Home > Products > Valid Products > AFD

000
FXAK68 PAFC 021412
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
612 AM AKDT TUE SEP 2 2014

.ANALYSIS AND UPPER LEVELS...
A COLD UPPER LOW OFF THE NORTHWEST COAST IS STREAMING ABUNDANT
MOISTURE AROUND THE BASE OF ITS TROUGH WITH THE HEAVY
PRECIPITATION ACROSS THE CENTRAL INTERIOR. THE COLD FRONT ALONG
THE NORTHWEST COAST YESTERDAY RACED ACROSS THE NORTHERN HALF OF
THE STATE AND IS NOW STALLED ALONG A LINE FROM JUST NORTH OF EAGLE
IN EASTERN ALASKA TO THE YUKON DELTA. CLOUDS ARE INCREASING ACROSS
THE SOUTHERN AREAS OF THE STATE WITH DEEP LEVEL MOISTURE AND THE
WARMEST AIR MASS SLIDING INTO THE SOUTHWEST FROM THE BERING. THE
WARM AIR MASS BROUGHT RECORD BREAKING WARM TEMPERATURES TO SAINT
PAUL IN THE PRIBILOF ISLANDS YESTERDAY...HIGH 56/LOW 51. PATCHY
FOG AND LIGHT RAIN DEVELOPED ALONG THE FRONTAL BOUNDARY OVERNIGHT
AROSS THE KUSKOKWIM AND WESTERN AREAS OF BRISTOL BAY. RAIN ALSO
ALONG THE WESTERN ALASKA RANGE AND SOUTH TO TALKEETNA.

&&

.MODEL DISCUSSION...
MODELS WERE IN GOOD AGREEMENT WITH THE GENERAL SYNOPTIC PATTERN THROUGH
FRIDAY MORNING. THE ARCTIC LOW SHIFTS EAST ACROSS THE BEAUFORT
SEA WITH THE RIDGE ACROSS THE BERING MOVING TO THE NORTHEAST
PACIFIC. ENERGY FROM THE UPPER LOW WORKS ON MOVING THE COLD FRONT
SOUTH TODAY AND TONIGHT. THE BIGGEST CHALLENGE IN THE SHORT TERM
FORECAST IS THE FRONTAL PROGRESSION THROUGH TONIGHT. THE NAM WAS
FAVORED MODEL ACROSS SOUTHCENTRAL AND ITS SURROUNDING WATERS AS IT
KEEPS THE FRONT ALONG THE ALASKA RANGE TODAY WITH MOST OF THE RAIN
ACTIVITY ALONG THE MOUNTAINS. BETTER FORCING MOVES ACROSS THE
SUSITNA AND COPPER RIVER VALLEYS TONIGHT AS THE COLD FRONT SAGS
FURTHER SOUTH...THEREFOR PRECIPITATION WAS ADJUSTED TO INCLUDE A
SNOW MIX WITH MINOR ACCUMULATIONS TONIGHT.

THE GFS WAS THE MODEL CHOICE FOR THE SOUTHWEST MAINLAND AND
BERING/ALEUTIANS AS IT INCLUDED A GENERAL BLEND OF ALL THE
OPERATIONAL SOLUTIONS. THE LOW SOUTH OF THE EASTERN ALEUTIANS
SENDS A SHORT WAVE ACROSS OF THE ALASKA PENINSULA TONIGHT. ZONAL
FLOW ACROSS THE BERING AND RIDGING OVER THE PACIFIC STEER THE
ENERGY ALONG THE SOUTHERN GULF TODAY NOT GENERATING MUCH
PRECIPITATION. AS THE RIDGE SHIFTS EAST A STRONGER WAVE MOVES
NORTH ACROSS THE ALASKA PENINSULA AND INTO THE WESTERN GULF
SPREADING RAIN NORTH ACROSS THE SOUTHWESTERN MAINLAND.

THE UPPER WEATHER PATTERN SHIFTS FOR THE SECOND HALF OF THE WEEK
WITH A BROAD TROUGH ACROSS THE WESTERN BERING SENDING MULTIPLE
WAVES EAST BREAKING DOWN THE RIDGE OVER THE NORTHEAST PACIFIC.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
RAIN CONTINUES TO DEVELOP ALONG THE ALASKA RANGE TODAY WITH
DOWNSLOPING KEEPING THE VALLEYS DRY UNTIL THE MAIN WAVE FORCES THE
FRONT TOWARD THE COAST OVERNIGHT. RAIN MIXED WITH SNOW IS POSSIBLE
ALONG THE ALASKA RANGE AND JUST SOUTH WITH ONLY MINOR ACCUMULATIONS
EXPECTED. PRECIPITATION TAPERS OFF ON WEDNESDAY AS THE SHORTWAVE
EXITS TO THE EAST. AS FOR WINDS...GENERALLY A LIGHT FLOW ACROSS
THE INLAND LOCATIONS AND GUSTY WINDS ACROSS THE WESTERN GULF AND
COOK INLET. WINDS TAPER OFF TONIGHT AS THE PRESSURE GRADIENT
RELAXES...HOWEVER THE SOUTHERN GULF KEEPS A STRONGER SOUTH TO
WESTERLY FLOW BETWEEN 20 TO 30 MPH. THE NEXT FRONT MOVES INTO THE
WESTERN GULF WEDNESDAY NIGHT SPREADING RAIN INTO THE NORTHERN GULF
THURSDAY AFTERNOON.

SOUTHWEST ALASKA...
THE FRONT BRINGS RAIN ACROSS THE SOUTHWESTERN MAINLAND THROUGH
TONIGHT AS IT SAGS SOUTHWARD. THE ALASKA PENINSULA WILL SEE
INCREASING CLOUDS THROUGH TODAY WITH RAIN CHANCES INCREASING
WEDNESDAY NIGHT AS A FRONT MOVES NORTH FROM THE PACIFIC. THIS
FRONT SPREADS RAIN INTO BRISTOL BAY THURSDAY AND THEN BECOMES
SCATTERED AS IT MOVES NORTH TOWARD THE ALASKA RANGE AND THE
KUSKOKWIM DELTA.


BERING SEA/ALEUTIANS...
QUIET WEATHER CONDITIONS CONTINUE THROUGH THE END OF THE WEEK AS
RIDGING OVER THE BERING BLOCKS LOW PRESSURE.

&&

.LONG TERM FORECAST...
THE PATTERN SHIFT FOR THE UPCOMING WEEKEND BRINGS INCREASED
CHANCES FOR PRECIPITATION ACROSS THE SOUTHERN MAINLAND AND
SURROUNDING WATERS. COOLER TEMPERATURES FILTER BACK ACROSS THE
WESTERN BERING THIS WEEKEND AS THE LONG WAVE TROUGH DEEPENS. WARM
AIR ADVECTION CONTINUES ALONG THE EASTERN BERING AND SOUTHERN
MAINLAND ON SATURDAY AND THEN POSSIBLE COOLER THAN NORMAL
TEMPERATURES SUNDAY AS A COOLER AIR MASS MOVES FROM NORTHERN
ALASKA.

&&

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

$$

KH SEP 14




000
FXAK68 PAFC 021412
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
612 AM AKDT TUE SEP 2 2014

.ANALYSIS AND UPPER LEVELS...
A COLD UPPER LOW OFF THE NORTHWEST COAST IS STREAMING ABUNDANT
MOISTURE AROUND THE BASE OF ITS TROUGH WITH THE HEAVY
PRECIPITATION ACROSS THE CENTRAL INTERIOR. THE COLD FRONT ALONG
THE NORTHWEST COAST YESTERDAY RACED ACROSS THE NORTHERN HALF OF
THE STATE AND IS NOW STALLED ALONG A LINE FROM JUST NORTH OF EAGLE
IN EASTERN ALASKA TO THE YUKON DELTA. CLOUDS ARE INCREASING ACROSS
THE SOUTHERN AREAS OF THE STATE WITH DEEP LEVEL MOISTURE AND THE
WARMEST AIR MASS SLIDING INTO THE SOUTHWEST FROM THE BERING. THE
WARM AIR MASS BROUGHT RECORD BREAKING WARM TEMPERATURES TO SAINT
PAUL IN THE PRIBILOF ISLANDS YESTERDAY...HIGH 56/LOW 51. PATCHY
FOG AND LIGHT RAIN DEVELOPED ALONG THE FRONTAL BOUNDARY OVERNIGHT
AROSS THE KUSKOKWIM AND WESTERN AREAS OF BRISTOL BAY. RAIN ALSO
ALONG THE WESTERN ALASKA RANGE AND SOUTH TO TALKEETNA.

