE WESTERN AND CENTRAL INTERIOR TUESDAY AND
WEDNESDAY. WILL CONTINUE TO MONITOR POTENTIAL FOR HIGH SURF ALONG
THE NORTHWEST COAST BEGINNING TUESDAY AND CONTINUING WEDNESDAY AS
MODERATE TO STRONG NORTHWEST ON SHORE FLOW IS EXPECTED TO DEVELOP.
WILL CONTINUE TO MONITOR POTENTIAL FOR SIGNIFICANT SNOW IN THE
BROOKS RANGE LATE MONDAY AND TUESDAY. NORTHWEST UPSLOPE FLOW MAY
ADD TO SNOW TOTALS ESPECIALLY OVER THE EASTERN BROOKS RANGE INTO
WEDNESDAY. SNOW LEVELS WILL BE DROPPING OVER THE WESTERN AND
CENTRAL INTERIOR TUESDAY AND WEDNESDAY HOWEVER ONLY LIGHT PRECIP
IS EXPECTED WITH MINIMAL SNOW ACCUMULATIONS ANTICIPATED OVER THE
WESTERN INTERIOR AT THIS TIME.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
CONTINUE TO MONITOR POTENTIAL FOR MODERATE TO STRONG NORTHWEST
WINDS ALONG THE NORTHWEST COAST DEVELOPING TUESDAY AND CONTINUING
THROUGH AT LEAST WEDNESDAY.



&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.
&&

$$

CCC SEP 15



000
FXAK69 PAFG 042013
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1213 PM AKDT FRI SEP 4 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 12Z
ANALYSIS. MODELS CONTINUE TO PERFORM WELL IN THE THE SHORT RANGE
BUT CONTINUE TO DISPLAY LARGE SPREAD BOTH BETWEEN MODEL FAMILIES
AND FROM RUN TO RUN IN BOTH THE MID RANGE AND IN THE LONG RANGE.

ALOFT AT 500 HPA...A 543 DAM LOW CURRENTLY OVER THE WESTERN
BERING SEA WILL MOVES SOUTH AND EAST TO BE LOCATED OVER THE
CENTRAL BERING SEA AS A 548 DAM LOW SATURDAY MORNING AND THEN AS A
552 DAM LOW OVER BRISTOL BAY SUNDAY MORNING. THE UPPER LEVEL LOW
CONTINUES TO MOVE SOUTH AND EAST OVER KODIAK ISLAND SUNDAY
EVENING AND INTO THE EASTERN GULF OF ALASKA MONDAY MORNING.
ANOTHER 543 DAM LOW MOVES INTO THE WESTERN BERING SEA AS A DEEP
TROUGH DIVES SOUTH AND EAST TOWARD THE NORTHWEST COAST MONDAY
MORNING. THESE TWO FEATURES PHASE WELL TUESDAY CREATING A DEEP
COLD LONG WAVE TROUGH ALONG A BARROW TO ST PAUL ISLAND AXIS.

ON THE SURFACE A 1009 MB LOW OVER THE CENTRAL BERING CONTINUES TO
WEAKEN AND WILL MOVE ON SHORE SATURDAY MORNING NEAR UNALAKLEET
AND MERGE WITH THE REMNANTS OF A WEAK FRONT OVER THE YK DELTA WHICH
IS CURRENTLY PRODUCING LIGHT RAIN OVER SOUTHWEST ALASKA. SCATTERED
SHOWERS ARE EXPECTED BOTH SATURDAY AND SUNDAY OVER THE SOUTHERN
WESTERN INTERIOR AND WEST COAST AS THIS FRONT CONTINUES TO
DISSIPATE. DRY AND SEASONABLE TEMPERATURES ARE EXPECTED OVER THE
CENTRAL AND EASTERN INTERIOR THROUGH THE WEEKEND NORTH OF A LINE
FROM TOK TO FAIRBANKS TO NOME.

FOCUS CONTINUES TO CENTER ON STRONG COLD FRONT MOVING SOUTHEAST
OUT OF THE HIGH ARCTIC AND ONTO THE NORTH SLOPE MONDAY AND
TUESDAY ACROSS THE WESTERN AND CENTRAL INTERIOR TUESDAY AND
WEDNESDAY. WILL CONTINUE TO MONITOR POTENTIAL FOR HIGH SURF ALONG
THE NORTHWEST COAST BEGINNING TUESDAY AND CONTINUING WEDNESDAY AS
MODERATE TO STRONG NORTHWEST ON SHORE FLOW IS EXPECTED TO DEVELOP.
WILL CONTINUE TO MONITOR POTENTIAL FOR SIGNIFICANT SNOW IN THE
BROOKS RANGE LATE MONDAY AND TUESDAY. NORTHWEST UPSLOPE FLOW MAY
ADD TO SNOW TOTALS ESPECIALLY OVER THE EASTERN BROOKS RANGE INTO
WEDNESDAY. SNOW LEVELS WILL BE DROPPING OVER THE WESTERN AND
CENTRAL INTERIOR TUESDAY AND WEDNESDAY HOWEVER ONLY LIGHT PRECIP
IS EXPECTED WITH MINIMAL SNOW ACCUMULATIONS ANTICIPATED OVER THE
WESTERN INTERIOR AT THIS TIME.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
CONTINUE TO MONITOR POTENTIAL FOR MODERATE TO STRONG NORTHWEST
WINDS ALONG THE NORTHWEST COAST DEVELOPING TUESDAY AND CONTINUING
THROUGH AT LEAST WEDNESDAY.



&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.
&&

$$

CCC SEP 15



  [top]

000
FXAK67 PAJK 041437
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
626 AM AKDT FRI SEP 4 2015

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS A LOW PRESSURE
SYSTEM OVER THE WESTERN GULF WITH AN ASSOCIATED WEATHER FRONT
OVER THE CENTRAL GULF. THIS LOW AND FRONT WILL DRIFT EAST THROUGH
THE SHORT TERM PERIOD WITH THE FRONT MOVING OVER THE COASTAL AREAS
LATE THIS AFTERNOON AND THROUGH THE PANHANDLE TONIGHT. THIS
SYSTEM HAS TROPICAL MOISTURE ASSOCIATED WITH THE FRONT AS SEEN
FROM THE PRECIPITABLE WATER IMAGERY PW VALUES OF 1.2 TO 1.5
INCHES ARE AROUND 150 PERCENT NORMAL FOR THIS TIME OF YEAR.

LIGHT RAIN HAS STARTED IN THE YAKUTAT AREA WHICH WILL INCREASE
THROUGH THE DAY, BECOMING HEAVY AT TIMES BY THE LATE MORNING
EXCESSIVE RAIN RATES WILL CONTINUE THROUGH THE EVENING. TOTAL RAINFALL
WILL BE NEAR 1.5 INCHES BEFORE THE FRONT DRIFTS EAST
OF YAKUTAT LATE TONIGHT. LOCAL RIVERS AND STREAMS WILL RISE
SIGNIFICANTLY BUT AT THIS TIME ARE EXPECTED TO REMAIN IN THEIR BANKS.
RAIN WILL SPREAD OVER THE REST OF THE FORECAST AREA THROUGH THIS
MORNING AND MOVE SOUTH THROUGH TONIGHT. THE RAIN WILL THE
HEAVIEST ALONG THE OUTER COAST WITH MODERATE RAIN OVER THE NORTH CENTRAL
AREAS. RAIN AMOUNTS WILL RANGE FROM 0.5 TO 1.25 INCHES THROUGH
TONIGHT.

A BARRIER JET ASSOCIATED WITH THE FRONT IS PRODUCING GALE FORCE WIND OVER
THE NORTHERN GULF AT THIS TIME. AS THE FRONT DRIFTS EAST THROUGH TODAY,
GALES TO SMALL CRAFT WINDS WILL SPREAD INTO THE EASTERN GULF WITH SEAS
BUILDING TO 8 TO 10 FEET. AS THE FRONT APPROACHES THE EASTERN GULF, SMALL
CRAFT WINDS WILL DEVELOP NEAR CROSS SOUND BY EARLY THIS EVENING. THE
INNER CHANNELS WILL SEE RELATIVELY LIGHT WINDS THROUGH TODAY BUT THE
SURFACE RIDGE WILL SHARPEN UP THIS AFTERNOON AS THE FRONT MOVES EAST.
MINIMAL SMALL CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 15 KTN OVER
SOUTHERN LYNN AS A RESULT. THESE WINDS WILL DIMINISH IN THE EVENING AND
SWITCH TO THE NORTH AS THE RIDGE GETS PUSHED OFF TO THE EAST BY THE
FRONT. WIND SPEEDS WILL BE LESS THAN 15 KT OVERNIGHT AS THE PRESSURE
GRADIENT WILL BE ON THE LIGHTER SIDE WITH PARALLEL FLOW. LIGHTER WINDS
WILL PERSIST OVER N/S CHANNELS TONIGHT GENERALLY LESS THAN 15 KT BUT
THE E/W CHANNELS WILL INCREASE TO 20 TO 25 KT THROUGH TONIGHT AND
THESE CONDITIONS WILL SPREAD OVER THE SOUTHERN HALF OF THE PANHANDLE
LATER ON TONIGHT.

LAND WINDS WILL BE THE STRONGEST ALONG THE COASTAL AREAS WITH SOME
HIGHER GUSTS THIS AFTERNOON OVER THE NORTHERN GULF AND TONIGHT
OVER THE EASTERN GULF. THE INNER CHANNELS WILL SEE SOME INCREASE
IN WIND SPEEDS BUT GENERALLY BE 10 TO 20 MPH.

OVERALL THERE IS AVERAGE FORECASTER CONFIDENCE THROUGH THE SHORT
TERM PERIOD AND A MIX OF THE 06ZNAM/GFS AND 00Z EC WAS USED.

.LONG TERM...HURRICANE IGNACIO IS STILL CAUSING MAJOR DIVERGENCE
IN MODEL SOLUTIONS. MOST RECENT BEST TRACK FROM THE CENTRAL
PACIFIC HURRICAN CENTER HAS THE STORM TRACKING ACROSS HAIDA GWAII
LATE MONDAY NIGHT OR EARLY TUESDAY. NCEP GFS ENSEMBLE TRACK
GUIDANCE FROM 4PM YESTERDAY AFTERNOON FANS OUT SIGNIFICANTLY EAST
OF 150W, SO CONFIDENCE IN THE CURRENT FORECAST IN TERMS OF LOW
TRACK AND ASSOCIATED WIND FIELD BEYOND MONDAY AFTERNOON IS
DECIDEDLY BELOW AVERAGE.

AHEAD OF IGNACIO, A WEATHER FRONT THAT MOVES ASHORE DURING THE
SHORT TERM FORECAST PERIOD WILL MOVE SOUTH ON SATURDAY. TROPICAL
MOISTURE CONNECTION UNRELATED TO IGNACIO WILL RESULT IN MODERATE
RAIN RATES FOR THE CENTRAL AND SOUTHERN OUTER COAST SATURDAY
MORNING. WRAP AROUND SHOWER ACTIVITY WILL KEEP MUCH OF SOUTHEAST
ALASKA WET FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. A WEAK LOW
WILL BRING MORE RAIN IN ON MONDAY AND IT CURRENT MODELS ARE
MERGING THIS PRECIP FIELD WITH SOME OF THE RAIN ASSOCIATED WITH
IGNACIO. CURRENT FORECAST REFLECTS MODERATE RAIN OVER THE NORTHERN
HALF OF THE PANHANDLE, BUT WIDESPREAD HEAVY RAIN FOR LOCATIONS
SOUTH OF ANGOON MONDAY NIGHT.

USED A BLEND OF GFS AND ECMWF FOR UPDATES TO PRESSURE AND WIND
OVER THE GULF THROUGH SUNDAY NIGHT, THEN TRENDED TOWARDS WPC ON
MONDAY. POP AND QPF FROM GFS, CANADIAN NH AND ECMWF. LITTLE CHANGE
TO TEMPS. OVERALL FORECAST CONFIDENCE IS AVERAGE THROUGH SUNDAY,
THEN FALLS TO BELOW AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-033-035-036-041-042.

&&

$$

ABJ/FRITSCH

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 041437
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
626 AM AKDT FRI SEP 4 2015

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS A LOW PRESSURE
SYSTEM OVER THE WESTERN GULF WITH AN ASSOCIATED WEATHER FRONT
OVER THE CENTRAL GULF. THIS LOW AND FRONT WILL DRIFT EAST THROUGH
THE SHORT TERM PERIOD WITH THE FRONT MOVING OVER THE COASTAL AREAS
LATE THIS AFTERNOON AND THROUGH THE PANHANDLE TONIGHT. THIS
SYSTEM HAS TROPICAL MOISTURE ASSOCIATED WITH THE FRONT AS SEEN
FROM THE PRECIPITABLE WATER IMAGERY PW VALUES OF 1.2 TO 1.5
INCHES ARE AROUND 150 PERCENT NORMAL FOR THIS TIME OF YEAR.

LIGHT RAIN HAS STARTED IN THE YAKUTAT AREA WHICH WILL INCREASE
THROUGH THE DAY, BECOMING HEAVY AT TIMES BY THE LATE MORNING
EXCESSIVE RAIN RATES WILL CONTINUE THROUGH THE EVENING. TOTAL RAINFALL
WILL BE NEAR 1.5 INCHES BEFORE THE FRONT DRIFTS EAST
OF YAKUTAT LATE TONIGHT. LOCAL RIVERS AND STREAMS WILL RISE
SIGNIFICANTLY BUT AT THIS TIME ARE EXPECTED TO REMAIN IN THEIR BANKS.
RAIN WILL SPREAD OVER THE REST OF THE FORECAST AREA THROUGH THIS
MORNING AND MOVE SOUTH THROUGH TONIGHT. THE RAIN WILL THE
HEAVIEST ALONG THE OUTER COAST WITH MODERATE RAIN OVER THE NORTH CENTRAL
AREAS. RAIN AMOUNTS WILL RANGE FROM 0.5 TO 1.25 INCHES THROUGH
TONIGHT.

A BARRIER JET ASSOCIATED WITH THE FRONT IS PRODUCING GALE FORCE WIND OVER
THE NORTHERN GULF AT THIS TIME. AS THE FRONT DRIFTS EAST THROUGH TODAY,
GALES TO SMALL CRAFT WINDS WILL SPREAD INTO THE EASTERN GULF WITH SEAS
BUILDING TO 8 TO 10 FEET. AS THE FRONT APPROACHES THE EASTERN GULF, SMALL
CRAFT WINDS WILL DEVELOP NEAR CROSS SOUND BY EARLY THIS EVENING. THE
INNER CHANNELS WILL SEE RELATIVELY LIGHT WINDS THROUGH TODAY BUT THE
SURFACE RIDGE WILL SHARPEN UP THIS AFTERNOON AS THE FRONT MOVES EAST.
MINIMAL SMALL CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 15 KTN OVER
SOUTHERN LYNN AS A RESULT. THESE WINDS WILL DIMINISH IN THE EVENING AND
SWITCH TO THE NORTH AS THE RIDGE GETS PUSHED OFF TO THE EAST BY THE
FRONT. WIND SPEEDS WILL BE LESS THAN 15 KT OVERNIGHT AS THE PRESSURE
GRADIENT WILL BE ON THE LIGHTER SIDE WITH PARALLEL FLOW. LIGHTER WINDS
WILL PERSIST OVER N/S CHANNELS TONIGHT GENERALLY LESS THAN 15 KT BUT
THE E/W CHANNELS WILL INCREASE TO 20 TO 25 KT THROUGH TONIGHT AND
THESE CONDITIONS WILL SPREAD OVER THE SOUTHERN HALF OF THE PANHANDLE
LATER ON TONIGHT.

LAND WINDS WILL BE THE STRONGEST ALONG THE COASTAL AREAS WITH SOME
HIGHER GUSTS THIS AFTERNOON OVER THE NORTHERN GULF AND TONIGHT
OVER THE EASTERN GULF. THE INNER CHANNELS WILL SEE SOME INCREASE
IN WIND SPEEDS BUT GENERALLY BE 10 TO 20 MPH.

OVERALL THERE IS AVERAGE FORECASTER CONFIDENCE THROUGH THE SHORT
TERM PERIOD AND A MIX OF THE 06ZNAM/GFS AND 00Z EC WAS USED.

.LONG TERM...HURRICANE IGNACIO IS STILL CAUSING MAJOR DIVERGENCE
IN MODEL SOLUTIONS. MOST RECENT BEST TRACK FROM THE CENTRAL
PACIFIC HURRICAN CENTER HAS THE STORM TRACKING ACROSS HAIDA GWAII
LATE MONDAY NIGHT OR EARLY TUESDAY. NCEP GFS ENSEMBLE TRACK
GUIDANCE FROM 4PM YESTERDAY AFTERNOON FANS OUT SIGNIFICANTLY EAST
OF 150W, SO CONFIDENCE IN THE CURRENT FORECAST IN TERMS OF LOW
TRACK AND ASSOCIATED WIND FIELD BEYOND MONDAY AFTERNOON IS
DECIDEDLY BELOW AVERAGE.

AHEAD OF IGNACIO, A WEATHER FRONT THAT MOVES ASHORE DURING THE
SHORT TERM FORECAST PERIOD WILL MOVE SOUTH ON SATURDAY. TROPICAL
MOISTURE CONNECTION UNRELATED TO IGNACIO WILL RESULT IN MODERATE
RAIN RATES FOR THE CENTRAL AND SOUTHERN OUTER COAST SATURDAY
MORNING. WRAP AROUND SHOWER ACTIVITY WILL KEEP MUCH OF SOUTHEAST
ALASKA WET FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. A WEAK LOW
WILL BRING MORE RAIN IN ON MONDAY AND IT CURRENT MODELS ARE
MERGING THIS PRECIP FIELD WITH SOME OF THE RAIN ASSOCIATED WITH
IGNACIO. CURRENT FORECAST REFLECTS MODERATE RAIN OVER THE NORTHERN
HALF OF THE PANHANDLE, BUT WIDESPREAD HEAVY RAIN FOR LOCATIONS
SOUTH OF ANGOON MONDAY NIGHT.

USED A BLEND OF GFS AND ECMWF FOR UPDATES TO PRESSURE AND WIND
OVER THE GULF THROUGH SUNDAY NIGHT, THEN TRENDED TOWARDS WPC ON
MONDAY. POP AND QPF FROM GFS, CANADIAN NH AND ECMWF. LITTLE CHANGE
TO TEMPS. OVERALL FORECAST CONFIDENCE IS AVERAGE THROUGH SUNDAY,
THEN FALLS TO BELOW AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-033-035-036-041-042.

&&

$$

ABJ/FRITSCH

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 041437
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
626 AM AKDT FRI SEP 4 2015

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS A LOW PRESSURE
SYSTEM OVER THE WESTERN GULF WITH AN ASSOCIATED WEATHER FRONT
OVER THE CENTRAL GULF. THIS LOW AND FRONT WILL DRIFT EAST THROUGH
THE SHORT TERM PERIOD WITH THE FRONT MOVING OVER THE COASTAL AREAS
LATE THIS AFTERNOON AND THROUGH THE PANHANDLE TONIGHT. THIS
SYSTEM HAS TROPICAL MOISTURE ASSOCIATED WITH THE FRONT AS SEEN
FROM THE PRECIPITABLE WATER IMAGERY PW VALUES OF 1.2 TO 1.5
INCHES ARE AROUND 150 PERCENT NORMAL FOR THIS TIME OF YEAR.

LIGHT RAIN HAS STARTED IN THE YAKUTAT AREA WHICH WILL INCREASE
THROUGH THE DAY, BECOMING HEAVY AT TIMES BY THE LATE MORNING
EXCESSIVE RAIN RATES WILL CONTINUE THROUGH THE EVENING. TOTAL RAINFALL
WILL BE NEAR 1.5 INCHES BEFORE THE FRONT DRIFTS EAST
OF YAKUTAT LATE TONIGHT. LOCAL RIVERS AND STREAMS WILL RISE
SIGNIFICANTLY BUT AT THIS TIME ARE EXPECTED TO REMAIN IN THEIR BANKS.
RAIN WILL SPREAD OVER THE REST OF THE FORECAST AREA THROUGH THIS
MORNING AND MOVE SOUTH THROUGH TONIGHT. THE RAIN WILL THE
HEAVIEST ALONG THE OUTER COAST WITH MODERATE RAIN OVER THE NORTH CENTRAL
AREAS. RAIN AMOUNTS WILL RANGE FROM 0.5 TO 1.25 INCHES THROUGH
TONIGHT.

A BARRIER JET ASSOCIATED WITH THE FRONT IS PRODUCING GALE FORCE WIND OVER
THE NORTHERN GULF AT THIS TIME. AS THE FRONT DRIFTS EAST THROUGH TODAY,
GALES TO SMALL CRAFT WINDS WILL SPREAD INTO THE EASTERN GULF WITH SEAS
BUILDING TO 8 TO 10 FEET. AS THE FRONT APPROACHES THE EASTERN GULF, SMALL
CRAFT WINDS WILL DEVELOP NEAR CROSS SOUND BY EARLY THIS EVENING. THE
INNER CHANNELS WILL SEE RELATIVELY LIGHT WINDS THROUGH TODAY BUT THE
SURFACE RIDGE WILL SHARPEN UP THIS AFTERNOON AS THE FRONT MOVES EAST.
MINIMAL SMALL CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 15 KTN OVER
SOUTHERN LYNN AS A RESULT. THESE WINDS WILL DIMINISH IN THE EVENING AND
SWITCH TO THE NORTH AS THE RIDGE GETS PUSHED OFF TO THE EAST BY THE
FRONT. WIND SPEEDS WILL BE LESS THAN 15 KT OVERNIGHT AS THE PRESSURE
GRADIENT WILL BE ON THE LIGHTER SIDE WITH PARALLEL FLOW. LIGHTER WINDS
WILL PERSIST OVER N/S CHANNELS TONIGHT GENERALLY LESS THAN 15 KT BUT
THE E/W CHANNELS WILL INCREASE TO 20 TO 25 KT THROUGH TONIGHT AND
THESE CONDITIONS WILL SPREAD OVER THE SOUTHERN HALF OF THE PANHANDLE
LATER ON TONIGHT.

LAND WINDS WILL BE THE STRONGEST ALONG THE COASTAL AREAS WITH SOME
HIGHER GUSTS THIS AFTERNOON OVER THE NORTHERN GULF AND TONIGHT
OVER THE EASTERN GULF. THE INNER CHANNELS WILL SEE SOME INCREASE
IN WIND SPEEDS BUT GENERALLY BE 10 TO 20 MPH.

OVERALL THERE IS AVERAGE FORECASTER CONFIDENCE THROUGH THE SHORT
TERM PERIOD AND A MIX OF THE 06ZNAM/GFS AND 00Z EC WAS USED.

.LONG TERM...HURRICANE IGNACIO IS STILL CAUSING MAJOR DIVERGENCE
IN MODEL SOLUTIONS. MOST RECENT BEST TRACK FROM THE CENTRAL
PACIFIC HURRICAN CENTER HAS THE STORM TRACKING ACROSS HAIDA GWAII
LATE MONDAY NIGHT OR EARLY TUESDAY. NCEP GFS ENSEMBLE TRACK
GUIDANCE FROM 4PM YESTERDAY AFTERNOON FANS OUT SIGNIFICANTLY EAST
OF 150W, SO CONFIDENCE IN THE CURRENT FORECAST IN TERMS OF LOW
TRACK AND ASSOCIATED WIND FIELD BEYOND MONDAY AFTERNOON IS
DECIDEDLY BELOW AVERAGE.

AHEAD OF IGNACIO, A WEATHER FRONT THAT MOVES ASHORE DURING THE
SHORT TERM FORECAST PERIOD WILL MOVE SOUTH ON SATURDAY. TROPICAL
MOISTURE CONNECTION UNRELATED TO IGNACIO WILL RESULT IN MODERATE
RAIN RATES FOR THE CENTRAL AND SOUTHERN OUTER COAST SATURDAY
MORNING. WRAP AROUND SHOWER ACTIVITY WILL KEEP MUCH OF SOUTHEAST
ALASKA WET FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. A WEAK LOW
WILL BRING MORE RAIN IN ON MONDAY AND IT CURRENT MODELS ARE
MERGING THIS PRECIP FIELD WITH SOME OF THE RAIN ASSOCIATED WITH
IGNACIO. CURRENT FORECAST REFLECTS MODERATE RAIN OVER THE NORTHERN
HALF OF THE PANHANDLE, BUT WIDESPREAD HEAVY RAIN FOR LOCATIONS
SOUTH OF ANGOON MONDAY NIGHT.

USED A BLEND OF GFS AND ECMWF FOR UPDATES TO PRESSURE AND WIND
OVER THE GULF THROUGH SUNDAY NIGHT, THEN TRENDED TOWARDS WPC ON
MONDAY. POP AND QPF FROM GFS, CANADIAN NH AND ECMWF. LITTLE CHANGE
TO TEMPS. OVERALL FORECAST CONFIDENCE IS AVERAGE THROUGH SUNDAY,
THEN FALLS TO BELOW AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-033-035-036-041-042.

&&

$$

ABJ/FRITSCH

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 041437
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
626 AM AKDT FRI SEP 4 2015

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS A LOW PRESSURE
SYSTEM OVER THE WESTERN GULF WITH AN ASSOCIATED WEATHER FRONT
OVER THE CENTRAL GULF. THIS LOW AND FRONT WILL DRIFT EAST THROUGH
THE SHORT TERM PERIOD WITH THE FRONT MOVING OVER THE COASTAL AREAS
LATE THIS AFTERNOON AND THROUGH THE PANHANDLE TONIGHT. THIS
SYSTEM HAS TROPICAL MOISTURE ASSOCIATED WITH THE FRONT AS SEEN
FROM THE PRECIPITABLE WATER IMAGERY PW VALUES OF 1.2 TO 1.5
INCHES ARE AROUND 150 PERCENT NORMAL FOR THIS TIME OF YEAR.

LIGHT RAIN HAS STARTED IN THE YAKUTAT AREA WHICH WILL INCREASE
THROUGH THE DAY, BECOMING HEAVY AT TIMES BY THE LATE MORNING
EXCESSIVE RAIN RATES WILL CONTINUE THROUGH THE EVENING. TOTAL RAINFALL
WILL BE NEAR 1.5 INCHES BEFORE THE FRONT DRIFTS EAST
OF YAKUTAT LATE TONIGHT. LOCAL RIVERS AND STREAMS WILL RISE
SIGNIFICANTLY BUT AT THIS TIME ARE EXPECTED TO REMAIN IN THEIR BANKS.
RAIN WILL SPREAD OVER THE REST OF THE FORECAST AREA THROUGH THIS
MORNING AND MOVE SOUTH THROUGH TONIGHT. THE RAIN WILL THE
HEAVIEST ALONG THE OUTER COAST WITH MODERATE RAIN OVER THE NORTH CENTRAL
AREAS. RAIN AMOUNTS WILL RANGE FROM 0.5 TO 1.25 INCHES THROUGH
TONIGHT.

A BARRIER JET ASSOCIATED WITH THE FRONT IS PRODUCING GALE FORCE WIND OVER
THE NORTHERN GULF AT THIS TIME. AS THE FRONT DRIFTS EAST THROUGH TODAY,
GALES TO SMALL CRAFT WINDS WILL SPREAD INTO THE EASTERN GULF WITH SEAS
BUILDING TO 8 TO 10 FEET. AS THE FRONT APPROACHES THE EASTERN GULF, SMALL
CRAFT WINDS WILL DEVELOP NEAR CROSS SOUND BY EARLY THIS EVENING. THE
INNER CHANNELS WILL SEE RELATIVELY LIGHT WINDS THROUGH TODAY BUT THE
SURFACE RIDGE WILL SHARPEN UP THIS AFTERNOON AS THE FRONT MOVES EAST.
MINIMAL SMALL CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 15 KTN OVER
SOUTHERN LYNN AS A RESULT. THESE WINDS WILL DIMINISH IN THE EVENING AND
SWITCH TO THE NORTH AS THE RIDGE GETS PUSHED OFF TO THE EAST BY THE
FRONT. WIND SPEEDS WILL BE LESS THAN 15 KT OVERNIGHT AS THE PRESSURE
GRADIENT WILL BE ON THE LIGHTER SIDE WITH PARALLEL FLOW. LIGHTER WINDS
WILL PERSIST OVER N/S CHANNELS TONIGHT GENERALLY LESS THAN 15 KT BUT
THE E/W CHANNELS WILL INCREASE TO 20 TO 25 KT THROUGH TONIGHT AND
THESE CONDITIONS WILL SPREAD OVER THE SOUTHERN HALF OF THE PANHANDLE
LATER ON TONIGHT.

LAND WINDS WILL BE THE STRONGEST ALONG THE COASTAL AREAS WITH SOME
HIGHER GUSTS THIS AFTERNOON OVER THE NORTHERN GULF AND TONIGHT
OVER THE EASTERN GULF. THE INNER CHANNELS WILL SEE SOME INCREASE
IN WIND SPEEDS BUT GENERALLY BE 10 TO 20 MPH.

OVERALL THERE IS AVERAGE FORECASTER CONFIDENCE THROUGH THE SHORT
TERM PERIOD AND A MIX OF THE 06ZNAM/GFS AND 00Z EC WAS USED.

.LONG TERM...HURRICANE IGNACIO IS STILL CAUSING MAJOR DIVERGENCE
IN MODEL SOLUTIONS. MOST RECENT BEST TRACK FROM THE CENTRAL
PACIFIC HURRICAN CENTER HAS THE STORM TRACKING ACROSS HAIDA GWAII
LATE MONDAY NIGHT OR EARLY TUESDAY. NCEP GFS ENSEMBLE TRACK
GUIDANCE FROM 4PM YESTERDAY AFTERNOON FANS OUT SIGNIFICANTLY EAST
OF 150W, SO CONFIDENCE IN THE CURRENT FORECAST IN TERMS OF LOW
TRACK AND ASSOCIATED WIND FIELD BEYOND MONDAY AFTERNOON IS
DECIDEDLY BELOW AVERAGE.

AHEAD OF IGNACIO, A WEATHER FRONT THAT MOVES ASHORE DURING THE
SHORT TERM FORECAST PERIOD WILL MOVE SOUTH ON SATURDAY. TROPICAL
MOISTURE CONNECTION UNRELATED TO IGNACIO WILL RESULT IN MODERATE
RAIN RATES FOR THE CENTRAL AND SOUTHERN OUTER COAST SATURDAY
MORNING. WRAP AROUND SHOWER ACTIVITY WILL KEEP MUCH OF SOUTHEAST
ALASKA WET FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. A WEAK LOW
WILL BRING MORE RAIN IN ON MONDAY AND IT CURRENT MODELS ARE
MERGING THIS PRECIP FIELD WITH SOME OF THE RAIN ASSOCIATED WITH
IGNACIO. CURRENT FORECAST REFLECTS MODERATE RAIN OVER THE NORTHERN
HALF OF THE PANHANDLE, BUT WIDESPREAD HEAVY RAIN FOR LOCATIONS
SOUTH OF ANGOON MONDAY NIGHT.

USED A BLEND OF GFS AND ECMWF FOR UPDATES TO PRESSURE AND WIND
OVER THE GULF THROUGH SUNDAY NIGHT, THEN TRENDED TOWARDS WPC ON
MONDAY. POP AND QPF FROM GFS, CANADIAN NH AND ECMWF. LITTLE CHANGE
TO TEMPS. OVERALL FORECAST CONFIDENCE IS AVERAGE THROUGH SUNDAY,
THEN FALLS TO BELOW AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-033-035-036-041-042.

&&

$$

ABJ/FRITSCH

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 041437
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
626 AM AKDT FRI SEP 4 2015

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS A LOW PRESSURE
SYSTEM OVER THE WESTERN GULF WITH AN ASSOCIATED WEATHER FRONT
OVER THE CENTRAL GULF. THIS LOW AND FRONT WILL DRIFT EAST THROUGH
THE SHORT TERM PERIOD WITH THE FRONT MOVING OVER THE COASTAL AREAS
LATE THIS AFTERNOON AND THROUGH THE PANHANDLE TONIGHT. THIS
SYSTEM HAS TROPICAL MOISTURE ASSOCIATED WITH THE FRONT AS SEEN
FROM THE PRECIPITABLE WATER IMAGERY PW VALUES OF 1.2 TO 1.5
INCHES ARE AROUND 150 PERCENT NORMAL FOR THIS TIME OF YEAR.