&&

.MODEL DISCUSSION...
MODELS WERE IN GOOD AGREEMENT WITH THE GENERAL SYNOPTIC PATTERN THROUGH
FRIDAY MORNING. THE ARCTIC LOW SHIFTS EAST ACROSS THE BEAUFORT
SEA WITH THE RIDGE ACROSS THE BERING MOVING TO THE NORTHEAST
PACIFIC. ENERGY FROM THE UPPER LOW WORKS ON MOVING THE COLD FRONT
SOUTH TODAY AND TONIGHT. THE BIGGEST CHALLENGE IN THE SHORT TERM
FORECAST IS THE FRONTAL PROGRESSION THROUGH TONIGHT. THE NAM WAS
FAVORED MODEL ACROSS SOUTHCENTRAL AND ITS SURROUNDING WATERS AS IT
KEEPS THE FRONT ALONG THE ALASKA RANGE TODAY WITH MOST OF THE RAIN
ACTIVITY ALONG THE MOUNTAINS. BETTER FORCING MOVES ACROSS THE
SUSITNA AND COPPER RIVER VALLEYS TONIGHT AS THE COLD FRONT SAGS
FURTHER SOUTH...THEREFOR PRECIPITATION WAS ADJUSTED TO INCLUDE A
SNOW MIX WITH MINOR ACCUMULATIONS TONIGHT.

THE GFS WAS THE MODEL CHOICE FOR THE SOUTHWEST MAINLAND AND
BERING/ALEUTIANS AS IT INCLUDED A GENERAL BLEND OF ALL THE
OPERATIONAL SOLUTIONS. THE LOW SOUTH OF THE EASTERN ALEUTIANS
SENDS A SHORT WAVE ACROSS OF THE ALASKA PENINSULA TONIGHT. ZONAL
FLOW ACROSS THE BERING AND RIDGING OVER THE PACIFIC STEER THE
ENERGY ALONG THE SOUTHERN GULF TODAY NOT GENERATING MUCH
PRECIPITATION. AS THE RIDGE SHIFTS EAST A STRONGER WAVE MOVES
NORTH ACROSS THE ALASKA PENINSULA AND INTO THE WESTERN GULF
SPREADING RAIN NORTH ACROSS THE SOUTHWESTERN MAINLAND.

THE UPPER WEATHER PATTERN SHIFTS FOR THE SECOND HALF OF THE WEEK
WITH A BROAD TROUGH ACROSS THE WESTERN BERING SENDING MULTIPLE
WAVES EAST BREAKING DOWN THE RIDGE OVER THE NORTHEAST PACIFIC.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
RAIN CONTINUES TO DEVELOP ALONG THE ALASKA RANGE TODAY WITH
DOWNSLOPING KEEPING THE VALLEYS DRY UNTIL THE MAIN WAVE FORCES THE
FRONT TOWARD THE COAST OVERNIGHT. RAIN MIXED WITH SNOW IS POSSIBLE
ALONG THE ALASKA RANGE AND JUST SOUTH WITH ONLY MINOR ACCUMULATIONS
EXPECTED. PRECIPITATION TAPERS OFF ON WEDNESDAY AS THE SHORTWAVE
EXITS TO THE EAST. AS FOR WINDS...GENERALLY A LIGHT FLOW ACROSS
THE INLAND LOCATIONS AND GUSTY WINDS ACROSS THE WESTERN GULF AND
COOK INLET. WINDS TAPER OFF TONIGHT AS THE PRESSURE GRADIENT
RELAXES...HOWEVER THE SOUTHERN GULF KEEPS A STRONGER SOUTH TO
WESTERLY FLOW BETWEEN 20 TO 30 MPH. THE NEXT FRONT MOVES INTO THE
WESTERN GULF WEDNESDAY NIGHT SPREADING RAIN INTO THE NORTHERN GULF
THURSDAY AFTERNOON.

SOUTHWEST ALASKA...
THE FRONT BRINGS RAIN ACROSS THE SOUTHWESTERN MAINLAND THROUGH
TONIGHT AS IT SAGS SOUTHWARD. THE ALASKA PENINSULA WILL SEE
INCREASING CLOUDS THROUGH TODAY WITH RAIN CHANCES INCREASING
WEDNESDAY NIGHT AS A FRONT MOVES NORTH FROM THE PACIFIC. THIS
FRONT SPREADS RAIN INTO BRISTOL BAY THURSDAY AND THEN BECOMES
SCATTERED AS IT MOVES NORTH TOWARD THE ALASKA RANGE AND THE
KUSKOKWIM DELTA.


BERING SEA/ALEUTIANS...
QUIET WEATHER CONDITIONS CONTINUE THROUGH THE END OF THE WEEK AS
RIDGING OVER THE BERING BLOCKS LOW PRESSURE.

&&

.LONG TERM FORECAST...
THE PATTERN SHIFT FOR THE UPCOMING WEEKEND BRINGS INCREASED
CHANCES FOR PRECIPITATION ACROSS THE SOUTHERN MAINLAND AND
SURROUNDING WATERS. COOLER TEMPERATURES FILTER BACK ACROSS THE
WESTERN BERING THIS WEEKEND AS THE LONG WAVE TROUGH DEEPENS. WARM
AIR ADVECTION CONTINUES ALONG THE EASTERN BERING AND SOUTHERN
MAINLAND ON SATURDAY AND THEN POSSIBLE COOLER THAN NORMAL
TEMPERATURES SUNDAY AS A COOLER AIR MASS MOVES FROM NORTHERN
ALASKA.

&&

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

$$

KH SEP 14





000
FXAK68 PAFC 012142
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
142 PM AKDT MON SEP 1 2014

.ANALYSIS AND UPPER LEVELS...THE LARGE COLD UPPER LEVEL LOW JUST
OFF THE ARCTIC COAST REMAINS IN PLACE TODAY AS THE NEXT TROUGH
EXTENDS OUT FROM IT AND INTO WESTERN ALASKA. THE RIDGE OVER SOUTH
CENTRAL ALASKA IS BEING DISPLACED EASTWARD BY THIS TROUGH AND
THEREFORE MORE CLOUDS ARE MOVING INTO THE REGION. THE SURFACE
RIDGE OVER THE ALASKA PENINSULA AND ALEUTIAN ISLANDS IS HOLDING
FIRM TODAY WHICH IS BRINGING ZONAL WESTERLY FLOW ACROSS THE BERING
SEA AND INTO SOUTHWEST ALASKA.
&&

.MODEL DISCUSSION...
MODELS ARE IN GOOD SYNOPTIC AGREEMENT FOR THE NEXT FEW DAYS. THE
BIGGEST AREA OF CONCERN BEGINS TUESDAY NIGHT SOUTH OF THE ALASKA
PENINSULA WHERE A NORTH PACIFIC LOW IS ELONGATING AND POSSIBLY
FORMING A TRIPLE POINT LOW. THE WAY THIS SYSTEM DEVELOPS IS
HANDLED MUCH DIFFERENTLY ESPECIALLY BETWEEN THE ECMWF AND THE
GFS. THE GFS APPEARS TO MOVE THE LOW FARTHER NORTH WAY TOO FAST
RESULTING IN IT PLACING THE LOW ABOUT 500 MILES NORTHEAST OF THE
ECMWF SOLUTION. THE OVERALL DYNAMICS SUPPORT THE MORE SOUTHERLY
ROUTE AND SLOWER TIMING CLOSER TO THE ECMWF MODEL. HOWEVER THERE
IS A GOOD CHANCE THAT THE TWO MODELS WILL CONVERGE ON A SOLUTION
THAT MAY BE BETWEEN THE TWO...BUT CLOSER TO THE ECMWF.
&&

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...THE RIDGE THAT HAS BROUGHT A NUMBER OF SUNNY
DAYS TO SOUTH CENTRAL ALASKA IS MOVING EASTWARD AS THE NEXT UPPER
LEVEL DISTURBANCE EMANATING FROM THE ARCTIC LOW MOVES TOWARD THE
AREA. THE BULK OF THE ENERGY WITH THIS TROUGH IS NORTH OF THE
ALASKA RANGE SO MOST OF THE PRECIPITATION ASSOCIATED WITH IT WILL
BE FROM TALKEETNA NORTHWARD. THE REST OF SOUTH CENTRAL WILL
LIKELY JUST SEE INCREASED CLOUDS.

SOUTHWEST ALASKA...
AS WITH SOUTH CENTRAL THE MAJORITY OF THE ENERGY WITH THIS TROUGH
IS NORTH OF THE AREA WHICH IS LIMITING THE HEAVIEST PRECIPITATION
TO THE KUSKOKWIM VALLEY. THE ZONAL WESTERLY FLOW IS BRINGING A
LARGE AMOUNT OF STRATUS INTO SOUTHWEST ALASKA WHICH IS ALREADY ON
SHORE IN THE KUSKOKWIM DELTA AREA AND WILL MOVE INTO THE BRISTOL
BAY REGION THIS EVENING. THERE MAY BE SOME LIGHT RAIN AND DRIZZLE
AS WELL AS FOG ASSOCIATED WITH THIS.

BERING SEA/ALEUTIANS...
THE MAJORITY OF THE BERING SEA IS UNDER THE MARINE STRATUS HOWEVER
THE RIDGE OVER THE ALEUTIANS AND ALASKA PENINSULA IS STRONG ENOUGH
TO BRING MOSTLY SUNNY SKIES FROM ADAK EASTWARD. THE STRATUS WILL
EVENTUALLY MAKE IN BACK INTO THE ALASKA PENINSULA OVERNIGHT AND
THE REST OF THE ALEUTIANS SOMETIME TUESDAY.

&&

.LONG TERM FORECAST...
THE SOUTHCENTRAL MAINLAND AND SOUTHWEST ALASKA WILL BE UNDER THE
INFLUENCE OF A LOW PRESSURE SYSTEM MOVING THROUGH THE BRISTOL BAY
REGION BY FRIDAY. THIS SYSTEM WILL MOVE INLAND OVER THE WEEKEND
BRINGING WIDESPREAD MOISTURE AND RAIN WITH GUSTY WINDS. THE
CENTRAL AND WESTERN BERING SEA WILL HAVE STRATUS AND FOG AS HIGH
PRESSURE BUILDS INTO THE AREA HEADING INTO NEXT WEEKEND. A NORTH
PACIFIC LOW WILL APPROACH THE CENTRAL ALEUTIANS BY SATURDAY
AFTERNOON BEFORE TRACKING INTO THE CENTRAL BERING SEA BY MONDAY.
THIS SYSTEM WILL BRING ABUNDANT MOISTURE AND PRECIPITATION WITH
GUSTY NORTHEASTERLY WINDS.

&&

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

$$

SEP 14




000
FXAK68 PAFC 012142
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
142 PM AKDT MON SEP 1 2014

.ANALYSIS AND UPPER LEVELS...THE LARGE COLD UPPER LEVEL LOW JUST
OFF THE ARCTIC COAST REMAINS IN PLACE TODAY AS THE NEXT TROUGH
EXTENDS OUT FROM IT AND INTO WESTERN ALASKA. THE RIDGE OVER SOUTH
CENTRAL ALASKA IS BEING DISPLACED EASTWARD BY THIS TROUGH AND
THEREFORE MORE CLOUDS ARE MOVING INTO THE REGION. THE SURFACE
RIDGE OVER THE ALASKA PENINSULA AND ALEUTIAN ISLANDS IS HOLDING
FIRM TODAY WHICH IS BRINGING ZONAL WESTERLY FLOW ACROSS THE BERING
SEA AND INTO SOUTHWEST ALASKA.
&&

.MODEL DISCUSSION...
MODELS ARE IN GOOD SYNOPTIC AGREEMENT FOR THE NEXT FEW DAYS. THE
BIGGEST AREA OF CONCERN BEGINS TUESDAY NIGHT SOUTH OF THE ALASKA
PENINSULA WHERE A NORTH PACIFIC LOW IS ELONGATING AND POSSIBLY
FORMING A TRIPLE POINT LOW. THE WAY THIS SYSTEM DEVELOPS IS
HANDLED MUCH DIFFERENTLY ESPECIALLY BETWEEN THE ECMWF AND THE
GFS. THE GFS APPEARS TO MOVE THE LOW FARTHER NORTH WAY TOO FAST
RESULTING IN IT PLACING THE LOW ABOUT 500 MILES NORTHEAST OF THE
ECMWF SOLUTION. THE OVERALL DYNAMICS SUPPORT THE MORE SOUTHERLY
ROUTE AND SLOWER TIMING CLOSER TO THE ECMWF MODEL. HOWEVER THERE
IS A GOOD CHANCE THAT THE TWO MODELS WILL CONVERGE ON A SOLUTION
THAT MAY BE BETWEEN THE TWO...BUT CLOSER TO THE ECMWF.
&&

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...THE RIDGE THAT HAS BROUGHT A NUMBER OF SUNNY
DAYS TO SOUTH CENTRAL ALASKA IS MOVING EASTWARD AS THE NEXT UPPER
LEVEL DISTURBANCE EMANATING FROM THE ARCTIC LOW MOVES TOWARD THE
AREA. THE BULK OF THE ENERGY WITH THIS TROUGH IS NORTH OF THE
ALASKA RANGE SO MOST OF THE PRECIPITATION ASSOCIATED WITH IT WILL
BE FROM TALKEETNA NORTHWARD. THE REST OF SOUTH CENTRAL WILL
LIKELY JUST SEE INCREASED CLOUDS.

SOUTHWEST ALASKA...
AS WITH SOUTH CENTRAL THE MAJORITY OF THE ENERGY WITH THIS TROUGH
IS NORTH OF THE AREA WHICH IS LIMITING THE HEAVIEST PRECIPITATION
TO THE KUSKOKWIM VALLEY. THE ZONAL WESTERLY FLOW IS BRINGING A
LARGE AMOUNT OF STRATUS INTO SOUTHWEST ALASKA WHICH IS ALREADY ON
SHORE IN THE KUSKOKWIM DELTA AREA AND WILL MOVE INTO THE BRISTOL
BAY REGION THIS EVENING. THERE MAY BE SOME LIGHT RAIN AND DRIZZLE
AS WELL AS FOG ASSOCIATED WITH THIS.

BERING SEA/ALEUTIANS...
THE MAJORITY OF THE BERING SEA IS UNDER THE MARINE STRATUS HOWEVER
THE RIDGE OVER THE ALEUTIANS AND ALASKA PENINSULA IS STRONG ENOUGH
TO BRING MOSTLY SUNNY SKIES FROM ADAK EASTWARD. THE STRATUS WILL
EVENTUALLY MAKE IN BACK INTO THE ALASKA PENINSULA OVERNIGHT AND
THE REST OF THE ALEUTIANS SOMETIME TUESDAY.

&&

.LONG TERM FORECAST...
THE SOUTHCENTRAL MAINLAND AND SOUTHWEST ALASKA WILL BE UNDER THE
INFLUENCE OF A LOW PRESSURE SYSTEM MOVING THROUGH THE BRISTOL BAY
REGION BY FRIDAY. THIS SYSTEM WILL MOVE INLAND OVER THE WEEKEND
BRINGING WIDESPREAD MOISTURE AND RAIN WITH GUSTY WINDS. THE
CENTRAL AND WESTERN BERING SEA WILL HAVE STRATUS AND FOG AS HIGH
PRESSURE BUILDS INTO THE AREA HEADING INTO NEXT WEEKEND. A NORTH
PACIFIC LOW WILL APPROACH THE CENTRAL ALEUTIANS BY SATURDAY
AFTERNOON BEFORE TRACKING INTO THE CENTRAL BERING SEA BY MONDAY.
THIS SYSTEM WILL BRING ABUNDANT MOISTURE AND PRECIPITATION WITH
GUSTY NORTHEASTERLY WINDS.

&&

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

$$

SEP 14





000
FXAK68 PAFC 011425
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
625 AM AKDT MON SEP 1 2014

.ANALYSIS AND UPPER LEVELS...
WATER VAPOR SATELLITE IMAGERY SHOWS A TROUGH OVER THE MAINLAND
WITH THE PARENT LOW SPINNING NORTH OF BARROW EARLY THIS MORNING. A
TROUGH AXIS EXTENDS FROM BARTER ISLAND TO THE NORTHERN KENAI AND
IS SWINGING EAST ACROSS THE STATE. SKIES ARE MOSTLY CLEAR FOR
SOUTH CENTRAL AS SUBSIDENCE IS DRYING THE ATMOSPHERE ALONG THE
BASE OF THE TROUGH. TO THE WEST...A RIDGE IS BUILDING INTO THE
BERING...STREAMING ABUNDANT MOISTURE AROUND TO THE NORTHWEST COAST
WHERE A FRONT IS A FOCUS FOR RAIN DEVELOPING ALONG THE SEWARD
PENINSULA TO LOWER YUKON VALLEY.