LIGHT RAIN HAS STARTED IN THE YAKUTAT AREA WHICH WILL INCREASE
THROUGH THE DAY, BECOMING HEAVY AT TIMES BY THE LATE MORNING
EXCESSIVE RAIN RATES WILL CONTINUE THROUGH THE EVENING. TOTAL RAINFALL
WILL BE NEAR 1.5 INCHES BEFORE THE FRONT DRIFTS EAST
OF YAKUTAT LATE TONIGHT. LOCAL RIVERS AND STREAMS WILL RISE
SIGNIFICANTLY BUT AT THIS TIME ARE EXPECTED TO REMAIN IN THEIR BANKS.
RAIN WILL SPREAD OVER THE REST OF THE FORECAST AREA THROUGH THIS
MORNING AND MOVE SOUTH THROUGH TONIGHT. THE RAIN WILL THE
HEAVIEST ALONG THE OUTER COAST WITH MODERATE RAIN OVER THE NORTH CENTRAL
AREAS. RAIN AMOUNTS WILL RANGE FROM 0.5 TO 1.25 INCHES THROUGH
TONIGHT.

A BARRIER JET ASSOCIATED WITH THE FRONT IS PRODUCING GALE FORCE WIND OVER
THE NORTHERN GULF AT THIS TIME. AS THE FRONT DRIFTS EAST THROUGH TODAY,
GALES TO SMALL CRAFT WINDS WILL SPREAD INTO THE EASTERN GULF WITH SEAS
BUILDING TO 8 TO 10 FEET. AS THE FRONT APPROACHES THE EASTERN GULF, SMALL
CRAFT WINDS WILL DEVELOP NEAR CROSS SOUND BY EARLY THIS EVENING. THE
INNER CHANNELS WILL SEE RELATIVELY LIGHT WINDS THROUGH TODAY BUT THE
SURFACE RIDGE WILL SHARPEN UP THIS AFTERNOON AS THE FRONT MOVES EAST.
MINIMAL SMALL CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 15 KTN OVER
SOUTHERN LYNN AS A RESULT. THESE WINDS WILL DIMINISH IN THE EVENING AND
SWITCH TO THE NORTH AS THE RIDGE GETS PUSHED OFF TO THE EAST BY THE
FRONT. WIND SPEEDS WILL BE LESS THAN 15 KT OVERNIGHT AS THE PRESSURE
GRADIENT WILL BE ON THE LIGHTER SIDE WITH PARALLEL FLOW. LIGHTER WINDS
WILL PERSIST OVER N/S CHANNELS TONIGHT GENERALLY LESS THAN 15 KT BUT
THE E/W CHANNELS WILL INCREASE TO 20 TO 25 KT THROUGH TONIGHT AND
THESE CONDITIONS WILL SPREAD OVER THE SOUTHERN HALF OF THE PANHANDLE
LATER ON TONIGHT.

LAND WINDS WILL BE THE STRONGEST ALONG THE COASTAL AREAS WITH SOME
HIGHER GUSTS THIS AFTERNOON OVER THE NORTHERN GULF AND TONIGHT
OVER THE EASTERN GULF. THE INNER CHANNELS WILL SEE SOME INCREASE
IN WIND SPEEDS BUT GENERALLY BE 10 TO 20 MPH.

OVERALL THERE IS AVERAGE FORECASTER CONFIDENCE THROUGH THE SHORT
TERM PERIOD AND A MIX OF THE 06ZNAM/GFS AND 00Z EC WAS USED.

.LONG TERM...HURRICANE IGNACIO IS STILL CAUSING MAJOR DIVERGENCE
IN MODEL SOLUTIONS. MOST RECENT BEST TRACK FROM THE CENTRAL
PACIFIC HURRICAN CENTER HAS THE STORM TRACKING ACROSS HAIDA GWAII
LATE MONDAY NIGHT OR EARLY TUESDAY. NCEP GFS ENSEMBLE TRACK
GUIDANCE FROM 4PM YESTERDAY AFTERNOON FANS OUT SIGNIFICANTLY EAST
OF 150W, SO CONFIDENCE IN THE CURRENT FORECAST IN TERMS OF LOW
TRACK AND ASSOCIATED WIND FIELD BEYOND MONDAY AFTERNOON IS
DECIDEDLY BELOW AVERAGE.

AHEAD OF IGNACIO, A WEATHER FRONT THAT MOVES ASHORE DURING THE
SHORT TERM FORECAST PERIOD WILL MOVE SOUTH ON SATURDAY. TROPICAL
MOISTURE CONNECTION UNRELATED TO IGNACIO WILL RESULT IN MODERATE
RAIN RATES FOR THE CENTRAL AND SOUTHERN OUTER COAST SATURDAY
MORNING. WRAP AROUND SHOWER ACTIVITY WILL KEEP MUCH OF SOUTHEAST
ALASKA WET FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. A WEAK LOW
WILL BRING MORE RAIN IN ON MONDAY AND IT CURRENT MODELS ARE
MERGING THIS PRECIP FIELD WITH SOME OF THE RAIN ASSOCIATED WITH
IGNACIO. CURRENT FORECAST REFLECTS MODERATE RAIN OVER THE NORTHERN
HALF OF THE PANHANDLE, BUT WIDESPREAD HEAVY RAIN FOR LOCATIONS
SOUTH OF ANGOON MONDAY NIGHT.

USED A BLEND OF GFS AND ECMWF FOR UPDATES TO PRESSURE AND WIND
OVER THE GULF THROUGH SUNDAY NIGHT, THEN TRENDED TOWARDS WPC ON
MONDAY. POP AND QPF FROM GFS, CANADIAN NH AND ECMWF. LITTLE CHANGE
TO TEMPS. OVERALL FORECAST CONFIDENCE IS AVERAGE THROUGH SUNDAY,
THEN FALLS TO BELOW AVERAGE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-033-035-036-041-042.

&&

$$

ABJ/FRITSCH

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU


  [top]

000
FXAK68 PAFC 041300
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT FRI SEP 4 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHWEST ALASKA
REGION WITH AN ASSOCIATED SHORTWAVE EXTENDING THROUGH THE AK
PENINSULA INTO THE NORTH PACIFIC. THIS IS PRODUCING WEAK
SOUTHWESTERLY FLOW IN THE LOWER LEVELS THROUGH THE SOUTHWEST
ALASKA REGION EXTENDING UP THROUGH THE SHELIKOF STRAIT AND COOK
INLET. WHILE...IN THE NORTHERN GULF THERE IS A WEAK LOW PRESSURE
SYSTEM AT THE SURFACE. THIS SYNOPTIC FEATURE IS RESULTING IN GALE
FORCE EASTERLY WINDS ALONG THE NORTHERN COAST AND DIMINISHES TO
SMALL CRAFT WINDS ON THE BACKSIDE OF THE LOW ALONG THE EASTERN
KENAI PENINSULA COASTLINE THIS MORNING. THE SATELLITE IMAGERY IS
SHOWING WIDESPREAD STRATUS AND FOG THROUGH THE BERING SEA AND
SPILLING OVER INTO THE SOUTHWEST COASTLINE. THE 110 KNOT JET
STREAK OVER THE LOWER GULF HAS TRANSITIONED TO A WESTERLY ZONAL
FLOW. THIS FEATURE IS STREAMING MOISTURE INTO THE GULF AND THE
SURFACE LOW IN THE NORTHERN GULF IS ADVECTING MOISTURE INTO THE
SOUTHCENTRAL ALASKA REGION WITH THE ONSHORE FLOW. THIS IS
REFLECTED WITH THE RADAR IMAGERY SHOWING WIDESPREAD RAIN THROUGH
THE SOUTHWEST/SOUTHCENTRAL REGION. WHILE...OVER IN THE WESTERN
BERING SEA THERE IS A WEAK SURFACE LOW THAT IS FALLING APART AND
WILL CONTINUE TO BRING STRATUS ACCOMPANIED WITH SHOWERY
PRECIPITATION/FOG THIS MORNING.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD AGREEMENT WITH THE WEAK LOW PRESSURE
SYSTEMS IN THE BERING SEA. WHILE...OVER IN THE GULF THERE IS A
WEAK LOW THAT THE MODELS ARE IN DISAGREEMENT AS IT TRACKS FARTHER
EASTWARD. THE NAM IS SLOWER WITH THIS LOW AND DEPICTS THE LOW
STALLING OVER THE EASTERN GULF BY SATURDAY BEFORE TRACKING NEAR
SITKA BY LATE SATURDAY NIGHT. WHERE...THE EC/GFS MODELS ARE IN
BETTER AGREEMENT AND MORE CONSISTENT WITH THIS SYNOPTIC FEATURE.
THE NAM WAS THE PREFERRED MODEL BRIEFLY AND TRANSITIONED TO EC/GFS
HEADING INTO THE WEEKEND. THE FORECAST CONFIDENCE IS ABOVE AVERAGE.

&&

.FIRE WEATHER...
THE SOUTHWEST ALASKA REGION WILL CONTINUE IN ONSHORE FLOW WITH
A WET SHOWERY WEATHER REGIME WITH COOLER TEMPERATURE THROUGH THE
NEXT SEVERAL DAYS. THE MOISTURE WILL SPREAD INTO THE SOUTHCENTRAL
AREA WITH WEAK WINDS AND RELATIVE HUMIDITIES REMAINING WELL ABOVE
ADVISORY OR WARNING THRESHOLDS AS WE HEAD INTO NEXT WEEK.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE UPPER LEVEL LOW WILL MOVE THROUGH SOUTHCENTRAL ALASKA TODAY
WHICH WILL TURN THE STEADY RAINFALL TO SHOWERS OVER MOST AREAS.
SOME OF THE SHOWERS IN THE COOK INLET AND SUSITNA VALLEY MAY BE
BRIEFLY HEAVY THIS MORNING. A TRANSITORY UPPER LEVEL RIDGE WILL
MOVE ACROSS THE REGION SATURDAY BUT THERE WILL BE ENOUGH MOISTURE
AROUND THAT THERE WILL NOT BE MUCH CLEARING DUE TO IT...JUST A
REDUCTION IN SHOWER ACTIVITY. A BARRIER JET ALONG THE NORTH GULF
COAST NEAR HINCHINBROOK ENTRANCE WILL SLOWLY WEAKEN THROUGH
TONIGHT AS THE SURFACE LOW MOVES EAST OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE
EASTERN BERING INTO THE MAINLAND...BRINGING A WIDESPREAD AREA OF
MOISTURE AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE
THROUGH TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE...EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE INLAND WITH
THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK IN RAIN
BEFORE ANOTHER LOW OVER THE BERING MOVES INTO SOUTHWEST
SATURDAY...BRINGING ANOTHER SHOT OF INTERMITTENT RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY...WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING...BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TO TAPER OFF ACROSS SOUTHERN ALASKA THIS
WEEKEND AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT
FURTHER INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER
THE PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS
PARTING SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING
SEA DROP SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN VS THE
AMPLIFIED PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH
OF ALASKA IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE
BERING SEA INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK
MODELS ARE HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE
MAINLAND AND JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING
IN AN UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS
A RESULT...NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING...BEFORE TRACKING INLAND OVER THE SOUTHERN
PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING AND PLACEMENT OF THIS SYSTEM...AS WELL AS OTHER SYSTEMS OUT
WEST...LEAVING FORECAST CONFIDENCE LOW THROUGH MUCH OF THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121 125.
MARINE...GALE WARNING...119.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...TP



000
FXAK68 PAFC 041300
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT FRI SEP 4 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHWEST ALASKA
REGION WITH AN ASSOCIATED SHORTWAVE EXTENDING THROUGH THE AK
PENINSULA INTO THE NORTH PACIFIC. THIS IS PRODUCING WEAK
SOUTHWESTERLY FLOW IN THE LOWER LEVELS THROUGH THE SOUTHWEST
ALASKA REGION EXTENDING UP THROUGH THE SHELIKOF STRAIT AND COOK
INLET. WHILE...IN THE NORTHERN GULF THERE IS A WEAK LOW PRESSURE
SYSTEM AT THE SURFACE. THIS SYNOPTIC FEATURE IS RESULTING IN GALE
FORCE EASTERLY WINDS ALONG THE NORTHERN COAST AND DIMINISHES TO
SMALL CRAFT WINDS ON THE BACKSIDE OF THE LOW ALONG THE EASTERN
KENAI PENINSULA COASTLINE THIS MORNING. THE SATELLITE IMAGERY IS
SHOWING WIDESPREAD STRATUS AND FOG THROUGH THE BERING SEA AND
SPILLING OVER INTO THE SOUTHWEST COASTLINE. THE 110 KNOT JET
STREAK OVER THE LOWER GULF HAS TRANSITIONED TO A WESTERLY ZONAL
FLOW. THIS FEATURE IS STREAMING MOISTURE INTO THE GULF AND THE
SURFACE LOW IN THE NORTHERN GULF IS ADVECTING MOISTURE INTO THE
SOUTHCENTRAL ALASKA REGION WITH THE ONSHORE FLOW. THIS IS
REFLECTED WITH THE RADAR IMAGERY SHOWING WIDESPREAD RAIN THROUGH
THE SOUTHWEST/SOUTHCENTRAL REGION. WHILE...OVER IN THE WESTERN
BERING SEA THERE IS A WEAK SURFACE LOW THAT IS FALLING APART AND
WILL CONTINUE TO BRING STRATUS ACCOMPANIED WITH SHOWERY
PRECIPITATION/FOG THIS MORNING.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD AGREEMENT WITH THE WEAK LOW PRESSURE
SYSTEMS IN THE BERING SEA. WHILE...OVER IN THE GULF THERE IS A
WEAK LOW THAT THE MODELS ARE IN DISAGREEMENT AS IT TRACKS FARTHER
EASTWARD. THE NAM IS SLOWER WITH THIS LOW AND DEPICTS THE LOW
STALLING OVER THE EASTERN GULF BY SATURDAY BEFORE TRACKING NEAR
SITKA BY LATE SATURDAY NIGHT. WHERE...THE EC/GFS MODELS ARE IN
BETTER AGREEMENT AND MORE CONSISTENT WITH THIS SYNOPTIC FEATURE.
THE NAM WAS THE PREFERRED MODEL BRIEFLY AND TRANSITIONED TO EC/GFS
HEADING INTO THE WEEKEND. THE FORECAST CONFIDENCE IS ABOVE AVERAGE.

&&

.FIRE WEATHER...
THE SOUTHWEST ALASKA REGION WILL CONTINUE IN ONSHORE FLOW WITH
A WET SHOWERY WEATHER REGIME WITH COOLER TEMPERATURE THROUGH THE
NEXT SEVERAL DAYS. THE MOISTURE WILL SPREAD INTO THE SOUTHCENTRAL
AREA WITH WEAK WINDS AND RELATIVE HUMIDITIES REMAINING WELL ABOVE
ADVISORY OR WARNING THRESHOLDS AS WE HEAD INTO NEXT WEEK.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE UPPER LEVEL LOW WILL MOVE THROUGH SOUTHCENTRAL ALASKA TODAY
WHICH WILL TURN THE STEADY RAINFALL TO SHOWERS OVER MOST AREAS.
SOME OF THE SHOWERS IN THE COOK INLET AND SUSITNA VALLEY MAY BE
BRIEFLY HEAVY THIS MORNING. A TRANSITORY UPPER LEVEL RIDGE WILL
MOVE ACROSS THE REGION SATURDAY BUT THERE WILL BE ENOUGH MOISTURE
AROUND THAT THERE WILL NOT BE MUCH CLEARING DUE TO IT...JUST A
REDUCTION IN SHOWER ACTIVITY. A BARRIER JET ALONG THE NORTH GULF
COAST NEAR HINCHINBROOK ENTRANCE WILL SLOWLY WEAKEN THROUGH
TONIGHT AS THE SURFACE LOW MOVES EAST OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE
EASTERN BERING INTO THE MAINLAND...BRINGING A WIDESPREAD AREA OF
MOISTURE AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE
THROUGH TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE...EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE INLAND WITH
THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK IN RAIN
BEFORE ANOTHER LOW OVER THE BERING MOVES INTO SOUTHWEST
SATURDAY...BRINGING ANOTHER SHOT OF INTERMITTENT RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY...WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING...BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TO TAPER OFF ACROSS SOUTHERN ALASKA THIS
WEEKEND AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT
FURTHER INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER
THE PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS
PARTING SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING
SEA DROP SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN VS THE
AMPLIFIED PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH
OF ALASKA IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE
BERING SEA INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK
MODELS ARE HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE
MAINLAND AND JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING
IN AN UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS
A RESULT...NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING...BEFORE TRACKING INLAND OVER THE SOUTHERN
PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING AND PLACEMENT OF THIS SYSTEM...AS WELL AS OTHER SYSTEMS OUT
WEST...LEAVING FORECAST CONFIDENCE LOW THROUGH MUCH OF THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121 125.
MARINE...GALE WARNING...119.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...TP



000
FXAK68 PAFC 041300
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT FRI SEP 4 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHWEST ALASKA
REGION WITH AN ASSOCIATED SHORTWAVE EXTENDING THROUGH THE AK
PENINSULA INTO THE NORTH PACIFIC. THIS IS PRODUCING WEAK
SOUTHWESTERLY FLOW IN THE LOWER LEVELS THROUGH THE SOUTHWEST
ALASKA REGION EXTENDING UP THROUGH THE SHELIKOF STRAIT AND COOK
INLET. WHILE...IN THE NORTHERN GULF THERE IS A WEAK LOW PRESSURE
SYSTEM AT THE SURFACE. THIS SYNOPTIC FEATURE IS RESULTING IN GALE
FORCE EASTERLY WINDS ALONG THE NORTHERN COAST AND DIMINISHES TO
SMALL CRAFT WINDS ON THE BACKSIDE OF THE LOW ALONG THE EASTERN
KENAI PENINSULA COASTLINE THIS MORNING. THE SATELLITE IMAGERY IS
SHOWING WIDESPREAD STRATUS AND FOG THROUGH THE BERING SEA AND
SPILLING OVER INTO THE SOUTHWEST COASTLINE. THE 110 KNOT JET
STREAK OVER THE LOWER GULF HAS TRANSITIONED TO A WESTERLY ZONAL
FLOW. THIS FEATURE IS STREAMING MOISTURE INTO THE GULF AND THE
SURFACE LOW IN THE NORTHERN GULF IS ADVECTING MOISTURE INTO THE
SOUTHCENTRAL ALASKA REGION WITH THE ONSHORE FLOW. THIS IS
REFLECTED WITH THE RADAR IMAGERY SHOWING WIDESPREAD RAIN THROUGH
THE SOUTHWEST/SOUTHCENTRAL REGION. WHILE...OVER IN THE WESTERN
BERING SEA THERE IS A WEAK SURFACE LOW THAT IS FALLING APART AND
WILL CONTINUE TO BRING STRATUS ACCOMPANIED WITH SHOWERY
PRECIPITATION/FOG THIS MORNING.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD AGREEMENT WITH THE WEAK LOW PRESSURE
SYSTEMS IN THE BERING SEA. WHILE...OVER IN THE GULF THERE IS A
WEAK LOW THAT THE MODELS ARE IN DISAGREEMENT AS IT TRACKS FARTHER
EASTWARD. THE NAM IS SLOWER WITH THIS LOW AND DEPICTS THE LOW
STALLING OVER THE EASTERN GULF BY SATURDAY BEFORE TRACKING NEAR
SITKA BY LATE SATURDAY NIGHT. WHERE...THE EC/GFS MODELS ARE IN
BETTER AGREEMENT AND MORE CONSISTENT WITH THIS SYNOPTIC FEATURE.
THE NAM WAS THE PREFERRED MODEL BRIEFLY AND TRANSITIONED TO EC/GFS
HEADING INTO THE WEEKEND. THE FORECAST CONFIDENCE IS ABOVE AVERAGE.

&&

.FIRE WEATHER...
THE SOUTHWEST ALASKA REGION WILL CONTINUE IN ONSHORE FLOW WITH
A WET SHOWERY WEATHER REGIME WITH COOLER TEMPERATURE THROUGH THE
NEXT SEVERAL DAYS. THE MOISTURE WILL SPREAD INTO THE SOUTHCENTRAL
AREA WITH WEAK WINDS AND RELATIVE HUMIDITIES REMAINING WELL ABOVE
ADVISORY OR WARNING THRESHOLDS AS WE HEAD INTO NEXT WEEK.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE UPPER LEVEL LOW WILL MOVE THROUGH SOUTHCENTRAL ALASKA TODAY
WHICH WILL TURN THE STEADY RAINFALL TO SHOWERS OVER MOST AREAS.
SOME OF THE SHOWERS IN THE COOK INLET AND SUSITNA VALLEY MAY BE
BRIEFLY HEAVY THIS MORNING. A TRANSITORY UPPER LEVEL RIDGE WILL
MOVE ACROSS THE REGION SATURDAY BUT THERE WILL BE ENOUGH MOISTURE
AROUND THAT THERE WILL NOT BE MUCH CLEARING DUE TO IT...JUST A
REDUCTION IN SHOWER ACTIVITY. A BARRIER JET ALONG THE NORTH GULF
COAST NEAR HINCHINBROOK ENTRANCE WILL SLOWLY WEAKEN THROUGH
TONIGHT AS THE SURFACE LOW MOVES EAST OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE
EASTERN BERING INTO THE MAINLAND...BRINGING A WIDESPREAD AREA OF
MOISTURE AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE
THROUGH TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE...EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE INLAND WITH
THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK IN RAIN
BEFORE ANOTHER LOW OVER THE BERING MOVES INTO SOUTHWEST
SATURDAY...BRINGING ANOTHER SHOT OF INTERMITTENT RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY...WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING...BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TO TAPER OFF ACROSS SOUTHERN ALASKA THIS
WEEKEND AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT
FURTHER INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER
THE PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS
PARTING SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING
SEA DROP SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN VS THE
AMPLIFIED PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH
OF ALASKA IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE
BERING SEA INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK
MODELS ARE HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE
MAINLAND AND JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING
IN AN UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS
A RESULT...NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING...BEFORE TRACKING INLAND OVER THE SOUTHERN
PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING AND PLACEMENT OF THIS SYSTEM...AS WELL AS OTHER SYSTEMS OUT
WEST...LEAVING FORECAST CONFIDENCE LOW THROUGH MUCH OF THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121 125.
MARINE...GALE WARNING...119.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...TP



000
FXAK68 PAFC 041300
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT FRI SEP 4 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHWEST ALASKA
REGION WITH AN ASSOCIATED SHORTWAVE EXTENDING THROUGH THE AK
PENINSULA INTO THE NORTH PACIFIC. THIS IS PRODUCING WEAK
SOUTHWESTERLY FLOW IN THE LOWER LEVELS THROUGH THE SOUTHWEST
ALASKA REGION EXTENDING UP THROUGH THE SHELIKOF STRAIT AND COOK
INLET. WHILE...IN THE NORTHERN GULF THERE IS A WEAK LOW PRESSURE
SYSTEM AT THE SURFACE. THIS SYNOPTIC FEATURE IS RESULTING IN GALE
FORCE EASTERLY WINDS ALONG THE NORTHERN COAST AND DIMINISHES TO
SMALL CRAFT WINDS ON THE BACKSIDE OF THE LOW ALONG THE EASTERN
KENAI PENINSULA COASTLINE THIS MORNING. THE SATELLITE IMAGERY IS
SHOWING WIDESPREAD STRATUS AND FOG THROUGH THE BERING SEA AND
SPILLING OVER INTO THE SOUTHWEST COASTLINE. THE 110 KNOT JET
STREAK OVER THE LOWER GULF HAS TRANSITIONED TO A WESTERLY ZONAL
FLOW. THIS FEATURE IS STREAMING MOISTURE INTO THE GULF AND THE
SURFACE LOW IN THE NORTHERN GULF IS ADVECTING MOISTURE INTO THE
SOUTHCENTRAL ALASKA REGION WITH THE ONSHORE FLOW. THIS IS
REFLECTED WITH THE RADAR IMAGERY SHOWING WIDESPREAD RAIN THROUGH
THE SOUTHWEST/SOUTHCENTRAL REGION. WHILE...OVER IN THE WESTERN
BERING SEA THERE IS A WEAK SURFACE LOW THAT IS FALLING APART AND
WILL CONTINUE TO BRING STRATUS ACCOMPANIED WITH SHOWERY
PRECIPITATION/FOG THIS MORNING.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD AGREEMENT WITH THE WEAK LOW PRESSURE
SYSTEMS IN THE BERING SEA. WHILE...OVER IN THE GULF THERE IS A
WEAK LOW THAT THE MODELS ARE IN DISAGREEMENT AS IT TRACKS FARTHER
EASTWARD. THE NAM IS SLOWER WITH THIS LOW AND DEPICTS THE LOW
STALLING OVER THE EASTERN GULF BY SATURDAY BEFORE TRACKING NEAR
SITKA BY LATE SATURDAY NIGHT. WHERE...THE EC/GFS MODELS ARE IN
BETTER AGREEMENT AND MORE CONSISTENT WITH THIS SYNOPTIC FEATURE.
THE NAM WAS THE PREFERRED MODEL BRIEFLY AND TRANSITIONED TO EC/GFS
HEADING INTO THE WEEKEND. THE FORECAST CONFIDENCE IS ABOVE AVERAGE.

&&

.FIRE WEATHER...
THE SOUTHWEST ALASKA REGION WILL CONTINUE IN ONSHORE FLOW WITH
A WET SHOWERY WEATHER REGIME WITH COOLER TEMPERATURE THROUGH THE
NEXT SEVERAL DAYS. THE MOISTURE WILL SPREAD INTO THE SOUTHCENTRAL
AREA WITH WEAK WINDS AND RELATIVE HUMIDITIES REMAINING WELL ABOVE
ADVISORY OR WARNING THRESHOLDS AS WE HEAD INTO NEXT WEEK.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE UPPER LEVEL LOW WILL MOVE THROUGH SOUTHCENTRAL ALASKA TODAY
WHICH WILL TURN THE STEADY RAINFALL TO SHOWERS OVER MOST AREAS.
SOME OF THE SHOWERS IN THE COOK INLET AND SUSITNA VALLEY MAY BE
BRIEFLY HEAVY THIS MORNING. A TRANSITORY UPPER LEVEL RIDGE WILL
MOVE ACROSS THE REGION SATURDAY BUT THERE WILL BE ENOUGH MOISTURE
AROUND THAT THERE WILL NOT BE MUCH CLEARING DUE TO IT...JUST A
REDUCTION IN SHOWER ACTIVITY. A BARRIER JET ALONG THE NORTH GULF
COAST NEAR HINCHINBROOK ENTRANCE WILL SLOWLY WEAKEN THROUGH
TONIGHT AS THE SURFACE LOW MOVES EAST OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE
EASTERN BERING INTO THE MAINLAND...BRINGING A WIDESPREAD AREA OF
MOISTURE AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE
THROUGH TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE...EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE INLAND WITH
THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK IN RAIN
BEFORE ANOTHER LOW OVER THE BERING MOVES INTO SOUTHWEST
SATURDAY...BRINGING ANOTHER SHOT OF INTERMITTENT RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY...WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING...BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TO TAPER OFF ACROSS SOUTHERN ALASKA THIS
WEEKEND AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT
FURTHER INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER
THE PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS
PARTING SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING
SEA DROP SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN VS THE
AMPLIFIED PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH
OF ALASKA IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE
BERING SEA INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK
MODELS ARE HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE
MAINLAND AND JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING
IN AN UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS
A RESULT...NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING...BEFORE TRACKING INLAND OVER THE SOUTHERN
PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING AND PLACEMENT OF THIS SYSTEM...AS WELL AS OTHER SYSTEMS OUT
WEST...LEAVING FORECAST CONFIDENCE LOW THROUGH MUCH OF THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121 125.
MARINE...GALE WARNING...119.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...TP



000
FXAK69 PAFG 041121
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
321 AM AKDT FRI SEP 4 2015

.DISCUSSION...

UPPER LEVELS...
AT 500 MB...AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN
MAINLAND OF NORTHERN ALASKA WILL PERSIST THROUGH TONIGHT...THEN
BECOME PARTIALLY PINCHED OFF BY SUNDAY NIGHT AS AN UPPER LOW
ADVANCES EASTWARD INTO THE GULF OF ALASKA AND A LOW PRESSURE
TROUGH DIGS SOUTHWARD INTO THE CHUKCHI SEA.

A WEAK UPPER LOW CENTERED NEAR BETHEL WILL DISSIPATE OVER
THE SOUTHWEST INTERIOR THIS AFTERNOON.

AN UPPER LOW CENTERED NEAR 50N/176E...ABOUT 250 MILES WEST OF
ST MATTHEW ISLAND...WILL MOVE EASTWARD TO NEAR BRISTOL BAY BY
SUNDAY MORNING AND INTO THE NORTHERN GULF OF ALASKA BY SUNDAY
NIGHT.

AN LOW AMPLITUDE SHORT WAVE TROUGH OVER THE FAR NORTHWEST ARCTIC
OCEAN WILL MOVE SOUTHEASTWARD...TROUGH AXIS SUNDAY MORNING WILL
EXTENDING ALONG 180W FROM 72N TO NEAR WRANGEL ISLAND. BY MONDAY
MORNING THE TROUGH WILL DIG SOUTHWARD AND INCREASE IN
AMPLITUDE...TROUGH AXIS ENDING FROM 80N/150W TO WAINWRIGHT AND
SOUTHWESTWARD TO THE BERING STRAIT. THE TROUGH WILL CONTINUE TO
DIG SOUTHWESTWARD THROUGH MONDAY MORNING...TROUGH AXIS MONDAY
MORNING EXTENDING FROM 78N/140W TO DEADHORSE AND SOUTHWESTWARD
TO KUSKOKWIM BAY. THE DIGGING TROUGH WILL BRING COLDER AIR
ALOFT INITIALLY TO THE ARCTIC COAST...SPREADING TO THE
EASTERN BERING SEA AND THE ALASKA WEST COAST BY TUESDAY
MORNING.

THROUGH TUESDAY MORNING...THERE ARE ONLY MINOR DIFFERENCES
BETWEEN THE OPERATIONAL GFS AND ECMWF RUNS FROM THE SEP 4/00Z
CYCLE.

SURFACE...
A 1005 MB LOW NEAR BETHEL WILL WEAKEN TO A BARELY DISCERNIBLE
1013 MB CENTER OVER THE CENTRAL SEWARD PENINSULA BY SATURDAY
MORNING. THE ASSOCIATED OCCLUDED FRONT...CURRENTLY EXTENDING
FROM THE YUKON DELTA TO ANCHORAGE AND VALDEZ...WILL CONTINUE TO
STRETCH OUT EASTWARD AND A BIT NORTHWARD...WHILE WEAKENING DURING
THE NEXT 24 HOURS. A 1027 MB HIGH CENTERED NEAR 76N/128E... ABOUT
250 MILES NORTHEAST OF BARTER ISLAND...WILL MOVE EASTWARD INTO
THE CANADIAN ARCHIPELAGO THROUGH FRIDAY NIGHT...WITH A WEAK RIDGE
PERSISTING ALONG 75-76N WESTWARD ACROSS THE BEAUFORT SEA AND INTO
THE RUSSIAN ARCTIC OCEAN. THIS RIDGE WILL WEAKEN AND BE PUSHED
SOUTHWARD TO JUST NORTH OF THE ALASKAN ARCTIC COAST BY SUNDAY
AFTERNOON AS A LOW PRESSURE TROUGH APPROACHES FROM THE NORTHWEST.

ARCTIC COAST...
OVER THE ARCTIC COAST EAST OF WAINWRIGHT...EAST WINDS 20-30 MPH
WITH LOCAL GUSTS TO AROUND 35 MPH WILL CONTINUE TODAY...DIMINISHING
TO 10-15 MPH BY SATURDAY MORNING. WINDS WILL BE LIGHTER OVER AREAS
TO THE WEST. WIDESPREAD LOW STRATUS WILL PERSIST OVER AREAS EAST
OF WAINWRIGHT...WITH AREAS OF FOG DURING THE LATE NIGHT AND
MORNING HOURS. LITTLE OR NO PRECIPITATION IS EXPECTED THROUGH
SUNDAY. SOMEWHAT COLDER TEMPERATURE ARE EXPECTED NEXT WEEK WITH
SNOW POSSIBLE...ESPECIALLY IN THE BROOKS RANGE.

CENTRAL AND EASTERN INTERIOR...
RAIN OVER THE ALASKA RANGE AND NEARBY AREAS TODAY...TAPERING TO
MAINLY SCATTERED SHOWERS BY LATE TONIGHT. ISOLATED TO SCATTERED
SHOWERS CONTINUING SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED
THROUGH SUNDAY.

WESTERN INTERIOR...
RAIN SOUTH OF GALENA SOUTH TODAY...TAPERING TO MAINLY SCATTERED
SHOWERS TONIGHT. ISOLATED TO SCATTERED SHOWERS OVER THE SOUTHERN
AREAS SATURDAY AND SATURDAY NIGHT.