&&

.MODEL DISCUSSION...
MODELS ARE IN AGREEMENT WITH THE SYNOPTIC PATTERN THROUGH WEDNESDAY
AFTERNOON AND THEN BEGIN TO STRAY ON THE EVOLUTION OF A LONG WAVE
TROUGH WITH MULTIPLE CLOSED CENTERS DEVELOPING WEDNESDAY NIGHT
INTO THURSDAY. MODEL SOLUTIONS SHIFT THE ARCTIC LOW NEAR BARROW
EASTWARD THROUGH THE WEEK...WITH ITS CENTER MOVING NORTHEAST OF
KAKTOVIK ALONG THE BEAUFORT SEA COAST EARLY THURSDAY. AS THE
ARCTIC LOW MOVES EAST NEARLY ZONAL FLOW SETS UP ACROSS THE
SOUTHERN MAINLAND INTO MID WEEK. THE BERING RIDGE SHIFTS TO THE
GULF AND NORTHEAST PACIFIC THROUGH WEDNESDAY. WEAK SHORTWAVES
MOVE FROM THE ARCTIC LOW...HOWEVER THE ENERGY IS SHUNTED BY THE
RIDGE KEEPING MOST PRECIPITATION ACROSS THE NORTHERN TIER OF THE
SOUTHERN ZONES.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
THE PRESSURE GRADIENT TIGHTENS ALONG THE WESTERN GULF AND ALONG
THE COAST THIS MORNING AS LOW PRESSURE DIVES SOUTH FROM THE
NORTHWEST PUSHING A FRONT TOWARD THE GULF COAST. GUSTY WINDS DEVELOP
THIS MORNING THROUGH CHANNELED TERRAIN ALONG THE COAST AND ACROSS
THE WESTERN GULF OF ALASKA. THE FRONT LOSES MOMENTUM AS IT MOVES
ALONG THE ALASKA RANGE AND WINDS TAPER OFF AS THE GRADIENT
RELAXES TONIGHT. CLOUDS WILL BE ON THE INCREASE TODAY ACROSS THE
SOUTHERN MAINLAND AS THE FRONT MOVES IN FROM THE NORTHWEST COAST.
RAIN CHANCES INCREASE LATE THIS AFTERNOON ALONG THE SUSITNA AND
COPER RIVER VALLEYS. DOWNSLOPING ALONG THE ALASKA RANGE AND A
DRIER AIR MASS TO ITS SOUTH WILL KEEP MOST OF THE RAIN ALONG THE
MOUNTAINS.

SOUTHWEST ALASKA...
A FRONT MOVES ACROSS THE SOUTHWEST TODAY BRINGING RAIN ACROSS THE
REGION. GUSTY WINDS ASSOCIATED WITH THE FRONT WILL CONTINUE
THROUGH TONIGHT AS THE PRESSURE GRADIENT TIGHTENS ALONG THE
SOUTHWEST. QUIETER WEATHER IS ON TAP FOR TUESDAY AS RIDGING SHIFTS EAST
FROM THE BERING.


BERING SEA/ALEUTIANS...
RIDGING KEEPS THE SOUTHERN BERING UNDER WEAK FLOW THROUGH MID
WEEK. WINDS ACROSS THE NORTHERN BERING INCREASE OUT OF THE WEST AS
THE PRESSURE GRADIENT TIGHTENS BETWEEN LOW PRESSURE ACROSS THE
BERING STRAIT AND RIDGING ALONG THE ALEUTIAN CHAIN. WESTERLY FLOW
ACROSS THE BERING BRINGS A WARMER AIR MASS THROUGH MID WEEK AND
THEN A DEVELOPING TROUGH WILL SLOWLY MODERATE TEMPERATURES BACK TO
NORMAL.

&&

.LONG TERM FORECAST...
A LONG WAVE PATTERN SETS UP OVER THE BERING AT THE END OF THE WEEK
PUSHING THE RIDGE INTO THE NORTHEAST PACIFIC. THE RIDGE SHOULD
HOLD ITS INFLUENCE ACROSS THE SOUTHERN MAINLAND THROUGH THE END OF
THE WEEK. HOWEVER...A COLD FRONT PROGRESSES SOUTH ALONG THE WEST
COAST AT THE END OF THE WEEK ON FRIDAY. MODELS ARE STRUGGLING
WITH THE LONGWAVE PATTERN AND THEREFORE CONFIDENCE DECREASES INTO
THE WEEKEND ON THE EVOLUTION OF THE LONGWAVE PATTERN.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 127.
FIRE WEATHER...NONE.

&&

$$

KH SEP 14




000
FXAK68 PAFC 011425
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
625 AM AKDT MON SEP 1 2014

.ANALYSIS AND UPPER LEVELS...
WATER VAPOR SATELLITE IMAGERY SHOWS A TROUGH OVER THE MAINLAND
WITH THE PARENT LOW SPINNING NORTH OF BARROW EARLY THIS MORNING. A
TROUGH AXIS EXTENDS FROM BARTER ISLAND TO THE NORTHERN KENAI AND
IS SWINGING EAST ACROSS THE STATE. SKIES ARE MOSTLY CLEAR FOR
SOUTH CENTRAL AS SUBSIDENCE IS DRYING THE ATMOSPHERE ALONG THE
BASE OF THE TROUGH. TO THE WEST...A RIDGE IS BUILDING INTO THE
BERING...STREAMING ABUNDANT MOISTURE AROUND TO THE NORTHWEST COAST
WHERE A FRONT IS A FOCUS FOR RAIN DEVELOPING ALONG THE SEWARD
PENINSULA TO LOWER YUKON VALLEY.

&&

.MODEL DISCUSSION...
MODELS ARE IN AGREEMENT WITH THE SYNOPTIC PATTERN THROUGH WEDNESDAY
AFTERNOON AND THEN BEGIN TO STRAY ON THE EVOLUTION OF A LONG WAVE
TROUGH WITH MULTIPLE CLOSED CENTERS DEVELOPING WEDNESDAY NIGHT
INTO THURSDAY. MODEL SOLUTIONS SHIFT THE ARCTIC LOW NEAR BARROW
EASTWARD THROUGH THE WEEK...WITH ITS CENTER MOVING NORTHEAST OF
KAKTOVIK ALONG THE BEAUFORT SEA COAST EARLY THURSDAY. AS THE
ARCTIC LOW MOVES EAST NEARLY ZONAL FLOW SETS UP ACROSS THE
SOUTHERN MAINLAND INTO MID WEEK. THE BERING RIDGE SHIFTS TO THE
GULF AND NORTHEAST PACIFIC THROUGH WEDNESDAY. WEAK SHORTWAVES
MOVE FROM THE ARCTIC LOW...HOWEVER THE ENERGY IS SHUNTED BY THE
RIDGE KEEPING MOST PRECIPITATION ACROSS THE NORTHERN TIER OF THE
SOUTHERN ZONES.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
THE PRESSURE GRADIENT TIGHTENS ALONG THE WESTERN GULF AND ALONG
THE COAST THIS MORNING AS LOW PRESSURE DIVES SOUTH FROM THE
NORTHWEST PUSHING A FRONT TOWARD THE GULF COAST. GUSTY WINDS DEVELOP
THIS MORNING THROUGH CHANNELED TERRAIN ALONG THE COAST AND ACROSS
THE WESTERN GULF OF ALASKA. THE FRONT LOSES MOMENTUM AS IT MOVES
ALONG THE ALASKA RANGE AND WINDS TAPER OFF AS THE GRADIENT
RELAXES TONIGHT. CLOUDS WILL BE ON THE INCREASE TODAY ACROSS THE
SOUTHERN MAINLAND AS THE FRONT MOVES IN FROM THE NORTHWEST COAST.
RAIN CHANCES INCREASE LATE THIS AFTERNOON ALONG THE SUSITNA AND
COPER RIVER VALLEYS. DOWNSLOPING ALONG THE ALASKA RANGE AND A
DRIER AIR MASS TO ITS SOUTH WILL KEEP MOST OF THE RAIN ALONG THE
MOUNTAINS.

SOUTHWEST ALASKA...
A FRONT MOVES ACROSS THE SOUTHWEST TODAY BRINGING RAIN ACROSS THE
REGION. GUSTY WINDS ASSOCIATED WITH THE FRONT WILL CONTINUE
THROUGH TONIGHT AS THE PRESSURE GRADIENT TIGHTENS ALONG THE
SOUTHWEST. QUIETER WEATHER IS ON TAP FOR TUESDAY AS RIDGING SHIFTS EAST
FROM THE BERING.