WEST COAST...
OVER AREAS SOUTH OF UNALAKLEET...WIDESPREAD RAIN OR SHOWERS
THIS MORNING...TAPERING TO SCATTERED SHOWERS THIS AFTERNOON.
SCATTERED SHOWERS OVER THE SOUTHERN SEWARD PENINSULA SOUTHWARD
TONIGHT THROUGH SUNDAY. SOMEWHAT COLDER TEMPERATURES ARE EXPECTED
FROM MONDAY THROUGH THE REST OF THE WEEK ARE THE DIGGING TROUGH
BRINGS IN COLDER AIR FROM THE NORTH.

ST LAWRENCE ISLAND...
ISOLATED TO SCATTERED SHOWERS EXPECTED THROUGH SUNDAY.
WINDS...MAINLY 10 MPH OR LESS TODAY THROUGH SATURDAY. NORTH WINDS
10-20 MPH SATURDAY NIGHT AND SUNDAY.

EXTENDED OUTLOOK...
OPERATIONAL GFS AND ECMWF RUNS CONTINUE DISPLAY LARGE DIFFERENCES
IN THE EXTENDED PERIOD. THE GEFS AND ECMWF ENSEMBLE MEANS ARE
MORE SIMILAR...WITH A COLD LONG WAVE TROUGH POSITION PREDOMINANT
OVER THE NORTHERN ALASKA MAINLAND. TEMPERATURES WILL MOST
LIKELY AVERAGE BELOW NORMAL OVER MOST AREAS...WITH AN ABOVE
NORMAL CHANCE OF PRECIPITATION.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE EXPECTED THROUGH MONDAY. THERE IS POTENTIAL FOR A MODERATE
INTENSITY SURFACE SYSTEM TO MOVE SOUTHEASTWARD OUT OF THE
NORTHWEST ARCTIC OCEAN AND AFFECT THE NORTHWEST ALASKA COAST WITH
HIGH SURF CONDITIONS POSSIBLE. AT THIS TIME...FORECAST CONFIDENCE
REMAINS LOW DUE TO LARGE DIFFERENCES BETWEEN MODEL RUNS AND POOR
RUN TO RUN CONTINUITY. CURRENT CANADIAN GLOBAL MODEL BRINGS A
MODERATE STRENGTH LOW CENTER TO NEAR BARROW BY TUESDAY
AFTERNOON...WITH THE GFS POSITION SUBSTANTIALLY FARTHER TO THE
SOUTHWEST..NEAR POINT LAY. GEFS ENSEMBLES SHOW A LARGE SPREAD OF
LOW CENTER POSITIONS AT THAT TIME...AND THE LOW CENTER IS TOTALLY
SMOOTHED OUT BY THE ENSEMBLE MEAN. THE ECMWF RUN SHOWS NO LOW
CENTER AT ALL. IT WILL BE NECESSARY TO MONITOR FUTURE MODEL RUNS
FOR POSSIBLE DEVELOPMENTS IN THE ARCTIC.


&&

.HYDROLOGY...
NO ISSUES. WATER LEVELS ON THE CHENA RIVER SOUTH OF THE MOOSE
CREEK DAM ARE STILL SLIGHTLY ELEVATED...BUT WILL CONTINUE TO FALL
SLOWLY.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF SEP 15




000
FXAK69 PAFG 041121
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
321 AM AKDT FRI SEP 4 2015

.DISCUSSION...

UPPER LEVELS...
AT 500 MB...AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN
MAINLAND OF NORTHERN ALASKA WILL PERSIST THROUGH TONIGHT...THEN
BECOME PARTIALLY PINCHED OFF BY SUNDAY NIGHT AS AN UPPER LOW
ADVANCES EASTWARD INTO THE GULF OF ALASKA AND A LOW PRESSURE
TROUGH DIGS SOUTHWARD INTO THE CHUKCHI SEA.

A WEAK UPPER LOW CENTERED NEAR BETHEL WILL DISSIPATE OVER
THE SOUTHWEST INTERIOR THIS AFTERNOON.

AN UPPER LOW CENTERED NEAR 50N/176E...ABOUT 250 MILES WEST OF
ST MATTHEW ISLAND...WILL MOVE EASTWARD TO NEAR BRISTOL BAY BY
SUNDAY MORNING AND INTO THE NORTHERN GULF OF ALASKA BY SUNDAY
NIGHT.

AN LOW AMPLITUDE SHORT WAVE TROUGH OVER THE FAR NORTHWEST ARCTIC
OCEAN WILL MOVE SOUTHEASTWARD...TROUGH AXIS SUNDAY MORNING WILL
EXTENDING ALONG 180W FROM 72N TO NEAR WRANGEL ISLAND. BY MONDAY
MORNING THE TROUGH WILL DIG SOUTHWARD AND INCREASE IN
AMPLITUDE...TROUGH AXIS ENDING FROM 80N/150W TO WAINWRIGHT AND
SOUTHWESTWARD TO THE BERING STRAIT. THE TROUGH WILL CONTINUE TO
DIG SOUTHWESTWARD THROUGH MONDAY MORNING...TROUGH AXIS MONDAY
MORNING EXTENDING FROM 78N/140W TO DEADHORSE AND SOUTHWESTWARD
TO KUSKOKWIM BAY. THE DIGGING TROUGH WILL BRING COLDER AIR
ALOFT INITIALLY TO THE ARCTIC COAST...SPREADING TO THE
EASTERN BERING SEA AND THE ALASKA WEST COAST BY TUESDAY
MORNING.

THROUGH TUESDAY MORNING...THERE ARE ONLY MINOR DIFFERENCES
BETWEEN THE OPERATIONAL GFS AND ECMWF RUNS FROM THE SEP 4/00Z
CYCLE.

SURFACE...
A 1005 MB LOW NEAR BETHEL WILL WEAKEN TO A BARELY DISCERNIBLE
1013 MB CENTER OVER THE CENTRAL SEWARD PENINSULA BY SATURDAY
MORNING. THE ASSOCIATED OCCLUDED FRONT...CURRENTLY EXTENDING
FROM THE YUKON DELTA TO ANCHORAGE AND VALDEZ...WILL CONTINUE TO
STRETCH OUT EASTWARD AND A BIT NORTHWARD...WHILE WEAKENING DURING
THE NEXT 24 HOURS. A 1027 MB HIGH CENTERED NEAR 76N/128E... ABOUT
250 MILES NORTHEAST OF BARTER ISLAND...WILL MOVE EASTWARD INTO
THE CANADIAN ARCHIPELAGO THROUGH FRIDAY NIGHT...WITH A WEAK RIDGE
PERSISTING ALONG 75-76N WESTWARD ACROSS THE BEAUFORT SEA AND INTO
THE RUSSIAN ARCTIC OCEAN. THIS RIDGE WILL WEAKEN AND BE PUSHED
SOUTHWARD TO JUST NORTH OF THE ALASKAN ARCTIC COAST BY SUNDAY
AFTERNOON AS A LOW PRESSURE TROUGH APPROACHES FROM THE NORTHWEST.

ARCTIC COAST...
OVER THE ARCTIC COAST EAST OF WAINWRIGHT...EAST WINDS 20-30 MPH
WITH LOCAL GUSTS TO AROUND 35 MPH WILL CONTINUE TODAY...DIMINISHING
TO 10-15 MPH BY SATURDAY MORNING. WINDS WILL BE LIGHTER OVER AREAS
TO THE WEST. WIDESPREAD LOW STRATUS WILL PERSIST OVER AREAS EAST
OF WAINWRIGHT...WITH AREAS OF FOG DURING THE LATE NIGHT AND
MORNING HOURS. LITTLE OR NO PRECIPITATION IS EXPECTED THROUGH
SUNDAY. SOMEWHAT COLDER TEMPERATURE ARE EXPECTED NEXT WEEK WITH
SNOW POSSIBLE...ESPECIALLY IN THE BROOKS RANGE.

CENTRAL AND EASTERN INTERIOR...
RAIN OVER THE ALASKA RANGE AND NEARBY AREAS TODAY...TAPERING TO
MAINLY SCATTERED SHOWERS BY LATE TONIGHT. ISOLATED TO SCATTERED
SHOWERS CONTINUING SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED
THROUGH SUNDAY.

WESTERN INTERIOR...
RAIN SOUTH OF GALENA SOUTH TODAY...TAPERING TO MAINLY SCATTERED
SHOWERS TONIGHT. ISOLATED TO SCATTERED SHOWERS OVER THE SOUTHERN
AREAS SATURDAY AND SATURDAY NIGHT.

WEST COAST...
OVER AREAS SOUTH OF UNALAKLEET...WIDESPREAD RAIN OR SHOWERS
THIS MORNING...TAPERING TO SCATTERED SHOWERS THIS AFTERNOON.
SCATTERED SHOWERS OVER THE SOUTHERN SEWARD PENINSULA SOUTHWARD
TONIGHT THROUGH SUNDAY. SOMEWHAT COLDER TEMPERATURES ARE EXPECTED
FROM MONDAY THROUGH THE REST OF THE WEEK ARE THE DIGGING TROUGH
BRINGS IN COLDER AIR FROM THE NORTH.

ST LAWRENCE ISLAND...
ISOLATED TO SCATTERED SHOWERS EXPECTED THROUGH SUNDAY.
WINDS...MAINLY 10 MPH OR LESS TODAY THROUGH SATURDAY. NORTH WINDS
10-20 MPH SATURDAY NIGHT AND SUNDAY.

EXTENDED OUTLOOK...
OPERATIONAL GFS AND ECMWF RUNS CONTINUE DISPLAY LARGE DIFFERENCES
IN THE EXTENDED PERIOD. THE GEFS AND ECMWF ENSEMBLE MEANS ARE
MORE SIMILAR...WITH A COLD LONG WAVE TROUGH POSITION PREDOMINANT
OVER THE NORTHERN ALASKA MAINLAND. TEMPERATURES WILL MOST
LIKELY AVERAGE BELOW NORMAL OVER MOST AREAS...WITH AN ABOVE
NORMAL CHANCE OF PRECIPITATION.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE EXPECTED THROUGH MONDAY. THERE IS POTENTIAL FOR A MODERATE
INTENSITY SURFACE SYSTEM TO MOVE SOUTHEASTWARD OUT OF THE
NORTHWEST ARCTIC OCEAN AND AFFECT THE NORTHWEST ALASKA COAST WITH
HIGH SURF CONDITIONS POSSIBLE. AT THIS TIME...FORECAST CONFIDENCE
REMAINS LOW DUE TO LARGE DIFFERENCES BETWEEN MODEL RUNS AND POOR
RUN TO RUN CONTINUITY. CURRENT CANADIAN GLOBAL MODEL BRINGS A
MODERATE STRENGTH LOW CENTER TO NEAR BARROW BY TUESDAY
AFTERNOON...WITH THE GFS POSITION SUBSTANTIALLY FARTHER TO THE
SOUTHWEST..NEAR POINT LAY. GEFS ENSEMBLES SHOW A LARGE SPREAD OF
LOW CENTER POSITIONS AT THAT TIME...AND THE LOW CENTER IS TOTALLY
SMOOTHED OUT BY THE ENSEMBLE MEAN. THE ECMWF RUN SHOWS NO LOW
CENTER AT ALL. IT WILL BE NECESSARY TO MONITOR FUTURE MODEL RUNS
FOR POSSIBLE DEVELOPMENTS IN THE ARCTIC.


&&

.HYDROLOGY...
NO ISSUES. WATER LEVELS ON THE CHENA RIVER SOUTH OF THE MOOSE
CREEK DAM ARE STILL SLIGHTLY ELEVATED...BUT WILL CONTINUE TO FALL
SLOWLY.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF SEP 15



000
FXAK69 PAFG 041121
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
321 AM AKDT FRI SEP 4 2015

.DISCUSSION...

UPPER LEVELS...
AT 500 MB...AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN
MAINLAND OF NORTHERN ALASKA WILL PERSIST THROUGH TONIGHT...THEN
BECOME PARTIALLY PINCHED OFF BY SUNDAY NIGHT AS AN UPPER LOW
ADVANCES EASTWARD INTO THE GULF OF ALASKA AND A LOW PRESSURE
TROUGH DIGS SOUTHWARD INTO THE CHUKCHI SEA.

A WEAK UPPER LOW CENTERED NEAR BETHEL WILL DISSIPATE OVER
THE SOUTHWEST INTERIOR THIS AFTERNOON.

AN UPPER LOW CENTERED NEAR 50N/176E...ABOUT 250 MILES WEST OF
ST MATTHEW ISLAND...WILL MOVE EASTWARD TO NEAR BRISTOL BAY BY
SUNDAY MORNING AND INTO THE NORTHERN GULF OF ALASKA BY SUNDAY
NIGHT.

AN LOW AMPLITUDE SHORT WAVE TROUGH OVER THE FAR NORTHWEST ARCTIC
OCEAN WILL MOVE SOUTHEASTWARD...TROUGH AXIS SUNDAY MORNING WILL
EXTENDING ALONG 180W FROM 72N TO NEAR WRANGEL ISLAND. BY MONDAY
MORNING THE TROUGH WILL DIG SOUTHWARD AND INCREASE IN
AMPLITUDE...TROUGH AXIS ENDING FROM 80N/150W TO WAINWRIGHT AND
SOUTHWESTWARD TO THE BERING STRAIT. THE TROUGH WILL CONTINUE TO
DIG SOUTHWESTWARD THROUGH MONDAY MORNING...TROUGH AXIS MONDAY
MORNING EXTENDING FROM 78N/140W TO DEADHORSE AND SOUTHWESTWARD
TO KUSKOKWIM BAY. THE DIGGING TROUGH WILL BRING COLDER AIR
ALOFT INITIALLY TO THE ARCTIC COAST...SPREADING TO THE
EASTERN BERING SEA AND THE ALASKA WEST COAST BY TUESDAY
MORNING.

THROUGH TUESDAY MORNING...THERE ARE ONLY MINOR DIFFERENCES
BETWEEN THE OPERATIONAL GFS AND ECMWF RUNS FROM THE SEP 4/00Z
CYCLE.

SURFACE...
A 1005 MB LOW NEAR BETHEL WILL WEAKEN TO A BARELY DISCERNIBLE
1013 MB CENTER OVER THE CENTRAL SEWARD PENINSULA BY SATURDAY
MORNING. THE ASSOCIATED OCCLUDED FRONT...CURRENTLY EXTENDING
FROM THE YUKON DELTA TO ANCHORAGE AND VALDEZ...WILL CONTINUE TO
STRETCH OUT EASTWARD AND A BIT NORTHWARD...WHILE WEAKENING DURING
THE NEXT 24 HOURS. A 1027 MB HIGH CENTERED NEAR 76N/128E... ABOUT
250 MILES NORTHEAST OF BARTER ISLAND...WILL MOVE EASTWARD INTO
THE CANADIAN ARCHIPELAGO THROUGH FRIDAY NIGHT...WITH A WEAK RIDGE
PERSISTING ALONG 75-76N WESTWARD ACROSS THE BEAUFORT SEA AND INTO
THE RUSSIAN ARCTIC OCEAN. THIS RIDGE WILL WEAKEN AND BE PUSHED
SOUTHWARD TO JUST NORTH OF THE ALASKAN ARCTIC COAST BY SUNDAY
AFTERNOON AS A LOW PRESSURE TROUGH APPROACHES FROM THE NORTHWEST.

ARCTIC COAST...
OVER THE ARCTIC COAST EAST OF WAINWRIGHT...EAST WINDS 20-30 MPH
WITH LOCAL GUSTS TO AROUND 35 MPH WILL CONTINUE TODAY...DIMINISHING
TO 10-15 MPH BY SATURDAY MORNING. WINDS WILL BE LIGHTER OVER AREAS
TO THE WEST. WIDESPREAD LOW STRATUS WILL PERSIST OVER AREAS EAST
OF WAINWRIGHT...WITH AREAS OF FOG DURING THE LATE NIGHT AND
MORNING HOURS. LITTLE OR NO PRECIPITATION IS EXPECTED THROUGH
SUNDAY. SOMEWHAT COLDER TEMPERATURE ARE EXPECTED NEXT WEEK WITH
SNOW POSSIBLE...ESPECIALLY IN THE BROOKS RANGE.

CENTRAL AND EASTERN INTERIOR...
RAIN OVER THE ALASKA RANGE AND NEARBY AREAS TODAY...TAPERING TO
MAINLY SCATTERED SHOWERS BY LATE TONIGHT. ISOLATED TO SCATTERED
SHOWERS CONTINUING SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED
THROUGH SUNDAY.

WESTERN INTERIOR...
RAIN SOUTH OF GALENA SOUTH TODAY...TAPERING TO MAINLY SCATTERED
SHOWERS TONIGHT. ISOLATED TO SCATTERED SHOWERS OVER THE SOUTHERN
AREAS SATURDAY AND SATURDAY NIGHT.

WEST COAST...
OVER AREAS SOUTH OF UNALAKLEET...WIDESPREAD RAIN OR SHOWERS
THIS MORNING...TAPERING TO SCATTERED SHOWERS THIS AFTERNOON.
SCATTERED SHOWERS OVER THE SOUTHERN SEWARD PENINSULA SOUTHWARD
TONIGHT THROUGH SUNDAY. SOMEWHAT COLDER TEMPERATURES ARE EXPECTED
FROM MONDAY THROUGH THE REST OF THE WEEK ARE THE DIGGING TROUGH
BRINGS IN COLDER AIR FROM THE NORTH.

ST LAWRENCE ISLAND...
ISOLATED TO SCATTERED SHOWERS EXPECTED THROUGH SUNDAY.
WINDS...MAINLY 10 MPH OR LESS TODAY THROUGH SATURDAY. NORTH WINDS
10-20 MPH SATURDAY NIGHT AND SUNDAY.

EXTENDED OUTLOOK...
OPERATIONAL GFS AND ECMWF RUNS CONTINUE DISPLAY LARGE DIFFERENCES
IN THE EXTENDED PERIOD. THE GEFS AND ECMWF ENSEMBLE MEANS ARE
MORE SIMILAR...WITH A COLD LONG WAVE TROUGH POSITION PREDOMINANT
OVER THE NORTHERN ALASKA MAINLAND. TEMPERATURES WILL MOST
LIKELY AVERAGE BELOW NORMAL OVER MOST AREAS...WITH AN ABOVE
NORMAL CHANCE OF PRECIPITATION.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE EXPECTED THROUGH MONDAY. THERE IS POTENTIAL FOR A MODERATE
INTENSITY SURFACE SYSTEM TO MOVE SOUTHEASTWARD OUT OF THE
NORTHWEST ARCTIC OCEAN AND AFFECT THE NORTHWEST ALASKA COAST WITH
HIGH SURF CONDITIONS POSSIBLE. AT THIS TIME...FORECAST CONFIDENCE
REMAINS LOW DUE TO LARGE DIFFERENCES BETWEEN MODEL RUNS AND POOR
RUN TO RUN CONTINUITY. CURRENT CANADIAN GLOBAL MODEL BRINGS A
MODERATE STRENGTH LOW CENTER TO NEAR BARROW BY TUESDAY
AFTERNOON...WITH THE GFS POSITION SUBSTANTIALLY FARTHER TO THE
SOUTHWEST..NEAR POINT LAY. GEFS ENSEMBLES SHOW A LARGE SPREAD OF
LOW CENTER POSITIONS AT THAT TIME...AND THE LOW CENTER IS TOTALLY
SMOOTHED OUT BY THE ENSEMBLE MEAN. THE ECMWF RUN SHOWS NO LOW
CENTER AT ALL. IT WILL BE NECESSARY TO MONITOR FUTURE MODEL RUNS
FOR POSSIBLE DEVELOPMENTS IN THE ARCTIC.


&&

.HYDROLOGY...
NO ISSUES. WATER LEVELS ON THE CHENA RIVER SOUTH OF THE MOOSE
CREEK DAM ARE STILL SLIGHTLY ELEVATED...BUT WILL CONTINUE TO FALL
SLOWLY.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF SEP 15



000
FXAK68 PAFC 040021
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
421 PM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGE THAT HAS PRODUCED NICE WEATHER FOR THE LAST FEW DAYS
ACROSS SOUTHERN ALASKA HAS SHIFTED EAST WITH THE RIDGE AXIS NOW
LOCATED NEAR THE ALCAN BORDER. THIS HAS USHERED IN BROAD AND MOIST
SOUTHWESTERLY FLOW TO THE MAINLAND. THE MOST NOTICEABLE FEATURE ON
AFTERNOON SATELLITE IMAGERY IS A FAIRLY VIGOROUS SHORTWAVE TROUGH
MOVING ACROSS THE ALASKA PENINSULA AND KODIAK ISLAND INTO LOWER
COOK INLET. THIS FEATURE IS FOCUSING A STEADIER AND MORE INTENSE
BAND OF RAIN THAT IS BRINGING WIDESPREAD RAIN FROM BRISTOL BAY
THROUGH THE NORTH GULF COAST AND ALL POINTS BETWEEN.

BEHIND THIS SHORTWAVE TROUGH ARE WEAKER BUT CONTINUED WESTERLY
WINDS ACROSS THE BERING SEA WITH WIDESPREAD FOG/STRATUS IN PLACE
ACROSS THE BERING SEA. FURTHER EAST EVEN ONCE THE RAIN ENDS
ACROSS SOUTHWEST ALASKA THINGS WILL NOT CLEAR OUT MUCH AS THIS
ONSHORE FLOW IS CONTINUALLY REINFORCING THE LOW CLOUDS ALREADY
MOVING ONSHORE.

&&

.MODEL DISCUSSION...

THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE KEY DETAILS OF
THE FORECAST OVER THE NEXT FEW DAYS. ONE OF THE MAIN QUESTIONS HAS
BEEN WHEN AND HOW A SURFACE LOW DEVELOPS IN THE NORTHERN GULF TONIGHT
AND TOMORROW. THE NAM AND ECMWF ARE NOW DEPICTING AN INITIAL LOW
TO DEVELOP OVER THE NORTHWEST GULF AND QUICKLY THEREAFTER IS
REPLACED BY A SECONDARY DEVELOPMENT FURTHER EAST. THIS MAKES SENSE
GIVEN FAIRLY DIFFUSE UPPER LEVEL FORCING MECHANISMS TO KEEP ENERGY
LOCKED INTO ONE CONSOLIDATED LOW CENTER (WHICH IS WHAT THE GFS IS
TRYING TO DO). THEREFORE WE WILL SHY AWAY FROM THE GFS SOLUTION
TODAY IN FAVOR OF THE NAM/EC/GEM-REGIONAL SOLUTIONS.

&&

.FIRE WEATHER...

A COOL AND WET WEATHER PATTERN HAS MOVED INTO MAINLAND ALASKA AND
WILL GENERALLY STICK AROUND THROUGH NEXT WEEK. NO LOW RH ISSUES OR
STRONG WINDS IN INTERIOR AREAS ARE EXPECTED AS WEAK SOUTHWEST FLOW
KEEPS THE STATE UNDER SIGNIFICANT CLOUD-COVER.

&&

.HYDROLOGY...

THE SNOW GLACIER-DAMMED LAKE DEEP IN THE KENAI MOUNTAINS CONTINUES
TO RELEASE WATER INTO SNOW RIVER KENAI LAKE AND THE KENAI RIVER.
THE KENAI RIVER AT COOPER LANDING HAS ENTERED MINOR FLOOD
STAGE AND A FLOOD ADVISORY REMAINS IN EFFECT FOR THE KENAI RIVER
FROM KENAI LAKE TO SKILAK LAKE AS WELL AS FOR LOW LYING AREAS
AROUND KENAI LAKE. SEE ADVISORY STATEMENTS FOR THE MOST UP TO
DATE INFORMATION.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
RAINFALL WILL CONTINUE TO SPREAD EAST INTO THE COPPER RIVER BASIN
AND THE NORTHERN GULF COAST OVERNIGHT AS THE SHORTWAVE CONTINUES
ITS MARCH EAST THROUGH THE REGION. THE BACKSIDE OF THE WAVE IS
VERY EVIDENT ON SATELLITE AND RADAR IMAGERY THIS AFTERNOON WITH
THE HEAVIEST OF THE RAINFALL HAVING CLEARED KODIAK ISLAND AND
BEGINNING TO TAPER OFF OVER THE SOUTHERN KENAI PENINSULA. THIS
TREND IS EXPECTED TO CONTINUE OVERNIGHT WITH STRATIFORM RAIN
TURNING INTO A MORE SHOWERY PATTERN IN THE WAKE OF THE SHORTWAVE.
BY SATURDAY A WEAK SHORTWAVE RIDGE WILL QUICKLY TRANSIT THROUGH
THE AREA LIMITING SHOWERS TO MAINLY THE ALASKA RANGE AND THE
WRANGELLS. ALTHOUGH THE RIDGE WILL BE MOVING THROUGH THE PATTERN
WILL REMAIN FAIRLY MOIST AND ZONAL OVER THE REGION WITH ENOUGH LOW
LEVEL MOISTURE TO KEEP SKIES MOSTLY CLOUDY OVER THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...

A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE EASTERN
BERING INTO THE MAINLAND BRINGING A WIDESPREAD AREA OF MOISTURE
AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE THROUGH
TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE OF THESE LOWS EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE
INLAND WITH THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK
IN RAIN BEFORE ANOTHER LOW OVER THE BERING SEA MOVES INTO
SOUTHWEST ALASKA SATURDAY BRINGING ANOTHER SHOT OF INTERMITTENT
RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...

A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TAPER OFF ACROSS SOUTHERN ALASKA THIS WEEKEND
AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT FURTHER
INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER THE
PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING
SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP
SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN AS COMPARED TO THE AMPLIFIED
PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA
IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE BERING SEA
INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK MODELS ARE
HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE MAINLAND AND
JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING IN AN
UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS A
RESULT NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING BEFORE TRACKING IT INLAND OVER THE
SOUTHERN PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY
WITH THE TIMING AND PLACEMENT OF THIS SYSTEM AS WELL AS OTHER
SYSTEMS OUT WEST LEAVING FORECAST CONFIDENCE LOW THROUGH THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY ZONE 121 AND 125.
MARINE...GALE 119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...AD
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...TP




000
FXAK68 PAFC 040021
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
421 PM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGE THAT HAS PRODUCED NICE WEATHER FOR THE LAST FEW DAYS
ACROSS SOUTHERN ALASKA HAS SHIFTED EAST WITH THE RIDGE AXIS NOW
LOCATED NEAR THE ALCAN BORDER. THIS HAS USHERED IN BROAD AND MOIST
SOUTHWESTERLY FLOW TO THE MAINLAND. THE MOST NOTICEABLE FEATURE ON
AFTERNOON SATELLITE IMAGERY IS A FAIRLY VIGOROUS SHORTWAVE TROUGH
MOVING ACROSS THE ALASKA PENINSULA AND KODIAK ISLAND INTO LOWER
COOK INLET. THIS FEATURE IS FOCUSING A STEADIER AND MORE INTENSE
BAND OF RAIN THAT IS BRINGING WIDESPREAD RAIN FROM BRISTOL BAY
THROUGH THE NORTH GULF COAST AND ALL POINTS BETWEEN.

BEHIND THIS SHORTWAVE TROUGH ARE WEAKER BUT CONTINUED WESTERLY
WINDS ACROSS THE BERING SEA WITH WIDESPREAD FOG/STRATUS IN PLACE
ACROSS THE BERING SEA. FURTHER EAST EVEN ONCE THE RAIN ENDS
ACROSS SOUTHWEST ALASKA THINGS WILL NOT CLEAR OUT MUCH AS THIS
ONSHORE FLOW IS CONTINUALLY REINFORCING THE LOW CLOUDS ALREADY
MOVING ONSHORE.

&&

.MODEL DISCUSSION...

THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE KEY DETAILS OF
THE FORECAST OVER THE NEXT FEW DAYS. ONE OF THE MAIN QUESTIONS HAS
BEEN WHEN AND HOW A SURFACE LOW DEVELOPS IN THE NORTHERN GULF TONIGHT
AND TOMORROW. THE NAM AND ECMWF ARE NOW DEPICTING AN INITIAL LOW
TO DEVELOP OVER THE NORTHWEST GULF AND QUICKLY THEREAFTER IS
REPLACED BY A SECONDARY DEVELOPMENT FURTHER EAST. THIS MAKES SENSE
GIVEN FAIRLY DIFFUSE UPPER LEVEL FORCING MECHANISMS TO KEEP ENERGY
LOCKED INTO ONE CONSOLIDATED LOW CENTER (WHICH IS WHAT THE GFS IS
TRYING TO DO). THEREFORE WE WILL SHY AWAY FROM THE GFS SOLUTION
TODAY IN FAVOR OF THE NAM/EC/GEM-REGIONAL SOLUTIONS.

&&

.FIRE WEATHER...

A COOL AND WET WEATHER PATTERN HAS MOVED INTO MAINLAND ALASKA AND
WILL GENERALLY STICK AROUND THROUGH NEXT WEEK. NO LOW RH ISSUES OR
STRONG WINDS IN INTERIOR AREAS ARE EXPECTED AS WEAK SOUTHWEST FLOW
KEEPS THE STATE UNDER SIGNIFICANT CLOUD-COVER.

&&

.HYDROLOGY...

THE SNOW GLACIER-DAMMED LAKE DEEP IN THE KENAI MOUNTAINS CONTINUES
TO RELEASE WATER INTO SNOW RIVER KENAI LAKE AND THE KENAI RIVER.
THE KENAI RIVER AT COOPER LANDING HAS ENTERED MINOR FLOOD
STAGE AND A FLOOD ADVISORY REMAINS IN EFFECT FOR THE KENAI RIVER
FROM KENAI LAKE TO SKILAK LAKE AS WELL AS FOR LOW LYING AREAS
AROUND KENAI LAKE. SEE ADVISORY STATEMENTS FOR THE MOST UP TO
DATE INFORMATION.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
RAINFALL WILL CONTINUE TO SPREAD EAST INTO THE COPPER RIVER BASIN
AND THE NORTHERN GULF COAST OVERNIGHT AS THE SHORTWAVE CONTINUES
ITS MARCH EAST THROUGH THE REGION. THE BACKSIDE OF THE WAVE IS
VERY EVIDENT ON SATELLITE AND RADAR IMAGERY THIS AFTERNOON WITH
THE HEAVIEST OF THE RAINFALL HAVING CLEARED KODIAK ISLAND AND
BEGINNING TO TAPER OFF OVER THE SOUTHERN KENAI PENINSULA. THIS
TREND IS EXPECTED TO CONTINUE OVERNIGHT WITH STRATIFORM RAIN
TURNING INTO A MORE SHOWERY PATTERN IN THE WAKE OF THE SHORTWAVE.
BY SATURDAY A WEAK SHORTWAVE RIDGE WILL QUICKLY TRANSIT THROUGH
THE AREA LIMITING SHOWERS TO MAINLY THE ALASKA RANGE AND THE
WRANGELLS. ALTHOUGH THE RIDGE WILL BE MOVING THROUGH THE PATTERN
WILL REMAIN FAIRLY MOIST AND ZONAL OVER THE REGION WITH ENOUGH LOW
LEVEL MOISTURE TO KEEP SKIES MOSTLY CLOUDY OVER THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...

A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE EASTERN
BERING INTO THE MAINLAND BRINGING A WIDESPREAD AREA OF MOISTURE
AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE THROUGH
TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE OF THESE LOWS EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE
INLAND WITH THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK
IN RAIN BEFORE ANOTHER LOW OVER THE BERING SEA MOVES INTO
SOUTHWEST ALASKA SATURDAY BRINGING ANOTHER SHOT OF INTERMITTENT
RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...

A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TAPER OFF ACROSS SOUTHERN ALASKA THIS WEEKEND
AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT FURTHER
INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER THE
PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING
SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP
SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN AS COMPARED TO THE AMPLIFIED
PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA
IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE BERING SEA
INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK MODELS ARE
HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE MAINLAND AND
JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING IN AN
UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS A
RESULT NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING BEFORE TRACKING IT INLAND OVER THE
SOUTHERN PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY
WITH THE TIMING AND PLACEMENT OF THIS SYSTEM AS WELL AS OTHER
SYSTEMS OUT WEST LEAVING FORECAST CONFIDENCE LOW THROUGH THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY ZONE 121 AND 125.
MARINE...GALE 119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...AD
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...TP



000
FXAK68 PAFC 040021
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
421 PM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGE THAT HAS PRODUCED NICE WEATHER FOR THE LAST FEW DAYS
ACROSS SOUTHERN ALASKA HAS SHIFTED EAST WITH THE RIDGE AXIS NOW
LOCATED NEAR THE ALCAN BORDER. THIS HAS USHERED IN BROAD AND MOIST
SOUTHWESTERLY FLOW TO THE MAINLAND. THE MOST NOTICEABLE FEATURE ON
AFTERNOON SATELLITE IMAGERY IS A FAIRLY VIGOROUS SHORTWAVE TROUGH
MOVING ACROSS THE ALASKA PENINSULA AND KODIAK ISLAND INTO LOWER
COOK INLET. THIS FEATURE IS FOCUSING A STEADIER AND MORE INTENSE
BAND OF RAIN THAT IS BRINGING WIDESPREAD RAIN FROM BRISTOL BAY
THROUGH THE NORTH GULF COAST AND ALL POINTS BETWEEN.

BEHIND THIS SHORTWAVE TROUGH ARE WEAKER BUT CONTINUED WESTERLY
WINDS ACROSS THE BERING SEA WITH WIDESPREAD FOG/STRATUS IN PLACE
ACROSS THE BERING SEA. FURTHER EAST EVEN ONCE THE RAIN ENDS
ACROSS SOUTHWEST ALASKA THINGS WILL NOT CLEAR OUT MUCH AS THIS
ONSHORE FLOW IS CONTINUALLY REINFORCING THE LOW CLOUDS ALREADY
MOVING ONSHORE.

&&

.MODEL DISCUSSION...

THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE KEY DETAILS OF
THE FORECAST OVER THE NEXT FEW DAYS. ONE OF THE MAIN QUESTIONS HAS
BEEN WHEN AND HOW A SURFACE LOW DEVELOPS IN THE NORTHERN GULF TONIGHT
AND TOMORROW. THE NAM AND ECMWF ARE NOW DEPICTING AN INITIAL LOW
TO DEVELOP OVER THE NORTHWEST GULF AND QUICKLY THEREAFTER IS
REPLACED BY A SECONDARY DEVELOPMENT FURTHER EAST. THIS MAKES SENSE
GIVEN FAIRLY DIFFUSE UPPER LEVEL FORCING MECHANISMS TO KEEP ENERGY
LOCKED INTO ONE CONSOLIDATED LOW CENTER (WHICH IS WHAT THE GFS IS
TRYING TO DO). THEREFORE WE WILL SHY AWAY FROM THE GFS SOLUTION
TODAY IN FAVOR OF THE NAM/EC/GEM-REGIONAL SOLUTIONS.

&&

.FIRE WEATHER...

A COOL AND WET WEATHER PATTERN HAS MOVED INTO MAINLAND ALASKA AND
WILL GENERALLY STICK AROUND THROUGH NEXT WEEK. NO LOW RH ISSUES OR
STRONG WINDS IN INTERIOR AREAS ARE EXPECTED AS WEAK SOUTHWEST FLOW
KEEPS THE STATE UNDER SIGNIFICANT CLOUD-COVER.

&&

.HYDROLOGY...

THE SNOW GLACIER-DAMMED LAKE DEEP IN THE KENAI MOUNTAINS CONTINUES
TO RELEASE WATER INTO SNOW RIVER KENAI LAKE AND THE KENAI RIVER.
THE KENAI RIVER AT COOPER LANDING HAS ENTERED MINOR FLOOD
STAGE AND A FLOOD ADVISORY REMAINS IN EFFECT FOR THE KENAI RIVER
FROM KENAI LAKE TO SKILAK LAKE AS WELL AS FOR LOW LYING AREAS
AROUND KENAI LAKE. SEE ADVISORY STATEMENTS FOR THE MOST UP TO
DATE INFORMATION.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
RAINFALL WILL CONTINUE TO SPREAD EAST INTO THE COPPER RIVER BASIN
AND THE NORTHERN GULF COAST OVERNIGHT AS THE SHORTWAVE CONTINUES
ITS MARCH EAST THROUGH THE REGION. THE BACKSIDE OF THE WAVE IS
VERY EVIDENT ON SATELLITE AND RADAR IMAGERY THIS AFTERNOON WITH
THE HEAVIEST OF THE RAINFALL HAVING CLEARED KODIAK ISLAND AND
BEGINNING TO TAPER OFF OVER THE SOUTHERN KENAI PENINSULA. THIS
TREND IS EXPECTED TO CONTINUE OVERNIGHT WITH STRATIFORM RAIN
TURNING INTO A MORE SHOWERY PATTERN IN THE WAKE OF THE SHORTWAVE.
BY SATURDAY A WEAK SHORTWAVE RIDGE WILL QUICKLY TRANSIT THROUGH
THE AREA LIMITING SHOWERS TO MAINLY THE ALASKA RANGE AND THE
WRANGELLS. ALTHOUGH THE RIDGE WILL BE MOVING THROUGH THE PATTERN
WILL REMAIN FAIRLY MOIST AND ZONAL OVER THE REGION WITH ENOUGH LOW
LEVEL MOISTURE TO KEEP SKIES MOSTLY CLOUDY OVER THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...

A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE EASTERN
BERING INTO THE MAINLAND BRINGING A WIDESPREAD AREA OF MOISTURE
AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE THROUGH
TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE OF THESE LOWS EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE
INLAND WITH THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK
IN RAIN BEFORE ANOTHER LOW OVER THE BERING SEA MOVES INTO
SOUTHWEST ALASKA SATURDAY BRINGING ANOTHER SHOT OF INTERMITTENT
RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...

A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TAPER OFF ACROSS SOUTHERN ALASKA THIS WEEKEND
AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT FURTHER
INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER THE
PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING
SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP
SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN AS COMPARED TO THE AMPLIFIED
PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA
IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE BERING SEA
INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK MODELS ARE
HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE MAINLAND AND
JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING IN AN
UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS A
RESULT NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING BEFORE TRACKING IT INLAND OVER THE
SOUTHERN PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY
WITH THE TIMING AND PLACEMENT OF THIS SYSTEM AS WELL AS OTHER
SYSTEMS OUT WEST LEAVING FORECAST CONFIDENCE LOW THROUGH THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY ZONE 121 AND 125.
MARINE...GALE 119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...AD
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...TP




000
FXAK68 PAFC 040021
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
421 PM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGE THAT HAS PRODUCED NICE WEATHER FOR THE LAST FEW DAYS
ACROSS SOUTHERN ALASKA HAS SHIFTED EAST WITH THE RIDGE AXIS NOW
LOCATED NEAR THE ALCAN BORDER. THIS HAS USHERED IN BROAD AND MOIST
SOUTHWESTERLY FLOW TO THE MAINLAND. THE MOST NOTICEABLE FEATURE ON
AFTERNOON SATELLITE IMAGERY IS A FAIRLY VIGOROUS SHORTWAVE TROUGH
MOVING ACROSS THE ALASKA PENINSULA AND KODIAK ISLAND INTO LOWER
COOK INLET. THIS FEATURE IS FOCUSING A STEADIER AND MORE INTENSE
BAND OF RAIN THAT IS BRINGING WIDESPREAD RAIN FROM BRISTOL BAY
THROUGH THE NORTH GULF COAST AND ALL POINTS BETWEEN.

BEHIND THIS SHORTWAVE TROUGH ARE WEAKER BUT CONTINUED WESTERLY
WINDS ACROSS THE BERING SEA WITH WIDESPREAD FOG/STRATUS IN PLACE
ACROSS THE BERING SEA. FURTHER EAST EVEN ONCE THE RAIN ENDS
ACROSS SOUTHWEST ALASKA THINGS WILL NOT CLEAR OUT MUCH AS THIS
ONSHORE FLOW IS CONTINUALLY REINFORCING THE LOW CLOUDS ALREADY
MOVING ONSHORE.

&&

.MODEL DISCUSSION...

THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE KEY DETAILS OF
THE FORECAST OVER THE NEXT FEW DAYS. ONE OF THE MAIN QUESTIONS HAS
BEEN WHEN AND HOW A SURFACE LOW DEVELOPS IN THE NORTHERN GULF TONIGHT
AND TOMORROW. THE NAM AND ECMWF ARE NOW DEPICTING AN INITIAL LOW
TO DEVELOP OVER THE NORTHWEST GULF AND QUICKLY THEREAFTER IS
REPLACED BY A SECONDARY DEVELOPMENT FURTHER EAST. THIS MAKES SENSE
GIVEN FAIRLY DIFFUSE UPPER LEVEL FORCING MECHANISMS TO KEEP ENERGY
LOCKED INTO ONE CONSOLIDATED LOW CENTER (WHICH IS WHAT THE GFS IS
TRYING TO DO). THEREFORE WE WILL SHY AWAY FROM THE GFS SOLUTION
TODAY IN FAVOR OF THE NAM/EC/GEM-REGIONAL SOLUTIONS.

&&

.FIRE WEATHER...

A COOL AND WET WEATHER PATTERN HAS MOVED INTO MAINLAND ALASKA AND
WILL GENERALLY STICK AROUND THROUGH NEXT WEEK. NO LOW RH ISSUES OR
STRONG WINDS IN INTERIOR AREAS ARE EXPECTED AS WEAK SOUTHWEST FLOW
KEEPS THE STATE UNDER SIGNIFICANT CLOUD-COVER.

&&

.HYDROLOGY...

THE SNOW GLACIER-DAMMED LAKE DEEP IN THE KENAI MOUNTAINS CONTINUES
TO RELEASE WATER INTO SNOW RIVER KENAI LAKE AND THE KENAI RIVER.
THE KENAI RIVER AT COOPER LANDING HAS ENTERED MINOR FLOOD
STAGE AND A FLOOD ADVISORY REMAINS IN EFFECT FOR THE KENAI RIVER
FROM KENAI LAKE TO SKILAK LAKE AS WELL AS FOR LOW LYING AREAS
AROUND KENAI LAKE. SEE ADVISORY STATEMENTS FOR THE MOST UP TO
DATE INFORMATION.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
RAINFALL WILL CONTINUE TO SPREAD EAST INTO THE COPPER RIVER BASIN
AND THE NORTHERN GULF COAST OVERNIGHT AS THE SHORTWAVE CONTINUES
ITS MARCH EAST THROUGH THE REGION. THE BACKSIDE OF THE WAVE IS
VERY EVIDENT ON SATELLITE AND RADAR IMAGERY THIS AFTERNOON WITH
THE HEAVIEST OF THE RAINFALL HAVING CLEARED KODIAK ISLAND AND
BEGINNING TO TAPER OFF OVER THE SOUTHERN KENAI PENINSULA. THIS
TREND IS EXPECTED TO CONTINUE OVERNIGHT WITH STRATIFORM RAIN
TURNING INTO A MORE SHOWERY PATTERN IN THE WAKE OF THE SHORTWAVE.
BY SATURDAY A WEAK SHORTWAVE RIDGE WILL QUICKLY TRANSIT THROUGH
THE AREA LIMITING SHOWERS TO MAINLY THE ALASKA RANGE AND THE
WRANGELLS. ALTHOUGH THE RIDGE WILL BE MOVING THROUGH THE PATTERN
WILL REMAIN FAIRLY MOIST AND ZONAL OVER THE REGION WITH ENOUGH LOW
LEVEL MOISTURE TO KEEP SKIES MOSTLY CLOUDY OVER THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...

A SERIES OF UPPER LEVEL DISTURBANCES ARE TRACKING FROM THE EASTERN
BERING INTO THE MAINLAND BRINGING A WIDESPREAD AREA OF MOISTURE
AND RAIN INTO SOUTHWEST ALASKA. THE HEAVIEST RAIN WILL BE THROUGH
TOMORROW MORNING BEFORE THE UPPER LOW MOVES EAST. IN THE
WAKE OF THESE LOWS EXTENSIVE LOW CLOUDS AND PATCHY FOG WILL MOVE
INLAND WITH THE ONSHORE FLOW REGIME. THERE WILL BE A BRIEF BREAK
IN RAIN BEFORE ANOTHER LOW OVER THE BERING SEA MOVES INTO
SOUTHWEST ALASKA SATURDAY BRINGING ANOTHER SHOT OF INTERMITTENT
RAIN TO THE AREA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...

A BROAD UPPER TROUGH WITH A SERIES OF EMBEDDED WAVES WILL MAKE
SLOW EASTWARD PROGRESS THROUGH SATURDAY WITH INTERMITTENT LIGHT
RAIN AND SHOWERS TRACKING OVER THE BERING AND ALEUTIANS. AN
ELONGATED FRONTAL ZONE WILL MOVE INTO THE WESTERN ALEUTIANS
SATURDAY EVENING BRINGING SOUTHERLY WINDS AND RAIN WITH IT.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
RAIN WILL GRADUALLY TAPER OFF ACROSS SOUTHERN ALASKA THIS WEEKEND
AS A POTENT SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT FURTHER
INTO THE EASTERN GULF OF ALASKA BEFORE FALLING APART OVER THE
PANHANDLE. WEAK RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING
SHORTWAVE AS A SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP
SOUTH AND CREATE A ZONAL UPPER LEVEL PATTERN AS COMPARED TO THE AMPLIFIED
PATTERN SEEN AS OF LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA
IN A FAVORABLE LOCATION FOR STORMS TO TRACK FROM THE BERING SEA
INTO INTERIOR LOCATIONS OF ALASKA. EARLY NEXT WEEK MODELS ARE
HINTING AT AN ARCTIC TROUGH DIGGING DOWN OVER THE MAINLAND AND
JOINING UP WITH THE NORTHERN STREAM. THIS CAN BRING IN AN
UNSEASONABLY COLD AIR MASS FROM THE ARCTIC OVER THE SOUTHERN
MAINLAND AS THE ARCTIC TROUGH DIVES FURTHER SOUTH BY MIDWEEK. AS A
RESULT NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH THE
BEGINNING OF NEXT WEEK AND WOULD DROP BELOW NORMAL BY THE MIDDLE
OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH OVER SOUTHWEST
AND SOUTHCENTRAL ALASKA. THE MOST NOTABLE CHANGE FROM PREVIOUS
MODEL RUNS IS THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW
KEEPING THE EXTRATROPICAL SYSTEM IGNACIO SOUTH OF THE GULF MONDAY
THROUGH TUESDAY MORNING BEFORE TRACKING IT INLAND OVER THE
SOUTHERN PANHANDLE. OVERALL THERE IS STILL A LOT OF UNCERTAINTY
WITH THE TIMING AND PLACEMENT OF THIS SYSTEM AS WELL AS OTHER
SYSTEMS OUT WEST LEAVING FORECAST CONFIDENCE LOW THROUGH THE LONG
TERM.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY ZONE 121 AND 125.
MARINE...GALE 119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...AD
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...TP



000
FXAK67 PAJK 032322
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
322 PM AKDT THU SEP 3 2015

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY CLEAR
SKIES OVER MOST OF THE PANHANDLE WITH INCREASING HIGH CLOUDS
BEGINNING TO STREAM INTO THE NORTHEAST GULF COASTAL AREA.
MEANWHILE...SURFACE FRONTAL SYSTEM STARTING TO TAKE SHAPE OVER THE
WESTERN GULF IN RESPONSE TO AN AREA OF ASCENT ASSOCIATED WITH AN
UPPER VORT LOBE NEAR KODIAK IS. THIS PIECE OF ENERGY IS FORECAST
TO BEGIN TO FLATTEN OUT THE UPPER RIDGE OVER THE CENTRAL AND
EASTERN GULF THIS EVENING AND ALLOW THE NW FLOW THAT HAS GIVEN SE
AK THE NICE WEATHER OVER THE PAST TWO DAYS TO TAKE MORE OF A
WESTERLY ZONAL COMPONENT.

AT THE SURFACE...A RIDGE OF HIGH PRESSURE OVER THE EASTERN GULF
WILL WEAKEN AND SLIDE EASTWARD INTO BC TONIGHT AS THE FRONTAL
SYSTEM BEGINS TO IMPINGE ON THE COASTAL WATERS FRIDAY MORNING. AS
THIS FRONT PUSHES EASTWARD...MODELS ARE SHOWING A DECENT BARRIER
JET DEVELOPING ALONG THE NE GULF COAST WITH THE NAM AND HIRES
MODELS INDICATING GALES DEVELOPING BY FRIDAY AFTERNOON. THIS WAS
WELL DEPICTED BY THE PREVIOUS SHIFT SO DID NOT MAKE ANY CHANGES TO
THE WINDS ON THE COASTAL WATERS FOR FRIDAY. MAIN CHANGES WERE TO
ADJUST THE WINDS OVER THE NORTHERN AND CENTRAL INNER CHANNELS TO
MORE OF A SELY COMPONENT AND TO INCREASE THE ELY WINDS FRIDAY
AFTERNOON IN ICY STRAIT IN RESPONSE TO THE APPROACHING FRONT AND
TIGHTENING GRADIENT.

12Z MODELS SEEMED TO SLIGHTLY SLOW DOWN THE ADVANCE OF RAIN INLAND
ON FRIDAY AFTERNOON BUT THE FLOW AT 700MB REMAINS OUT OF THE SW
WHICH IS A GOOD INDICATOR OF INCREASING ONSHORE FLOW AND LENDS
CREDENCE TO KEEPING LIKELY POPS FRIDAY AFTERNOON FOR NORTHERN
ZONES WITH CATEGORICAL POPS ALONG THE GULF COAST NORTH OF SITKA.

MADE MINOR ADJUSTMENTS TO TEMPERATURES OVER THE NORTHERN AND
CENTRAL AREAS TO RAISE OVER NIGHT LOWS IN PLACES WITH MORE CLOUD
COVER EXPECTED TONIGHT. ALSO ADDED PATCHY FOG TO THE
KLAWOCK...KETCHIKAN AND HYDER AREAS AS GOOD RADIATIONAL COOLING
EXPECTED AGAIN TONIGHT SIMILAR TO THIS MORNING WHEN THERE WAS SOME
LOCALLY DENSE FOG ON THE WEBCAMS IN THESE AREAS. DEBATED ABOUT
ADDING FOG TO PETERSBURG AND WRANGELL TONIGHT BUT THEY WILL BE ON
THE EDGE OF THE HIGH CLOUD COVER LATER TONIGHT AND NO FOG WAS
REPORTED THIS MORNING.

.LONG TERM...LONG TERM PERIOD REMAINS WET FOR THE WEEKEND AND
BEYOND AS UPPER LEVEL PATTERN STAYS MOSTLY WITH A FLAT, EAST TO
WEST FLOW. EMBEDDED IN THIS WESTERLY FLOW ARE A FEW SHORT WAVES
AS WELL AS THE REMAINS OF FORMER TYPHOON IGNACIO.

FIRST RATHER VIGOROUS SHORT WAVE CROSSES THE PANHANDLE ON SAT
BRINGING MORE RAIN AND SOME WIND TO THE AREA. THERE IS SOME
TROPICAL MOISTURE THAT HAS BEEN ABSORBED BY THE SYSTEM SO SOME
HEAVY RAIN IS EXPECTED AS THE FRONT MOVES THROUGH. AS THE FRONT
WILL NOT BE STICKING AROUND FOR ANY SIGNIFICANT LENGTH OF TIME
TOTAL RAINFALL AMOUNTS WILL ONLY BE AROUND HALF AN INCH TO 1 INCH.
WINDS WILL ALSO NOT BE THAT BAD WITH MOSTLY SMALL CRAFT WINDS IN
THE INNER CHANNELS AND GULF EXPECTED ON SAT.

ONE MORE WEAKER SHORT WAVE IS EXPECTED ON MON INTO TUE WITH MORE
RAIN EXPECTED. AFTER THAT IS THE REMAINS OF FORMER TYPHOON
IGNACIO. LONG RANGE MODELS CONTINUE TO HAVE TROUBLE DECIDING ON
WHERE EXACTLY IT WILL GO RESULTING IN A LOW CONFIDENCE FORECAST.
PREVIOUS RUNS HAVE HAD IT GO UP AS FAR AS THE NORTHERN GULF.
CURRENT RUNS ARE SHOWING MUCH LESS OF A SCATTER EFFECT ON
POSITION AND HAVE MOVED THE SYSTEM MUCH FURTHER SOUTH. THE CURRENT
FORECAST HAS THE REMAINS MOVING ACROSS THE EXTREME SE GULF AND
INTO THE SOUTHERN PANHANDLE OR HAIDA GWAII TUE EVENING.
CONSEQUENTLY THE WIND FORECAST FOR TUE INTO WED HAS CHANGED
PARTICULARLY IN THE GULF WITH SOME PLACES HAVING THE WIND FORECAST
LOWER AND DIRECTION CHANGE BY AROUND 180 DEGREES. THIS ALSO
RESULTS IN A POSSIBLY DRIER FORECAST FOR THE NORTHERN PANHANDLE
DUE TO MORE OFFSHORE FLOW DRYING THE AREA OUT AS MOST OF THE
FORECAST PRECIP IS AIMED AT THE SOUTHERN PANHANDLE. SO POPS HAVE
BEEN LOWERED TO CHANCE FOR THE NORTHERN PANHANDLE FOR THAT TIME
PERIOD.

FORECAST CONFIDENCE REMAINS LOW INTO MID TO LATE NEXT WEEK AS MORE
SHORT WAVES MOVE INTO THE PANHANDLE FROM THE WEST BUT TIMING AND
TRACK ARE STILL UP FOR DEBATE. THE ONLY THING THAT I CAN SAY WITH
SOME CERTAINTY IS THAT NEXT WEEK WILL BE DAMP. DECIDED TO LEAN
MOSTLY ON THE WPC DATA FOR THE EXTENDED RANGE FOR IT`S USE OF
MORE ENSEMBLE DATA IN THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-042-043.

&&

$$

DEL/JWA/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 032322
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
322 PM AKDT THU SEP 3 2015

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY CLEAR
SKIES OVER MOST OF THE PANHANDLE WITH INCREASING HIGH CLOUDS
BEGINNING TO STREAM INTO THE NORTHEAST GULF COASTAL AREA.
MEANWHILE...SURFACE FRONTAL SYSTEM STARTING TO TAKE SHAPE OVER THE
WESTERN GULF IN RESPONSE TO AN AREA OF ASCENT ASSOCIATED WITH AN
UPPER VORT LOBE NEAR KODIAK IS. THIS PIECE OF ENERGY IS FORECAST
TO BEGIN TO FLATTEN OUT THE UPPER RIDGE OVER THE CENTRAL AND
EASTERN GULF THIS EVENING AND ALLOW THE NW FLOW THAT HAS GIVEN SE
AK THE NICE WEATHER OVER THE PAST TWO DAYS TO TAKE MORE OF A
WESTERLY ZONAL COMPONENT.

AT THE SURFACE...A RIDGE OF HIGH PRESSURE OVER THE EASTERN GULF
WILL WEAKEN AND SLIDE EASTWARD INTO BC TONIGHT AS THE FRONTAL
SYSTEM BEGINS TO IMPINGE ON THE COASTAL WATERS FRIDAY MORNING. AS
THIS FRONT PUSHES EASTWARD...MODELS ARE SHOWING A DECENT BARRIER
JET DEVELOPING ALONG THE NE GULF COAST WITH THE NAM AND HIRES
MODELS INDICATING GALES DEVELOPING BY FRIDAY AFTERNOON. THIS WAS
WELL DEPICTED BY THE PREVIOUS SHIFT SO DID NOT MAKE ANY CHANGES TO
THE WINDS ON THE COASTAL WATERS FOR FRIDAY. MAIN CHANGES WERE TO
ADJUST THE WINDS OVER THE NORTHERN AND CENTRAL INNER CHANNELS TO
MORE OF A SELY COMPONENT AND TO INCREASE THE ELY WINDS FRIDAY
AFTERNOON IN ICY STRAIT IN RESPONSE TO THE APPROACHING FRONT AND
TIGHTENING GRADIENT.

12Z MODELS SEEMED TO SLIGHTLY SLOW DOWN THE ADVANCE OF RAIN INLAND
ON FRIDAY AFTERNOON BUT THE FLOW AT 700MB REMAINS OUT OF THE SW
WHICH IS A GOOD INDICATOR OF INCREASING ONSHORE FLOW AND LENDS
CREDENCE TO KEEPING LIKELY POPS FRIDAY AFTERNOON FOR NORTHERN
ZONES WITH CATEGORICAL POPS ALONG THE GULF COAST NORTH OF SITKA.

MADE MINOR ADJUSTMENTS TO TEMPERATURES OVER THE NORTHERN AND
CENTRAL AREAS TO RAISE OVER NIGHT LOWS IN PLACES WITH MORE CLOUD
COVER EXPECTED TONIGHT. ALSO ADDED PATCHY FOG TO THE
KLAWOCK...KETCHIKAN AND HYDER AREAS AS GOOD RADIATIONAL COOLING
EXPECTED AGAIN TONIGHT SIMILAR TO THIS MORNING WHEN THERE WAS SOME
LOCALLY DENSE FOG ON THE WEBCAMS IN THESE AREAS. DEBATED ABOUT
ADDING FOG TO PETERSBURG AND WRANGELL TONIGHT BUT THEY WILL BE ON
THE EDGE OF THE HIGH CLOUD COVER LATER TONIGHT AND NO FOG WAS
REPORTED THIS MORNING.

.LONG TERM...LONG TERM PERIOD REMAINS WET FOR THE WEEKEND AND
BEYOND AS UPPER LEVEL PATTERN STAYS MOSTLY WITH A FLAT, EAST TO
WEST FLOW. EMBEDDED IN THIS WESTERLY FLOW ARE A FEW SHORT WAVES
AS WELL AS THE REMAINS OF FORMER TYPHOON IGNACIO.

FIRST RATHER VIGOROUS SHORT WAVE CROSSES THE PANHANDLE ON SAT
BRINGING MORE RAIN AND SOME WIND TO THE AREA. THERE IS SOME
TROPICAL MOISTURE THAT HAS BEEN ABSORBED BY THE SYSTEM SO SOME
HEAVY RAIN IS EXPECTED AS THE FRONT MOVES THROUGH. AS THE FRONT
WILL NOT BE STICKING AROUND FOR ANY SIGNIFICANT LENGTH OF TIME
TOTAL RAINFALL AMOUNTS WILL ONLY BE AROUND HALF AN INCH TO 1 INCH.
WINDS WILL ALSO NOT BE THAT BAD WITH MOSTLY SMALL CRAFT WINDS IN
THE INNER CHANNELS AND GULF EXPECTED ON SAT.

ONE MORE WEAKER SHORT WAVE IS EXPECTED ON MON INTO TUE WITH MORE
RAIN EXPECTED. AFTER THAT IS THE REMAINS OF FORMER TYPHOON
IGNACIO. LONG RANGE MODELS CONTINUE TO HAVE TROUBLE DECIDING ON
WHERE EXACTLY IT WILL GO RESULTING IN A LOW CONFIDENCE FORECAST.
PREVIOUS RUNS HAVE HAD IT GO UP AS FAR AS THE NORTHERN GULF.
CURRENT RUNS ARE SHOWING MUCH LESS OF A SCATTER EFFECT ON
POSITION AND HAVE MOVED THE SYSTEM MUCH FURTHER SOUTH. THE CURRENT
FORECAST HAS THE REMAINS MOVING ACROSS THE EXTREME SE GULF AND
INTO THE SOUTHERN PANHANDLE OR HAIDA GWAII TUE EVENING.
CONSEQUENTLY THE WIND FORECAST FOR TUE INTO WED HAS CHANGED
PARTICULARLY IN THE GULF WITH SOME PLACES HAVING THE WIND FORECAST
LOWER AND DIRECTION CHANGE BY AROUND 180 DEGREES. THIS ALSO
RESULTS IN A POSSIBLY DRIER FORECAST FOR THE NORTHERN PANHANDLE
DUE TO MORE OFFSHORE FLOW DRYING THE AREA OUT AS MOST OF THE
FORECAST PRECIP IS AIMED AT THE SOUTHERN PANHANDLE. SO POPS HAVE
BEEN LOWERED TO CHANCE FOR THE NORTHERN PANHANDLE FOR THAT TIME
PERIOD.

FORECAST CONFIDENCE REMAINS LOW INTO MID TO LATE NEXT WEEK AS MORE
SHORT WAVES MOVE INTO THE PANHANDLE FROM THE WEST BUT TIMING AND
TRACK ARE STILL UP FOR DEBATE. THE ONLY THING THAT I CAN SAY WITH
SOME CERTAINTY IS THAT NEXT WEEK WILL BE DAMP. DECIDED TO LEAN
MOSTLY ON THE WPC DATA FOR THE EXTENDED RANGE FOR IT`S USE OF
MORE ENSEMBLE DATA IN THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-042-043.

&&

$$

DEL/JWA/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 032322
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
322 PM AKDT THU SEP 3 2015

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY CLEAR
SKIES OVER MOST OF THE PANHANDLE WITH INCREASING HIGH CLOUDS
BEGINNING TO STREAM INTO THE NORTHEAST GULF COASTAL AREA.
MEANWHILE...SURFACE FRONTAL SYSTEM STARTING TO TAKE SHAPE OVER THE
WESTERN GULF IN RESPONSE TO AN AREA OF ASCENT ASSOCIATED WITH AN
UPPER VORT LOBE NEAR KODIAK IS. THIS PIECE OF ENERGY IS FORECAST
TO BEGIN TO FLATTEN OUT THE UPPER RIDGE OVER THE CENTRAL AND
EASTERN GULF THIS EVENING AND ALLOW THE NW FLOW THAT HAS GIVEN SE
AK THE NICE WEATHER OVER THE PAST TWO DAYS TO TAKE MORE OF A
WESTERLY ZONAL COMPONENT.

AT THE SURFACE...A RIDGE OF HIGH PRESSURE OVER THE EASTERN GULF
WILL WEAKEN AND SLIDE EASTWARD INTO BC TONIGHT AS THE FRONTAL
SYSTEM BEGINS TO IMPINGE ON THE COASTAL WATERS FRIDAY MORNING. AS
THIS FRONT PUSHES EASTWARD...MODELS ARE SHOWING A DECENT BARRIER
JET DEVELOPING ALONG THE NE GULF COAST WITH THE NAM AND HIRES
MODELS INDICATING GALES DEVELOPING BY FRIDAY AFTERNOON. THIS WAS
WELL DEPICTED BY THE PREVIOUS SHIFT SO DID NOT MAKE ANY CHANGES TO
THE WINDS ON THE COASTAL WATERS FOR FRIDAY. MAIN CHANGES WERE TO
ADJUST THE WINDS OVER THE NORTHERN AND CENTRAL INNER CHANNELS TO
MORE OF A SELY COMPONENT AND TO INCREASE THE ELY WINDS FRIDAY
AFTERNOON IN ICY STRAIT IN RESPONSE TO THE APPROACHING FRONT AND
TIGHTENING GRADIENT.

12Z MODELS SEEMED TO SLIGHTLY SLOW DOWN THE ADVANCE OF RAIN INLAND
ON FRIDAY AFTERNOON BUT THE FLOW AT 700MB REMAINS OUT OF THE SW
WHICH IS A GOOD INDICATOR OF INCREASING ONSHORE FLOW AND LENDS
CREDENCE TO KEEPING LIKELY POPS FRIDAY AFTERNOON FOR NORTHERN
ZONES WITH CATEGORICAL POPS ALONG THE GULF COAST NORTH OF SITKA.

MADE MINOR ADJUSTMENTS TO TEMPERATURES OVER THE NORTHERN AND
CENTRAL AREAS TO RAISE OVER NIGHT LOWS IN PLACES WITH MORE CLOUD
COVER EXPECTED TONIGHT. ALSO ADDED PATCHY FOG TO THE
KLAWOCK...KETCHIKAN AND HYDER AREAS AS GOOD RADIATIONAL COOLING
EXPECTED AGAIN TONIGHT SIMILAR TO THIS MORNING WHEN THERE WAS SOME
LOCALLY DENSE FOG ON THE WEBCAMS IN THESE AREAS. DEBATED ABOUT
ADDING FOG TO PETERSBURG AND WRANGELL TONIGHT BUT THEY WILL BE ON
THE EDGE OF THE HIGH CLOUD COVER LATER TONIGHT AND NO FOG WAS
REPORTED THIS MORNING.

.LONG TERM...LONG TERM PERIOD REMAINS WET FOR THE WEEKEND AND
BEYOND AS UPPER LEVEL PATTERN STAYS MOSTLY WITH A FLAT, EAST TO
WEST FLOW. EMBEDDED IN THIS WESTERLY FLOW ARE A FEW SHORT WAVES
AS WELL AS THE REMAINS OF FORMER TYPHOON IGNACIO.