BERING SEA/ALEUTIANS...
RIDGING KEEPS THE SOUTHERN BERING UNDER WEAK FLOW THROUGH MID
WEEK. WINDS ACROSS THE NORTHERN BERING INCREASE OUT OF THE WEST AS
THE PRESSURE GRADIENT TIGHTENS BETWEEN LOW PRESSURE ACROSS THE
BERING STRAIT AND RIDGING ALONG THE ALEUTIAN CHAIN. WESTERLY FLOW
ACROSS THE BERING BRINGS A WARMER AIR MASS THROUGH MID WEEK AND
THEN A DEVELOPING TROUGH WILL SLOWLY MODERATE TEMPERATURES BACK TO
NORMAL.

&&

.LONG TERM FORECAST...
A LONG WAVE PATTERN SETS UP OVER THE BERING AT THE END OF THE WEEK
PUSHING THE RIDGE INTO THE NORTHEAST PACIFIC. THE RIDGE SHOULD
HOLD ITS INFLUENCE ACROSS THE SOUTHERN MAINLAND THROUGH THE END OF
THE WEEK. HOWEVER...A COLD FRONT PROGRESSES SOUTH ALONG THE WEST
COAST AT THE END OF THE WEEK ON FRIDAY. MODELS ARE STRUGGLING
WITH THE LONGWAVE PATTERN AND THEREFORE CONFIDENCE DECREASES INTO
THE WEEKEND ON THE EVOLUTION OF THE LONGWAVE PATTERN.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 127.
FIRE WEATHER...NONE.

&&

$$

KH SEP 14





000
FXAK68 PAFC 312134
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
134 PM AKDT SUN AUG 31 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP UPPER LEVEL LOW CENTERED OVER THE ARCTIC OCEAN TO
THE NORTHWEST OF ALASKA. THERE IS AN UPPER LEVEL RIDGE OVER THE
WESTERN BERING SEA. A WEAK SHORT-WAVE TROUGH IS OVER THE
CENTRAL/EASTERN ALEUTIANS AND ALASKA PENINSULA WHICH IS MOVING
TOWARDS THE SOUTH. THERE IS A WEAK SHORT-WAVE TROUGH OVER THE
KUSKOKWIM DELTA AND LOWER KUSKOKWIM VALLEY. THERE IS YET ANOTHER
WEAK TROUGH OVER THE COPPER RIVER BASIN. THERE IS A STRONGER
TROUGH OVER EXTREME NORTHEAST RUSSIA MOVING RAPIDLY WESTWARD.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH ABOUT 48
HOURS...THEN BEGIN TO DIVERGE. THE MAIN ARE OF DISAGREEMENT AFTER
48 HOURS IS HOW THE MODELS HANDLE THE ENTRAINMENT OF NORTH PACIFIC
MOISTURE INTO THE ARCTIC JET STREAM OVER ALASKA. THE AMERICAN
MODELS SEEM TO BE A LITTLE FASTER AND MORE AGGRESSIVE WITH
PUSHING THE MOISTURE NORTH (ESPECIALLY THE NAM) WHILE THE ECMWF
AND CANADIAN NH GEM PREFER TO KEEP THE MOISTURE SEPARATED AND A
LITTLE FURTHER SOUTH.

&&

.SHORT TERM FORECAST...

FOR SOUTH CENTRAL ALASKA...THE WEAK TROUGH THAT HAS BEEN OVER THE
COPPER RIVER BASIN THE LAST FEW DAYS WILL FINALLY MOVE EAST LATER
TONIGHT. THIS WILL BE IN RESPONSE TO THE SYSTEM CURRENTLY OVER
NORTHEAST RUSSIA...WHICH WILL PUSH INTO SOUTHWEST ALASKA LATE
TONIGHT AND INTO SOUTH CENTRAL MONDAY NIGHT AND TUESDAY. NOT MUCH
PRECIPITATION IS EXPECTED FROM THIS SYSTEM DUE TO THE WESTERLY
FLOW ALOFT...WITH THE BEST CHANCES OVER THE SUSITNA VALLEY AND
NORTHERN COPPER RIVER BASIN. FLOW ALOFT WILL BACK TO A LITTLE MORE
SOUTHWESTERLY ON WEDNESDAY WHICH MAY SPREAD SOME SHOWERS
SOUTHWARD. ALSO ON WEDNESDAY...MOISTURE OVER THE NORTH PACIFIC
WILL BE DRAWN NORTHEASTWARD TOWARD SOUTHERN ALASKA. AS MENTIONED
IN THE PREVIOUS SECTION...SOME UNCERTAINTY EXISTS AS TO WHERE THIS
MOISTURE WILL GO. THERE IS A CHANCE SOME OF IT WILL GET TO KODIAK
ISLAND...BUT FURTHER NORTHWEST THAN THAT IS UNLIKELY.

FOR SOUTHWEST ALASKA...THE WEAK TROUGH OVER THE LOWER KUSKOKWIM
AND KUSKOKWIM DELTA WILL PROVIDE A CHANCE OF SHOWERS OVERNIGHT.
BETTER CHANCES OF PRECIPITATION WILL PUSH SOUTH AND EAST ON MONDAY
AS THE NEXT STRONGER SYSTEM MOVES ACROSS THE AREA. THE SYSTEM
ITSELF WILL MAINLY MOVE ACROSS THE INTERIOR...SO FURTHER NORTH
AREAS ARE MOST LIKELY TO SEE PRECIPITATION. SOME LINGERING SHOWERS
ARE POSSIBLE THROUGH WEDNESDAY IN THE WESTERLY FLOW ALOFT.

FOR THE BERING SEA/ALEUTIANS...AS THE ALEUTIAN/PENINSULA TROUGH
MOVES SOUTHWARD TONIGHT...THE WESTERN BERING RIDGE WILL PUSH INTO
THE SOUTHERN BERING AND ALEUTIANS. THIS RIDGE WILL BASICALLY
REMAIN IN PLACE THROUGH WEDNESDAY. LOW PRESSURE TO THE NORTH WILL
PROVIDE FAIRLY BREEZY CONDITIONS ACROSS THE NORTHERN BERING...WITH
THE STRONGEST WINDS TONIGHT INTO MONDAY AS THE NORTHEAST RUSSIAN
SYSTEM MOVES OVER THE BERING STRAIT AND INTO MAINLAND ALASKA.

&&

.LONG TERM FORECAST (SEP 4TH - SEP 7TH)...
THE SOUTH CENTRAL MAINLAND AND THE NORTHERN GULF WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL RIDGE. THIS WILL BRING A BRIEF
PERIOD OF DRIER CONDITIONS BY MIDWEEK BEFORE AN INCREASE IN CLOUDS
AND PRECIPITATION AS A NORTH PACIFIC LOW TRACKS TOWARDS THE
EASTERN ALEUTIANS HEADING INTO NEXT WEEKEND. AN UPPER LEVEL TROUGH
WILL DROP THROUGH THE NORTHERN AND CENTRAL BERING SEA BY MIDWEEK.
THIS WILL BRING COOLER TEMPERATURES WITH SCATTERED SHOWERS AND
NORTHERLY FLOW TO SOUTHWEST ALASKA HEADING INTO FRIDAY. THE
CENTRAL AND WESTERN BERING SEA WILL HAVE STRATUS AND FOG AS HIGH
PRESSURE BUILDS INTO THE AREA HEADING INTO THE WEEKEND. BY
THURSDAY A NORTH PACIFIC LOW WILL TRACK SOUTH OF EASTERN ALEUTIANS
AND MOVE INTO THE NORTHERN GULF BY SATURDAY. THIS WILL RESULT IN
NORTHEASTERLY WINDS WITH AN INCREASE IN CLOUDS AND PRECIPITATION
ALONG THE STORM PATH GOING INTO THE WEEKEND. A SECOND NORTH
PACIFIC LOW WILL APPROACH THE CENTRAL ALEUTIANS BY SATURDAY
AFTERNOON BRINGING MORE MOISTURE AND PRECIPITATION WITH
NORTHEASTERLY WINDS WHICH WILL SPREAD INTO THE THE CENTRAL BERING
SEA FOR REST OF NEXT WEEKEND.

&&

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

$$

LUDWIG/PLD AUG 14




000
FXAK68 PAFC 312134
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
134 PM AKDT SUN AUG 31 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP UPPER LEVEL LOW CENTERED OVER THE ARCTIC OCEAN TO
THE NORTHWEST OF ALASKA. THERE IS AN UPPER LEVEL RIDGE OVER THE
WESTERN BERING SEA. A WEAK SHORT-WAVE TROUGH IS OVER THE
CENTRAL/EASTERN ALEUTIANS AND ALASKA PENINSULA WHICH IS MOVING
TOWARDS THE SOUTH. THERE IS A WEAK SHORT-WAVE TROUGH OVER THE
KUSKOKWIM DELTA AND LOWER KUSKOKWIM VALLEY. THERE IS YET ANOTHER
WEAK TROUGH OVER THE COPPER RIVER BASIN. THERE IS A STRONGER
TROUGH OVER EXTREME NORTHEAST RUSSIA MOVING RAPIDLY WESTWARD.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH ABOUT 48
HOURS...THEN BEGIN TO DIVERGE. THE MAIN ARE OF DISAGREEMENT AFTER
48 HOURS IS HOW THE MODELS HANDLE THE ENTRAINMENT OF NORTH PACIFIC
MOISTURE INTO THE ARCTIC JET STREAM OVER ALASKA. THE AMERICAN
MODELS SEEM TO BE A LITTLE FASTER AND MORE AGGRESSIVE WITH
PUSHING THE MOISTURE NORTH (ESPECIALLY THE NAM) WHILE THE ECMWF
AND CANADIAN NH GEM PREFER TO KEEP THE MOISTURE SEPARATED AND A
LITTLE FURTHER SOUTH.

&&

.SHORT TERM FORECAST...

FOR SOUTH CENTRAL ALASKA...THE WEAK TROUGH THAT HAS BEEN OVER THE
COPPER RIVER BASIN THE LAST FEW DAYS WILL FINALLY MOVE EAST LATER
TONIGHT. THIS WILL BE IN RESPONSE TO THE SYSTEM CURRENTLY OVER
NORTHEAST RUSSIA...WHICH WILL PUSH INTO SOUTHWEST ALASKA LATE
TONIGHT AND INTO SOUTH CENTRAL MONDAY NIGHT AND TUESDAY. NOT MUCH
PRECIPITATION IS EXPECTED FROM THIS SYSTEM DUE TO THE WESTERLY
FLOW ALOFT...WITH THE BEST CHANCES OVER THE SUSITNA VALLEY AND
NORTHERN COPPER RIVER BASIN. FLOW ALOFT WILL BACK TO A LITTLE MORE
SOUTHWESTERLY ON WEDNESDAY WHICH MAY SPREAD SOME SHOWERS
SOUTHWARD. ALSO ON WEDNESDAY...MOISTURE OVER THE NORTH PACIFIC
WILL BE DRAWN NORTHEASTWARD TOWARD SOUTHERN ALASKA. AS MENTIONED
IN THE PREVIOUS SECTION...SOME UNCERTAINTY EXISTS AS TO WHERE THIS
MOISTURE WILL GO. THERE IS A CHANCE SOME OF IT WILL GET TO KODIAK
ISLAND...BUT FURTHER NORTHWEST THAN THAT IS UNLIKELY.

FOR SOUTHWEST ALASKA...THE WEAK TROUGH OVER THE LOWER KUSKOKWIM
AND KUSKOKWIM DELTA WILL PROVIDE A CHANCE OF SHOWERS OVERNIGHT.
BETTER CHANCES OF PRECIPITATION WILL PUSH SOUTH AND EAST ON MONDAY
AS THE NEXT STRONGER SYSTEM MOVES ACROSS THE AREA. THE SYSTEM
ITSELF WILL MAINLY MOVE ACROSS THE INTERIOR...SO FURTHER NORTH
AREAS ARE MOST LIKELY TO SEE PRECIPITATION. SOME LINGERING SHOWERS
ARE POSSIBLE THROUGH WEDNESDAY IN THE WESTERLY FLOW ALOFT.

FOR THE BERING SEA/ALEUTIANS...AS THE ALEUTIAN/PENINSULA TROUGH
MOVES SOUTHWARD TONIGHT...THE WESTERN BERING RIDGE WILL PUSH INTO
THE SOUTHERN BERING AND ALEUTIANS. THIS RIDGE WILL BASICALLY
REMAIN IN PLACE THROUGH WEDNESDAY. LOW PRESSURE TO THE NORTH WILL
PROVIDE FAIRLY BREEZY CONDITIONS ACROSS THE NORTHERN BERING...WITH
THE STRONGEST WINDS TONIGHT INTO MONDAY AS THE NORTHEAST RUSSIAN
SYSTEM MOVES OVER THE BERING STRAIT AND INTO MAINLAND ALASKA.

&&

.LONG TERM FORECAST (SEP 4TH - SEP 7TH)...
THE SOUTH CENTRAL MAINLAND AND THE NORTHERN GULF WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL RIDGE. THIS WILL BRING A BRIEF
PERIOD OF DRIER CONDITIONS BY MIDWEEK BEFORE AN INCREASE IN CLOUDS
AND PRECIPITATION AS A NORTH PACIFIC LOW TRACKS TOWARDS THE
EASTERN ALEUTIANS HEADING INTO NEXT WEEKEND. AN UPPER LEVEL TROUGH
WILL DROP THROUGH THE NORTHERN AND CENTRAL BERING SEA BY MIDWEEK.
THIS WILL BRING COOLER TEMPERATURES WITH SCATTERED SHOWERS AND
NORTHERLY FLOW TO SOUTHWEST ALASKA HEADING INTO FRIDAY. THE
CENTRAL AND WESTERN BERING SEA WILL HAVE STRATUS AND FOG AS HIGH
PRESSURE BUILDS INTO THE AREA HEADING INTO THE WEEKEND. BY
THURSDAY A NORTH PACIFIC LOW WILL TRACK SOUTH OF EASTERN ALEUTIANS
AND MOVE INTO THE NORTHERN GULF BY SATURDAY. THIS WILL RESULT IN
NORTHEASTERLY WINDS WITH AN INCREASE IN CLOUDS AND PRECIPITATION
ALONG THE STORM PATH GOING INTO THE WEEKEND. A SECOND NORTH
PACIFIC LOW WILL APPROACH THE CENTRAL ALEUTIANS BY SATURDAY
AFTERNOON BRINGING MORE MOISTURE AND PRECIPITATION WITH
NORTHEASTERLY WINDS WHICH WILL SPREAD INTO THE THE CENTRAL BERING
SEA FOR REST OF NEXT WEEKEND.

&&

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

$$

LUDWIG/PLD AUG 14





000
FXAK68 PAFC 311355
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
555 AM AKDT SUN AUG 31 2014

.ANALYSIS AND UPPER LEVELS...
WATER VAPOR SATELLITE THIS MORNING SHOWS A CLOSED LOW NORTH OF THE
NORTHWEST COAST WITH A LONG WAVE TROUGH EXTENDING SOUTH ACROSS THE
SOUTHERN BERING. A STRONG RIDGE IS BUILDING ACROSS EASTERN RUSSIA
AND IT STARTING TO SHIFT EAST. AT THE SURFACE...DRIER CONDITIONS
ENSUE ACROSS MUCH OF THE SOUTHERN MAINLAND WITH RIDGING BUILDING
IN FROM THE EASTERN BERING. HOWEVER...RAIN IN THE NORTHEASTERN
GULF CONTINUES TO DEVELOP ALONG A SURFACE LOW MOVING RAIN INLAND.

&&

.MODEL DISCUSSION...
MODELS WERE IN GOOD AGREEMENT FOR THE MORNING PACKAGE UPDATES...WITH
THE MAIN FOCUS CONCENTRATED ON THE GUSTY WINDS THROUGH CHANNELED
TERRAIN AS OFFSHORE FLOW INCREASES ACROSS THE GULF COAST AND
PRINCE WILLIAM SOUND TONIGHT. THE NAM WAS THE FAVORED MODEL FOR
THE SOUTHEAST AND CANADIAN REGIONAL MODEL USED FOR THE WEST.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
RAIN WILL CONTINUE TO DEVELOP TODAY AROUND THE SURFACE LOW IN THE
NORTHEASTERN GULF AND THEN DIMINISH AS IT SHIFTS EAST TONIGHT.
OFFSHORE FLOW INCREASES LATE TODAY BRINGING GUSTY WINDS TONIGHT THROUGH
CHANNELED TERRAIN. THE PRESSURE GRADIENT RELAXES LATE MONDAY
AFTERNOON AND WINDS TAPER OFF. OTHERWISE...MAINLY DRY CONDITIONS
FOR SOUTHCENTRAL TODAY AS A DRIER AIR MASS SETTLED ACROSS THE
REGION SATURDAY. ON MONDAY...A SHORT WAVE MOVES IN FROM THE
NORTHWEST ALONG WITH INCREASING MOISTURE FROM EASTERN
RUSSIA...THIS WILL BRING INCREASED CHANCES FOR RAIN INTO THE
MIDDLE OF THE WEEK FOR THE NORTHERN SUSITNA VALLEY AND COPPER
RIVER.