FIRST RATHER VIGOROUS SHORT WAVE CROSSES THE PANHANDLE ON SAT
BRINGING MORE RAIN AND SOME WIND TO THE AREA. THERE IS SOME
TROPICAL MOISTURE THAT HAS BEEN ABSORBED BY THE SYSTEM SO SOME
HEAVY RAIN IS EXPECTED AS THE FRONT MOVES THROUGH. AS THE FRONT
WILL NOT BE STICKING AROUND FOR ANY SIGNIFICANT LENGTH OF TIME
TOTAL RAINFALL AMOUNTS WILL ONLY BE AROUND HALF AN INCH TO 1 INCH.
WINDS WILL ALSO NOT BE THAT BAD WITH MOSTLY SMALL CRAFT WINDS IN
THE INNER CHANNELS AND GULF EXPECTED ON SAT.

ONE MORE WEAKER SHORT WAVE IS EXPECTED ON MON INTO TUE WITH MORE
RAIN EXPECTED. AFTER THAT IS THE REMAINS OF FORMER TYPHOON
IGNACIO. LONG RANGE MODELS CONTINUE TO HAVE TROUBLE DECIDING ON
WHERE EXACTLY IT WILL GO RESULTING IN A LOW CONFIDENCE FORECAST.
PREVIOUS RUNS HAVE HAD IT GO UP AS FAR AS THE NORTHERN GULF.
CURRENT RUNS ARE SHOWING MUCH LESS OF A SCATTER EFFECT ON
POSITION AND HAVE MOVED THE SYSTEM MUCH FURTHER SOUTH. THE CURRENT
FORECAST HAS THE REMAINS MOVING ACROSS THE EXTREME SE GULF AND
INTO THE SOUTHERN PANHANDLE OR HAIDA GWAII TUE EVENING.
CONSEQUENTLY THE WIND FORECAST FOR TUE INTO WED HAS CHANGED
PARTICULARLY IN THE GULF WITH SOME PLACES HAVING THE WIND FORECAST
LOWER AND DIRECTION CHANGE BY AROUND 180 DEGREES. THIS ALSO
RESULTS IN A POSSIBLY DRIER FORECAST FOR THE NORTHERN PANHANDLE
DUE TO MORE OFFSHORE FLOW DRYING THE AREA OUT AS MOST OF THE
FORECAST PRECIP IS AIMED AT THE SOUTHERN PANHANDLE. SO POPS HAVE
BEEN LOWERED TO CHANCE FOR THE NORTHERN PANHANDLE FOR THAT TIME
PERIOD.

FORECAST CONFIDENCE REMAINS LOW INTO MID TO LATE NEXT WEEK AS MORE
SHORT WAVES MOVE INTO THE PANHANDLE FROM THE WEST BUT TIMING AND
TRACK ARE STILL UP FOR DEBATE. THE ONLY THING THAT I CAN SAY WITH
SOME CERTAINTY IS THAT NEXT WEEK WILL BE DAMP. DECIDED TO LEAN
MOSTLY ON THE WPC DATA FOR THE EXTENDED RANGE FOR IT`S USE OF
MORE ENSEMBLE DATA IN THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-042-043.

&&

$$

DEL/JWA/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 032322
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
322 PM AKDT THU SEP 3 2015

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY CLEAR
SKIES OVER MOST OF THE PANHANDLE WITH INCREASING HIGH CLOUDS
BEGINNING TO STREAM INTO THE NORTHEAST GULF COASTAL AREA.
MEANWHILE...SURFACE FRONTAL SYSTEM STARTING TO TAKE SHAPE OVER THE
WESTERN GULF IN RESPONSE TO AN AREA OF ASCENT ASSOCIATED WITH AN
UPPER VORT LOBE NEAR KODIAK IS. THIS PIECE OF ENERGY IS FORECAST
TO BEGIN TO FLATTEN OUT THE UPPER RIDGE OVER THE CENTRAL AND
EASTERN GULF THIS EVENING AND ALLOW THE NW FLOW THAT HAS GIVEN SE
AK THE NICE WEATHER OVER THE PAST TWO DAYS TO TAKE MORE OF A
WESTERLY ZONAL COMPONENT.

AT THE SURFACE...A RIDGE OF HIGH PRESSURE OVER THE EASTERN GULF
WILL WEAKEN AND SLIDE EASTWARD INTO BC TONIGHT AS THE FRONTAL
SYSTEM BEGINS TO IMPINGE ON THE COASTAL WATERS FRIDAY MORNING. AS
THIS FRONT PUSHES EASTWARD...MODELS ARE SHOWING A DECENT BARRIER
JET DEVELOPING ALONG THE NE GULF COAST WITH THE NAM AND HIRES
MODELS INDICATING GALES DEVELOPING BY FRIDAY AFTERNOON. THIS WAS
WELL DEPICTED BY THE PREVIOUS SHIFT SO DID NOT MAKE ANY CHANGES TO
THE WINDS ON THE COASTAL WATERS FOR FRIDAY. MAIN CHANGES WERE TO
ADJUST THE WINDS OVER THE NORTHERN AND CENTRAL INNER CHANNELS TO
MORE OF A SELY COMPONENT AND TO INCREASE THE ELY WINDS FRIDAY
AFTERNOON IN ICY STRAIT IN RESPONSE TO THE APPROACHING FRONT AND
TIGHTENING GRADIENT.

12Z MODELS SEEMED TO SLIGHTLY SLOW DOWN THE ADVANCE OF RAIN INLAND
ON FRIDAY AFTERNOON BUT THE FLOW AT 700MB REMAINS OUT OF THE SW
WHICH IS A GOOD INDICATOR OF INCREASING ONSHORE FLOW AND LENDS
CREDENCE TO KEEPING LIKELY POPS FRIDAY AFTERNOON FOR NORTHERN
ZONES WITH CATEGORICAL POPS ALONG THE GULF COAST NORTH OF SITKA.

MADE MINOR ADJUSTMENTS TO TEMPERATURES OVER THE NORTHERN AND
CENTRAL AREAS TO RAISE OVER NIGHT LOWS IN PLACES WITH MORE CLOUD
COVER EXPECTED TONIGHT. ALSO ADDED PATCHY FOG TO THE
KLAWOCK...KETCHIKAN AND HYDER AREAS AS GOOD RADIATIONAL COOLING
EXPECTED AGAIN TONIGHT SIMILAR TO THIS MORNING WHEN THERE WAS SOME
LOCALLY DENSE FOG ON THE WEBCAMS IN THESE AREAS. DEBATED ABOUT
ADDING FOG TO PETERSBURG AND WRANGELL TONIGHT BUT THEY WILL BE ON
THE EDGE OF THE HIGH CLOUD COVER LATER TONIGHT AND NO FOG WAS
REPORTED THIS MORNING.

.LONG TERM...LONG TERM PERIOD REMAINS WET FOR THE WEEKEND AND
BEYOND AS UPPER LEVEL PATTERN STAYS MOSTLY WITH A FLAT, EAST TO
WEST FLOW. EMBEDDED IN THIS WESTERLY FLOW ARE A FEW SHORT WAVES
AS WELL AS THE REMAINS OF FORMER TYPHOON IGNACIO.

FIRST RATHER VIGOROUS SHORT WAVE CROSSES THE PANHANDLE ON SAT
BRINGING MORE RAIN AND SOME WIND TO THE AREA. THERE IS SOME
TROPICAL MOISTURE THAT HAS BEEN ABSORBED BY THE SYSTEM SO SOME
HEAVY RAIN IS EXPECTED AS THE FRONT MOVES THROUGH. AS THE FRONT
WILL NOT BE STICKING AROUND FOR ANY SIGNIFICANT LENGTH OF TIME
TOTAL RAINFALL AMOUNTS WILL ONLY BE AROUND HALF AN INCH TO 1 INCH.
WINDS WILL ALSO NOT BE THAT BAD WITH MOSTLY SMALL CRAFT WINDS IN
THE INNER CHANNELS AND GULF EXPECTED ON SAT.

ONE MORE WEAKER SHORT WAVE IS EXPECTED ON MON INTO TUE WITH MORE
RAIN EXPECTED. AFTER THAT IS THE REMAINS OF FORMER TYPHOON
IGNACIO. LONG RANGE MODELS CONTINUE TO HAVE TROUBLE DECIDING ON
WHERE EXACTLY IT WILL GO RESULTING IN A LOW CONFIDENCE FORECAST.
PREVIOUS RUNS HAVE HAD IT GO UP AS FAR AS THE NORTHERN GULF.
CURRENT RUNS ARE SHOWING MUCH LESS OF A SCATTER EFFECT ON
POSITION AND HAVE MOVED THE SYSTEM MUCH FURTHER SOUTH. THE CURRENT
FORECAST HAS THE REMAINS MOVING ACROSS THE EXTREME SE GULF AND
INTO THE SOUTHERN PANHANDLE OR HAIDA GWAII TUE EVENING.
CONSEQUENTLY THE WIND FORECAST FOR TUE INTO WED HAS CHANGED
PARTICULARLY IN THE GULF WITH SOME PLACES HAVING THE WIND FORECAST
LOWER AND DIRECTION CHANGE BY AROUND 180 DEGREES. THIS ALSO
RESULTS IN A POSSIBLY DRIER FORECAST FOR THE NORTHERN PANHANDLE
DUE TO MORE OFFSHORE FLOW DRYING THE AREA OUT AS MOST OF THE
FORECAST PRECIP IS AIMED AT THE SOUTHERN PANHANDLE. SO POPS HAVE
BEEN LOWERED TO CHANCE FOR THE NORTHERN PANHANDLE FOR THAT TIME
PERIOD.

FORECAST CONFIDENCE REMAINS LOW INTO MID TO LATE NEXT WEEK AS MORE
SHORT WAVES MOVE INTO THE PANHANDLE FROM THE WEST BUT TIMING AND
TRACK ARE STILL UP FOR DEBATE. THE ONLY THING THAT I CAN SAY WITH
SOME CERTAINTY IS THAT NEXT WEEK WILL BE DAMP. DECIDED TO LEAN
MOSTLY ON THE WPC DATA FOR THE EXTENDED RANGE FOR IT`S USE OF
MORE ENSEMBLE DATA IN THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-042-043.

&&

$$

DEL/JWA/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 032322
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
322 PM AKDT THU SEP 3 2015

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY CLEAR
SKIES OVER MOST OF THE PANHANDLE WITH INCREASING HIGH CLOUDS
BEGINNING TO STREAM INTO THE NORTHEAST GULF COASTAL AREA.
MEANWHILE...SURFACE FRONTAL SYSTEM STARTING TO TAKE SHAPE OVER THE
WESTERN GULF IN RESPONSE TO AN AREA OF ASCENT ASSOCIATED WITH AN
UPPER VORT LOBE NEAR KODIAK IS. THIS PIECE OF ENERGY IS FORECAST
TO BEGIN TO FLATTEN OUT THE UPPER RIDGE OVER THE CENTRAL AND
EASTERN GULF THIS EVENING AND ALLOW THE NW FLOW THAT HAS GIVEN SE
AK THE NICE WEATHER OVER THE PAST TWO DAYS TO TAKE MORE OF A
WESTERLY ZONAL COMPONENT.

AT THE SURFACE...A RIDGE OF HIGH PRESSURE OVER THE EASTERN GULF
WILL WEAKEN AND SLIDE EASTWARD INTO BC TONIGHT AS THE FRONTAL
SYSTEM BEGINS TO IMPINGE ON THE COASTAL WATERS FRIDAY MORNING. AS
THIS FRONT PUSHES EASTWARD...MODELS ARE SHOWING A DECENT BARRIER
JET DEVELOPING ALONG THE NE GULF COAST WITH THE NAM AND HIRES
MODELS INDICATING GALES DEVELOPING BY FRIDAY AFTERNOON. THIS WAS
WELL DEPICTED BY THE PREVIOUS SHIFT SO DID NOT MAKE ANY CHANGES TO
THE WINDS ON THE COASTAL WATERS FOR FRIDAY. MAIN CHANGES WERE TO
ADJUST THE WINDS OVER THE NORTHERN AND CENTRAL INNER CHANNELS TO
MORE OF A SELY COMPONENT AND TO INCREASE THE ELY WINDS FRIDAY
AFTERNOON IN ICY STRAIT IN RESPONSE TO THE APPROACHING FRONT AND
TIGHTENING GRADIENT.

12Z MODELS SEEMED TO SLIGHTLY SLOW DOWN THE ADVANCE OF RAIN INLAND
ON FRIDAY AFTERNOON BUT THE FLOW AT 700MB REMAINS OUT OF THE SW
WHICH IS A GOOD INDICATOR OF INCREASING ONSHORE FLOW AND LENDS
CREDENCE TO KEEPING LIKELY POPS FRIDAY AFTERNOON FOR NORTHERN
ZONES WITH CATEGORICAL POPS ALONG THE GULF COAST NORTH OF SITKA.

MADE MINOR ADJUSTMENTS TO TEMPERATURES OVER THE NORTHERN AND
CENTRAL AREAS TO RAISE OVER NIGHT LOWS IN PLACES WITH MORE CLOUD
COVER EXPECTED TONIGHT. ALSO ADDED PATCHY FOG TO THE
KLAWOCK...KETCHIKAN AND HYDER AREAS AS GOOD RADIATIONAL COOLING
EXPECTED AGAIN TONIGHT SIMILAR TO THIS MORNING WHEN THERE WAS SOME
LOCALLY DENSE FOG ON THE WEBCAMS IN THESE AREAS. DEBATED ABOUT
ADDING FOG TO PETERSBURG AND WRANGELL TONIGHT BUT THEY WILL BE ON
THE EDGE OF THE HIGH CLOUD COVER LATER TONIGHT AND NO FOG WAS
REPORTED THIS MORNING.

.LONG TERM...LONG TERM PERIOD REMAINS WET FOR THE WEEKEND AND
BEYOND AS UPPER LEVEL PATTERN STAYS MOSTLY WITH A FLAT, EAST TO
WEST FLOW. EMBEDDED IN THIS WESTERLY FLOW ARE A FEW SHORT WAVES
AS WELL AS THE REMAINS OF FORMER TYPHOON IGNACIO.

FIRST RATHER VIGOROUS SHORT WAVE CROSSES THE PANHANDLE ON SAT
BRINGING MORE RAIN AND SOME WIND TO THE AREA. THERE IS SOME
TROPICAL MOISTURE THAT HAS BEEN ABSORBED BY THE SYSTEM SO SOME
HEAVY RAIN IS EXPECTED AS THE FRONT MOVES THROUGH. AS THE FRONT
WILL NOT BE STICKING AROUND FOR ANY SIGNIFICANT LENGTH OF TIME
TOTAL RAINFALL AMOUNTS WILL ONLY BE AROUND HALF AN INCH TO 1 INCH.
WINDS WILL ALSO NOT BE THAT BAD WITH MOSTLY SMALL CRAFT WINDS IN
THE INNER CHANNELS AND GULF EXPECTED ON SAT.

ONE MORE WEAKER SHORT WAVE IS EXPECTED ON MON INTO TUE WITH MORE
RAIN EXPECTED. AFTER THAT IS THE REMAINS OF FORMER TYPHOON
IGNACIO. LONG RANGE MODELS CONTINUE TO HAVE TROUBLE DECIDING ON
WHERE EXACTLY IT WILL GO RESULTING IN A LOW CONFIDENCE FORECAST.
PREVIOUS RUNS HAVE HAD IT GO UP AS FAR AS THE NORTHERN GULF.
CURRENT RUNS ARE SHOWING MUCH LESS OF A SCATTER EFFECT ON
POSITION AND HAVE MOVED THE SYSTEM MUCH FURTHER SOUTH. THE CURRENT
FORECAST HAS THE REMAINS MOVING ACROSS THE EXTREME SE GULF AND
INTO THE SOUTHERN PANHANDLE OR HAIDA GWAII TUE EVENING.
CONSEQUENTLY THE WIND FORECAST FOR TUE INTO WED HAS CHANGED
PARTICULARLY IN THE GULF WITH SOME PLACES HAVING THE WIND FORECAST
LOWER AND DIRECTION CHANGE BY AROUND 180 DEGREES. THIS ALSO
RESULTS IN A POSSIBLY DRIER FORECAST FOR THE NORTHERN PANHANDLE
DUE TO MORE OFFSHORE FLOW DRYING THE AREA OUT AS MOST OF THE
FORECAST PRECIP IS AIMED AT THE SOUTHERN PANHANDLE. SO POPS HAVE
BEEN LOWERED TO CHANCE FOR THE NORTHERN PANHANDLE FOR THAT TIME
PERIOD.

FORECAST CONFIDENCE REMAINS LOW INTO MID TO LATE NEXT WEEK AS MORE
SHORT WAVES MOVE INTO THE PANHANDLE FROM THE WEST BUT TIMING AND
TRACK ARE STILL UP FOR DEBATE. THE ONLY THING THAT I CAN SAY WITH
SOME CERTAINTY IS THAT NEXT WEEK WILL BE DAMP. DECIDED TO LEAN
MOSTLY ON THE WPC DATA FOR THE EXTENDED RANGE FOR IT`S USE OF
MORE ENSEMBLE DATA IN THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-042-043.

&&

$$

DEL/JWA/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 032322
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
322 PM AKDT THU SEP 3 2015

.SHORT TERM...EARLY AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY CLEAR
SKIES OVER MOST OF THE PANHANDLE WITH INCREASING HIGH CLOUDS
BEGINNING TO STREAM INTO THE NORTHEAST GULF COASTAL AREA.
MEANWHILE...SURFACE FRONTAL SYSTEM STARTING TO TAKE SHAPE OVER THE
WESTERN GULF IN RESPONSE TO AN AREA OF ASCENT ASSOCIATED WITH AN
UPPER VORT LOBE NEAR KODIAK IS. THIS PIECE OF ENERGY IS FORECAST
TO BEGIN TO FLATTEN OUT THE UPPER RIDGE OVER THE CENTRAL AND
EASTERN GULF THIS EVENING AND ALLOW THE NW FLOW THAT HAS GIVEN SE
AK THE NICE WEATHER OVER THE PAST TWO DAYS TO TAKE MORE OF A
WESTERLY ZONAL COMPONENT.

AT THE SURFACE...A RIDGE OF HIGH PRESSURE OVER THE EASTERN GULF
WILL WEAKEN AND SLIDE EASTWARD INTO BC TONIGHT AS THE FRONTAL
SYSTEM BEGINS TO IMPINGE ON THE COASTAL WATERS FRIDAY MORNING. AS
THIS FRONT PUSHES EASTWARD...MODELS ARE SHOWING A DECENT BARRIER
JET DEVELOPING ALONG THE NE GULF COAST WITH THE NAM AND HIRES
MODELS INDICATING GALES DEVELOPING BY FRIDAY AFTERNOON. THIS WAS
WELL DEPICTED BY THE PREVIOUS SHIFT SO DID NOT MAKE ANY CHANGES TO
THE WINDS ON THE COASTAL WATERS FOR FRIDAY. MAIN CHANGES WERE TO
ADJUST THE WINDS OVER THE NORTHERN AND CENTRAL INNER CHANNELS TO
MORE OF A SELY COMPONENT AND TO INCREASE THE ELY WINDS FRIDAY
AFTERNOON IN ICY STRAIT IN RESPONSE TO THE APPROACHING FRONT AND
TIGHTENING GRADIENT.

12Z MODELS SEEMED TO SLIGHTLY SLOW DOWN THE ADVANCE OF RAIN INLAND
ON FRIDAY AFTERNOON BUT THE FLOW AT 700MB REMAINS OUT OF THE SW
WHICH IS A GOOD INDICATOR OF INCREASING ONSHORE FLOW AND LENDS
CREDENCE TO KEEPING LIKELY POPS FRIDAY AFTERNOON FOR NORTHERN
ZONES WITH CATEGORICAL POPS ALONG THE GULF COAST NORTH OF SITKA.

MADE MINOR ADJUSTMENTS TO TEMPERATURES OVER THE NORTHERN AND
CENTRAL AREAS TO RAISE OVER NIGHT LOWS IN PLACES WITH MORE CLOUD
COVER EXPECTED TONIGHT. ALSO ADDED PATCHY FOG TO THE
KLAWOCK...KETCHIKAN AND HYDER AREAS AS GOOD RADIATIONAL COOLING
EXPECTED AGAIN TONIGHT SIMILAR TO THIS MORNING WHEN THERE WAS SOME
LOCALLY DENSE FOG ON THE WEBCAMS IN THESE AREAS. DEBATED ABOUT
ADDING FOG TO PETERSBURG AND WRANGELL TONIGHT BUT THEY WILL BE ON
THE EDGE OF THE HIGH CLOUD COVER LATER TONIGHT AND NO FOG WAS
REPORTED THIS MORNING.

.LONG TERM...LONG TERM PERIOD REMAINS WET FOR THE WEEKEND AND
BEYOND AS UPPER LEVEL PATTERN STAYS MOSTLY WITH A FLAT, EAST TO
WEST FLOW. EMBEDDED IN THIS WESTERLY FLOW ARE A FEW SHORT WAVES
AS WELL AS THE REMAINS OF FORMER TYPHOON IGNACIO.

FIRST RATHER VIGOROUS SHORT WAVE CROSSES THE PANHANDLE ON SAT
BRINGING MORE RAIN AND SOME WIND TO THE AREA. THERE IS SOME
TROPICAL MOISTURE THAT HAS BEEN ABSORBED BY THE SYSTEM SO SOME
HEAVY RAIN IS EXPECTED AS THE FRONT MOVES THROUGH. AS THE FRONT
WILL NOT BE STICKING AROUND FOR ANY SIGNIFICANT LENGTH OF TIME
TOTAL RAINFALL AMOUNTS WILL ONLY BE AROUND HALF AN INCH TO 1 INCH.
WINDS WILL ALSO NOT BE THAT BAD WITH MOSTLY SMALL CRAFT WINDS IN
THE INNER CHANNELS AND GULF EXPECTED ON SAT.

ONE MORE WEAKER SHORT WAVE IS EXPECTED ON MON INTO TUE WITH MORE
RAIN EXPECTED. AFTER THAT IS THE REMAINS OF FORMER TYPHOON
IGNACIO. LONG RANGE MODELS CONTINUE TO HAVE TROUBLE DECIDING ON
WHERE EXACTLY IT WILL GO RESULTING IN A LOW CONFIDENCE FORECAST.
PREVIOUS RUNS HAVE HAD IT GO UP AS FAR AS THE NORTHERN GULF.
CURRENT RUNS ARE SHOWING MUCH LESS OF A SCATTER EFFECT ON
POSITION AND HAVE MOVED THE SYSTEM MUCH FURTHER SOUTH. THE CURRENT
FORECAST HAS THE REMAINS MOVING ACROSS THE EXTREME SE GULF AND
INTO THE SOUTHERN PANHANDLE OR HAIDA GWAII TUE EVENING.
CONSEQUENTLY THE WIND FORECAST FOR TUE INTO WED HAS CHANGED
PARTICULARLY IN THE GULF WITH SOME PLACES HAVING THE WIND FORECAST
LOWER AND DIRECTION CHANGE BY AROUND 180 DEGREES. THIS ALSO
RESULTS IN A POSSIBLY DRIER FORECAST FOR THE NORTHERN PANHANDLE
DUE TO MORE OFFSHORE FLOW DRYING THE AREA OUT AS MOST OF THE
FORECAST PRECIP IS AIMED AT THE SOUTHERN PANHANDLE. SO POPS HAVE
BEEN LOWERED TO CHANCE FOR THE NORTHERN PANHANDLE FOR THAT TIME
PERIOD.

FORECAST CONFIDENCE REMAINS LOW INTO MID TO LATE NEXT WEEK AS MORE
SHORT WAVES MOVE INTO THE PANHANDLE FROM THE WEST BUT TIMING AND
TRACK ARE STILL UP FOR DEBATE. THE ONLY THING THAT I CAN SAY WITH
SOME CERTAINTY IS THAT NEXT WEEK WILL BE DAMP. DECIDED TO LEAN
MOSTLY ON THE WPC DATA FOR THE EXTENDED RANGE FOR IT`S USE OF
MORE ENSEMBLE DATA IN THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ051-052.
         SMALL CRAFT ADVISORY FOR PKZ012-022-042-043.

&&

$$

DEL/JWA/EAL

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU




000
FXAK67 PAJK 032133 COR
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS
EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W Gradient WILL ALSO INCREASE AS THE
FRONT Approaches SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODELS ARE HAVING A DIFFICULT TIME
TRYING TO GET A HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL GO.
THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE GFS
LIFTS THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SO MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THE MODELS ARE NOT HANDLING WELL. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

Visit us at http://WWW.WEATHER.GOV/JUNEAU




000
FXAK67 PAJK 032133 COR
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS
EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W Gradient WILL ALSO INCREASE AS THE
FRONT Approaches SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODELS ARE HAVING A DIFFICULT TIME
TRYING TO GET A HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL GO.
THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE GFS
LIFTS THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SO MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THE MODELS ARE NOT HANDLING WELL. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

Visit us at http://WWW.WEATHER.GOV/JUNEAU




000
FXAK67 PAJK 032133 COR
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS
EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W Gradient WILL ALSO INCREASE AS THE
FRONT Approaches SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODELS ARE HAVING A DIFFICULT TIME
TRYING TO GET A HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL GO.
THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE GFS
LIFTS THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SO MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THE MODELS ARE NOT HANDLING WELL. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

Visit us at http://WWW.WEATHER.GOV/JUNEAU




000
FXAK67 PAJK 032133 COR
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS
EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W Gradient WILL ALSO INCREASE AS THE
FRONT Approaches SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODELS ARE HAVING A DIFFICULT TIME
TRYING TO GET A HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL GO.
THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE GFS
LIFTS THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SO MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THE MODELS ARE NOT HANDLING WELL. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

Visit us at http://WWW.WEATHER.GOV/JUNEAU




000
FXAK69 PAFG 032128
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
128 PM AKDT THU SEP 3 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 12Z
ANALYSIS. MODEL SPREAD BOTH BETWEEN MODEL FAMILIES AND FROM RUN TO
RUN REMAINS REASONABLE THROUGH SUNDAY BUT SIGNIFICANT SPREAD IN
MODEL SOLUTIONS DEVELOP BY EARLY NEXT WEEK.

ALOFT AT 500 HPA...A 562 DAM RIDGE OVER THE WESTERN INTERIOR WILL
CONTINUE TO WEAKEN AS A 545 DAM LOW SLIDES TO THE SOUTH OVER THE
YUKON SATURDAY. THE LONG WAVE TROUGH OVER THE WESTERN BERING SEA
WILL DEEPEN AND MOVE SOUTH AND EAST THROUGH MONDAY WHERE PHASING
WITH A STRONG SHORTWAVE DIVING SOUTH OUT OF THE HIGH ARCTIC
PUNCHES EAST OVER THE NORTH SLOPE MONDAY.

ON THE SURFACE A 1029 MB HIGH PRESSURE SYSTEM 300 NM NORTH OF
DEMARCATION POINT COMBINED WITH A 1004 MB LOW OVER BRISTOL BAY ARE
PRODUCING SMALL CRAFT LEVEL WINDS OVER THE EASTERN NORTH SLOPE.
THE LOW OVER BRISTOL BAY WILL CONTINUE TO MOVE NORTH INTO THE
LOWER YK DELTA TONIGHT AND WEAKENS TO 1006 FRIDAY MORNING WHILE
SPREADING LIGHT RAIN OVER SOUTHWEST ALASKA SOUTH OF THE SEWARD
PENINSULA THOUGH SATURDAY. THE FRONT WITH THE LOW PRESSURE
CONTINUES TO STREACH AND WEAKEN IN PLACE INTO SUNDAY. EXPECT
MOSTLY SUNNY CONDITIONS OVER THE CENTRAL AND EASTERN INTERIOR.
GUSTY EASTERLY WINDS WILL CONTINUE OVER THE NORTH SLOPE WITH LOW
CEILINGS AND FOG EXPECTED TO CONTINUE.

A FRONT APPROACHES THE NORTHWEST COAST MONDAY AS THE FIRST OF A
TWO OF LOWS PASSES 500 NM NORTH OF BARROW. A SECOND AND MUCH
STRONGER LOW AND ATTENDING FRONT APPROACHES FROM THE NORTHWEST
TUESDAY. CONSIDERABLE MODEL SPREAD EXISTS ON EXACT STRENGTH AND
TRACK WITH THE GFS DROPPING A 990 MB LOW TO A POINT 300 NM NORTH
OF BARROW BY 12Z TUESDAY AND THE ECMWF DROPPING A 1000 MB LOW TO A
POINT 450 NM NORTHWEST OF BARROW TUESDAY MORNING. WILL NEED TO
MONITOR AS EITHER SOLUTION WILL BRING WEST TO NORTHWEST WINDS TO
THE NORTH SLOPE FROM BARROW WEST AND WILL INTRODUCE THE POTENTIAL
AGAIN FOR HIGH SURF AND BEACH EROSION TUESDAY AND WEDNESDAY OF
NEXT WEEK.



COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
CONTINUE TO MONITOR TRACK AND INTENSITY OF POTENTIAL STORM TUESDAY
AND WEDNESDAY ALONG THE NORTHWEST COAST WEST OF BARROW. SUSTAINED
NORTHWEST WINDS AROUND 35 KTS DEPENDING ON STORM TRACK COMBINED
WITH SIGNIFICANT WIND WAVES WILL HAVE THE POTENTIAL TO PRODUCE
HIGH SURF AND SIGNIFICANT BEACH EROSION WEST OF POINT BARROW
TUESDAY AND WEDNESDAY.


&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CCC SEP 15




000
FXAK69 PAFG 032128
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
128 PM AKDT THU SEP 3 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 12Z
ANALYSIS. MODEL SPREAD BOTH BETWEEN MODEL FAMILIES AND FROM RUN TO
RUN REMAINS REASONABLE THROUGH SUNDAY BUT SIGNIFICANT SPREAD IN
MODEL SOLUTIONS DEVELOP BY EARLY NEXT WEEK.

ALOFT AT 500 HPA...A 562 DAM RIDGE OVER THE WESTERN INTERIOR WILL
CONTINUE TO WEAKEN AS A 545 DAM LOW SLIDES TO THE SOUTH OVER THE
YUKON SATURDAY. THE LONG WAVE TROUGH OVER THE WESTERN BERING SEA
WILL DEEPEN AND MOVE SOUTH AND EAST THROUGH MONDAY WHERE PHASING
WITH A STRONG SHORTWAVE DIVING SOUTH OUT OF THE HIGH ARCTIC
PUNCHES EAST OVER THE NORTH SLOPE MONDAY.

ON THE SURFACE A 1029 MB HIGH PRESSURE SYSTEM 300 NM NORTH OF
DEMARCATION POINT COMBINED WITH A 1004 MB LOW OVER BRISTOL BAY ARE
PRODUCING SMALL CRAFT LEVEL WINDS OVER THE EASTERN NORTH SLOPE.
THE LOW OVER BRISTOL BAY WILL CONTINUE TO MOVE NORTH INTO THE
LOWER YK DELTA TONIGHT AND WEAKENS TO 1006 FRIDAY MORNING WHILE
SPREADING LIGHT RAIN OVER SOUTHWEST ALASKA SOUTH OF THE SEWARD
PENINSULA THOUGH SATURDAY. THE FRONT WITH THE LOW PRESSURE
CONTINUES TO STREACH AND WEAKEN IN PLACE INTO SUNDAY. EXPECT
MOSTLY SUNNY CONDITIONS OVER THE CENTRAL AND EASTERN INTERIOR.
GUSTY EASTERLY WINDS WILL CONTINUE OVER THE NORTH SLOPE WITH LOW
CEILINGS AND FOG EXPECTED TO CONTINUE.

A FRONT APPROACHES THE NORTHWEST COAST MONDAY AS THE FIRST OF A
TWO OF LOWS PASSES 500 NM NORTH OF BARROW. A SECOND AND MUCH
STRONGER LOW AND ATTENDING FRONT APPROACHES FROM THE NORTHWEST
TUESDAY. CONSIDERABLE MODEL SPREAD EXISTS ON EXACT STRENGTH AND
TRACK WITH THE GFS DROPPING A 990 MB LOW TO A POINT 300 NM NORTH
OF BARROW BY 12Z TUESDAY AND THE ECMWF DROPPING A 1000 MB LOW TO A
POINT 450 NM NORTHWEST OF BARROW TUESDAY MORNING. WILL NEED TO
MONITOR AS EITHER SOLUTION WILL BRING WEST TO NORTHWEST WINDS TO
THE NORTH SLOPE FROM BARROW WEST AND WILL INTRODUCE THE POTENTIAL
AGAIN FOR HIGH SURF AND BEACH EROSION TUESDAY AND WEDNESDAY OF
NEXT WEEK.



COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
CONTINUE TO MONITOR TRACK AND INTENSITY OF POTENTIAL STORM TUESDAY
AND WEDNESDAY ALONG THE NORTHWEST COAST WEST OF BARROW. SUSTAINED
NORTHWEST WINDS AROUND 35 KTS DEPENDING ON STORM TRACK COMBINED
WITH SIGNIFICANT WIND WAVES WILL HAVE THE POTENTIAL TO PRODUCE
HIGH SURF AND SIGNIFICANT BEACH EROSION WEST OF POINT BARROW
TUESDAY AND WEDNESDAY.


&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CCC SEP 15




000
FXAK69 PAFG 032128
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
128 PM AKDT THU SEP 3 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 12Z
ANALYSIS. MODEL SPREAD BOTH BETWEEN MODEL FAMILIES AND FROM RUN TO
RUN REMAINS REASONABLE THROUGH SUNDAY BUT SIGNIFICANT SPREAD IN
MODEL SOLUTIONS DEVELOP BY EARLY NEXT WEEK.

ALOFT AT 500 HPA...A 562 DAM RIDGE OVER THE WESTERN INTERIOR WILL
CONTINUE TO WEAKEN AS A 545 DAM LOW SLIDES TO THE SOUTH OVER THE
YUKON SATURDAY. THE LONG WAVE TROUGH OVER THE WESTERN BERING SEA
WILL DEEPEN AND MOVE SOUTH AND EAST THROUGH MONDAY WHERE PHASING
WITH A STRONG SHORTWAVE DIVING SOUTH OUT OF THE HIGH ARCTIC
PUNCHES EAST OVER THE NORTH SLOPE MONDAY.

ON THE SURFACE A 1029 MB HIGH PRESSURE SYSTEM 300 NM NORTH OF
DEMARCATION POINT COMBINED WITH A 1004 MB LOW OVER BRISTOL BAY ARE
PRODUCING SMALL CRAFT LEVEL WINDS OVER THE EASTERN NORTH SLOPE.
THE LOW OVER BRISTOL BAY WILL CONTINUE TO MOVE NORTH INTO THE
LOWER YK DELTA TONIGHT AND WEAKENS TO 1006 FRIDAY MORNING WHILE
SPREADING LIGHT RAIN OVER SOUTHWEST ALASKA SOUTH OF THE SEWARD
PENINSULA THOUGH SATURDAY. THE FRONT WITH THE LOW PRESSURE
CONTINUES TO STREACH AND WEAKEN IN PLACE INTO SUNDAY. EXPECT
MOSTLY SUNNY CONDITIONS OVER THE CENTRAL AND EASTERN INTERIOR.
GUSTY EASTERLY WINDS WILL CONTINUE OVER THE NORTH SLOPE WITH LOW
CEILINGS AND FOG EXPECTED TO CONTINUE.

A FRONT APPROACHES THE NORTHWEST COAST MONDAY AS THE FIRST OF A
TWO OF LOWS PASSES 500 NM NORTH OF BARROW. A SECOND AND MUCH
STRONGER LOW AND ATTENDING FRONT APPROACHES FROM THE NORTHWEST
TUESDAY. CONSIDERABLE MODEL SPREAD EXISTS ON EXACT STRENGTH AND
TRACK WITH THE GFS DROPPING A 990 MB LOW TO A POINT 300 NM NORTH
OF BARROW BY 12Z TUESDAY AND THE ECMWF DROPPING A 1000 MB LOW TO A
POINT 450 NM NORTHWEST OF BARROW TUESDAY MORNING. WILL NEED TO
MONITOR AS EITHER SOLUTION WILL BRING WEST TO NORTHWEST WINDS TO
THE NORTH SLOPE FROM BARROW WEST AND WILL INTRODUCE THE POTENTIAL
AGAIN FOR HIGH SURF AND BEACH EROSION TUESDAY AND WEDNESDAY OF
NEXT WEEK.



COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
CONTINUE TO MONITOR TRACK AND INTENSITY OF POTENTIAL STORM TUESDAY
AND WEDNESDAY ALONG THE NORTHWEST COAST WEST OF BARROW. SUSTAINED
NORTHWEST WINDS AROUND 35 KTS DEPENDING ON STORM TRACK COMBINED
WITH SIGNIFICANT WIND WAVES WILL HAVE THE POTENTIAL TO PRODUCE
HIGH SURF AND SIGNIFICANT BEACH EROSION WEST OF POINT BARROW
TUESDAY AND WEDNESDAY.


&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CCC SEP 15




000
FXAK69 PAFG 032128
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
128 PM AKDT THU SEP 3 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 12Z
ANALYSIS. MODEL SPREAD BOTH BETWEEN MODEL FAMILIES AND FROM RUN TO
RUN REMAINS REASONABLE THROUGH SUNDAY BUT SIGNIFICANT SPREAD IN
MODEL SOLUTIONS DEVELOP BY EARLY NEXT WEEK.

ALOFT AT 500 HPA...A 562 DAM RIDGE OVER THE WESTERN INTERIOR WILL
CONTINUE TO WEAKEN AS A 545 DAM LOW SLIDES TO THE SOUTH OVER THE
YUKON SATURDAY. THE LONG WAVE TROUGH OVER THE WESTERN BERING SEA
WILL DEEPEN AND MOVE SOUTH AND EAST THROUGH MONDAY WHERE PHASING
WITH A STRONG SHORTWAVE DIVING SOUTH OUT OF THE HIGH ARCTIC
PUNCHES EAST OVER THE NORTH SLOPE MONDAY.

ON THE SURFACE A 1029 MB HIGH PRESSURE SYSTEM 300 NM NORTH OF
DEMARCATION POINT COMBINED WITH A 1004 MB LOW OVER BRISTOL BAY ARE
PRODUCING SMALL CRAFT LEVEL WINDS OVER THE EASTERN NORTH SLOPE.
THE LOW OVER BRISTOL BAY WILL CONTINUE TO MOVE NORTH INTO THE
LOWER YK DELTA TONIGHT AND WEAKENS TO 1006 FRIDAY MORNING WHILE
SPREADING LIGHT RAIN OVER SOUTHWEST ALASKA SOUTH OF THE SEWARD
PENINSULA THOUGH SATURDAY. THE FRONT WITH THE LOW PRESSURE
CONTINUES TO STREACH AND WEAKEN IN PLACE INTO SUNDAY. EXPECT
MOSTLY SUNNY CONDITIONS OVER THE CENTRAL AND EASTERN INTERIOR.
GUSTY EASTERLY WINDS WILL CONTINUE OVER THE NORTH SLOPE WITH LOW
CEILINGS AND FOG EXPECTED TO CONTINUE.

A FRONT APPROACHES THE NORTHWEST COAST MONDAY AS THE FIRST OF A
TWO OF LOWS PASSES 500 NM NORTH OF BARROW. A SECOND AND MUCH
STRONGER LOW AND ATTENDING FRONT APPROACHES FROM THE NORTHWEST
TUESDAY. CONSIDERABLE MODEL SPREAD EXISTS ON EXACT STRENGTH AND
TRACK WITH THE GFS DROPPING A 990 MB LOW TO A POINT 300 NM NORTH
OF BARROW BY 12Z TUESDAY AND THE ECMWF DROPPING A 1000 MB LOW TO A
POINT 450 NM NORTHWEST OF BARROW TUESDAY MORNING. WILL NEED TO
MONITOR AS EITHER SOLUTION WILL BRING WEST TO NORTHWEST WINDS TO
THE NORTH SLOPE FROM BARROW WEST AND WILL INTRODUCE THE POTENTIAL
AGAIN FOR HIGH SURF AND BEACH EROSION TUESDAY AND WEDNESDAY OF
NEXT WEEK.



COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
CONTINUE TO MONITOR TRACK AND INTENSITY OF POTENTIAL STORM TUESDAY
AND WEDNESDAY ALONG THE NORTHWEST COAST WEST OF BARROW. SUSTAINED
NORTHWEST WINDS AROUND 35 KTS DEPENDING ON STORM TRACK COMBINED
WITH SIGNIFICANT WIND WAVES WILL HAVE THE POTENTIAL TO PRODUCE
HIGH SURF AND SIGNIFICANT BEACH EROSION WEST OF POINT BARROW
TUESDAY AND WEDNESDAY.


&&

.HYDROLOGY...
NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CCC SEP 15




000
FXAK67 PAJK 031436
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W GRADIENT WILL ALSO INCREASE AS THE
FRONT APPROACHES SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODEL ARE HAVING A HELL OF A TIME
TRYING TO GET AN HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL
GO. THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE
GFS LIFTS THE THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SOME MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THEY MODEL ARE NOT DOING WELL WITH. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 031436
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W GRADIENT WILL ALSO INCREASE AS THE
FRONT APPROACHES SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODEL ARE HAVING A HELL OF A TIME
TRYING TO GET AN HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL
GO. THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE
GFS LIFTS THE THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SOME MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THEY MODEL ARE NOT DOING WELL WITH. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 031436
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W GRADIENT WILL ALSO INCREASE AS THE
FRONT APPROACHES SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODEL ARE HAVING A HELL OF A TIME
TRYING TO GET AN HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL
GO. THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE
GFS LIFTS THE THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SOME MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THEY MODEL ARE NOT DOING WELL WITH. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 031436
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
636 AM AKDT THU SEP 3 2015

.SHORT TERM...UPPER TROF JUST E OF SE AK WILL DIG SE TOWARD THE
PAC NW STATES THRU TONIGHT. AN ELONGATED SHORTWAVE TROF WILL DIVE
SWD THRU THE SRN PANHANDLE THIS AFTERNOON. A COMPLEX FRONTAL
SYSTEM OVER THE ERN AKPEN WILL MOVE E TO THE CENTRAL GULF BY LATE
TONIGHT. MODELS WERE IN FAIRLY GOOD AGREEMENT ON THESE
FEATURES...AND ENDED UP USING A BLEND OF THE 00Z GFS22 AND NAM12.

MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL AND WINDS. AS
SHORTWAVE MOVES THRU SRN AREA THIS AFTERNOON...SOME SHOWERS MAY
DEVELOP NEAR HYDER. ONCE SHORTWAVE GOES PAST THEM THIS EVENING...ANY
SHOWERS NEAR HYDER SHOULD DIMINISH. PRECIP WITH THE COMPLEX
FRONTAL SYSTEM SHOULD BE MOVING SLOWLY E INTO THE CENTRAL AND PART
OF THE ERN GULF TONIGHT. THINK THIS PRECIP WILL MAKE IT TO THE
PAYA AREA AROUND MIDNIGHT TONIGHT. THE MODELS DID DIFFER A BIT ON
THE TIMING...AND THE MIDNIGHT TIMING INTO PAYA IS A MIDDLE GROUND
COMPROMISE. SOME SPRINKLES COULD REACH THE FAR NRN AREA LATE
TONIGHT...SO WENT WITH A LOW POP THERE TO COVER THAT.

WIND WISE...STRONGEST WINDS ARE GENERALLY OVER THE NRN INNER
CHANNELS ATTM. 20-25 KT NLY WINDS ARE OCCURRING IN LYNN
CANAL...BUT WITH A RAPIDLY WEAKENING NLY PRESSURE GRADIENT THIS
MORNING...THEY SHOULD DROP OFF INTO THE 10-15 KT RANGE BY LATE
MORNING. THE GRADIENT WILL LIKELY FLIP TO SLY THIS AFTERNOON AS
SWLY FLOW ALOFT LOWERS PRESSURES OVER THE YUKON AND FAR NRN
PANHANDLE. DO NOT SEE MORE THAN 15 KT S WINDS FROM THIS. FURTHER
S...N-NW WINDS OF 10-15 KT ARE COMMON OVER THE CENTRAL INNER
CHANNELS...WITH GENERALLY LESS THAN 10 KT OVER THE SRN AREA. THESE
WINDS WILL LIKELY DIMINISH THIS AFTERNOON. AS COMPLEX FRONTAL
SYSTEM MOVES CLOSER TO THE AREA TONIGHT...SOME INCREASE IN E-SE
WINDS WILL OCCUR...BUT MOST PLACES WILL BE 15 KT OR LESS. MAY BE A
SMALL AREA OF 20 KT E WINDS NEAR SCULL ISLAND TONIGHT AS ELY
PRESSURE GRADIENT WILL BE LOCALLY ENHANCED BY THE NEARBY TERRAIN
THERE. OVER THE GULF...E-SE WINDS WILL PICK UP OVER THE NRN GULF
TONIGHT...WITH AREAS W OF ICY BAY INCREASING TO SCA LEVELS AS WEAK
BARRIER JET DEVELOPS AHEAD OF THE FRONTAL SYSTEM.

.LONG TERM...AT THE START OF THE LONG TERM PERIOD A LOW WILL BE
OVER THE NORTHERN GULF WITH AN ASSOCIATED COMPLEX WEATHER FRONT
EXTENDING EAST TOWARDS YAKUTAT. THIS FRONT WILL PRODUCE A BARRIER
JET TO MIN GALES OVER THE NORTHERN GULF AND THEN 25 TO 35 KT ALONG
THE FRONT ON FRIDAY. THE E/W GRADIENT WILL ALSO INCREASE AS THE
FRONT APPROACHES SO INCREASED THE WINDS TO 25 KT OVER CROSS SOUND
AND 20 KT OVER ICY STRAIT. THE WINDS OVER THE INNER CHANNELS WILL
INCREASE SOME FRIDAY FROM THE SOUTH AS THE SURFACE RIDGE OVER THE
AREA SHARPENS UP AS IT FEELS THE AFFECTS OF THE FRONT. SMALL
CRAFT WINDS WILL DEVELOP OVER NORTHERN LYNN AND 20 KT OVER
SOUTHERN LYNN THE REST OF THE INNER CHANNELS WILL SEE SOUTH WINDS
LESS THAN 15 KT THROUGH FRIDAY. THE RIDGE WILL PUSH TO THE EAST AS
THE FRONT MOVES INTO THE EASTERN GULF AND THE SOUTH WINDS OVER N/S
CHANNELS WILL DIMINISH. LAND WINDS WITH THIS FRONT WILL BE THE
STRONGEST OVER THE GULF COAST WITH 15 TO 25 MPH AND THEN SPREADS
INLAND WITH THE FRONT LATE FRIDAY INTO SATURDAY MORNING BUT IT
WILL BE WEAKENING SO WINDS WILL BE MORE LIKE 10 TO 20 MPH WITH
SOME HIGHER GUSTS.

THE FRONT HAS SOME TROPICAL CONNECTION AS SEEN ON SATELLITE
IMAGERY AND AS IT MOVES OVER THE FORECAST AREA IT WILL PRODUCE
SOME HEAVY RAIN. THE RAIN WILL SPREAD FROM THE NORTHERN GULF
FRIDAY MORNING AND OVER THE NORTHERN HALF THROUGH FRIDAY
AFTERNOON THEN OVER THE SOUTHERN HALF BY FRIDAY NIGHT. AT THIS
TIME THE HEAVY RAIN WILL BE ALONG THE COASTAL AREAS WITH THE
GUSTAVUS AND HOONAH AREAS ALSO SEEING SOME SIGNIFICANT RAIN
AMOUNTS. RAIN TOTAL ACROSS THE AREA WILL RANGE FROM 1 TO 2 INCHES
FROM FRIDAY MORNING THROUGH SATURDAY MORNING. THE LOW WILL SLOWLY
WEAKEN THROUGH SATURDAY AND SHOWERS WILL PERSIST OVER MOST OF THE
AREA. THE SHOWERS WILL BECOME MORE SCATTERED THROUGH SATURDAY
NIGHT.

THERE REMAINS A LOT OF MODEL DISAGREEMENT FROM SUNDAY INTO NEXT
WEEK. THE GEM AND EC WANT TO KEEP THE PANHANDLE ON THE DRIER SIDE
ON SUNDAY WHILE THE GFS KEEPS MORE SHOWERS OVER THE AREA. TO
COMPLICATE THE SITUATION EVEN MORE HURRICANE IGNACIO IS FORECASTED
TO MOVE NORTH OUT OF THE CENTRAL PACIFIC AND INTO THE NORTH
PACIFIC EARLY NEXT WEEK. THE MODEL ARE HAVING A HELL OF A TIME
TRYING TO GET AN HANDLE ON WHERE THIS EXTRA-TROPICAL SYSTEM WILL
GO. THE EC AND GEM KEEPS THIS SYSTEM SOUTH OF OUR AREA WHILE THE
GFS LIFTS THE THE SYSTEM RIGHT OVER SEAK ON TUESDAY MORNING.
THERE IS SOME MUCH UNCERTAINTY AT THIS TIME THAT EVEN BEFORE
IGNACIO MOVES INTO THE GULF THERE ARE ISSUES WITH A LEADING WAVE
AHEAD OF THE SYSTEM THAT THEY MODEL ARE NOT DOING WELL WITH. THE
EC DEVELOPS THIS WAVE MOVING OUT OF THE NORTH PACIFIC AND INTO THE
EASTERN GULF SUNDAY INTO MONDAY. THE GEM DEVELOPS A WAVE MOVING
OUT OF THE BRISTOL BAY AREA AND INTO THE GULF ON MONDAY.

SO WITH THAT SAID THERE IS VERY LOW FORECASTER CONFIDENCE FROM
SUNDAY INTO NEXT WEEK. THE MAIN POINT IS THAT SOMETHING WILL MOVE
INTO THE GULF FROM THE TROPICS BUT WHERE IT WILL GO AND WHEN IS
STILL YET TO BE SEEN.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-051-052.

&&

$$

RWT/ABJ

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK68 PAFC 031313
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM MOVING
INTO THE BRISTOL BAY REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES FARTHER
INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW DEVELOPING IN THE
GULF BY FRIDAY AND TRACKING TO THE SOUTHEAST ALASKA REGION BY
SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS WAS MOVING THIS LOW
THROUGH THE GULF FASTER THEN THE OTHER MODELS. THE BIGGEST CHALLENGE
WILL BE WITH THE TIMING OF PRECIPITATION AS THE DIFFERENT SYNOPTIC
FEATURES MOVE THROUGH THE SOUTHWEST AND SOUTHCENTRAL REGION. THE
PREFERRED MODEL OF CHOICE WAS THE NAM. THE FORECAST CONFIDENCE IS
ABOVE AVERAGE AS WE HEAD INTO THE WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY LATE FRIDAY. IN THE WAKE OF THE RAIN THE AIRMASS
WILL REMAIN QUITE MOIST WITH GENERALLY WEAK AND DIFFUSE FLOW.
THEREFORE EXTENSIVE CLOUDINESS WILL PERSISTS INTO THE WEEKEND
MAINTAINING FAIRLY COOL TEMPERATURES AND RELATIVELY HIGH RHS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC



000
FXAK68 PAFC 031313
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM MOVING
INTO THE BRISTOL BAY REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES FARTHER
INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW DEVELOPING IN THE
GULF BY FRIDAY AND TRACKING TO THE SOUTHEAST ALASKA REGION BY
SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS WAS MOVING THIS LOW
THROUGH THE GULF FASTER THEN THE OTHER MODELS. THE BIGGEST CHALLENGE
WILL BE WITH THE TIMING OF PRECIPITATION AS THE DIFFERENT SYNOPTIC
FEATURES MOVE THROUGH THE SOUTHWEST AND SOUTHCENTRAL REGION. THE
PREFERRED MODEL OF CHOICE WAS THE NAM. THE FORECAST CONFIDENCE IS
ABOVE AVERAGE AS WE HEAD INTO THE WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY LATE FRIDAY. IN THE WAKE OF THE RAIN THE AIRMASS
WILL REMAIN QUITE MOIST WITH GENERALLY WEAK AND DIFFUSE FLOW.
THEREFORE EXTENSIVE CLOUDINESS WILL PERSISTS INTO THE WEEKEND
MAINTAINING FAIRLY COOL TEMPERATURES AND RELATIVELY HIGH RHS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC




000
FXAK68 PAFC 031313
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM MOVING
INTO THE BRISTOL BAY REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES FARTHER
INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW DEVELOPING IN THE
GULF BY FRIDAY AND TRACKING TO THE SOUTHEAST ALASKA REGION BY
SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS WAS MOVING THIS LOW
THROUGH THE GULF FASTER THEN THE OTHER MODELS. THE BIGGEST CHALLENGE
WILL BE WITH THE TIMING OF PRECIPITATION AS THE DIFFERENT SYNOPTIC
FEATURES MOVE THROUGH THE SOUTHWEST AND SOUTHCENTRAL REGION. THE
PREFERRED MODEL OF CHOICE WAS THE NAM. THE FORECAST CONFIDENCE IS
ABOVE AVERAGE AS WE HEAD INTO THE WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY LATE FRIDAY. IN THE WAKE OF THE RAIN THE AIRMASS
WILL REMAIN QUITE MOIST WITH GENERALLY WEAK AND DIFFUSE FLOW.
THEREFORE EXTENSIVE CLOUDINESS WILL PERSISTS INTO THE WEEKEND
MAINTAINING FAIRLY COOL TEMPERATURES AND RELATIVELY HIGH RHS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC




000
FXAK68 PAFC 031313
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM MOVING
INTO THE BRISTOL BAY REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES FARTHER
INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW DEVELOPING IN THE
GULF BY FRIDAY AND TRACKING TO THE SOUTHEAST ALASKA REGION BY
SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS WAS MOVING THIS LOW
THROUGH THE GULF FASTER THEN THE OTHER MODELS. THE BIGGEST CHALLENGE
WILL BE WITH THE TIMING OF PRECIPITATION AS THE DIFFERENT SYNOPTIC
FEATURES MOVE THROUGH THE SOUTHWEST AND SOUTHCENTRAL REGION. THE
PREFERRED MODEL OF CHOICE WAS THE NAM. THE FORECAST CONFIDENCE IS
ABOVE AVERAGE AS WE HEAD INTO THE WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY LATE FRIDAY. IN THE WAKE OF THE RAIN THE AIRMASS
WILL REMAIN QUITE MOIST WITH GENERALLY WEAK AND DIFFUSE FLOW.
THEREFORE EXTENSIVE CLOUDINESS WILL PERSISTS INTO THE WEEKEND
MAINTAINING FAIRLY COOL TEMPERATURES AND RELATIVELY HIGH RHS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC



000
FXAK68 PAFC 031302
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM
MOVING INTO THE BRISTOL REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES
FARTHER INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW
DEVELOPING IN THE GULF BY FRIDAY AND TRACKS TO THE SOUTHEAST
ALASKA REGION BY SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS
WAS MOVING THIS LOW THROUGH THE GULF FASTER THEN THE OTHER MODELS.
THE BIGGEST CHALLENGE WILL BE WITH THE TIMING OF PRECIPITATION AS
THE DIFFERENT SYNOPTIC FEATURES MOVE THROUGH THE SOUTHWEST AND
SOUTHCENTRAL REGION. THE PREFERRED MODEL OF CHOICE WAS THE
NAM. THE FORECAST CONFIDENCE IS ABOVE AVERAGE AS WE HEAD INTO THE
WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY EARLY SATURDAY MORNING. THIS WILL BRING COOLER
TEMPERATURES AND LIGHT WINDS AS WE HEAD INTO THE WEEKEND. BY
SATURDAY WEAK RIDGING BUILDS INTO THE REGION WITH PARTIAL CLEARING
SKIES AND TEMPERATURES REMAINING COOLER WITH LIGHT WINDS THROUGH
THE WEEKEND. THEREFORE...FIRE WEATHER CONDITIONS WILL REMAIN LOW.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC



000
FXAK68 PAFC 031302
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM
MOVING INTO THE BRISTOL REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES
FARTHER INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW
DEVELOPING IN THE GULF BY FRIDAY AND TRACKS TO THE SOUTHEAST
ALASKA REGION BY SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS
WAS MOVING THIS LOW THROUGH THE GULF FASTER THEN THE OTHER MODELS.
THE BIGGEST CHALLENGE WILL BE WITH THE TIMING OF PRECIPITATION AS
THE DIFFERENT SYNOPTIC FEATURES MOVE THROUGH THE SOUTHWEST AND
SOUTHCENTRAL REGION. THE PREFERRED MODEL OF CHOICE WAS THE
NAM. THE FORECAST CONFIDENCE IS ABOVE AVERAGE AS WE HEAD INTO THE
WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY EARLY SATURDAY MORNING. THIS WILL BRING COOLER
TEMPERATURES AND LIGHT WINDS AS WE HEAD INTO THE WEEKEND. BY
SATURDAY WEAK RIDGING BUILDS INTO THE REGION WITH PARTIAL CLEARING
SKIES AND TEMPERATURES REMAINING COOLER WITH LIGHT WINDS THROUGH
THE WEEKEND. THEREFORE...FIRE WEATHER CONDITIONS WILL REMAIN LOW.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC




000
FXAK68 PAFC 031302
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU SEP 3 2015

.ANALYSIS AND UPPER LEVELS...
THERE IS A 120 KNOT SOUTHWESTERLY JET STREAK TRACKING INTO THE
ALASKA PENINSULA AND KODIAK ISLAND REGION THIS MORNING. THIS
SYNOPTIC FEATURE WILL MOVE THE UPPER LEVEL RIDGE POSITIONED OVER
THE CENTRAL GULF EXTENDING INTO COPPER RIVER BASIN EASTWARD.
UPSTREAM THERE ARE SEVERAL SHORTWAVES WITH THE FIRST SHORTWAVE
LOCATED OVER THE BRISTOL BAY INTERIOR. THE SECOND UPPER LEVEL
SHORTWAVE OVER THE CENTRAL ALEUTIANS IS ASSOCIATED WITH THE
CLOSED LOW AT 500 MB LOCATED JUST EAST OF THE KAMCHATKA PENINSULA.
AT THE SURFACE THERE IS A 1006 MB NORTH PACIFIC LOW PRESSURE
SYSTEM THAT HAS CROSSED OVER THE EASTERN ALEUTIANS INTO THE
BRISTOL BAY REGION THIS MORNING. THIS FEATURE IS BRINGING
WIDESPREAD RAIN AND FOG TO THE EASTERN BERING SEA AND THROUGH THE
SOUTHWEST ALASKA REGION BEFORE SPILLING OVER INTO THE SOUTHCENTRAL
REGION. THE SATELLITE IMAGERY REFLECTS A LARGE SWATH OF MOISTURE
OVER THE AFOREMENTIONED REGIONS WITH THE ASSOCIATED WEATHER FRONT
MOVING THROUGH THE SOUTHWESTERN GULF REGION. THIS IS REFLECTED ON
THE RADAR IMAGERY WITH NUMEROUS SHOWERS MOVING UP THROUGH THE COOK
INLET AND THE WESTERN GULF AREA.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM
MOVING INTO THE BRISTOL REGION AND THE WEATHER FRONT THROUGH THE
WESTERN GULF THIS MORNING. THIS LOW WILL MOVE INTO THE BRISTOL BAY
INTERIOR BY THE AFTERNOON BEFORE FALLING APART AS IT MOVES
FARTHER INLAND. THE MODELS ARE SHOWING A TRIPLE POINT LOW
DEVELOPING IN THE GULF BY FRIDAY AND TRACKS TO THE SOUTHEAST
ALASKA REGION BY SATURDAY AFTERNOON BEFORE DISSIPATING. THE GFS
WAS MOVING THIS LOW THROUGH THE GULF FASTER THEN THE OTHER MODELS.
THE BIGGEST CHALLENGE WILL BE WITH THE TIMING OF PRECIPITATION AS
THE DIFFERENT SYNOPTIC FEATURES MOVE THROUGH THE SOUTHWEST AND
SOUTHCENTRAL REGION. THE PREFERRED MODEL OF CHOICE WAS THE
NAM. THE FORECAST CONFIDENCE IS ABOVE AVERAGE AS WE HEAD INTO THE
WEEKEND.

&&

.FIRE WEATHER...
THE SOUTHWESTERLY FLOW WILL CONTINUE TO BRING MOISTURE AND WIDESPREAD
WETTING RAINS TO THE SOUTHWEST/SOUTHCENTRAL ALASKA REGION BEFORE
TAPERING OFF BY EARLY SATURDAY MORNING. THIS WILL BRING COOLER
TEMPERATURES AND LIGHT WINDS AS WE HEAD INTO THE WEEKEND. BY
SATURDAY WEAK RIDGING BUILDS INTO THE REGION WITH PARTIAL CLEARING
SKIES AND TEMPERATURES REMAINING COOLER WITH LIGHT WINDS THROUGH
THE WEEKEND. THEREFORE...FIRE WEATHER CONDITIONS WILL REMAIN LOW.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SUBTROPICAL JET IS POINTED RIGHT TOWARD THE SOUTHERN MAINLAND
OF ALASKA TODAY HELPING TO TRANSPORT DEEP TROPICAL MOISTURE INTO
THE REGION. A SERIES OF UPPER LEVEL WAVES WILL FOCUS THE RAIN AS
IT OVERSPREADS SOUTHCENTRAL ALASKA DURING THE DAY. SINCE THE
ENERGY IS SPLIT AMONG MULTIPLE FEATURES RAINFALL INTENSITY WILL BE
VARIABLE...BUT MOSTLY ON THE LIGHT SIDE. THE GULF COAST WILL SEE
HEAVIER RAIN ASSOCIATED WITH A SURFACE FRONTAL SYSTEM AND A WEAK
SURFACE LOW WHICH DEVELOPS NEAR KODIAK ISLAND THIS AFTERNOON.

ANOTHER UPPER LEVEL SHORT-WAVE TROUGH TRACKING EASTWARD ACROSS
THE BERING WILL ARRIVE IN THE GULF FRIDAY AND KICK THE SURFACE LOW
AND MUCH OF THE RAIN EASTWARD AND OUT OF SOUTHCENTRAL. BROAD AND
WEAK CYCLONIC FLOW WILL PERSIST WITH VERY WEAK RIDGING UPSTREAM.
WITH NOTHING TO HELP DRY OUT THE AIRMASS MOSTLY CLOUDY SKIES WILL
PERSIST THROUGH SATURDAY...AND LIKELY BEYOND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2...THU AND
FRI)...WET AND MILD WEATHER WILL CONTINUE FOR THE END OF THE WEEK.
A SURFACE LOW IS ACTIVELY DEVELOPING JUST NORTH OF THE ALASKA
PENINSULA. THIS SYSTEM COUPLED WITH DECENT UPPER LEVEL JET SUPPORT
AND PRECIPITABLE WATER VALUES NEAR 1.2 INCHES (COLD BAY) WILL
CONTINUE TO PUSH WIDESPREAD RAIN INTO BRISTOL BAY. WINDS ARE
RELATIVELY LIGHT WITH THIS SYSTEM AND THAT IS ALLOWING FOG TO
BECOME WIDESPREAD AND LOCALLY DENSE IN SPOTS. THE LOW WILL TRACK
INLAND TO THE NORTHEAST THROUGH THE DAY TODAY AND BRING RAIN ALL
THE WAY UP THROUGH LOWER KUSKOKWIM VALLEY AND THE Y-K DELTA. THE
LOW WILL FALL APART OVER THE ALASKA RANGE LATE TONIGHT INTO EARLY
FRIDAY. THIS WILL ALLOW PRECIPITATION TO BECOME MORE SHOWERY IN
NATURE...BUT THE SHOWERS WILL STILL BE WIDESPREAD ACROSS SOUTHWEST
AK. FLOW WILL SHIFT FROM SOUTHERLY TO WESTERLY FRIDAY. THIS WILL
BRING MORE FOG TO JUST ABOUT ALL AREAS...ESPECIALLY THE ALASKA
PENINSULA AND THE COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2...THU AND
FRI)...THE UPPER LEVEL LOW OFF THE COAST OF KAMCHATKA CONTINUES TO
DRIVE THE SENSIBLE WEATHER FOR THIS REGION. AS IT PUSHES YET
ANOTHER WEAK UPPER LEVEL WAVE ACROSS THE BERING...WINDS WILL
REMAIN SOUTH TO WEST WITH WIDESPREAD FOG AND SHOWERS. SPEEDS
SHOULD SUB-SMALL CRAFT FOR THE ENTIRE AREA. THE LOW FINALLY
STARTS ITS SLOW TRACK ACROSS THE BERING SEA LATE FRIDAY. THIS WILL
BRING A SLIGHTLY MORE FOCUSED AREA OF SHOWERS MOVING FROM WEST TO
EAST AS WE START INTO THE WEEKEND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART OF THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD WATCH...121
         FLOOD ADVISORY...125
MARINE...GALE WARNING...119 131.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MO
LONG TERM...MC




000
FXAK69 PAFG 031123
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
323 AM AKDT THU SEP 3 2015

.DISCUSSION...

UPPER LEVELS...
OPERATIONAL MODEL RUNS FROM THE SEP 3/00Z FORECAST CYCLE ARE IN
GENERAL AGREEMENT ON THE UPPER AIR FEATURES OUT THROUGH 84
HOURS/4 AM SUNDAY...AND AGREE WELL WITH THE GEFS ENSEMBLE MEAN.

AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN NORTHERN ALASKA
MAINLAND WILL WEAKEN FRIDAY NIGHT THROUGH SUNDAY. 850 MB
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL THROUGH
SUNDAY...ELSEWHERE ACROSS NORTHERN ALASKA 850 MB TEMPERATURES
ARE EXPECTED TO BE NEAR NORMAL.

A WEAKENING SHORT WAVE TROUGH MOVING UP THE WEST SIDE OF
THE RIDGE EXTENDS FROM THE GULF OF ANADYR TO NEAR KOTZEBUE.
THIS FEATURE WILL BECOME DAMPENED OUT BY THIS AFTERNOON AS IT
CONTINUE TO MOVE SLOWLY NORTHWARD. ONLY A NARROWING BAND OF MID
AND HIGH LEVEL CLOUDS REMAINS WITH THIS DECAYING FEATURE.

THE NEXT INCOMING SHORT WAVE TROUGH EXTENDS FROM NEAR
55N/170E IN THE FAR SOUTHWESTERN BERING SEA TO NEAR AMCHITKA.
THE TROUGH WILL MOVE EAST TO EXTEND FROM THE NORTHEASTERN
ALASKA PENINSULA SOUTHWARD INTO THE GULF OF ALASKA
BY FRIDAY MORNING...CONTINUING EASTWARD ACROSS THE
NORTHERN GULF OF ALASKA FRIDAY AFTERNOON AND FRIDAY EVENING.

AN UPPER LOW CENTERED NEAR 58N/170E WILL MOVE EASTWARD
TO BRISTOL BAY BY LATE SATURDAY NIGHT...UNDERCUTTING
THE UPPER LEVEL RIDGE OVER THE MAINLAND.

CURRENT MODEL RUNS ARE IN GENERALLY GOOD AGREEMENT THROUGH
SATURDAY NIGHT.

SURFACE...
A 1004 MB LOW NEAR GAMBELL WILL WEAKEN TO A 1008 MB LOW NEAR
THE BERING STRAIT FRIDAY MORNING THEN DISSIPATE FRIDAY AFTERNOON.
A 1027 MB HIGH CENTERED 150 MILES NORTH OF THE MACKENZIE RIVER
DELTA WILL MOVE TO THE NORTHWESTERN CANADA ARCHIPELAGO BY FRIDAY
MORNING. A RIDGE EXTENDING FROM THE HIGH CENTER WESTWARD ACROSS
THE BEAUFORT SEA WILL GRADUALLY WEAKEN AS IT MOVES NORTHWARD TO
LATITUDE 76N BY LATE FRIDAY NIGHT.

A 1005 MB LOW OVER THE CENTRAL ALASKA PENINSULA WILL MOVE
TO NEAR ANIAK BY FRIDAY MORNING THEN DISSIPATE FRIDAY
AFTERNOON. THIS LOW WILL BRING RAIN TO THE WEST COAST AREAS
SOUTH OF UNALAKLEET AND TO THE SOUTHERN PARTS OF THE WESTERN
INTERIOR.

ARCTIC COAST...
EAST WINDS 15-25 MPH TODAY AND 20-30 MPH TONIGHT AND
FRIDAY...DECREASING FRIDAY NIGHT. WEST OF BARROW...WINDS WILL BE
LESS THAN 20 MPH. LITTLE OR NO PRECIPITATION EXPECTED THROUGH
SATURDAY. MAINLY CLEAR OR PARTLY CLOUDY SKIES THROUGH
FRIDAY...PATCHY STRATUS AND FOG POSSIBLE AT NIGHT.

CENTRAL AND EASTERN INTERIOR...
A CHANCE OF RAIN OR SHOWERS IN THE ALASKA RANGE TONIGHT
THROUGH SATURDAY...ELSEWHERE NO PRECIPITATION EXPECTED.

WESTERN INTERIOR...
LOWER YUKON VALLEY...RAIN LIKELY DEVELOPING TODAY. RAIN TONIGHT
 AND RAIN LIKELY FRIDAY AND FRIDAY EVENING.
UPPER KUSKOKWIM VALLEY...RAIN TONIGHT AND FRIDAY MORNING. RAIN
LIKELY FRIDAY AFTERNOON. CHANCE OF RAIN OR SHOWERS FRIDAY NIGHT.
MIDDLE YUKON VALLEY...CHANCE OF RAIN IN THE SOUTHERN PARTS TONIGHT
THROUGH SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED THROUGH
SATURDAY

WEST COAST...
RAIN LIKELY MOST AREAS FROM THE SEWARD PENINSULA SOUTHWARD TODAY.
RAIN TONIGHT AND FRIDAY OVER AREAS SOUTH OF UNALAKLEET...A CHANCE
OF RAIN OVER OTHER AREAS FROM THE SEWARD PENINSULA SOUTH. WINDS 15
MPH OR LESS THROUGH SATURDAY.

ST LAWRENCE ISLAND...
NO MORE THAN SCATTERED RAIN SHOWERS ARE EXPECTED THROUGH
SATURDAY. WINDS...15 MPH OR LESS TODAY THROUGH SATURDAY. NORTH
WINDS 15-20 MPH SATURDAY NIGHT AND SUNDAY.

IN THE EXTENDED FORECAST PERIOD...
RECENT MODEL RUNS HAVE BEEN SHOWING RATHER VOLATILE
RESULTS...WITH LARGE DIFFERENCES BETWEEN MODELS AND POOR RUN TO
RUN CONTINUITY. BOTH THE GEFS AND ECMWF ENSEMBLE MEANS FROM THE
SEP 3/00Z CYCLE INDICATE A POLAR VORTEX NORTH OF 80N WITH WEST TO
NORTHWEST FLOW OVER THE ARCTIC COAST AND BEAUFORT SEA. THERE IS A
POSSIBILITY OF A MORE ACTIVE WEATHER PATTERN OVER THE ARCTIC
REGION. GFS AND ECMWF PROGS FROM THE SEP 3/00Z CYCLE INDICATE A
STRONG SHORT WAVE TROUGH DROPPING SOUTHEASTWARD OUT OF THE ARCTIC
TUESDAY NIGHT AND WEDNESDAY...ACCOMPANIED BY A 995-1000 MB
SURFACE LOW. FORECAST LOW POSITION AT 4 AM TUE IS NEAR
75N/158W...ABOUT 300 MILES NORTH OF BARROW. BY 4 PM TUESDAY...MEAN
OF THE GFS AND ECMWF PUTS A 1000 MB CENTER NEAR 73N/149W. GEFS
ENSEMBLE SPREAD APPEARS TO BE MODERATE. THIS SCENARIO WOULD
PRODUCE NORTH TO NORTHWEST WINDS 25-35 MPH OVER THE ARCTIC COAST
TUESDAY AND TUESDAY NIGHT WITH A LIKELIHOOD OF HIGH SURF
CONDITIONS ON THE ARCTIC COAST FROM BARROW WEST. BUT DUE TO THE
RECENT VARIABILITY IN MODEL RUNS...FORECAST CONFIDENCE REMAINS LOW
AT THIS TIME. IT SHOULD BE NOTED HOWEVER...GFS/ECMWF RUNS FROM
THE SEP 2/00Z CYCLE ALSO INDICATED THAT THE NORTHWEST ARCTIC
COAST COULD BE AFFECTED BY A MODERATE INTENSITY SURFACE SYSTEM
IN THE SAME GENERAL LOCATION AND TIME FRAME. THE OVERALL LARGE
SCALE PATTERN POINTING TO COLDER TEMPERATURES NORTH OF THE BROOKS
RANGE.


COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE SATURDAY AND SUNDAY. HIGH SURF CONDITIONS POSSIBLE ON THE
ARCTIC COAST FROM BARROW WESTWARD TUESDAY AND TUESDAY NIGHT IF
CURRENT GFS/ECMWF RUNS FROM THE SEP 3/00Z CYCLE ARE CORRECT...WITH
NORTH TO NORTHWEST WINDS 25-35 MPH. FORECAST CONFIDENCE AT THIS
TIME HOWEVER REMAINS LOW DUE TO RECENT VARIABILITY OF MODEL RUNS.

&&

.HYDROLOGY...
RIVER LEVELS ON THE CHENA RIVER FROM THE MOOSE CREEK
DOWNSTREAM ARE STILL ELEVATED BUT ARE CONTINUING TO
FALL. THE STAGE OF THE CHENA RIVER AT FAIRBANKS WAS
6.4 FEET AT 1 AM THIS MORNING...AND FORECAST TO FALL
TO ABOUT 5.2 FEET BY MIDNIGHT SATURDAY NIGHT.
ELSEWHERE...NO HYDROLOGIC ISSUES.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF  SEP 15



000
FXAK69 PAFG 031123
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
323 AM AKDT THU SEP 3 2015

.DISCUSSION...

UPPER LEVELS...
OPERATIONAL MODEL RUNS FROM THE SEP 3/00Z FORECAST CYCLE ARE IN
GENERAL AGREEMENT ON THE UPPER AIR FEATURES OUT THROUGH 84
HOURS/4 AM SUNDAY...AND AGREE WELL WITH THE GEFS ENSEMBLE MEAN.

AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN NORTHERN ALASKA
MAINLAND WILL WEAKEN FRIDAY NIGHT THROUGH SUNDAY. 850 MB
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL THROUGH
SUNDAY...ELSEWHERE ACROSS NORTHERN ALASKA 850 MB TEMPERATURES
ARE EXPECTED TO BE NEAR NORMAL.

A WEAKENING SHORT WAVE TROUGH MOVING UP THE WEST SIDE OF
THE RIDGE EXTENDS FROM THE GULF OF ANADYR TO NEAR KOTZEBUE.
THIS FEATURE WILL BECOME DAMPENED OUT BY THIS AFTERNOON AS IT
CONTINUE TO MOVE SLOWLY NORTHWARD. ONLY A NARROWING BAND OF MID
AND HIGH LEVEL CLOUDS REMAINS WITH THIS DECAYING FEATURE.

THE NEXT INCOMING SHORT WAVE TROUGH EXTENDS FROM NEAR
55N/170E IN THE FAR SOUTHWESTERN BERING SEA TO NEAR AMCHITKA.
THE TROUGH WILL MOVE EAST TO EXTEND FROM THE NORTHEASTERN
ALASKA PENINSULA SOUTHWARD INTO THE GULF OF ALASKA
BY FRIDAY MORNING...CONTINUING EASTWARD ACROSS THE
NORTHERN GULF OF ALASKA FRIDAY AFTERNOON AND FRIDAY EVENING.

AN UPPER LOW CENTERED NEAR 58N/170E WILL MOVE EASTWARD
TO BRISTOL BAY BY LATE SATURDAY NIGHT...UNDERCUTTING
THE UPPER LEVEL RIDGE OVER THE MAINLAND.

CURRENT MODEL RUNS ARE IN GENERALLY GOOD AGREEMENT THROUGH
SATURDAY NIGHT.

SURFACE...
A 1004 MB LOW NEAR GAMBELL WILL WEAKEN TO A 1008 MB LOW NEAR
THE BERING STRAIT FRIDAY MORNING THEN DISSIPATE FRIDAY AFTERNOON.
A 1027 MB HIGH CENTERED 150 MILES NORTH OF THE MACKENZIE RIVER
DELTA WILL MOVE TO THE NORTHWESTERN CANADA ARCHIPELAGO BY FRIDAY
MORNING. A RIDGE EXTENDING FROM THE HIGH CENTER WESTWARD ACROSS
THE BEAUFORT SEA WILL GRADUALLY WEAKEN AS IT MOVES NORTHWARD TO
LATITUDE 76N BY LATE FRIDAY NIGHT.

A 1005 MB LOW OVER THE CENTRAL ALASKA PENINSULA WILL MOVE
TO NEAR ANIAK BY FRIDAY MORNING THEN DISSIPATE FRIDAY
AFTERNOON. THIS LOW WILL BRING RAIN TO THE WEST COAST AREAS
SOUTH OF UNALAKLEET AND TO THE SOUTHERN PARTS OF THE WESTERN
INTERIOR.

ARCTIC COAST...
EAST WINDS 15-25 MPH TODAY AND 20-30 MPH TONIGHT AND
FRIDAY...DECREASING FRIDAY NIGHT. WEST OF BARROW...WINDS WILL BE
LESS THAN 20 MPH. LITTLE OR NO PRECIPITATION EXPECTED THROUGH
SATURDAY. MAINLY CLEAR OR PARTLY CLOUDY SKIES THROUGH
FRIDAY...PATCHY STRATUS AND FOG POSSIBLE AT NIGHT.

CENTRAL AND EASTERN INTERIOR...
A CHANCE OF RAIN OR SHOWERS IN THE ALASKA RANGE TONIGHT
THROUGH SATURDAY...ELSEWHERE NO PRECIPITATION EXPECTED.

WESTERN INTERIOR...
LOWER YUKON VALLEY...RAIN LIKELY DEVELOPING TODAY. RAIN TONIGHT
 AND RAIN LIKELY FRIDAY AND FRIDAY EVENING.
UPPER KUSKOKWIM VALLEY...RAIN TONIGHT AND FRIDAY MORNING. RAIN
LIKELY FRIDAY AFTERNOON. CHANCE OF RAIN OR SHOWERS FRIDAY NIGHT.
MIDDLE YUKON VALLEY...CHANCE OF RAIN IN THE SOUTHERN PARTS TONIGHT
THROUGH SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED THROUGH
SATURDAY

WEST COAST...
RAIN LIKELY MOST AREAS FROM THE SEWARD PENINSULA SOUTHWARD TODAY.
RAIN TONIGHT AND FRIDAY OVER AREAS SOUTH OF UNALAKLEET...A CHANCE
OF RAIN OVER OTHER AREAS FROM THE SEWARD PENINSULA SOUTH. WINDS 15
MPH OR LESS THROUGH SATURDAY.

ST LAWRENCE ISLAND...
NO MORE THAN SCATTERED RAIN SHOWERS ARE EXPECTED THROUGH
SATURDAY. WINDS...15 MPH OR LESS TODAY THROUGH SATURDAY. NORTH
WINDS 15-20 MPH SATURDAY NIGHT AND SUNDAY.

IN THE EXTENDED FORECAST PERIOD...
RECENT MODEL RUNS HAVE BEEN SHOWING RATHER VOLATILE
RESULTS...WITH LARGE DIFFERENCES BETWEEN MODELS AND POOR RUN TO
RUN CONTINUITY. BOTH THE GEFS AND ECMWF ENSEMBLE MEANS FROM THE
SEP 3/00Z CYCLE INDICATE A POLAR VORTEX NORTH OF 80N WITH WEST TO
NORTHWEST FLOW OVER THE ARCTIC COAST AND BEAUFORT SEA. THERE IS A
POSSIBILITY OF A MORE ACTIVE WEATHER PATTERN OVER THE ARCTIC
REGION. GFS AND ECMWF PROGS FROM THE SEP 3/00Z CYCLE INDICATE A
STRONG SHORT WAVE TROUGH DROPPING SOUTHEASTWARD OUT OF THE ARCTIC
TUESDAY NIGHT AND WEDNESDAY...ACCOMPANIED BY A 995-1000 MB
SURFACE LOW. FORECAST LOW POSITION AT 4 AM TUE IS NEAR
75N/158W...ABOUT 300 MILES NORTH OF BARROW. BY 4 PM TUESDAY...MEAN
OF THE GFS AND ECMWF PUTS A 1000 MB CENTER NEAR 73N/149W. GEFS
ENSEMBLE SPREAD APPEARS TO BE MODERATE. THIS SCENARIO WOULD
PRODUCE NORTH TO NORTHWEST WINDS 25-35 MPH OVER THE ARCTIC COAST
TUESDAY AND TUESDAY NIGHT WITH A LIKELIHOOD OF HIGH SURF
CONDITIONS ON THE ARCTIC COAST FROM BARROW WEST. BUT DUE TO THE
RECENT VARIABILITY IN MODEL RUNS...FORECAST CONFIDENCE REMAINS LOW
AT THIS TIME. IT SHOULD BE NOTED HOWEVER...GFS/ECMWF RUNS FROM
THE SEP 2/00Z CYCLE ALSO INDICATED THAT THE NORTHWEST ARCTIC
COAST COULD BE AFFECTED BY A MODERATE INTENSITY SURFACE SYSTEM
IN THE SAME GENERAL LOCATION AND TIME FRAME. THE OVERALL LARGE
SCALE PATTERN POINTING TO COLDER TEMPERATURES NORTH OF THE BROOKS
RANGE.


COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE SATURDAY AND SUNDAY. HIGH SURF CONDITIONS POSSIBLE ON THE
ARCTIC COAST FROM BARROW WESTWARD TUESDAY AND TUESDAY NIGHT IF
CURRENT GFS/ECMWF RUNS FROM THE SEP 3/00Z CYCLE ARE CORRECT...WITH
NORTH TO NORTHWEST WINDS 25-35 MPH. FORECAST CONFIDENCE AT THIS
TIME HOWEVER REMAINS LOW DUE TO RECENT VARIABILITY OF MODEL RUNS.

&&

.HYDROLOGY...
RIVER LEVELS ON THE CHENA RIVER FROM THE MOOSE CREEK
DOWNSTREAM ARE STILL ELEVATED BUT ARE CONTINUING TO
FALL. THE STAGE OF THE CHENA RIVER AT FAIRBANKS WAS
6.4 FEET AT 1 AM THIS MORNING...AND FORECAST TO FALL
TO ABOUT 5.2 FEET BY MIDNIGHT SATURDAY NIGHT.
ELSEWHERE...NO HYDROLOGIC ISSUES.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF  SEP 15




000
FXAK69 PAFG 031123
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
323 AM AKDT THU SEP 3 2015

.DISCUSSION...

UPPER LEVELS...
OPERATIONAL MODEL RUNS FROM THE SEP 3/00Z FORECAST CYCLE ARE IN
GENERAL AGREEMENT ON THE UPPER AIR FEATURES OUT THROUGH 84
HOURS/4 AM SUNDAY...AND AGREE WELL WITH THE GEFS ENSEMBLE MEAN.

AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN NORTHERN ALASKA
MAINLAND WILL WEAKEN FRIDAY NIGHT THROUGH SUNDAY. 850 MB
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL THROUGH
SUNDAY...ELSEWHERE ACROSS NORTHERN ALASKA 850 MB TEMPERATURES
ARE EXPECTED TO BE NEAR NORMAL.

A WEAKENING SHORT WAVE TROUGH MOVING UP THE WEST SIDE OF
THE RIDGE EXTENDS FROM THE GULF OF ANADYR TO NEAR KOTZEBUE.
THIS FEATURE WILL BECOME DAMPENED OUT BY THIS AFTERNOON AS IT
CONTINUE TO MOVE SLOWLY NORTHWARD. ONLY A NARROWING BAND OF MID
AND HIGH LEVEL CLOUDS REMAINS WITH THIS DECAYING FEATURE.

THE NEXT INCOMING SHORT WAVE TROUGH EXTENDS FROM NEAR
55N/170E IN THE FAR SOUTHWESTERN BERING SEA TO NEAR AMCHITKA.
THE TROUGH WILL MOVE EAST TO EXTEND FROM THE NORTHEASTERN
ALASKA PENINSULA SOUTHWARD INTO THE GULF OF ALASKA
BY FRIDAY MORNING...CONTINUING EASTWARD ACROSS THE
NORTHERN GULF OF ALASKA FRIDAY AFTERNOON AND FRIDAY EVENING.

AN UPPER LOW CENTERED NEAR 58N/170E WILL MOVE EASTWARD
TO BRISTOL BAY BY LATE SATURDAY NIGHT...UNDERCUTTING
THE UPPER LEVEL RIDGE OVER THE MAINLAND.

CURRENT MODEL RUNS ARE IN GENERALLY GOOD AGREEMENT THROUGH
SATURDAY NIGHT.

SURFACE...
A 1004 MB LOW NEAR GAMBELL WILL WEAKEN TO A 1008 MB LOW NEAR
THE BERING STRAIT FRIDAY MORNING THEN DISSIPATE FRIDAY AFTERNOON.
A 1027 MB HIGH CENTERED 150 MILES NORTH OF THE MACKENZIE RIVER
DELTA WILL MOVE TO THE NORTHWESTERN CANADA ARCHIPELAGO BY FRIDAY
MORNING. A RIDGE EXTENDING FROM THE HIGH CENTER WESTWARD ACROSS
THE BEAUFORT SEA WILL GRADUALLY WEAKEN AS IT MOVES NORTHWARD TO
LATITUDE 76N BY LATE FRIDAY NIGHT.

A 1005 MB LOW OVER THE CENTRAL ALASKA PENINSULA WILL MOVE
TO NEAR ANIAK BY FRIDAY MORNING THEN DISSIPATE FRIDAY
AFTERNOON. THIS LOW WILL BRING RAIN TO THE WEST COAST AREAS
SOUTH OF UNALAKLEET AND TO THE SOUTHERN PARTS OF THE WESTERN
INTERIOR.

ARCTIC COAST...
EAST WINDS 15-25 MPH TODAY AND 20-30 MPH TONIGHT AND
FRIDAY...DECREASING FRIDAY NIGHT. WEST OF BARROW...WINDS WILL BE
LESS THAN 20 MPH. LITTLE OR NO PRECIPITATION EXPECTED THROUGH
SATURDAY. MAINLY CLEAR OR PARTLY CLOUDY SKIES THROUGH
FRIDAY...PATCHY STRATUS AND FOG POSSIBLE AT NIGHT.

CENTRAL AND EASTERN INTERIOR...
A CHANCE OF RAIN OR SHOWERS IN THE ALASKA RANGE TONIGHT
THROUGH SATURDAY...ELSEWHERE NO PRECIPITATION EXPECTED.

WESTERN INTERIOR...
LOWER YUKON VALLEY...RAIN LIKELY DEVELOPING TODAY. RAIN TONIGHT
 AND RAIN LIKELY FRIDAY AND FRIDAY EVENING.
UPPER KUSKOKWIM VALLEY...RAIN TONIGHT AND FRIDAY MORNING. RAIN
LIKELY FRIDAY AFTERNOON. CHANCE OF RAIN OR SHOWERS FRIDAY NIGHT.
MIDDLE YUKON VALLEY...CHANCE OF RAIN IN THE SOUTHERN PARTS TONIGHT
THROUGH SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED THROUGH
SATURDAY

WEST COAST...
RAIN LIKELY MOST AREAS FROM THE SEWARD PENINSULA SOUTHWARD TODAY.
RAIN TONIGHT AND FRIDAY OVER AREAS SOUTH OF UNALAKLEET...A CHANCE
OF RAIN OVER OTHER AREAS FROM THE SEWARD PENINSULA SOUTH. WINDS 15
MPH OR LESS THROUGH SATURDAY.

ST LAWRENCE ISLAND...
NO MORE THAN SCATTERED RAIN SHOWERS ARE EXPECTED THROUGH
SATURDAY. WINDS...15 MPH OR LESS TODAY THROUGH SATURDAY. NORTH
WINDS 15-20 MPH SATURDAY NIGHT AND SUNDAY.

IN THE EXTENDED FORECAST PERIOD...
RECENT MODEL RUNS HAVE BEEN SHOWING RATHER VOLATILE
RESULTS...WITH LARGE DIFFERENCES BETWEEN MODELS AND POOR RUN TO
RUN CONTINUITY. BOTH THE GEFS AND ECMWF ENSEMBLE MEANS FROM THE
SEP 3/00Z CYCLE INDICATE A POLAR VORTEX NORTH OF 80N WITH WEST TO
NORTHWEST FLOW OVER THE ARCTIC COAST AND BEAUFORT SEA. THERE IS A
POSSIBILITY OF A MORE ACTIVE WEATHER PATTERN OVER THE ARCTIC
REGION. GFS AND ECMWF PROGS FROM THE SEP 3/00Z CYCLE INDICATE A
STRONG SHORT WAVE TROUGH DROPPING SOUTHEASTWARD OUT OF THE ARCTIC
TUESDAY NIGHT AND WEDNESDAY...ACCOMPANIED BY A 995-1000 MB
SURFACE LOW. FORECAST LOW POSITION AT 4 AM TUE IS NEAR
75N/158W...ABOUT 300 MILES NORTH OF BARROW. BY 4 PM TUESDAY...MEAN
OF THE GFS AND ECMWF PUTS A 1000 MB CENTER NEAR 73N/149W. GEFS
ENSEMBLE SPREAD APPEARS TO BE MODERATE. THIS SCENARIO WOULD
PRODUCE NORTH TO NORTHWEST WINDS 25-35 MPH OVER THE ARCTIC COAST
TUESDAY AND TUESDAY NIGHT WITH A LIKELIHOOD OF HIGH SURF
CONDITIONS ON THE ARCTIC COAST FROM BARROW WEST. BUT DUE TO THE
RECENT VARIABILITY IN MODEL RUNS...FORECAST CONFIDENCE REMAINS LOW
AT THIS TIME. IT SHOULD BE NOTED HOWEVER...GFS/ECMWF RUNS FROM
THE SEP 2/00Z CYCLE ALSO INDICATED THAT THE NORTHWEST ARCTIC
COAST COULD BE AFFECTED BY A MODERATE INTENSITY SURFACE SYSTEM
IN THE SAME GENERAL LOCATION AND TIME FRAME. THE OVERALL LARGE
SCALE PATTERN POINTING TO COLDER TEMPERATURES NORTH OF THE BROOKS
RANGE.


COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE SATURDAY AND SUNDAY. HIGH SURF CONDITIONS POSSIBLE ON THE
ARCTIC COAST FROM BARROW WESTWARD TUESDAY AND TUESDAY NIGHT IF
CURRENT GFS/ECMWF RUNS FROM THE SEP 3/00Z CYCLE ARE CORRECT...WITH
NORTH TO NORTHWEST WINDS 25-35 MPH. FORECAST CONFIDENCE AT THIS
TIME HOWEVER REMAINS LOW DUE TO RECENT VARIABILITY OF MODEL RUNS.

&&

.HYDROLOGY...
RIVER LEVELS ON THE CHENA RIVER FROM THE MOOSE CREEK
DOWNSTREAM ARE STILL ELEVATED BUT ARE CONTINUING TO
FALL. THE STAGE OF THE CHENA RIVER AT FAIRBANKS WAS
6.4 FEET AT 1 AM THIS MORNING...AND FORECAST TO FALL
TO ABOUT 5.2 FEET BY MIDNIGHT SATURDAY NIGHT.
ELSEWHERE...NO HYDROLOGIC ISSUES.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF  SEP 15



000
FXAK69 PAFG 031123
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
323 AM AKDT THU SEP 3 2015

.DISCUSSION...

UPPER LEVELS...
OPERATIONAL MODEL RUNS FROM THE SEP 3/00Z FORECAST CYCLE ARE IN
GENERAL AGREEMENT ON THE UPPER AIR FEATURES OUT THROUGH 84
HOURS/4 AM SUNDAY...AND AGREE WELL WITH THE GEFS ENSEMBLE MEAN.

AN UPPER LEVEL RIDGE OVER THE CENTRAL AND WESTERN NORTHERN ALASKA
MAINLAND WILL WEAKEN FRIDAY NIGHT THROUGH SUNDAY. 850 MB
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL THROUGH
SUNDAY...ELSEWHERE ACROSS NORTHERN ALASKA 850 MB TEMPERATURES
ARE EXPECTED TO BE NEAR NORMAL.

A WEAKENING SHORT WAVE TROUGH MOVING UP THE WEST SIDE OF
THE RIDGE EXTENDS FROM THE GULF OF ANADYR TO NEAR KOTZEBUE.
THIS FEATURE WILL BECOME DAMPENED OUT BY THIS AFTERNOON AS IT
CONTINUE TO MOVE SLOWLY NORTHWARD. ONLY A NARROWING BAND OF MID
AND HIGH LEVEL CLOUDS REMAINS WITH THIS DECAYING FEATURE.

THE NEXT INCOMING SHORT WAVE TROUGH EXTENDS FROM NEAR
55N/170E IN THE FAR SOUTHWESTERN BERING SEA TO NEAR AMCHITKA.
THE TROUGH WILL MOVE EAST TO EXTEND FROM THE NORTHEASTERN
ALASKA PENINSULA SOUTHWARD INTO THE GULF OF ALASKA
BY FRIDAY MORNING...CONTINUING EASTWARD ACROSS THE
NORTHERN GULF OF ALASKA FRIDAY AFTERNOON AND FRIDAY EVENING.

AN UPPER LOW CENTERED NEAR 58N/170E WILL MOVE EASTWARD
TO BRISTOL BAY BY LATE SATURDAY NIGHT...UNDERCUTTING
THE UPPER LEVEL RIDGE OVER THE MAINLAND.

CURRENT MODEL RUNS ARE IN GENERALLY GOOD AGREEMENT THROUGH
SATURDAY NIGHT.

SURFACE...
A 1004 MB LOW NEAR GAMBELL WILL WEAKEN TO A 1008 MB LOW NEAR
THE BERING STRAIT FRIDAY MORNING THEN DISSIPATE FRIDAY AFTERNOON.
A 1027 MB HIGH CENTERED 150 MILES NORTH OF THE MACKENZIE RIVER
DELTA WILL MOVE TO THE NORTHWESTERN CANADA ARCHIPELAGO BY FRIDAY
MORNING. A RIDGE EXTENDING FROM THE HIGH CENTER WESTWARD ACROSS
THE BEAUFORT SEA WILL GRADUALLY WEAKEN AS IT MOVES NORTHWARD TO
LATITUDE 76N BY LATE FRIDAY NIGHT.

A 1005 MB LOW OVER THE CENTRAL ALASKA PENINSULA WILL MOVE
TO NEAR ANIAK BY FRIDAY MORNING THEN DISSIPATE FRIDAY
AFTERNOON. THIS LOW WILL BRING RAIN TO THE WEST COAST AREAS
SOUTH OF UNALAKLEET AND TO THE SOUTHERN PARTS OF THE WESTERN
INTERIOR.

ARCTIC COAST...
EAST WINDS 15-25 MPH TODAY AND 20-30 MPH TONIGHT AND
FRIDAY...DECREASING FRIDAY NIGHT. WEST OF BARROW...WINDS WILL BE
LESS THAN 20 MPH. LITTLE OR NO PRECIPITATION EXPECTED THROUGH
SATURDAY. MAINLY CLEAR OR PARTLY CLOUDY SKIES THROUGH
FRIDAY...PATCHY STRATUS AND FOG POSSIBLE AT NIGHT.

CENTRAL AND EASTERN INTERIOR...
A CHANCE OF RAIN OR SHOWERS IN THE ALASKA RANGE TONIGHT
THROUGH SATURDAY...ELSEWHERE NO PRECIPITATION EXPECTED.

WESTERN INTERIOR...
LOWER YUKON VALLEY...RAIN LIKELY DEVELOPING TODAY. RAIN TONIGHT
 AND RAIN LIKELY FRIDAY AND FRIDAY EVENING.
UPPER KUSKOKWIM VALLEY...RAIN TONIGHT AND FRIDAY MORNING. RAIN
LIKELY FRIDAY AFTERNOON. CHANCE OF RAIN OR SHOWERS FRIDAY NIGHT.
MIDDLE YUKON VALLEY...CHANCE OF RAIN IN THE SOUTHERN PARTS TONIGHT
THROUGH SATURDAY. ELSEWHERE...NO PRECIPITATION EXPECTED THROUGH
SATURDAY

WEST COAST...
RAIN LIKELY MOST AREAS FROM THE SEWARD PENINSULA SOUTHWARD TODAY.
RAIN TONIGHT AND FRIDAY OVER AREAS SOUTH OF UNALAKLEET...A CHANCE
OF RAIN OVER OTHER AREAS FROM THE SEWARD PENINSULA SOUTH. WINDS 15
MPH OR LESS THROUGH SATURDAY.

ST LAWRENCE ISLAND...
NO MORE THAN SCATTERED RAIN SHOWERS ARE EXPECTED THROUGH
SATURDAY. WINDS...15 MPH OR LESS TODAY THROUGH SATURDAY. NORTH
WINDS 15-20 MPH SATURDAY NIGHT AND SUNDAY.

IN THE EXTENDED FORECAST PERIOD...
RECENT MODEL RUNS HAVE BEEN SHOWING RATHER VOLATILE
RESULTS...WITH LARGE DIFFERENCES BETWEEN MODELS AND POOR RUN TO
RUN CONTINUITY. BOTH THE GEFS AND ECMWF ENSEMBLE MEANS FROM THE
SEP 3/00Z CYCLE INDICATE A POLAR VORTEX NORTH OF 80N WITH WEST TO
NORTHWEST FLOW OVER THE ARCTIC COAST AND BEAUFORT SEA. THERE IS A
POSSIBILITY OF A MORE ACTIVE WEATHER PATTERN OVER THE ARCTIC
REGION. GFS AND ECMWF PROGS FROM THE SEP 3/00Z CYCLE INDICATE A
STRONG SHORT WAVE TROUGH DROPPING SOUTHEASTWARD OUT OF THE ARCTIC
TUESDAY NIGHT AND WEDNESDAY...ACCOMPANIED BY A 995-1000 MB
SURFACE LOW. FORECAST LOW POSITION AT 4 AM TUE IS NEAR
75N/158W...ABOUT 300 MILES NORTH OF BARROW. BY 4 PM TUESDAY...MEAN
OF THE GFS AND ECMWF PUTS A 1000 MB CENTER NEAR 73N/149W. GEFS
ENSEMBLE SPREAD APPEARS TO BE MODERATE. THIS SCENARIO WOULD
PRODUCE NORTH TO NORTHWEST WINDS 25-35 MPH OVER THE ARCTIC COAST
TUESDAY AND TUESDAY NIGHT WITH A LIKELIHOOD OF HIGH SURF
CONDITIONS ON THE ARCTIC COAST FROM BARROW WEST. BUT DUE TO THE
RECENT VARIABILITY IN MODEL RUNS...FORECAST CONFIDENCE REMAINS LOW
AT THIS TIME. IT SHOULD BE NOTED HOWEVER...GFS/ECMWF RUNS FROM
THE SEP 2/00Z CYCLE ALSO INDICATED THAT THE NORTHWEST ARCTIC
COAST COULD BE AFFECTED BY A MODERATE INTENSITY SURFACE SYSTEM
IN THE SAME GENERAL LOCATION AND TIME FRAME. THE OVERALL LARGE
SCALE PATTERN POINTING TO COLDER TEMPERATURES NORTH OF THE BROOKS
RANGE.


COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NONE SATURDAY AND SUNDAY. HIGH SURF CONDITIONS POSSIBLE ON THE
ARCTIC COAST FROM BARROW WESTWARD TUESDAY AND TUESDAY NIGHT IF
CURRENT GFS/ECMWF RUNS FROM THE SEP 3/00Z CYCLE ARE CORRECT...WITH
NORTH TO NORTHWEST WINDS 25-35 MPH. FORECAST CONFIDENCE AT THIS
TIME HOWEVER REMAINS LOW DUE TO RECENT VARIABILITY OF MODEL RUNS.

&&

.HYDROLOGY...
RIVER LEVELS ON THE CHENA RIVER FROM THE MOOSE CREEK
DOWNSTREAM ARE STILL ELEVATED BUT ARE CONTINUING TO
FALL. THE STAGE OF THE CHENA RIVER AT FAIRBANKS WAS
6.4 FEET AT 1 AM THIS MORNING...AND FORECAST TO FALL
TO ABOUT 5.2 FEET BY MIDNIGHT SATURDAY NIGHT.
ELSEWHERE...NO HYDROLOGIC ISSUES.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ235-PKZ240-PKZ245.

&&

$$

RF  SEP 15




000
FXAK68 PAFC 030018
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC




000
FXAK68 PAFC 030018 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
HYDRO....FLOOD WATCH ZONE 121

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC




000
FXAK68 PAFC 030018 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
HYDRO....FLOOD WATCH ZONE 121

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC




000
FXAK68 PAFC 030018 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
HYDRO....FLOOD WATCH ZONE 121

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC




000
FXAK68 PAFC 030018 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
HYDRO....FLOOD WATCH ZONE 121

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC




000
FXAK68 PAFC 030018 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
HYDRO....FLOOD WATCH ZONE 121

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC




000
FXAK68 PAFC 030018 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
HYDRO....FLOOD WATCH ZONE 121

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC



000
FXAK68 PAFC 030018
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC



000
FXAK68 PAFC 030018
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC



000
FXAK68 PAFC 030018
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC



000
FXAK68 PAFC 030018
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC



000
FXAK68 PAFC 030018
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
418 PM AKDT WED SEP 2 2015

.ANALYSIS AND UPPER LEVELS...
THE RIDGING THAT BROUGHT CLEAR SKIES AND COOL TEMPERATURES TO MUCH
OF THE SOUTH MAINLAND OVERNIGHT CONTINUES TO STRETCH FROM THE
SOUTHEAST MAINLAND INTO THE EASTERN GULF AND THE PANHANDLE. THIS
RIDGE IS BEING PUSHED EASTWARD BY A 100 KT JET STREAK OVER THE
NORTH PACIFIC THAT IS MOVING NORTHEAST TOWARDS THE SOUTHWEST
COAST. A SERIES OF SHORTWAVES ARE RIDING ALONG THIS JET
STREAK. THE FIRST WAS ASSOCIATED WITH A FRONTAL SYSTEM THAT MOVED
FROM THE CENTRAL BERING ONTO THE SOUTHWEST COAST OVERNIGHT...AND IS
BRINGING WIDESPREAD RAIN FROM BRISTOL BAY NORTHWARD INTO THE
KUSKOKWIM VALLEY. UPSTREAM OF THIS...A STRONGER SHORTWAVE PASSING
OVER THE EASTERN ALEUTIANS IS BRINGING ANOTHER ROUND OF RAIN TO
THAT AREA. THIS SHORTWAVE WILL CONTINUE TO PRESS TOWARDS THE
SOUTHWEST COAST THIS EVENING...AND HELP TO REINVIGORATE RAINFALL
THROUGHOUT THE SOUTH MAINLAND. THESE SHORTWAVES ARE ASSOCIATED
WITH A BROAD AND NEARLY STATIONARY UPPER LEVEL LOW CENTERED JUST
EAST OF THE KAMCHATKA PENINSULA. THIS LOW WILL SLOWLY DRIFT TO THE
EAST OVER THE NEXT FEW DAYS...AND HELP KEEP ACTIVE WEATHER WITH
CYCLONIC FLOW ALOFT FROM THE BERING SEA INTO THE SOUTH MAINLAND.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT WITH THE GENERAL PATTERN
THROUGH THE WORK WEEK...HOWEVER THE DEVIL REMAINS IN THE DETAILS
WITH REGARDS TO TIMING OF THE RAINFALL THROUGHOUT THE SOUTHWEST
MAINLAND. THERE IS SLIGHTLY BETTER AGREEMENT WITH THE ONSET OF
RAINFALL OVER SOUTHCENTRAL LATE THURSDAY MORNING...BUT THEY STILL
ARE STRUGGLING WITH HOW QUICKLY TO BRING THIS RAINFALL NORTH OF
ANCHORAGE. THE NAM/EC HAVE BOTH BEEN CONSISTENT IN A SLIGHTLY
FASTER SOLUTION THAN THE GFS/GEM...HOWEVER BY THURSDAY AFTERNOON
ALL THE MODELS HAVE GOOD CONSENSUS THAT WIDESPREAD RAIN SHOULD BE
FALLING THROUGHOUT MUCH OF THE SOUTH MAINLAND (WITH THE EXCEPTION
OF THE COPPER RIVER BASIN). FOR NOW THE FORECAST WILL CONTINUE TO
REFLECT THE SLIGHTLY FASTER SOLUTION. OTHERWISE THEY HAVE COME
INTO BETTER AGREEMENT SINCE YESTERDAY IN BOTH THE TIMING AND
INTENSITY OF A WEAK TRIPLE POINT LOW NEAR KODIAK ISLAND THURSDAY
NIGHT...ALLOWING FOR WINDS TO BE INCREASED OVER THE NORTH GULF
COAST TODAY. HOWEVER...WITH REGARDS TO RAINFALL THE MODELS
CONTINUE TO STRUGGLE WITH PLACING INDIVIDUAL WAVES FROM THE UPPER
LEVEL TROUGH THAT WILL SETUP ON FRIDAY...SO THE RAINFALL FORECAST
FOR FRIDAY REMAINS PAINTED WITH A BROAD BRUSH (A CHANCE OF RAIN
FOR SOUTHCENTRAL WITH LIKELY OR GREATER CHANCES ALONG THE NORTH
GULF COAST AND FURTHER EAST).

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL CONTINUE TO DIMINISH THIS EVENING AS
CLOUDS INCREASE AND MOIST SOUTHWESTERLY FLOW DEVELOPS AHEAD OF THE
INCOMING RAIN. SKIES WILL REMAIN CLEAR THIS EVENING OVER THE
COPPER RIVER BASIN...BUT WITH LIMITED HEATING THIS LATE IN THE
SEASON AND WEAK SURFACE WINDS DRY CONDITIONS ARE NOT EXPECTED. BY
THURSDAY AFTERNOON AND EVENING...RAINFALL SHOULD SPREAD THROUGHOUT
SOUTHCENTRAL INCLUDING THE COPPER RIVER BASIN...ALLOWING FOR COOL
AND MOIST CONDITIONS TO SETUP THAT WILL PERSIST INTO FRIDAY. WEAK
RIDGING WILL THEN DEVELOP ON SATURDAY ALLOWING FOR PARTIAL
CLEARING SKIES...BUT WITH CONTINUED COOL TEMPERATURES AND LIGHT
WINDS FIRE WEATHER CONDITIONS SHOULD REMAIN LOW.

&&

.HYDROLOGY...
RISING WATER LEVELS AT THE SNOW LAKE (A GLACIER DAMMED LAKE ON
THE KENAI PENINSULA) TODAY IS INDICATING THAT THE LAKE IS
BEGINNING TO RELEASE INTO KENAI LAKE AND THE KENAI RIVER. AS A
RESULT A FLOOD WATCH HAS BEEN ISSUED FOR THE KENAI RIVER FROM
KENAI LAKE DOWNSTREAM TO THE RUSSIAN RIVER AS WATER LEVELS MAY
RISE TO MINOR FLOOD STAGE BETWEEN THURSDAY EVENING AND SATURDAY
MORNING. IN ADDITION...DUE TO CONCERNS ALONG LOW LYING AREAS OF
KENAI LAKE (INCLUDING THE PRIMROSE CAMPGROUND AREA) A FLOOD
ADVISORY HAS ALSO BEEN ISSUED. CONDITIONS THROUGHOUT THE AREA ARE
CURRENTLY EXPECTED TO BEGIN TO IMPROVE THIS WEEKEND AS THE RELEASE
AT KENAI LAKE ENDS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE EXPECTED PATTERN SHIFT FROM THE LAST FEW DAYS OVER
SOUTHCENTRAL ALASKA IS UNDERWAY WITH INCREASING CLOUDS OVER THE
REGION THIS AFTERNOON. THE FLOW ALOFT IS BEGINNING TO TURN
SOUTHWEST OVER THE AREA AS SEEN ON THE AFTERNOON SOUNDINGS AND
SATELLITE DATA...BRINGING A MOIST AIRMASS INTO THE REGION WITH
CURRENT SATELLITE DATA INDICATING PRECIPITABLE WATER VALUES OF
AROUND 1.5-1.85 INCHES /ABOUT 150-200 PERCENT OF NORMAL/. RAINFALL
HAS ALREADY STARTED ON KODIAK ISLAND AND THE LEADING EDGE OF THE
RAIN SHIELD IS VISIBLE ON RADAR OVER THE BARREN ISLANDS THIS
AFTERNOON. RAINFALL SHOULD CONTINUE TO PROGRESS EASTWARD OVERNIGHT
WITH RAIN STARTING IN THE ANCHORAGE AREA AFTER MIDNIGHT AND
PROGRESSING THURSDAY AFTERNOON INTO THE NORTHERN GULF COAST AND
THE COPPER RIVER BASIN. CONFIDENCE IN THE EXACT LOCATION AND
AMOUNTS OF THE HEAVIEST RAINFALL TOTALS REMAIN BELOW AVERAGE...BUT
OVERALL 48 HOUR RAINFALL TOTALS OF UP 0.50-0.75 INCHES ARE
EXPECTED...MAINLY OVER COASTAL AREAS.

AS A WEAK AND SHALLOW LOW DEVELOPS IN THE NORTHERN GULF
THURSDAY AFTERNOON...THE FOCUS OF THE STEADY RAINFALL WILL SHIFT
TO PRINCE WILLIAM SOUND AND INTO THE COPPER RIVER BASIN WITH
SHOWERS EXPECTED IN THE WESTERN PART OF THE AREA.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN WILL CONTINUE OVER MUCH OF THE SOUTHWEST MAINLAND TONIGHT...AS
THE REMNANTS OF A FRONTAL SYSTEM OVER THE MAINLAND CONTINUE TO
WEAKEN THROUGH THE EVENING. THE ONLY EXCEPTION TO THIS BEING THE
KUSKOKWIM DELTA...WHERE THE FRONTAL PRECIPITATION TAPERED OFF
EARLIER TODAY AND SHIFTED NORTHWARD INTO THE NORTHWEST INTERIOR.
MULTIPLE WAVES TRACKING UP FROM THE NORTH PACIFIC WITH A SURFACE
CIRCULATION CROSSING THE ALASKA PENINSULA TONIGHT WILL REINFORCE
RAINS OVER THE MUCH OF THE SOUTHWEST MAINLAND TONIGHT...INCLUDING
THE KUSKOKWIM DELTA BY TOMORROW MORNING AS THE LOW TRACKS FURTHER
INTO BRISTOL BAY. RAIN WILL THEN TRANSITION TO MORE SHOWERY
CONDITIONS OVER THE AREA...AS A TROUGH OVER THE BERING EVENTUALLY
PUSHES THE BULK OF PRECIPITATION FURTHER EASTWARD AND MAKES WAY
FOR ANOTHER SET OF UPPER LEVEL WAVES TO TRACK INTO THE SOUTHWEST
MAINLAND FROM THE EASTERN BERING BY FRIDAY MORNING. THESE WAVES
WILL KEEP SCATTERED TO NUMEROUS SHOWERS OVER THE MAINLAND INTO THE
WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE LARGE UPPER LEVEL LOW SLOWLY ENTERING THE WESTERN BERING WILL
CONTINUE ITS EASTWARD PROGRESSION INTO THE CENTRAL BERING BY THE
WEEKEND. TROUGHS ASSOCIATED WITH THIS LARGE UPPER LOW WILL ROTATE
AROUND THE BASE OF THE LOW...KEEPING SHOWERY CONDITIONS ALONG THE
WESTERN AND CENTRAL ALEUTIANS/BERING THROUGH THE END OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

RAIN WILL CONTINUE TO TAPER OFF ACROSS SOUTHERN ALASKA FRIDAY
EVENING THROUGH THE START OF THE UPCOMING WEEKEND AS A POTENT
SHORTWAVE AND A WEAK SURFACE REFLECTION SHIFT INTO THE EASTERN
GULF OF ALASKA BEFORE FALLING APART AT THE PANHANDLE. SHORTWAVE
RIDGING WILL DEVELOP BRIEFLY BEHIND THIS PARTING SHORTWAVE AS A
SERIES OF UPPER LEVEL LOWS IN THE BERING SEA DROP SOUTH AND CREATE
A ZONAL UPPER LEVEL PATTERN VS THE AMPLIFIED PATTERN SEEN AS OF
LATE. THIS ZONAL FLOW WILL KEEP MUCH OF ALASKA IN A FAVORABLE
LOCATION FOR STORMS TO TRACK FROM THE BERING SEA INTO INTERIOR
LOCATIONS OF ALASKA. THE MOST NOTABLE CHANGE FROM YESTERDAY IS
THAT ALL GUIDANCE IS NOW HINTING AT THE ZONAL FLOW AMPLIFYING
TOWARD THE MIDDLE OF NEXT WEEK WHICH WILL ALLOW THE PHASING OF THE
AMPLIFYING TROUGH OVER THE NORTH PACIFIC TO MERGE WITH THE
NORTHERN STREAM. THE PHASING OF THESE SYSTEMS LOOKS TO USHER IN
ANOTHER UNSEASONABLY COLD AIR MASS FROM THE ARCTIC AS AN ARCTIC
TROUGH DIVES SOUTH. THERE IS STILL A LOT OF UNCERTAINTY WITH THE
TIMING OF THIS HAPPENING BUT GUIDANCE HAS BEEN HINTING AT THIS FOR
MULTIPLE DAYS AND MODELS ARE GETTING CLOSER TO A SOLUTION EACH
DAY. IT LOOKS AS IF NEAR NORMAL TEMPERATURES WILL PERSIST THROUGH
THE BEGINNING OF NEXT WEEK AND WOULD DROP A GOOD BIT BELOW NORMAL
BY THE MIDDLE OF NEXT WEEK SHOULD THIS ARCTIC TROUGH DIVE SOUTH
OVER SOUTHWEST AND SOUTHCENTRAL ALASKA.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...RF
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...MC



000
FXAK67 PAJK 022349
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
349 PM AKDT WED SEP 2 2015

.SHORT TERM...MAIN STORY CONTINUES TO BE THE TIGHT GRADIENT OVER
THE NORTHERN PANHANDLE WITH SMALL CRAFT WINDS IN NORTHERN/SOUTHERN
LYNN AND CROSS SOUND THIS AFTERNOON. PRESSURE GRADIENT OVER THE
PANHANDLE WILL GRADUALLY WEAKEN THIS EVENING AND THURSDAY WITH A
WEAK SOUTHERLY GRADIENT DEVELOPING BY THURSDAY AFTERNOON. THUS,
EXPECT WINDS TO SUBSIDE DURING THIS TIME FRAME. HAVE CONTINUED
WITH ISOLATED SHOWERS AND THUNDERSTORMS EARLY THIS EVENING IN THE
HYDER AREA, BUT THE THREAT WILL DIMINISH QUICKLY THEREAFTER.

CLOUD COVER WILL DECREASE OVER THE NORTHERN PANHANDLE THROUGH THE
EVENING AS THE UPPER LEVEL SHORTWAVE DROPS TO THE SOUTHEAST. GAVE
CONSIDERATION TO ADDING PATCHY FOG IN TONIGHT FOR THE FAR SOUTHERN
PANHANDLE BUT OPTED AGAINST IT AS FELT ENOUGH DRYING OCCURRED
LEADING TO LITTLE FOG THREAT.

ONE MORE SUNNY DAY ON TAP FOR SOUTHEAST ALASKA ON THURSDAY.
HOWEVER CLOUD COVER WILL BE PROGRESSING EASTWARD AHEAD OF THE
APPROACHING FRONTAL SYSTEM. EXPECT HIGH CLOUDS TO REACH THE
YAKUTAT AREA BY LATE AFTERNOON. TEMPERATURES WILL AGAIN BE SIMILAR
TO TODAY WITH 30S AND 40S OVERNIGHT AND HIGHS REACHING AROUND 60
DEGREES. AS MENTIONED ABOVE WITH A WEAKENING PRESSURE GRADIENT,
EXPECT SUBSTANTIALLY LESS WIND BY THURSDAY AFTERNOON ACROSS THE
ENTIRE PANHANDLE.

USED THE 12Z NAM ALONG WITH 06Z HIRES ARW FOR UPDATES TO THE
FORECAST THROUGH THE NEXT 24 HOURS. CHANGES WERE MINIMAL AND
MAINLY LIMITED TO LOCAL EFFECT EDITS. FORECASTER CONFIDENCE IS
ABOVE AVERAGE THROUGH THURSDAY AFTERNOON.

.LONG TERM...TRANSITION BACK TO A MORE TYPICAL WET PATTERN
EXPECTED TO TAKE PLACE ON FRIDAY AS A SHORTWAVE CURRENTLY OVER THE
BERING SEA EMERGES INTO THE GULF WITH THE ASSOCIATED SURFACE FRONT
APPROACHING THE COAST BY EARLY SATURDAY MORNING. THE 12Z EC
TRENDED MORE TOWARDS THE NAM IN REGARDS TO THE PLACEMENT OF THE
SURFACE LOW...HOLDING ON TO MORE OF THE NORTHERN STREAM ENERGY
WHILE A LITTLE WEAKER WITH THE SOUTHERN STREAM. THIS RESULTS IN A
MORE CONSOLIDATED SURFACE LOW OVER THE NE GULF ON FRIDAY NIGHT
INTO SATURDAY AS OPPOSED TO THE FRONTAL WAVE DEVELOPMENT INDICATED
BY LAST NIGHTS EC/GEM. THE FRONT IS FORECAST TO PUSH QUICKLY
INLAND ON SATURDAY WITH THE SURFACE LOW SLOWLY WEAKENING OVER THE
EASTERN GULF ON SUNDAY.

EXPECT SE WINDS TO INCREASE OVER THE COASTAL WATERS AHEAD OF THE
FRONT ON FRIDAY NIGHT BEFORE DECREASING SATURDAY AS THE FRONT
MOVES INLAND. ADJUSTED WINDS UPWARD IN THE FAVORED EAST/WEST
CHANNELS AS THE PRESSURE GRADIENT TIGHTENS ON FRIDAY NIGHT. ALSO
INCREASED THE SOUTHEAST WINDS IN SOME OF THE SOUTHERN INNER
CHANNELS AS THE NAM AND EC ARE INDICATING AROUND 35 KTS AT 925MB
EARLY SATURDAY MORNING. EXPECT SMALL CRAFT CONDITIONS IN THESE
AREAS DURING THIS TIME.

MODELS DIVERGE SIGNIFICANTLY FOR THE SUNDAY THROUGH WEDNESDAY TIME
FRAME...PARTICULARLY WITH THE HANDLING OF HEAT AND MOISTURE
ASSOCIATED WITH THE REMNANTS OF TROPICAL CYCLONE ACTIVITY OVER THE
CENTRAL PACIFIC...PARTICULARLY WITH HOW THEY INTERACT WITH
INDIVIDUAL SHORTWAVES MOVING THROUGH THE NORTHERN STREAM.
OVERALL...WENT WITH WPC FOR THIS TIME FRAME BUT INCREASED POP DUE
TO THE PRESENCE OF MOIST ONSHORE FLOW. FORECAST CONFIDENCE IS HIGH
FOR THE FRIDAY NIGHT AND SATURDAY SYSTEM WITH LOW CONFIDENCE FROM
SUNDAY ONWARD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-013-022-031.

&&

$$

TPS/LEVIN

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU



000
FXAK67 PAJK 022349
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
349 PM AKDT WED SEP 2 2015

.SHORT TERM...MAIN STORY CONTINUES TO BE THE TIGHT GRADIENT OVER
THE NORTHERN PANHANDLE WITH SMALL CRAFT WINDS IN NORTHERN/SOUTHERN
LYNN AND CROSS SOUND THIS AFTERNOON. PRESSURE GRADIENT OVER THE
PANHANDLE WILL GRADUALLY WEAKEN THIS EVENING AND THURSDAY WITH A
WEAK SOUTHERLY GRADIENT DEVELOPING BY THURSDAY AFTERNOON. THUS,
EXPECT WINDS TO SUBSIDE DURING THIS TIME FRAME. HAVE CONTINUED
WITH ISOLATED SHOWERS AND THUNDERSTORMS EARLY THIS EVENING IN THE
HYDER AREA, BUT THE THREAT WILL DIMINISH QUICKLY THEREAFTER.

CLOUD COVER WILL DECREASE OVER THE NORTHERN PANHANDLE THROUGH THE
EVENING AS THE UPPER LEVEL SHORTWAVE DROPS TO THE SOUTHEAST. GAVE
CONSIDERATION TO ADDING PATCHY FOG IN TONIGHT FOR THE FAR SOUTHERN
PANHANDLE BUT OPTED AGAINST IT AS FELT ENOUGH DRYING OCCURRED
LEADING TO LITTLE FOG THREAT.

ONE MORE SUNNY DAY ON TAP FOR SOUTHEAST ALASKA ON THURSDAY.
HOWEVER CLOUD COVER WILL BE PROGRESSING EASTWARD AHEAD OF THE
APPROACHING FRONTAL SYSTEM. EXPECT HIGH CLOUDS TO REACH THE
YAKUTAT AREA BY LATE AFTERNOON. TEMPERATURES WILL AGAIN BE SIMILAR
TO TODAY WITH 30S AND 40S OVERNIGHT AND HIGHS REACHING AROUND 60
DEGREES. AS MENTIONED ABOVE WITH A WEAKENING PRESSURE GRADIENT,
EXPECT SUBSTANTIALLY LESS WIND BY THURSDAY AFTERNOON ACROSS THE
ENTIRE PANHANDLE.

USED THE 12Z NAM ALONG WITH 06Z HIRES ARW FOR UPDATES TO THE
FORECAST THROUGH THE NEXT 24 HOURS. CHANGES WERE MINIMAL AND
MAINLY LIMITED TO LOCAL EFFECT EDITS. FORECASTER CONFIDENCE IS
ABOVE AVERAGE THROUGH THURSDAY AFTERNOON.

.LONG TERM...TRANSITION BACK TO A MORE TYPICAL WET PATTERN
EXPECTED TO TAKE PLACE ON FRIDAY AS A SHORTWAVE CURRENTLY OVER THE
BERING SEA EMERGES INTO THE GULF WITH THE ASSOCIATED SURFACE FRONT
APPROACHING THE COAST BY EARLY SATURDAY MORNING. THE 12Z EC
TRENDED MORE TOWARDS THE NAM IN REGARDS TO THE PLACEMENT OF THE
SURFACE LOW...HOLDING ON TO MORE OF THE NORTHERN STREAM ENERGY
WHILE A LITTLE WEAKER WITH THE SOUTHERN STREAM. THIS RESULTS IN A
MORE CONSOLIDATED SURFACE LOW OVER THE NE GULF ON FRIDAY NIGHT
INTO SATURDAY AS OPPOSED TO THE FRONTAL WAVE DEVELOPMENT INDICATED
BY LAST NIGHTS EC/GEM. THE FRONT IS FORECAST TO PUSH QUICKLY
INLAND ON SATURDAY WITH THE SURFACE LOW SLOWLY WEAKENING OVER THE
EASTERN GULF ON SUNDAY.

EXPECT SE WINDS TO INCREASE OVER THE COASTAL WATERS AHEAD OF THE
FRONT ON FRIDAY NIGHT BEFORE DECREASING SATURDAY AS THE FRONT
MOVES INLAND. ADJUSTED WINDS UPWARD IN THE FAVORED EAST/WEST
CHANNELS AS THE PRESSURE GRADIENT TIGHTENS ON FRIDAY NIGHT. ALSO
INCREASED THE SOUTHEAST WINDS IN SOME OF THE SOUTHERN INNER
CHANNELS AS THE NAM AND EC ARE INDICATING AROUND 35 KTS AT 925MB
EARLY SATURDAY MORNING. EXPECT SMALL CRAFT CONDITIONS IN THESE
AREAS DURING THIS TIME.

MODELS DIVERGE SIGNIFICANTLY FOR THE SUNDAY THROUGH WEDNESDAY TIME
FRAME...PARTICULARLY WITH THE HANDLING OF HEAT AND MOISTURE
ASSOCIATED WITH THE REMNANTS OF TROPICAL CYCLONE ACTIVITY OVER THE
CENTRAL PACIFIC...PARTICULARLY WITH HOW THEY INTERACT WITH
INDIVIDUAL SHORTWAVES MOVING THROUGH THE NORTHERN STREAM.
OVERALL...WENT WITH WPC FOR THIS TIME FRAME BUT INCREASED POP DUE
TO THE PRESENCE OF MOIST ONSHORE FLOW. FORECAST CONFIDENCE IS HIGH
FOR THE FRIDAY NIGHT AND SATURDAY SYSTEM WITH LOW CONFIDENCE FROM
SUNDAY ONWARD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-013-022-031.

&&

$$

TPS/LEVIN

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU




000
FXAK67 PAJK 022349
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
349 PM AKDT WED SEP 2 2015

.SHORT TERM...MAIN STORY CONTINUES TO BE THE TIGHT GRADIENT OVER
THE NORTHERN PANHANDLE WITH SMALL CRAFT WINDS IN NORTHERN/SOUTHERN
LYNN AND CROSS SOUND THIS AFTERNOON. PRESSURE GRADIENT OVER THE
PANHANDLE WILL GRADUALLY WEAKEN THIS EVENING AND THURSDAY WITH A
WEAK SOUTHERLY GRADIENT DEVELOPING BY THURSDAY AFTERNOON. THUS,
EXPECT WINDS TO SUBSIDE DURING THIS TIME FRAME. HAVE CONTINUED
WITH ISOLATED SHOWERS AND THUNDERSTORMS EARLY THIS EVENING IN THE
HYDER AREA, BUT THE THREAT WILL DIMINISH QUICKLY THEREAFTER.

CLOUD COVER WILL DECREASE OVER THE NORTHERN PANHANDLE THROUGH THE
EVENING AS THE UPPER LEVEL SHORTWAVE DROPS TO THE SOUTHEAST. GAVE
CONSIDERATION TO ADDING PATCHY FOG IN TONIGHT FOR THE FAR SOUTHERN
PANHANDLE BUT OPTED AGAINST IT AS FELT ENOUGH DRYING OCCURRED
LEADING TO LITTLE FOG THREAT.

ONE MORE SUNNY DAY ON TAP FOR SOUTHEAST ALASKA ON THURSDAY.
HOWEVER CLOUD COVER WILL BE PROGRESSING EASTWARD AHEAD OF THE
APPROACHING FRONTAL SYSTEM. EXPECT HIGH CLOUDS TO REACH THE
YAKUTAT AREA BY LATE AFTERNOON. TEMPERATURES WILL AGAIN BE SIMILAR
TO TODAY WITH 30S AND 40S OVERNIGHT AND HIGHS REACHING AROUND 60
DEGREES. AS MENTIONED ABOVE WITH A WEAKENING PRESSURE GRADIENT,
EXPECT SUBSTANTIALLY LESS WIND BY THURSDAY AFTERNOON ACROSS THE
ENTIRE PANHANDLE.

USED THE 12Z NAM ALONG WITH 06Z HIRES ARW FOR UPDATES TO THE
FORECAST THROUGH THE NEXT 24 HOURS. CHANGES WERE MINIMAL AND
MAINLY LIMITED TO LOCAL EFFECT EDITS. FORECASTER CONFIDENCE IS
ABOVE AVERAGE THROUGH THURSDAY AFTERNOON.

.LONG TERM...TRANSITION BACK TO A MORE TYPICAL WET PATTERN
EXPECTED TO TAKE PLACE ON FRIDAY AS A SHORTWAVE CURRENTLY OVER THE
BERING SEA EMERGES INTO THE GULF WITH THE ASSOCIATED SURFACE FRONT
APPROACHING THE COAST BY EARLY SATURDAY MORNING. THE 12Z EC
TRENDED MORE TOWARDS THE NAM IN REGARDS TO THE PLACEMENT OF THE
SURFACE LOW...HOLDING ON TO MORE OF THE NORTHERN STREAM ENERGY
WHILE A LITTLE WEAKER WITH THE SOUTHERN STREAM. THIS RESULTS IN A
MORE CONSOLIDATED SURFACE LOW OVER THE NE GULF ON FRIDAY NIGHT
INTO SATURDAY AS OPPOSED TO THE FRONTAL WAVE DEVELOPMENT INDICATED
BY LAST NIGHTS EC/GEM. THE FRONT IS FORECAST TO PUSH QUICKLY
INLAND ON SATURDAY WITH THE SURFACE LOW SLOWLY WEAKENING OVER THE
EASTERN GULF ON SUNDAY.

EXPECT SE WINDS TO INCREASE OVER THE COASTAL WATERS AHEAD OF THE
FRONT ON FRIDAY NIGHT BEFORE DECREASING SATURDAY AS THE FRONT
MOVES INLAND. ADJUSTED WINDS UPWARD IN THE FAVORED EAST/WEST
CHANNELS AS THE PRESSURE GRADIENT TIGHTENS ON FRIDAY NIGHT. ALSO
INCREASED THE SOUTHEAST WINDS IN SOME OF THE SOUTHERN INNER
CHANNELS AS THE NAM AND EC ARE INDICATING AROUND 35 KTS AT 925MB
EARLY SATURDAY MORNING. EXPECT SMALL CRAFT CONDITIONS IN THESE
AREAS DURING THIS TIME.

MODELS DIVERGE SIGNIFICANTLY FOR THE SUNDAY THROUGH WEDNESDAY TIME
FRAME...PARTICULARLY WITH THE HANDLING OF HEAT AND MOISTURE
ASSOCIATED WITH THE REMNANTS OF TROPICAL CYCLONE ACTIVITY OVER THE
CENTRAL PACIFIC...PARTICULARLY WITH HOW THEY INTERACT WITH
INDIVIDUAL SHORTWAVES MOVING THROUGH THE NORTHERN STREAM.
OVERALL...WENT WITH WPC FOR THIS TIME FRAME BUT INCREASED POP DUE
TO THE PRESENCE OF MOIST ONSHORE FLOW. FORECAST CONFIDENCE IS HIGH
FOR THE FRIDAY NIGHT AND SATURDAY SYSTEM WITH LOW CONFIDENCE FROM
SUNDAY ONWARD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-013-022-031.

&&

$$

TPS/LEVIN

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU




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