SOUTHWEST ALASKA...
A SHORTWAVE MOVES OVER THE KUSKOKWIM DELTA AND VALLEY TODAY
BRINGING SCATTERED SHOWERS AND THEN TO BRISTOL BAY OVERNIGHT. RAIN
WILL BE LIGHT WITH THE WAVE TODAY...WITH A BETTER CHANCE FOR
MEASURABLE RAIN ON MONDAY AS ABUNDANT MOISTURE STREAMS INTO THE
BERING STRAIT ALONG ANOTHER WAVE MOVING SOUTH FROM THE ARCTIC LOW.


BERING SEA/ALEUTIANS...
RIDGING BUILDS ACROSS THE SOUTHERN BERING BRINGING DRIER CONDITIONS
AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.

&&

.LONG TERM FORECAST...
A WARMER AIR MASS MOVES BACK INTO THE SOUTHERN MAINLAND AS RIDGING
SHIFTS EAST FROM THE BERING. THE ARCTIC LOW MEANDERS ALONG THE
NORTH COAST SENDING MULTIPLE WAVES SOUTH. THE STRONG RIDGE
INHIBITS MOST OF THE ENERGY KEEPING THE FORECAST DRIER WEDNESDAY.
MODELS ARE BREAKING DOWN THE RIDGE LATE WEDNESDAY WITH A LOW
FORMING SOUTH OF THE CENTRAL ALEUTIANS...HOWEVER THERE ARE
SIGNIFICANT DIFFERENCES IN THE EVOLUTION OF THIS LOW. THERE IS LOWER
CONFIDENCE IN THE LONG RANGE FORECAST WITH A CHANCE OF A WETTER
PATTERN SETTING UP SOONER IF THE LOW DEVELOPS FASTER IN THE NORTH
PACIFIC.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 127 130 131.
FIRE WEATHER...NONE. &&

$$

KH AUG 14





000
FXAK68 PAFC 311355
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
555 AM AKDT SUN AUG 31 2014

.ANALYSIS AND UPPER LEVELS...
WATER VAPOR SATELLITE THIS MORNING SHOWS A CLOSED LOW NORTH OF THE
NORTHWEST COAST WITH A LONG WAVE TROUGH EXTENDING SOUTH ACROSS THE
SOUTHERN BERING. A STRONG RIDGE IS BUILDING ACROSS EASTERN RUSSIA
AND IT STARTING TO SHIFT EAST. AT THE SURFACE...DRIER CONDITIONS
ENSUE ACROSS MUCH OF THE SOUTHERN MAINLAND WITH RIDGING BUILDING
IN FROM THE EASTERN BERING. HOWEVER...RAIN IN THE NORTHEASTERN
GULF CONTINUES TO DEVELOP ALONG A SURFACE LOW MOVING RAIN INLAND.

&&

.MODEL DISCUSSION...
MODELS WERE IN GOOD AGREEMENT FOR THE MORNING PACKAGE UPDATES...WITH
THE MAIN FOCUS CONCENTRATED ON THE GUSTY WINDS THROUGH CHANNELED
TERRAIN AS OFFSHORE FLOW INCREASES ACROSS THE GULF COAST AND
PRINCE WILLIAM SOUND TONIGHT. THE NAM WAS THE FAVORED MODEL FOR
THE SOUTHEAST AND CANADIAN REGIONAL MODEL USED FOR THE WEST.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
RAIN WILL CONTINUE TO DEVELOP TODAY AROUND THE SURFACE LOW IN THE
NORTHEASTERN GULF AND THEN DIMINISH AS IT SHIFTS EAST TONIGHT.
OFFSHORE FLOW INCREASES LATE TODAY BRINGING GUSTY WINDS TONIGHT THROUGH
CHANNELED TERRAIN. THE PRESSURE GRADIENT RELAXES LATE MONDAY
AFTERNOON AND WINDS TAPER OFF. OTHERWISE...MAINLY DRY CONDITIONS
FOR SOUTHCENTRAL TODAY AS A DRIER AIR MASS SETTLED ACROSS THE
REGION SATURDAY. ON MONDAY...A SHORT WAVE MOVES IN FROM THE
NORTHWEST ALONG WITH INCREASING MOISTURE FROM EASTERN
RUSSIA...THIS WILL BRING INCREASED CHANCES FOR RAIN INTO THE
MIDDLE OF THE WEEK FOR THE NORTHERN SUSITNA VALLEY AND COPPER
RIVER.


SOUTHWEST ALASKA...
A SHORTWAVE MOVES OVER THE KUSKOKWIM DELTA AND VALLEY TODAY
BRINGING SCATTERED SHOWERS AND THEN TO BRISTOL BAY OVERNIGHT. RAIN
WILL BE LIGHT WITH THE WAVE TODAY...WITH A BETTER CHANCE FOR
MEASURABLE RAIN ON MONDAY AS ABUNDANT MOISTURE STREAMS INTO THE
BERING STRAIT ALONG ANOTHER WAVE MOVING SOUTH FROM THE ARCTIC LOW.


BERING SEA/ALEUTIANS...
RIDGING BUILDS ACROSS THE SOUTHERN BERING BRINGING DRIER CONDITIONS
AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.

&&

.LONG TERM FORECAST...
A WARMER AIR MASS MOVES BACK INTO THE SOUTHERN MAINLAND AS RIDGING
SHIFTS EAST FROM THE BERING. THE ARCTIC LOW MEANDERS ALONG THE
NORTH COAST SENDING MULTIPLE WAVES SOUTH. THE STRONG RIDGE
INHIBITS MOST OF THE ENERGY KEEPING THE FORECAST DRIER WEDNESDAY.
MODELS ARE BREAKING DOWN THE RIDGE LATE WEDNESDAY WITH A LOW
FORMING SOUTH OF THE CENTRAL ALEUTIANS...HOWEVER THERE ARE
SIGNIFICANT DIFFERENCES IN THE EVOLUTION OF THIS LOW. THERE IS LOWER
CONFIDENCE IN THE LONG RANGE FORECAST WITH A CHANCE OF A WETTER
PATTERN SETTING UP SOONER IF THE LOW DEVELOPS FASTER IN THE NORTH
PACIFIC.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 127 130 131.
FIRE WEATHER...NONE. &&

$$

KH AUG 14




000
FXAK68 PAFC 302134
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
134 PM AKDT SAT AUG 30 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP UPPER LOW OVER THE ARCTIC OCEAN CENTERED TO THE
NORTH OF THE NORTHWEST COAST. STRONG FLOW ALOFT ASSOCIATED
WITH THIS LOW IS PUSHING SYSTEMS FROM SIBERIA TOWARD ALASKA. THE
FLOW IS WEAKER FURTHER TO THE SOUTH...WITH A FEW WEAK SHORT-WAVE
TROUGHS. ONE OF THESE IS ALONG THE ALASKA/CANADA BORDER. ANOTHER
IS JUST ENTERING THE GULF OF ALASKA FROM THE ALASKA PENINSULA AND
A THIRD IS OVER THE SOUTH CENTRAL BERING SEA.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH 60 HOURS...THEN
IN FAIRLY GOOD AGREEMENT THROUGH THE NEXT 24 HOURS. THERE ARE SOME
MINOR DIFFERENCES ON TIMING AND STRENGTH OF VARIOUS UPPER LEVEL
SYSTEMS...BUT THESE ARE ONLY MINOR AND FORECAST CONFIDENCE IS A
BIT HIGHER THAN NORMAL TODAY.

&&

.SHORT TERM FORECAST...

FOR SOUTH CENTRAL ALASKA...THE WEATHER WILL REMAIN BASICALLY DRY
THROUGH TUESDAY WITH WESTERLY FLOW ALOFT. THERE ARE A COUPLE OF
EXCEPTIONS TO THIS. OVER THE EASTERN COPPER RIVER BASIN AND FROM
ABOUT CORDOVA EASTWARD...THE WEAK SYSTEM ALONG THE CANADIAN BORDER
WILL CONTINUE TO PRODUCE SHOWERS. THIS SYSTEM WILL GET A LITTLE
EXTRA PUSH OF MOISTURE ON SUNDAY...BUT WILL FINALLY PUSH EAST ON
MONDAY. THE SECOND EXCEPTION IS ASSOCIATED WITH A SYSTEM CURRENTLY
IN SIBERIA...BUT WITH THE FAST WESTERLY FLOW WILL PUSH INTO
CENTRAL ALASKA BY MONDAY AFTERNOON. THIS SYSTEM WILL BRING A
CHANCE OF PRECIPITATION TO THE SUSITNA VALLEY (AND MAYBE EVEN THE
MATANUSKA VALLEY) AND NORTHWEST PORTIONS OF THE COPPER RIVER
BASIN LATER MONDAY INTO TUESDAY.

FOR SOUTHWEST ALASKA...DRY CONDITIONS WILL CONTINUE INTO SUNDAY
WITH WEAK RIDGING OVER THE AREA. A WEAK UPPER LEVEL SYSTEM MAY
BRING SOME RAIN TO THE KUSKOKWIM DELTA AND LOWER KUSKOKWIM VALLEY
LATER SUNDAY. A STRONGER SYSTEM MOVING INTO CENTRAL ALASKA ON
MONDAY WILL BRING A GOOD CHANCE OF RAIN TO MOST OF THE
AREA...SPREADING EAST AND SOUTH THROUGH THE DAY MONDAY. LINGERING
SHOWERS ARE EXPECTED MONDAY NIGHT AND TUESDAY AS WESTERLY FLOW
ALOFT CONTINUES.

FOR THE BERING SEA/ALEUTIANS...THE SYSTEM NEAR THE PANHANDLE AND
THE ONE OVER THE SOUTHERN BERING SEA WILL BOTH PUSH SOUTHEASTWARD
AND WEAKEN/DISSIPATE TONIGHT INTO MONDAY. STRONG HIGH PRESSURE
WILL BUILD OVER THE SOUTHERN BERING SEA MONDAY AND REMAIN THROUGH
TUESDAY. THE (LOW PRESSURE) SYSTEM SLIDING BY TO THE NORTH LATER
TONIGHT INTO MONDAY WILL STRENGTHEN THE SURFACE GRADIENT OVER THE
CENTRAL AND NORTHERN BERING SEA...AND THEN WEAKEN AGAIN AS THE
SYSTEM MOVES EASTWARD.

&&

.LONG TERM FORECAST (SEP 3RD - SEP 6TH)...
AN UPPER LEVEL LOW CENTERED OVER THE BEAUFORT SEA WILL BRING
SOUTHWEST TO WESTERLY WINDS TO THE BERING SEA AND SOUTHWEST ALASKA
FROM MIDWEEK HEADING INTO NEXT WEEKEND. THIS WILL GENERALLY BRING
MORE CLOUDY AND COOLER CONDITIONS WITH SCATTERED SHOWERS FOR
SOUTHWEST ALASKA. THE SOUTHCENTRAL MAINLAND AND THE NORTHERN GULF
WILL START OFF UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE. THIS
WILL BRING DRIER CONDITIONS BY MIDWEEK AS THE RIDGE CONTINUES TO
PROPAGATE TO THE EAST THROUGH WEEKEND. THERE WILL BE WESTERLY
WINDS BY MIDWEEK AND SHIFT TO SOUTH TO SOUTHWESTERLY BY THURSDAY.
THESE WINDS WILL CONTINUE INTO NEXT WEEKEND RESULTING IN AN
INCREASE IN CLOUDS AND THE CHANCE FOR PRECIPITATION.

&&

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

$$

LUDWIG/PLD AUG 14




000
FXAK68 PAFC 302134
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
134 PM AKDT SAT AUG 30 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP UPPER LOW OVER THE ARCTIC OCEAN CENTERED TO THE
NORTH OF THE NORTHWEST COAST. STRONG FLOW ALOFT ASSOCIATED
WITH THIS LOW IS PUSHING SYSTEMS FROM SIBERIA TOWARD ALASKA. THE
FLOW IS WEAKER FURTHER TO THE SOUTH...WITH A FEW WEAK SHORT-WAVE
TROUGHS. ONE OF THESE IS ALONG THE ALASKA/CANADA BORDER. ANOTHER
IS JUST ENTERING THE GULF OF ALASKA FROM THE ALASKA PENINSULA AND
A THIRD IS OVER THE SOUTH CENTRAL BERING SEA.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH 60 HOURS...THEN
IN FAIRLY GOOD AGREEMENT THROUGH THE NEXT 24 HOURS. THERE ARE SOME
MINOR DIFFERENCES ON TIMING AND STRENGTH OF VARIOUS UPPER LEVEL
SYSTEMS...BUT THESE ARE ONLY MINOR AND FORECAST CONFIDENCE IS A
BIT HIGHER THAN NORMAL TODAY.

&&

.SHORT TERM FORECAST...

FOR SOUTH CENTRAL ALASKA...THE WEATHER WILL REMAIN BASICALLY DRY
THROUGH TUESDAY WITH WESTERLY FLOW ALOFT. THERE ARE A COUPLE OF
EXCEPTIONS TO THIS. OVER THE EASTERN COPPER RIVER BASIN AND FROM
ABOUT CORDOVA EASTWARD...THE WEAK SYSTEM ALONG THE CANADIAN BORDER
WILL CONTINUE TO PRODUCE SHOWERS. THIS SYSTEM WILL GET A LITTLE
EXTRA PUSH OF MOISTURE ON SUNDAY...BUT WILL FINALLY PUSH EAST ON
MONDAY. THE SECOND EXCEPTION IS ASSOCIATED WITH A SYSTEM CURRENTLY
IN SIBERIA...BUT WITH THE FAST WESTERLY FLOW WILL PUSH INTO
CENTRAL ALASKA BY MONDAY AFTERNOON. THIS SYSTEM WILL BRING A
CHANCE OF PRECIPITATION TO THE SUSITNA VALLEY (AND MAYBE EVEN THE
MATANUSKA VALLEY) AND NORTHWEST PORTIONS OF THE COPPER RIVER
BASIN LATER MONDAY INTO TUESDAY.

FOR SOUTHWEST ALASKA...DRY CONDITIONS WILL CONTINUE INTO SUNDAY
WITH WEAK RIDGING OVER THE AREA. A WEAK UPPER LEVEL SYSTEM MAY
BRING SOME RAIN TO THE KUSKOKWIM DELTA AND LOWER KUSKOKWIM VALLEY
LATER SUNDAY. A STRONGER SYSTEM MOVING INTO CENTRAL ALASKA ON
MONDAY WILL BRING A GOOD CHANCE OF RAIN TO MOST OF THE
AREA...SPREADING EAST AND SOUTH THROUGH THE DAY MONDAY. LINGERING
SHOWERS ARE EXPECTED MONDAY NIGHT AND TUESDAY AS WESTERLY FLOW
ALOFT CONTINUES.

FOR THE BERING SEA/ALEUTIANS...THE SYSTEM NEAR THE PANHANDLE AND
THE ONE OVER THE SOUTHERN BERING SEA WILL BOTH PUSH SOUTHEASTWARD
AND WEAKEN/DISSIPATE TONIGHT INTO MONDAY. STRONG HIGH PRESSURE
WILL BUILD OVER THE SOUTHERN BERING SEA MONDAY AND REMAIN THROUGH
TUESDAY. THE (LOW PRESSURE) SYSTEM SLIDING BY TO THE NORTH LATER
TONIGHT INTO MONDAY WILL STRENGTHEN THE SURFACE GRADIENT OVER THE
CENTRAL AND NORTHERN BERING SEA...AND THEN WEAKEN AGAIN AS THE
SYSTEM MOVES EASTWARD.

&&

.LONG TERM FORECAST (SEP 3RD - SEP 6TH)...
AN UPPER LEVEL LOW CENTERED OVER THE BEAUFORT SEA WILL BRING
SOUTHWEST TO WESTERLY WINDS TO THE BERING SEA AND SOUTHWEST ALASKA
FROM MIDWEEK HEADING INTO NEXT WEEKEND. THIS WILL GENERALLY BRING
MORE CLOUDY AND COOLER CONDITIONS WITH SCATTERED SHOWERS FOR
SOUTHWEST ALASKA. THE SOUTHCENTRAL MAINLAND AND THE NORTHERN GULF
WILL START OFF UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE. THIS
WILL BRING DRIER CONDITIONS BY MIDWEEK AS THE RIDGE CONTINUES TO
PROPAGATE TO THE EAST THROUGH WEEKEND. THERE WILL BE WESTERLY
WINDS BY MIDWEEK AND SHIFT TO SOUTH TO SOUTHWESTERLY BY THURSDAY.
THESE WINDS WILL CONTINUE INTO NEXT WEEKEND RESULTING IN AN
INCREASE IN CLOUDS AND THE CHANCE FOR PRECIPITATION.

&&

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

$$

LUDWIG/PLD AUG 14





    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities