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000
FXAK68 PAFC 260259
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
559 PM AKST TUE NOV 25 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP (506 DM AT 500 MB) UPPER LOW OVER THE WESTERN
BERING SEA WITH TWO DEVELOPING LOWS AROUND IT...ONE JUST SOUTH OF
THE CENTRAL ALEUTIANS AND ON SOUTHWEST OF THE WESTERN ALEUTIANS.
THERE IS A BUILDING RIDGE TO THE EAST OF THIS LOW ALONG THE WEST
COAST OF ALASKA. THERE IS A TROUGH OVER THE PANHANDLE AND THE YUKON
TERRITORY. A WEAK UPPER LEVEL "WAVE" IS OVER SOUTH CENTRAL ALASKA
PRODUCING SOME SHOWERS...MAINLY OVER HIGHER ELEVATIONS INLAND SUCH
AS THE TALKEETNA MOUNTAINS.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT THROUGH 84 HOURS.
THIS LEADS TO HIGHER THAN NORMAL CONFIDENCE IN THE FORECAST FOR
THE AFTERNOON PACKAGE. MODELS OF CHOICE FOR THE FIRST 48 HOURS OF
THE FORECAST ARE THE NAM AND REGIONAL GEM FOR THEIR BETTER
HANDLING OF SMALL SCALE DETAILS.

&&

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

SPOTTY SNOW SHOWERS ACROSS PORTIONS OF COOK INLET NORTHWARD TO THE
ALASKA RANGE AND TALKEETNA MOUNTAINS WILL DIMINISH TONIGHT AS
UPPER LEVEL RIDGING BUILDS OVER THE REGION. THE OFFSHORE PRESSURE
GRADIENT WILL TIGHTEN TONIGHT AS A WEAK UPPER DISTURBANCE MOVES
ALONG THE EASTERN PERIPHERY OF THE AFOREMENTIONED RIDGE...WHICH
WILL HELP TO INCREASE GAP WINDS THROUGH THURSDAY...ESPECIALLY
FROM PRINCE WILLIAM SOUND EASTWARD. PATCHY FOG WILL BE POSSIBLE
NEAR COOK INLET AS THE HIGH BUILDS ALOFT...BUT OTHERWISE PLEASANT
CONDITIONS WILL PREVAIL THROUGH THE THANKSGIVING HOLIDAY.

&&

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

A RELATIVELY DRY PERIOD IS EXPECTED ACROSS MUCH OF SOUTHWEST ALASKA
THROUGH THANKSGIVING DUE IN LARGE PART TO AN UPPER LEVEL RIDGE
THAT CONTINUES TO STRENGTHEN OVER SOUTHWEST ALASKA. SUBSIDENCE
ASSOCIATED WITH THIS RIDGE WILL ALLOW CLOUD COVER TO GRADUALLY
DIMINISH OVER THE NEXT SEVERAL DAYS. THIS WILL ALLOW AREAS TO
RADIATE OUT MORE OVERNIGHT THAN OVER THE PAST SEVERAL DAYS WHICH
WILL LEAD TO MORE SEASONAL TEMPERATURES. IN THE MEAN TIME...A WEAK
UPPER LEVEL DISTURBANCE RIDING ALONG THE NORTHERN PERIPHERY OF
THE RIDGE NEAR THE KUSKOKWIM DELTA WILL PRODUCE SCATTERED SNOW
SHOWERS OVER THE KUSKOKWIM DELTA AND ISOLATED SNOW SHOWERS OVER
PARTS OF THE LOWER KUSKOKWIM VALLEY. AN ISOLATED SHOWER OF LIGHT
FREEZING RAIN CANNOT BE RULED OUT OF THE KUSKOKWIM DELTA AT THIS
TIME AS THE 00Z RAOB FROM PABE SHOWS THERE IS A SMALL POCKET OF
WARM AIR ALOFT. ANY FREEZING PRECIPITATION WOULD BE SHORT LIVED
AND LITTLE TO NO IMPACT.

FOG WILL BE A CONCERN ACROSS THE KUSKOKWIM VALLEY AND THE BRISTOL
BAY AREA TONIGHT. THE MARINE LAYER THAT BROUGHT AREAS OF DENSE
FOG TO DILLINGHAM AND SURROUNDING AREAS REMAINS INLAND AND
VISIBILITIES HAVE ALREADY BEGUN TO DROP. THIS TREND SHOULD
CONTINUE THROUGH THE OVERNIGHT HOURS...WITH THE REST OF THE
BRISTOL BAY AREA SEEING SOME PATCHY FOG. THE LOWER KUSKOKWIM
VALLEY WILL HAVE SOME BREAKS IN THE CLOUDS WHICH SHOULD ALLOW SOME
LOCATIONS IN THE VALLEYS TO SATURATE LEADING TO SOME PATCHY FOG.

&&

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

AN AREA OF LOW PRESSURE OVER THE NORTH PACIFIC CONTINUE TO MAKE
QUICK PROGRESS TOWARD THE CENTRAL AND ALEUTIANS. THIS WILL ALLOW
RAIN TO OVERSPREAD THE CENTRAL AND EASTERN ALEUTIANS AND INTO THE
BERING SEA. IN ADDITION...STORM FORCE WINDS WILL BE SEEN OVER THE
COASTAL WATERS NEAR THE CENTRAL ALEUTIANS...WITH A LARGE AREA OF
GALES EXTENDING FROM THE WESTERN ALEUTIANS...TO THE EASTERN
ALEUTIANS AND INTO THE CENTRAL BERING SEA. A SECOND LOW FROM THE
NORTH PACIFIC WILL IMPACT THE WESTERN ALEUTIANS STARTING WEDNESDAY
MORNING AND PUSH INTO THE CENTRAL BERING SEA BY THURSDAY MORNING.
THIS WILL BRING ANOTHER LARGE SWATH OF GALE FORCE WINDS TO THE
WESTERN HALF OF THE BERING SEA WHICH WILL PERSIST THROUGH AT LEAST
THANKSGIVING. THIS IN TURN WILL FORM A COMPLEX LOW PATTERN OVER
THE BERING SEA...WHICH WILL KEEP ELEVATED RAIN CHANCES IN THE
FORECAST THROUGH THE REMAINDER OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
BY FRIDAY...THERE IS INCREASING MODEL AGREEMENT THAT THE GENERAL
PATTERN RECENTLY WITH A TROUGH OVER THE BERING AND A RIDGE OVER
THE MAINLAND WILL BEGIN TO BREAK DOWN. THIS WILL BEGIN LATE ON
FRIDAY AS THE BERING TROUGH AND ASSOCIATED SURFACE LOW MOVE
TOWARDS THE BERING STRAIT...AND RIDGING QUICKLY BUILDS OVER THE
BERING. THERE IS A POTENTIAL THAT A WEAK SHORTWAVE RIDING OVER TOP
OF THIS BUILDING RIDGE COULD BRING SNOW TO SOUTHCENTRAL LATE
SATURDAY/EARLY SUNDAY...HOWEVER THERE IS NOT ENOUGH CONFIDENCE IN
THIS BEYOND JUST A CHANCE OF SNOW.

A MUCH BETTER CHANCE OF ACTIVE WEATHER THROUGHOUT THE SOUTHERN
MAINLAND LOOKS TO OCCUR EARLY NEXT WEEK. THIS IS WHEN A LOW
MOVING INTO THE EASTWARD INTO THE GULF MERGES WITH AN ARCTIC
TROUGH DESCENDING THROUGH THE MAINLAND ON TUESDAY. THIS LOOKS TO
BRING A PERIOD OF STORMY WEATHER TO THE GULF COAST...EASTERN
BERING...AND SOUTHERN MAINLAND NEXT WEEK. IT IS ALSO IMPORTANT TO
NOTE THAT THERE IS VERY GOOD MODEL AGREEMENT THAT RIDGING WILL NOT
REFORM ANYWHERE FROM THE MAINLAND OR NORTHWEST CANADA NEXT WEEK.
THIS IS A MAJOR CHANGE FROM THE PERSISTENT PATTERN MUCH ALASKA HAS
BEEN UNDER THE INFLUENCE OF FOR THE PAST FEW WEEKS...A CLEAR
SIGNAL THAT THE AREA WILL EXPERIENCE A PROLONGED PATTERN CHANGE.
THIS LACK OF RIDGING WILL ALSO CUT OFF THE DEEP MOIST/WARM
SOUTHERLY FLOW...INCREASING SNOW CHANCES OVER INTERIOR LOCATIONS
GOING INTO NEXT WEEK.

&&


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

&&

$$




000
FXAK68 PAFC 260259
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
559 PM AKST TUE NOV 25 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP (506 DM AT 500 MB) UPPER LOW OVER THE WESTERN
BERING SEA WITH TWO DEVELOPING LOWS AROUND IT...ONE JUST SOUTH OF
THE CENTRAL ALEUTIANS AND ON SOUTHWEST OF THE WESTERN ALEUTIANS.
THERE IS A BUILDING RIDGE TO THE EAST OF THIS LOW ALONG THE WEST
COAST OF ALASKA. THERE IS A TROUGH OVER THE PANHANDLE AND THE YUKON
TERRITORY. A WEAK UPPER LEVEL "WAVE" IS OVER SOUTH CENTRAL ALASKA
PRODUCING SOME SHOWERS...MAINLY OVER HIGHER ELEVATIONS INLAND SUCH
AS THE TALKEETNA MOUNTAINS.

&&

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT THROUGH 84 HOURS.
THIS LEADS TO HIGHER THAN NORMAL CONFIDENCE IN THE FORECAST FOR
THE AFTERNOON PACKAGE. MODELS OF CHOICE FOR THE FIRST 48 HOURS OF
THE FORECAST ARE THE NAM AND REGIONAL GEM FOR THEIR BETTER
HANDLING OF SMALL SCALE DETAILS.

&&

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

SPOTTY SNOW SHOWERS ACROSS PORTIONS OF COOK INLET NORTHWARD TO THE
ALASKA RANGE AND TALKEETNA MOUNTAINS WILL DIMINISH TONIGHT AS
UPPER LEVEL RIDGING BUILDS OVER THE REGION. THE OFFSHORE PRESSURE
GRADIENT WILL TIGHTEN TONIGHT AS A WEAK UPPER DISTURBANCE MOVES
ALONG THE EASTERN PERIPHERY OF THE AFOREMENTIONED RIDGE...WHICH
WILL HELP TO INCREASE GAP WINDS THROUGH THURSDAY...ESPECIALLY
FROM PRINCE WILLIAM SOUND EASTWARD. PATCHY FOG WILL BE POSSIBLE
NEAR COOK INLET AS THE HIGH BUILDS ALOFT...BUT OTHERWISE PLEASANT
CONDITIONS WILL PREVAIL THROUGH THE THANKSGIVING HOLIDAY.

&&

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

A RELATIVELY DRY PERIOD IS EXPECTED ACROSS MUCH OF SOUTHWEST ALASKA
THROUGH THANKSGIVING DUE IN LARGE PART TO AN UPPER LEVEL RIDGE
THAT CONTINUES TO STRENGTHEN OVER SOUTHWEST ALASKA. SUBSIDENCE
ASSOCIATED WITH THIS RIDGE WILL ALLOW CLOUD COVER TO GRADUALLY
DIMINISH OVER THE NEXT SEVERAL DAYS. THIS WILL ALLOW AREAS TO
RADIATE OUT MORE OVERNIGHT THAN OVER THE PAST SEVERAL DAYS WHICH
WILL LEAD TO MORE SEASONAL TEMPERATURES. IN THE MEAN TIME...A WEAK
UPPER LEVEL DISTURBANCE RIDING ALONG THE NORTHERN PERIPHERY OF
THE RIDGE NEAR THE KUSKOKWIM DELTA WILL PRODUCE SCATTERED SNOW
SHOWERS OVER THE KUSKOKWIM DELTA AND ISOLATED SNOW SHOWERS OVER
PARTS OF THE LOWER KUSKOKWIM VALLEY. AN ISOLATED SHOWER OF LIGHT
FREEZING RAIN CANNOT BE RULED OUT OF THE KUSKOKWIM DELTA AT THIS
TIME AS THE 00Z RAOB FROM PABE SHOWS THERE IS A SMALL POCKET OF
WARM AIR ALOFT. ANY FREEZING PRECIPITATION WOULD BE SHORT LIVED
AND LITTLE TO NO IMPACT.

FOG WILL BE A CONCERN ACROSS THE KUSKOKWIM VALLEY AND THE BRISTOL
BAY AREA TONIGHT. THE MARINE LAYER THAT BROUGHT AREAS OF DENSE
FOG TO DILLINGHAM AND SURROUNDING AREAS REMAINS INLAND AND
VISIBILITIES HAVE ALREADY BEGUN TO DROP. THIS TREND SHOULD
CONTINUE THROUGH THE OVERNIGHT HOURS...WITH THE REST OF THE
BRISTOL BAY AREA SEEING SOME PATCHY FOG. THE LOWER KUSKOKWIM
VALLEY WILL HAVE SOME BREAKS IN THE CLOUDS WHICH SHOULD ALLOW SOME
LOCATIONS IN THE VALLEYS TO SATURATE LEADING TO SOME PATCHY FOG.

&&

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

AN AREA OF LOW PRESSURE OVER THE NORTH PACIFIC CONTINUE TO MAKE
QUICK PROGRESS TOWARD THE CENTRAL AND ALEUTIANS. THIS WILL ALLOW
RAIN TO OVERSPREAD THE CENTRAL AND EASTERN ALEUTIANS AND INTO THE
BERING SEA. IN ADDITION...STORM FORCE WINDS WILL BE SEEN OVER THE
COASTAL WATERS NEAR THE CENTRAL ALEUTIANS...WITH A LARGE AREA OF
GALES EXTENDING FROM THE WESTERN ALEUTIANS...TO THE EASTERN
ALEUTIANS AND INTO THE CENTRAL BERING SEA. A SECOND LOW FROM THE
NORTH PACIFIC WILL IMPACT THE WESTERN ALEUTIANS STARTING WEDNESDAY
MORNING AND PUSH INTO THE CENTRAL BERING SEA BY THURSDAY MORNING.
THIS WILL BRING ANOTHER LARGE SWATH OF GALE FORCE WINDS TO THE
WESTERN HALF OF THE BERING SEA WHICH WILL PERSIST THROUGH AT LEAST
THANKSGIVING. THIS IN TURN WILL FORM A COMPLEX LOW PATTERN OVER
THE BERING SEA...WHICH WILL KEEP ELEVATED RAIN CHANCES IN THE
FORECAST THROUGH THE REMAINDER OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
BY FRIDAY...THERE IS INCREASING MODEL AGREEMENT THAT THE GENERAL
PATTERN RECENTLY WITH A TROUGH OVER THE BERING AND A RIDGE OVER
THE MAINLAND WILL BEGIN TO BREAK DOWN. THIS WILL BEGIN LATE ON
FRIDAY AS THE BERING TROUGH AND ASSOCIATED SURFACE LOW MOVE
TOWARDS THE BERING STRAIT...AND RIDGING QUICKLY BUILDS OVER THE
BERING. THERE IS A POTENTIAL THAT A WEAK SHORTWAVE RIDING OVER TOP
OF THIS BUILDING RIDGE COULD BRING SNOW TO SOUTHCENTRAL LATE
SATURDAY/EARLY SUNDAY...HOWEVER THERE IS NOT ENOUGH CONFIDENCE IN
THIS BEYOND JUST A CHANCE OF SNOW.

A MUCH BETTER CHANCE OF ACTIVE WEATHER THROUGHOUT THE SOUTHERN
MAINLAND LOOKS TO OCCUR EARLY NEXT WEEK. THIS IS WHEN A LOW
MOVING INTO THE EASTWARD INTO THE GULF MERGES WITH AN ARCTIC
TROUGH DESCENDING THROUGH THE MAINLAND ON TUESDAY. THIS LOOKS TO
BRING A PERIOD OF STORMY WEATHER TO THE GULF COAST...EASTERN
BERING...AND SOUTHERN MAINLAND NEXT WEEK. IT IS ALSO IMPORTANT TO
NOTE THAT THERE IS VERY GOOD MODEL AGREEMENT THAT RIDGING WILL NOT
REFORM ANYWHERE FROM THE MAINLAND OR NORTHWEST CANADA NEXT WEEK.
THIS IS A MAJOR CHANGE FROM THE PERSISTENT PATTERN MUCH ALASKA HAS
BEEN UNDER THE INFLUENCE OF FOR THE PAST FEW WEEKS...A CLEAR
SIGNAL THAT THE AREA WILL EXPERIENCE A PROLONGED PATTERN CHANGE.
THIS LACK OF RIDGING WILL ALSO CUT OFF THE DEEP MOIST/WARM
SOUTHERLY FLOW...INCREASING SNOW CHANCES OVER INTERIOR LOCATIONS
GOING INTO NEXT WEEK.

&&


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

&&

$$





000
FXAK68 PAFC 251428
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
528 AM AKST TUE NOV 25 2014

.ANALYSIS AND UPPER LEVELS...

LARGE AND SEASONABLY STRONG LOW PRESSURE CONTINUES TO SPIN IN
PLACE OVER THE FAR WESTERN BERING JUST EAST OF KAMCHATKA RUSSIA
THIS MORNING...WITH A STRONG AMPLIFYING RIDGE DOWNSTREAM BUILDING
NORTH AND EAST OVER THE SOUTHEASTERN BERING AND SOUTHWESTERN
MAINLAND OF ALASKA. AN ASSOCIATED WEAKENING OCCLUDED FRONT IS
MOVING NORTH AND EAST OVER THE NORTHERN AND EASTERN BERING IN THE
DIRECTION OF THE KUSKOKWIM DELTA REGION.

BETWEEN THE PARENT LOW OVER THE FAR WESTERN BERING AND THE
AMPLIFYING RIDGE OVER THE WESTERN MAINLAND...AN EXTREMELY ACTIVE
STORM TRACK PATTERN ASSOCIATED WITH THE VIGOROUS EAST ASIAN JET
EXTENDS FROM OFF THE COAST OF JAPAN NORTH AND EAST TO THE CENTRAL
BERING SEA.

A SEASONABLY STRONG 979 MB LOW WITH STORM FORCE WINDS IS
CURRENTLY LOCATED 430 NAUTICAL MILES SOUTH OF ADAK AND IS MOVING
NORTH TO NORTH-NORTHEAST IN THE GENERAL DIRECTION OF THE CENTRAL
ALEUTIANS AND CENTRAL BERING SEA.

MEANWHILE...A WEAK DISTURBANCE IS MOVING ALONG THE NORTH SIDE OF
THE BUILDING RIDGE OVER SOUTHWEST ALASKA AND HEADING TOWARD
SOUTHCENTRAL ALASKA THIS MORNING. THIS LOW IS RESPONSIBLE FOR SOME
LIGHT RAIN OVER INTERIOR BRISTOL BAY THIS MORNING...WITH GENERALLY
LOW CLOUDS AND FOG OTHERWISE IN THE LARGE-SCALE SUBSIDENCE
UNDERNEATH THE BUILDING RIDGE.

&&

.MODEL DISCUSSION...

THE GFS AND EUROPEAN MODELS HAVE THE BEST AGREEMENT AND WERE
PREFERRED WITH THE ACTIVE STORMY PATTERN FROM THE NORTHWEST
PACIFIC TO THE BERING SEA. BOTH MODELS HAVE INITIALIZED THE
PRINCIPLE WEATHER FEATURES IN THE BERING FAIRLY WELL...AND ANY
DIFFERENCES IN THE OVERALL TRACKS OF THE LOWS TO IMPACT THE REGION
ARE RELATIVELY MINOR.

THE FAR WESTERN BERING SURFACE AND PARENT LOW WILL SLOWLY WEAKEN
THROUGH WEDNESDAY NIGHT BEFORE BECOMING ABSORBED INTO A DEVELOPING
STORM WHICH IS CURRENTLY LOCATED NEAR JAPAN BUT WILL MOVE ACROSS
THE WESTERN AND CENTRAL ALEUTIANS INTO THE SOUTHERN BERING
WEDNESDAY INTO THURSDAY. THE CURRENT 979 MB LOW 430 NAUTICAL
MILES SOUTH OF THE ALEUTIANS WILL MOVE NORTH AND INTO THE CENTRAL
BERING SEA WEDNESDAY MORNING BEFORE BECOMING ABSORBED INTO THE
GENERAL CIRCULATION OF THE WESTERN BERING LOW. WHILE THIS IS
OCCURRING...THE RIDGE OVER THE NORTH PACIFIC AND EXTENDING NORTH
OVER THE WESTERN MAINLAND WILL CONTINUE TO AMPLIFY THROUGH
THURSDAY AND SLOWLY CRAWL EASTWARD...WITH ITS RIDGE AXIS LIKELY
REACHING THE COOK INLET REGION THURSDAY AFTERNOON AS A WARM FRONT
BEGINS TO PUSH NORTH AND EAST ACROSS THE BERING TOWARD THE
SOUTHWEST MAINLAND.


&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE MAIN WEATHER FEATURES OF IMPORTANCE FOR THE SHORT TERM
FORECAST PERIOD INCLUDE A SHORTWAVE TROUGH CROSSING INTERIOR
ALASKA AND A DIFFUSE UPPER TROUGH AND DISSIPATING SURFACE LOW
CROSSING THE GULF OF ALASKA. THE SHORTWAVE TROUGH MOVING THROUGH
TO THE NORTH IS BRINGING LIGHT SNOW AS IT CROSSES THE AREA TODAY.
THE TALKEETNA MOUNTAINS WILL SEE THE MOST ACCUMULATIONS DUE TO
UPSLOPE FLOW. THERE IS UNCERTAINTY IN THE SOUTHERN EXTENT OF
SNOWFALL. WITH WEAKER VERTICAL MOTION FURTHER TO THE SOUTH EXPECT
SNOW FALL ACCUMULATIONS TO TAPER OFF WITH MINIMAL ACCUMULATIONS BY
THE TIME YOU REACH THE SOUTHERN MAT VALLEY AND ANCHORAGE AREAS.
THE SNOW WILL PUSH EAST AND RAPIDLY TAPER OFF TONIGHT AS THE FLOW
ALOFT TURNS MORE NORTHWESTERLY AND DRIER AIR SPREADS ACROSS THE
AREA.

OFFSHORE FLOW WILL STRENGTHEN WEDNESDAY AS THE RIDGE ALOFT TO THE
WEST CONTINUES TO AMPLIFY AND PUSHES A 500 MB JET OVER CENTRAL
ALASKA. THE STRONGEST OFFSHORE GRADIENT WILL FORM BETWEEN HIGH
PRESSURE BUILDING INLAND OVER THE COPPER RIVER BASIN AND THE
SURFACE LOW DEPARTING THE EASTERN GULF MAKING THE VALDEZ AND
COPPER RIVER DELTA AREAS THE PRIMARY CONCERNS FOR WINDS. HOWEVER
WITH LIMITED COLD AIR ADVECTION AND PROGRESSIVE UPPER LEVEL FLOW
THIS EVENT WILL BE SHORT LIVED AND FAIRLY WEAK.

AS THE RIDGE BUILDS OVER NORTHERN COOK INLET THE ENVIRONMENT WILL
RAPIDLY STABILIZE AND BECOME FAVORABLE FOR DEVELOPMENT OF FOG.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH THURSDAY)...
A WARM FRONT ALONG THE EASTERN BERING IS PUSHING INTO THE WEST
COAST FROM HOOPER BAY TO CAPE NEWENHAM. PRECIPITATION ALONG THE
FRONT DEVELOPS AS SNOW EARLY THIS MORNING AND THEN MIXES WITH
RAIN LATE MORNING AS THE WARMER AIR MASS NUDGES INLAND.
PRECIPITATION MAINLY STAYS CONFINED TO THE KUSKOKWIM DELTA AS THE
ASSOCIATED LOW PUSHES INTO THE NORTHERN BERING. TEMPERATURES WILL
BE SLOWER TO WARM AT THE SURFACE AND THEREFORE ISOLATED POCKETS OF
FREEZING RAIN WILL BE POSSIBLE. PRECIPITATION TAPERS OFF THIS
EVENING AS THE FRONT DIMINISHES. FOG HAS DEVELOPED ACROSS A MOIST
STABLE BOUNDARY LAYER ACROSS THE KUSKOKWIM VALLEY AND INLAND AREAS
OF BRISTOL BAY...EXPECT IMPROVEMENT DURING THE AFTERNOON AND THEN
REDEVELOPMENT OVERNIGHT AS TEMPERATURES DROP.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH
THURSDAY)...
A WARM FRONT HAS SPREAD ACROSS THE CENTRAL BERING BRINGING RAIN
INTO THE NORTHERN WATERS. SLIGHTLY COOLER TEMPERATURES HAVE
WORKED INTO THE WESTERN BERING BEHIND THE MAIN FRONT BRINGING A
CHANCE FOR SCATTERED RAIN AND SNOW SHOWERS TODAY AS A WEAK
SHORTWAVE MOVES AHEAD OF LOW PRESSURE OFF OF THE KAMCHATKA
PENINSULA. THE MAIN CHALLENGE IN THE CURRENT FORECAST IS THE LOW
CURRENTLY HEADING TOWARD THE CENTRAL ALEUTIANS. THIS STORM LOOKS
TO MOVE UP FASTER THAN ORIGINALLY ANTICIPATED WITH STORM FORCE
WINDS AROUND THE CORE OF THE SYSTEM. THE STORM QUICKLY TRACKS INTO THE
CENTRAL ALEUTIANS THIS AFTERNOON MAKING IT TO THE PRIBILOFS ON
WEDNESDAY. MODERATE TO HEAVY RAIN WILL ACCOMPANY THIS SUBTROPICAL
SYSTEM WITH ANOTHER STRONG STORM SYSTEM TO FOLLOW WEDNESDAY NIGHT
AS THE NEXT FRONT PUSHES INTO WESTERN/CENTRAL ALEUTIANS.

&&

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

ON THU AND FRI MODELS AGREE THAT A BLOCKING UPPER RIDGE WILL BE
OVER MAINLAND AK WITH A A CUT-OFF LOW EMBEDDED IN A LARGE TROUGH
OVER THE BERING. ANOTHER RIDGE WILL BE NEAR KAMCHATKA WITH A
DEVELOPING TROUGH EAST OF JAPAN. ON FRI NIGHT A PATTERN CHANGE
BEGINS AS THE KAMCHATKA RIDGE BEGINS TO MIGRATE EAST. THIS WILL
PINCH OFF THE SOUTHERN PORTION OF THE BERING TROUGH...WHICH THEN
UNDERCUTS THE MAINLAND AK RIDGE. THIS BREAKDOWN OF THE BLOCKING
RIDGE WILL ALLOW THE KAMCHATKA RIDGE TO MOVE TO THE BERING ON SAT
AND WESTERN AK ON SUN.

AT THE SURFACE...HIGH PRESSURE WITH WEAK DISTURBANCES WILL REMAIN
OVER THE GULF THROUGH EARLY NEXT WEEK. A LOW IN THE BERING WILL
DRIFT NORTH TO THE BERING STRAIT AND DISSIPATE ON SAT...WHILE AN
ASSOCIATED FRONT MOVES INTO WESTERN AK. FINALLY...A LOW ASSOCIATED
WITH THE DEVELOPING TROUGH OFF JAPAN WILL APPROACH THE WESTERN
ALEUTIANS SAT INTO SUN. MODELS BEGIN TO LOSE AGREEMENT WHEN IT
COMES TO THE DISPOSITION OF THIS LOW. FOR NOW THE FORECAST REMAINS
WITH THE WPC SOLUTION OF KEEPING THE LOW SOUTH OF THE BERING.

FORECAST CONFIDENCE REMAINS HIGH THAT GENERALLY DRY
CONDITIONS ARE EXPECTED FOR SOUTHCENTRAL THROUGH MON...ALTHOUGH
RAIN AND SNOW MAY AFFECT COASTAL ZONES BY THE WEEKEND. CONFIDENCE
IS ALSO HIGH THAT RAIN AND SNOW SHOWERS WILL BEGIN TO AFFECT
SOUTHWEST AK BEGINNING ON FRI. THE ALEUTIANS WILL ALSO HAVE RAIN
INTO EARLY NEXT WEEK...AND WINDS ARE EXPECTED TO INCREASE
BEGINNING THIS WEEKEND.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 165 171 175 177 178
         STORMS 170 172 173 174 176 179 181 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...KH
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JER/SEB
LONG TERM...DS




000
FXAK68 PAFC 251428
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
528 AM AKST TUE NOV 25 2014

.ANALYSIS AND UPPER LEVELS...

LARGE AND SEASONABLY STRONG LOW PRESSURE CONTINUES TO SPIN IN
PLACE OVER THE FAR WESTERN BERING JUST EAST OF KAMCHATKA RUSSIA
THIS MORNING...WITH A STRONG AMPLIFYING RIDGE DOWNSTREAM BUILDING
NORTH AND EAST OVER THE SOUTHEASTERN BERING AND SOUTHWESTERN
MAINLAND OF ALASKA. AN ASSOCIATED WEAKENING OCCLUDED FRONT IS
MOVING NORTH AND EAST OVER THE NORTHERN AND EASTERN BERING IN THE
DIRECTION OF THE KUSKOKWIM DELTA REGION.

BETWEEN THE PARENT LOW OVER THE FAR WESTERN BERING AND THE
AMPLIFYING RIDGE OVER THE WESTERN MAINLAND...AN EXTREMELY ACTIVE
STORM TRACK PATTERN ASSOCIATED WITH THE VIGOROUS EAST ASIAN JET
EXTENDS FROM OFF THE COAST OF JAPAN NORTH AND EAST TO THE CENTRAL
BERING SEA.

A SEASONABLY STRONG 979 MB LOW WITH STORM FORCE WINDS IS
CURRENTLY LOCATED 430 NAUTICAL MILES SOUTH OF ADAK AND IS MOVING
NORTH TO NORTH-NORTHEAST IN THE GENERAL DIRECTION OF THE CENTRAL
ALEUTIANS AND CENTRAL BERING SEA.

MEANWHILE...A WEAK DISTURBANCE IS MOVING ALONG THE NORTH SIDE OF
THE BUILDING RIDGE OVER SOUTHWEST ALASKA AND HEADING TOWARD
SOUTHCENTRAL ALASKA THIS MORNING. THIS LOW IS RESPONSIBLE FOR SOME
LIGHT RAIN OVER INTERIOR BRISTOL BAY THIS MORNING...WITH GENERALLY
LOW CLOUDS AND FOG OTHERWISE IN THE LARGE-SCALE SUBSIDENCE
UNDERNEATH THE BUILDING RIDGE.

&&

.MODEL DISCUSSION...

THE GFS AND EUROPEAN MODELS HAVE THE BEST AGREEMENT AND WERE
PREFERRED WITH THE ACTIVE STORMY PATTERN FROM THE NORTHWEST
PACIFIC TO THE BERING SEA. BOTH MODELS HAVE INITIALIZED THE
PRINCIPLE WEATHER FEATURES IN THE BERING FAIRLY WELL...AND ANY
DIFFERENCES IN THE OVERALL TRACKS OF THE LOWS TO IMPACT THE REGION
ARE RELATIVELY MINOR.

THE FAR WESTERN BERING SURFACE AND PARENT LOW WILL SLOWLY WEAKEN
THROUGH WEDNESDAY NIGHT BEFORE BECOMING ABSORBED INTO A DEVELOPING
STORM WHICH IS CURRENTLY LOCATED NEAR JAPAN BUT WILL MOVE ACROSS
THE WESTERN AND CENTRAL ALEUTIANS INTO THE SOUTHERN BERING
WEDNESDAY INTO THURSDAY. THE CURRENT 979 MB LOW 430 NAUTICAL
MILES SOUTH OF THE ALEUTIANS WILL MOVE NORTH AND INTO THE CENTRAL
BERING SEA WEDNESDAY MORNING BEFORE BECOMING ABSORBED INTO THE
GENERAL CIRCULATION OF THE WESTERN BERING LOW. WHILE THIS IS
OCCURRING...THE RIDGE OVER THE NORTH PACIFIC AND EXTENDING NORTH
OVER THE WESTERN MAINLAND WILL CONTINUE TO AMPLIFY THROUGH
THURSDAY AND SLOWLY CRAWL EASTWARD...WITH ITS RIDGE AXIS LIKELY
REACHING THE COOK INLET REGION THURSDAY AFTERNOON AS A WARM FRONT
BEGINS TO PUSH NORTH AND EAST ACROSS THE BERING TOWARD THE
SOUTHWEST MAINLAND.


&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THE MAIN WEATHER FEATURES OF IMPORTANCE FOR THE SHORT TERM
FORECAST PERIOD INCLUDE A SHORTWAVE TROUGH CROSSING INTERIOR
ALASKA AND A DIFFUSE UPPER TROUGH AND DISSIPATING SURFACE LOW
CROSSING THE GULF OF ALASKA. THE SHORTWAVE TROUGH MOVING THROUGH
TO THE NORTH IS BRINGING LIGHT SNOW AS IT CROSSES THE AREA TODAY.
THE TALKEETNA MOUNTAINS WILL SEE THE MOST ACCUMULATIONS DUE TO
UPSLOPE FLOW. THERE IS UNCERTAINTY IN THE SOUTHERN EXTENT OF
SNOWFALL. WITH WEAKER VERTICAL MOTION FURTHER TO THE SOUTH EXPECT
SNOW FALL ACCUMULATIONS TO TAPER OFF WITH MINIMAL ACCUMULATIONS BY
THE TIME YOU REACH THE SOUTHERN MAT VALLEY AND ANCHORAGE AREAS.
THE SNOW WILL PUSH EAST AND RAPIDLY TAPER OFF TONIGHT AS THE FLOW
ALOFT TURNS MORE NORTHWESTERLY AND DRIER AIR SPREADS ACROSS THE
AREA.

OFFSHORE FLOW WILL STRENGTHEN WEDNESDAY AS THE RIDGE ALOFT TO THE
WEST CONTINUES TO AMPLIFY AND PUSHES A 500 MB JET OVER CENTRAL
ALASKA. THE STRONGEST OFFSHORE GRADIENT WILL FORM BETWEEN HIGH
PRESSURE BUILDING INLAND OVER THE COPPER RIVER BASIN AND THE
SURFACE LOW DEPARTING THE EASTERN GULF MAKING THE VALDEZ AND
COPPER RIVER DELTA AREAS THE PRIMARY CONCERNS FOR WINDS. HOWEVER
WITH LIMITED COLD AIR ADVECTION AND PROGRESSIVE UPPER LEVEL FLOW
THIS EVENT WILL BE SHORT LIVED AND FAIRLY WEAK.

AS THE RIDGE BUILDS OVER NORTHERN COOK INLET THE ENVIRONMENT WILL
RAPIDLY STABILIZE AND BECOME FAVORABLE FOR DEVELOPMENT OF FOG.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH THURSDAY)...
A WARM FRONT ALONG THE EASTERN BERING IS PUSHING INTO THE WEST
COAST FROM HOOPER BAY TO CAPE NEWENHAM. PRECIPITATION ALONG THE
FRONT DEVELOPS AS SNOW EARLY THIS MORNING AND THEN MIXES WITH
RAIN LATE MORNING AS THE WARMER AIR MASS NUDGES INLAND.
PRECIPITATION MAINLY STAYS CONFINED TO THE KUSKOKWIM DELTA AS THE
ASSOCIATED LOW PUSHES INTO THE NORTHERN BERING. TEMPERATURES WILL
BE SLOWER TO WARM AT THE SURFACE AND THEREFORE ISOLATED POCKETS OF
FREEZING RAIN WILL BE POSSIBLE. PRECIPITATION TAPERS OFF THIS
EVENING AS THE FRONT DIMINISHES. FOG HAS DEVELOPED ACROSS A MOIST
STABLE BOUNDARY LAYER ACROSS THE KUSKOKWIM VALLEY AND INLAND AREAS
OF BRISTOL BAY...EXPECT IMPROVEMENT DURING THE AFTERNOON AND THEN
REDEVELOPMENT OVERNIGHT AS TEMPERATURES DROP.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH
THURSDAY)...
A WARM FRONT HAS SPREAD ACROSS THE CENTRAL BERING BRINGING RAIN
INTO THE NORTHERN WATERS. SLIGHTLY COOLER TEMPERATURES HAVE
WORKED INTO THE WESTERN BERING BEHIND THE MAIN FRONT BRINGING A
CHANCE FOR SCATTERED RAIN AND SNOW SHOWERS TODAY AS A WEAK
SHORTWAVE MOVES AHEAD OF LOW PRESSURE OFF OF THE KAMCHATKA
PENINSULA. THE MAIN CHALLENGE IN THE CURRENT FORECAST IS THE LOW
CURRENTLY HEADING TOWARD THE CENTRAL ALEUTIANS. THIS STORM LOOKS
TO MOVE UP FASTER THAN ORIGINALLY ANTICIPATED WITH STORM FORCE
WINDS AROUND THE CORE OF THE SYSTEM. THE STORM QUICKLY TRACKS INTO THE
CENTRAL ALEUTIANS THIS AFTERNOON MAKING IT TO THE PRIBILOFS ON
WEDNESDAY. MODERATE TO HEAVY RAIN WILL ACCOMPANY THIS SUBTROPICAL
SYSTEM WITH ANOTHER STRONG STORM SYSTEM TO FOLLOW WEDNESDAY NIGHT
AS THE NEXT FRONT PUSHES INTO WESTERN/CENTRAL ALEUTIANS.

&&

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

ON THU AND FRI MODELS AGREE THAT A BLOCKING UPPER RIDGE WILL BE
OVER MAINLAND AK WITH A A CUT-OFF LOW EMBEDDED IN A LARGE TROUGH
OVER THE BERING. ANOTHER RIDGE WILL BE NEAR KAMCHATKA WITH A
DEVELOPING TROUGH EAST OF JAPAN. ON FRI NIGHT A PATTERN CHANGE
BEGINS AS THE KAMCHATKA RIDGE BEGINS TO MIGRATE EAST. THIS WILL
PINCH OFF THE SOUTHERN PORTION OF THE BERING TROUGH...WHICH THEN
UNDERCUTS THE MAINLAND AK RIDGE. THIS BREAKDOWN OF THE BLOCKING
RIDGE WILL ALLOW THE KAMCHATKA RIDGE TO MOVE TO THE BERING ON SAT
AND WESTERN AK ON SUN.

AT THE SURFACE...HIGH PRESSURE WITH WEAK DISTURBANCES WILL REMAIN
OVER THE GULF THROUGH EARLY NEXT WEEK. A LOW IN THE BERING WILL
DRIFT NORTH TO THE BERING STRAIT AND DISSIPATE ON SAT...WHILE AN
ASSOCIATED FRONT MOVES INTO WESTERN AK. FINALLY...A LOW ASSOCIATED
WITH THE DEVELOPING TROUGH OFF JAPAN WILL APPROACH THE WESTERN
ALEUTIANS SAT INTO SUN. MODELS BEGIN TO LOSE AGREEMENT WHEN IT
COMES TO THE DISPOSITION OF THIS LOW. FOR NOW THE FORECAST REMAINS
WITH THE WPC SOLUTION OF KEEPING THE LOW SOUTH OF THE BERING.

FORECAST CONFIDENCE REMAINS HIGH THAT GENERALLY DRY
CONDITIONS ARE EXPECTED FOR SOUTHCENTRAL THROUGH MON...ALTHOUGH
RAIN AND SNOW MAY AFFECT COASTAL ZONES BY THE WEEKEND. CONFIDENCE
IS ALSO HIGH THAT RAIN AND SNOW SHOWERS WILL BEGIN TO AFFECT
SOUTHWEST AK BEGINNING ON FRI. THE ALEUTIANS WILL ALSO HAVE RAIN
INTO EARLY NEXT WEEK...AND WINDS ARE EXPECTED TO INCREASE
BEGINNING THIS WEEKEND.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 165 171 175 177 178
         STORMS 170 172 173 174 176 179 181 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...KH
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JER/SEB
LONG TERM...DS





000
FXAK68 PAFC 250305
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
605 PM AKST MON NOV 24 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP (503 DM AT 500 MB) UPPER LOW OVER THE SOUTHWEST
BERING SEA. THERE IS A BUILDING RIDGE OVER THE EASTERN BERING.
THERE IS A BROAD NORTH/SOUTH TROUGH OVER THE ALASKA MAINLAND AND
THE GULF OF ALASKA. THERE IS A LONG OCCLUDED FRONT ASSOCIATED WITH
THE SOUTHWEST BERING LOW THAT STRETCHES FROM THE KAMCHATKA
PENINSULA EAST INTO THE CENTRAL BERING AND THEN SOUTHEAST TO NEAR
ATKA...THEN AS A COLD FRONT SOUTHWEST INTO THE NORTH PACIFIC.
THERE IS SOME MOISTURE ASSOCIATED WITH THE MAINLAND/GULF TROUGH
PRODUCING SOME ISOLATED/SCATTERED SHOWERS OVER THOSE AREAS.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH 60 HOURS
(WEDNESDAY AFTERNOON). THE MAIN DIFFERENCES INVOLVE THE SURFACE
LOWS OUT WEST. THE 12Z MODELS ARE IN MUCH BETTER AGREEMENT THAN
PREVIOUS RUNS WITH A LOW THAT FORMS ON THE COLD FRONT OVER THE
NORTH PACIFIC AND RACES NORTH ACROSS THE ALEUTIANS AND INTO THE
BERING SEA TUE NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 2)...

A DISTURBANCE ACROSS CENTRAL ALASKA WILL BEGIN TO MOVE EAST
TUESDAY...WITH INCREASING MOISTURE SPREADING NORTH INTO THE
SUSITNA AND MATANUSKA VALLEY. THE BEST CHANCE FOR
ACCUMULATING LIGHT SNOW WILL BE ALONG THE TALKEETNA MOUNTAINS
NORTHWARD TOWARDS THE ALASKA RANGE...WITH LIGHTER AND MORE
SPORADIC SNOW SHOWERS TOWARD THE CHUGACH MOUNTAINS AND ANCHORAGE.
THE ATMOSPHERE WILL RAPIDLY DRY OUT ON WEDNESDAY AS AN UPPER RIDGE
BUILDS OVER SOUTHCENTRAL. NORTHWEST FLOW ALOFT WILL PROMOTE AN
OFFSHORE PRESSURE GRADIENT...WITH INCREASING GAP WINDS NEAR THE
GULF COAST. THE STRONGEST WINDS WILL BE AROUND PRINCE WILLIAM
SOUND AND TOWARD THE COPPER RIVER BASIN.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH THURSDAY)...
STRONG INVERSIONS THAT HAVE DEVELOPED FROM THE KUSKOKWIM VALLEY
INTO BRISTOL BAY WILL CAUSE FOR PERSISTENT FOG AND STRATUS IN LOW
LYING AREAS AT LEAST UNTIL TUESDAY...AND POSSIBLY CONTINUING INTO
WEDNESDAY. THIS STRATUS WILL KEEP OVERNIGHT LOWS SLIGHTLY WARMER
THAN PREVIOUSLY EXPECTED...ESPECIALLY IN THE CENTRAL KUSKOKWIM
VALLEY. PRECIPITATION WILL BE LARGELY LIMITED TO A FRONTAL SYSTEM
THAT WILL BRING RAIN AND SNOW TO THE KUSKOKWIM DELTA TUESDAY
AFTERNOON INTO MONDAY MORNING. OTHERWISE THE WEATHER WILL REMAIN
FAIRLY QUIET WITH RIDGING CONTINUING UNTIL EARLY THURSDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH
THURSDAY)...
THE FRONTAL SYSTEM ASSOCIATED WITH THE LOW CENTERED NORTHWEST OF
SHEMYA WILL BECOME LOW COMPLEX OVER MUCH OF THE BERING THROUGH MID
WEEK. THERE IS NOW MUCH BETTER AGREEMENT THAT A LOW APPROACHING
ATKA LATE TUESDAY WILL BRING RAIN AND GUSTY GALE FORCE WINDS TO THE
CENTRAL TO EASTERN ALEUTIANS THROUGH WEDNESDAY AFTERNOON. YET
ANOTHER GALE FORCE LOW WILL THEN QUICKLY DEVELOP BEHIND IT ON
WEDNESDAY...WHICH WILL SPREAD RAIN AND GALE FORCE WINDS INTO THE
BERING AND APPROACHING THE PRIBILOF ISLANDS BY THURSDAY.


&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
MODELS REMAIN IN GOOD AGREEMENT WITH A HIGH AMPLITUDE BLOCKING
RIDGE DEVELOPING OVER MAINLAND AK AND THE GULF WEDNESDAY...WITH A
CUT-OFF LOW EMBEDDED IN A TROUGH OVER THE BERING SEA. THIS CREATES
FAIRLY HIGH CONFIDENCE THAT SOUTHCENTRAL WILL REMAIN DRY BENEATH
THE RIDGE THROUGH THE END OF THE WEEK. THE RIDGE WILL REMAIN IN
PLACE INTO FRIDAY WHEN THE BERING CUT-OFF LOW CUTS THROUGH THE
RIDGE...CHANGING THE DRIER AND COOLER HIGH AMPLITUDE PATTERN INTO
ONE WITH SHORTWAVES TRACKING THROUGH THE FORECAST AREA. AS A
RESULT...AREAS AROUND THE SOUTHWEST MAINLAND AND NORTHERN GULF
COAST MAY EXPERIENCE SOME SHOWERY CONDITIONS BEGINNING FRIDAY AND
PERSISTING THROUGH THE WEEKEND. AS IS TYPICAL WITH WAVES MOVING
THROUGH RELATIVELY ZONAL FLOW...THERE IS LESS CONFIDENCE IN THE
TIMING AND STRENGTH OF THESE WAVES AS THEY TRAVERSE THE AREA.

THE FORECAST FOR THE BERING IS OF LOWER CONFIDENCE DUE TO
CONTINUED TIMING UNCERTAINTY. HOWEVER...MODELS HAVE COME SLIGHTLY
CLOSER TO A SOLUTION REGARDING THE COMPLEX LOW AND MULTIPLE
VORTICIES THAT TRACK THROUGH THE CENTRAL/EASTERN ALEUTIANS AND
BERING BEFORE CONSOLIDATING OVER THE BERING SEA THURSDAY. MODELS
HAVE STARTED TO COME CLOSER TO THE EXPECTED MIDDLE GROUND SOLUTION
BETWEEN THE GFS AND ECMWF FROM PREVIOUS RUNS. THIS SOLUTION WILL
TRACK THE LOW IN THE NORTHERN PACIFIC THROUGH INTO THE CENTRAL
BERING BY THURSDAY...KEEPING PRECIPITATION AND GUSTY WINDS AROUND
THE AREA THROUGH THE END OF THE WEEK. A NEW LOW OFF THE COAST OF
JAPAN WILL APPROACH THE WESTERN/CENTRAL ALEUTIANS
SATURDAY...BRINGING ANOTHER WAVE OF RAIN AND GUSTY WINDS TO THE
CHAIN THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 170 172 173 174 175 176 178 185.
FIRE WEATHER...NONE.

&&

$$

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





000
FXAK68 PAFC 250305
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
605 PM AKST MON NOV 24 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS A DEEP (503 DM AT 500 MB) UPPER LOW OVER THE SOUTHWEST
BERING SEA. THERE IS A BUILDING RIDGE OVER THE EASTERN BERING.
THERE IS A BROAD NORTH/SOUTH TROUGH OVER THE ALASKA MAINLAND AND
THE GULF OF ALASKA. THERE IS A LONG OCCLUDED FRONT ASSOCIATED WITH
THE SOUTHWEST BERING LOW THAT STRETCHES FROM THE KAMCHATKA
PENINSULA EAST INTO THE CENTRAL BERING AND THEN SOUTHEAST TO NEAR
ATKA...THEN AS A COLD FRONT SOUTHWEST INTO THE NORTH PACIFIC.
THERE IS SOME MOISTURE ASSOCIATED WITH THE MAINLAND/GULF TROUGH
PRODUCING SOME ISOLATED/SCATTERED SHOWERS OVER THOSE AREAS.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH 60 HOURS
(WEDNESDAY AFTERNOON). THE MAIN DIFFERENCES INVOLVE THE SURFACE
LOWS OUT WEST. THE 12Z MODELS ARE IN MUCH BETTER AGREEMENT THAN
PREVIOUS RUNS WITH A LOW THAT FORMS ON THE COLD FRONT OVER THE
NORTH PACIFIC AND RACES NORTH ACROSS THE ALEUTIANS AND INTO THE
BERING SEA TUE NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 2)...

A DISTURBANCE ACROSS CENTRAL ALASKA WILL BEGIN TO MOVE EAST
TUESDAY...WITH INCREASING MOISTURE SPREADING NORTH INTO THE
SUSITNA AND MATANUSKA VALLEY. THE BEST CHANCE FOR
ACCUMULATING LIGHT SNOW WILL BE ALONG THE TALKEETNA MOUNTAINS
NORTHWARD TOWARDS THE ALASKA RANGE...WITH LIGHTER AND MORE
SPORADIC SNOW SHOWERS TOWARD THE CHUGACH MOUNTAINS AND ANCHORAGE.
THE ATMOSPHERE WILL RAPIDLY DRY OUT ON WEDNESDAY AS AN UPPER RIDGE
BUILDS OVER SOUTHCENTRAL. NORTHWEST FLOW ALOFT WILL PROMOTE AN
OFFSHORE PRESSURE GRADIENT...WITH INCREASING GAP WINDS NEAR THE
GULF COAST. THE STRONGEST WINDS WILL BE AROUND PRINCE WILLIAM
SOUND AND TOWARD THE COPPER RIVER BASIN.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH THURSDAY)...
STRONG INVERSIONS THAT HAVE DEVELOPED FROM THE KUSKOKWIM VALLEY
INTO BRISTOL BAY WILL CAUSE FOR PERSISTENT FOG AND STRATUS IN LOW
LYING AREAS AT LEAST UNTIL TUESDAY...AND POSSIBLY CONTINUING INTO
WEDNESDAY. THIS STRATUS WILL KEEP OVERNIGHT LOWS SLIGHTLY WARMER
THAN PREVIOUSLY EXPECTED...ESPECIALLY IN THE CENTRAL KUSKOKWIM
VALLEY. PRECIPITATION WILL BE LARGELY LIMITED TO A FRONTAL SYSTEM
THAT WILL BRING RAIN AND SNOW TO THE KUSKOKWIM DELTA TUESDAY
AFTERNOON INTO MONDAY MORNING. OTHERWISE THE WEATHER WILL REMAIN
FAIRLY QUIET WITH RIDGING CONTINUING UNTIL EARLY THURSDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH
THURSDAY)...
THE FRONTAL SYSTEM ASSOCIATED WITH THE LOW CENTERED NORTHWEST OF
SHEMYA WILL BECOME LOW COMPLEX OVER MUCH OF THE BERING THROUGH MID
WEEK. THERE IS NOW MUCH BETTER AGREEMENT THAT A LOW APPROACHING
ATKA LATE TUESDAY WILL BRING RAIN AND GUSTY GALE FORCE WINDS TO THE
CENTRAL TO EASTERN ALEUTIANS THROUGH WEDNESDAY AFTERNOON. YET
ANOTHER GALE FORCE LOW WILL THEN QUICKLY DEVELOP BEHIND IT ON
WEDNESDAY...WHICH WILL SPREAD RAIN AND GALE FORCE WINDS INTO THE
BERING AND APPROACHING THE PRIBILOF ISLANDS BY THURSDAY.


&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
MODELS REMAIN IN GOOD AGREEMENT WITH A HIGH AMPLITUDE BLOCKING
RIDGE DEVELOPING OVER MAINLAND AK AND THE GULF WEDNESDAY...WITH A
CUT-OFF LOW EMBEDDED IN A TROUGH OVER THE BERING SEA. THIS CREATES
FAIRLY HIGH CONFIDENCE THAT SOUTHCENTRAL WILL REMAIN DRY BENEATH
THE RIDGE THROUGH THE END OF THE WEEK. THE RIDGE WILL REMAIN IN
PLACE INTO FRIDAY WHEN THE BERING CUT-OFF LOW CUTS THROUGH THE
RIDGE...CHANGING THE DRIER AND COOLER HIGH AMPLITUDE PATTERN INTO
ONE WITH SHORTWAVES TRACKING THROUGH THE FORECAST AREA. AS A
RESULT...AREAS AROUND THE SOUTHWEST MAINLAND AND NORTHERN GULF
COAST MAY EXPERIENCE SOME SHOWERY CONDITIONS BEGINNING FRIDAY AND
PERSISTING THROUGH THE WEEKEND. AS IS TYPICAL WITH WAVES MOVING
THROUGH RELATIVELY ZONAL FLOW...THERE IS LESS CONFIDENCE IN THE
TIMING AND STRENGTH OF THESE WAVES AS THEY TRAVERSE THE AREA.

THE FORECAST FOR THE BERING IS OF LOWER CONFIDENCE DUE TO
CONTINUED TIMING UNCERTAINTY. HOWEVER...MODELS HAVE COME SLIGHTLY
CLOSER TO A SOLUTION REGARDING THE COMPLEX LOW AND MULTIPLE
VORTICIES THAT TRACK THROUGH THE CENTRAL/EASTERN ALEUTIANS AND
BERING BEFORE CONSOLIDATING OVER THE BERING SEA THURSDAY. MODELS
HAVE STARTED TO COME CLOSER TO THE EXPECTED MIDDLE GROUND SOLUTION
BETWEEN THE GFS AND ECMWF FROM PREVIOUS RUNS. THIS SOLUTION WILL
TRACK THE LOW IN THE NORTHERN PACIFIC THROUGH INTO THE CENTRAL
BERING BY THURSDAY...KEEPING PRECIPITATION AND GUSTY WINDS AROUND
THE AREA THROUGH THE END OF THE WEEK. A NEW LOW OFF THE COAST OF
JAPAN WILL APPROACH THE WESTERN/CENTRAL ALEUTIANS
SATURDAY...BRINGING ANOTHER WAVE OF RAIN AND GUSTY WINDS TO THE
CHAIN THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 170 172 173 174 175 176 178 185.
FIRE WEATHER...NONE.

&&

$$

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




000
FXAK68 PAFC 241337
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
437 AM AKST MON NOV 24 2014

.ANALYSIS AND UPPER LEVELS...
A 997 MB LOW CURRENTLY 110 MILES SOUTHWEST OF SITKINAK ISLAND IS
SLOWLY MOVING IN THE GENERAL DIRECTION OF THE GULF OF
ALASKA...WEAKENING RAPIDLY AS STRONG HIGH PRESSURE RIDGING
CONTINUES TO MOVE RAPIDLY NORTH AND EAST TOWARD THE MAINLAND FROM
THE CENTRAL BERING SEA. THIS RIDGING IS GETTING AMPLIFIED IN PART
DUE TO A SEASONABLY STRONG AND QUASI-STATIONARY LOW PRESSURE
SYSTEM SITTING APPROXIMATELY HALFWAY BETWEEN ATTU AND THE
KAMCHATKA PENINSULA OF RUSSIA. NUMEROUS VIGOROUS DISTURBANCES ARE
ROTATING AROUND THE BROAD CYCLONIC CIRCULATION WITH A VERY ACTIVE
UPPER LEVEL JET STREAM.

&&

.MODEL DISCUSSION ...
MODELS ARE HANDLING THE LARGE-SCALE SYNOPTIC ENVIRONMENT WELL IN
DEVELOPING SIGNIFICANT UPPER LEVEL RIDGING OVER THE MAINLAND OF
ALASKA TUESDAY THROUGH THURSDAY. MOST OF THE SIGNIFICANT
DISCREPANCIES IN THE NEXT 2 TO 3 DAYS LIES WITH THE ACTIVE JET
STREAK PATTERN THAT WILL CONTINUE TO EVOLVE TO THE SOUTH OF THE
BROAD LOW OVER THE FAR WESTERN BERING AS IT CONTINUES TO SIT AND
SPIN THROUGH THE EARLY TO MID-WEEK PERIOD. MODELS DEPICT A PAIR OF
LOWS MOVING NORTH AND EAST ACROSS THE ALEUTIANS AND INTO THE
BERING SEA TUESDAY INTO THURSDAY BEFORE MERGING INTO THE PARENT
LOW CENTER. THE EUROPEAN MODEL WAS PREFERRED SLIGHTLY OVER THE GFS
AND CANADIAN MODELS FOR THIS FORECAST PACKAGE.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 2)...
THE STAGNANT PATTERN OF THE PAST FEW DAYS WILL BEGIN TO CHANGE
TODAY AS AMPLIFYING UPSTREAM FLOW OVER THE NORTH CENTRAL PACIFIC
AND BERING SEA HELPS KICK THE LOW ALONG THE ALASKA PENINSULA
EASTWARD ACROSS THE GULF. AS A RESULT THE MEAN FLOW IN THE LOW
TO MID LEVELS OVER SOUTHCENTRAL ALASKA WILL GRADUALLY VEER FROM
SOUTH-SOUTHEAST TO SOUTHWEST OVER THE NEXT 12 HOURS. THIS CHANGE
IN FLOW WILL START TO BREAK UP THE PERSISTENT SHOWER ACTIVITY IN
THE PRINCE WILLIAM SOUND REGION.

MEANWHILE THE DEVELOPMENT OF UPSLOPE FLOW ON THE WEST SIDE OF THE
CHUGACH AND TALKEETNA MOUNTAINS COMBINED WITH WEAK VERTICAL MOTION
FROM UPPER LEVEL DISTURBANCES EMBEDDED IN THE FLOW WILL DEEPEN
MOISTURE FROM ANCHORAGE UP TO THE MATANUSKA VALLEY AND EASTERN
SUSITNA VALLEY...PLACES WHICH HAVE REMAINED QUITE DRY UNDER THE
CURRENT FLOW. ASIDE FROM AN INCREASE IN CLOUDS IN THESE
LOCATIONS...THIS WILL SET THE STAGE FOR A POSSIBLE LIGHT SNOW
EVENT TUESDAY/TUESDAY NIGHT AS AN UPPER TROUGH MOVES THROUGH. THE
TROUGH WILL BE WEAKENING DUE TO INCREASED ANTICYCLONIC FLOW WITH
A BUILDING UPSTREAM RIDGE. THERE IS A MODEL CONSENSUS THAT THE
BEST VERTICAL MOTION WILL BE OVER THE NORTHERN TIER OF THE SUSITNA
VALLEY. SINCE NUMERICAL GUIDANCE HAS JUST RECENTLY LOCKED IN TO
THIS FEATURE AND IT IS ON THE WEAK SIDE WILL GENERALLY STICK WITH
CHANCE POPS FOR NOW.

A STRONG RIDGE WILL BUILD IN FROM THE WEST TUESDAY NIGHT BRINGING
IDEAL CONDITIONS FOR RADIATIONAL COOLING...SO HAVE TRENDED
DOWNWARD WITH NIGHT-TIME TEMPERATURES. STABLE CONDITIONS AND
LIGHT WINDS AT THE SURFACE ALSO FAVORS FORMATION OF FOG IN COOK
INLET. THIS ALWAYS MAKES FOR CHALLENGING SKY AND TEMPERATURE
FORECASTS. FARTHER EAST WEAK COLD ADVECTION IN THE WAKE OF THE
UPPER TROUGH COMBINED WITH TIGHTENING PRESSURE GRADIENTS AS A
SURFACE HIGH BUILDS OVER THE INTERIOR WILL LEAD TO WEAK OUTFLOW
WINDS (FOR THIS TIME OF YEAR) ALONG THE NORTH GULF COAST/PRINCE
WILLIAM SOUND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH TUESDAY
NIGHT)...
A FEW SNOW SHOWERS WILL CONTINUE TO DEVELOP ACROSS SOUTHWEST
ALASKA ALONG THE BACKSIDE OF LOW PRESSURE SYSTEM AS IT MOVES EAST.
OTHERWISE DRY COOL CONDITIONS PERSIST THROUGH TUESDAY NIGHT. A
WARM FRONT APPROACHES THE WEST COAST ALONG THE KUSKOKWIM DELTA
TUESDAY NIGHT BRINGING A CHANCE FOR SNOW.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH TUESDAY
NIGHT)...
A FRONT HAS PUSHED INTO THE WESTERN ALEUTIANS BRINGING GUSTY GALE
WINDS AND RAIN. THE FRONTAL BOUNDARY PUSHES SLOWLY INTO THE
CENTRAL ALEUTIANS AND NORTHERN BERING TONIGHT. COLD AIR ADVECTION
BEHIND THE FRONT WILL BRING MIXED SHOWERY PRECIPITATION BACK INTO
THE WESTERN ALEUTIANS TONIGHT. GUSTY WINDS WILL BRIEFLY DIMINISH
BEHIND THE FRONT AS THE PARENT LOW STEERS THE NEXT TWO LOW CENTERS
TOWARD THE WESTERN AND EASTERN ALEUTIANS TUESDAY NIGHT.



&&

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

MODELS ARE IN GOOD AGREEMENT THAT A HIGH AMPLITUDE BLOCKING UPPER
RIDGE WILL DEVELOP BY WED OVER MAINLAND AK AND THE GULF...WITH A
CUT-OFF LOW EMBEDDED IN A TROUGH OVER THE BERING. THE RIDGE WILL
REMAIN IN PLACE INTO FRI WHEN A MAJOR PATTERN CHANGE OCCURS. THE
BERING CUT-OFF LOW CUTS THROUGH THE RIDGE...TRANSFORMING THE HIGH
AMPLITUDE PATTERN INTO ONE WITH SHORTER WAVES MOVING PROGRESSIVELY
ACROSS THE FORECAST AREA. AS IS TYPICAL WITH WAVES MOVING THROUGH
RELATIVELY ZONAL FLOW...TIMING IS THE MAIN ISSUE SAT THROUGH MON.

THERE IS FAIRLY HIGH CONFIDENCE THAT SOUTHCENTRAL WILL REMAIN DRY
BENEATH THE RIDGE INTO THE WEEKEND...ALTHOUGH RAIN AND SNOW MAY
AFFECT THE COAST BY SUN. THE FORECAST FOR THE BERING IS OF LOWER
CONFIDENCE DUE TO TIMING UNCERTAINTY. IT UTILIZES A BLEND OF THE
GFS...EC..AND WPC GUIDANCE...AND HAS THE SURFACE REFLECTION OF THE
UPPER BERING LOW SLOWLY WEAKENING AS IT MOVES THROUGH THE BERING
WED THROUGH FRI. THIS LOW WILL BRING RAIN WITH GALES AND THEN
SMALL CRAFT WINDS TO THE BERING AND ALEUTIANS BEFORE IT CROSSES
THE EASTERN ALEUTIANS AND DISSIPATES IN THE NORTH PACIFIC ON SAT.
A NEW LOW FROM JAPAN WILL APPROACH THE WESTERN ALEUTIANS SAT AND
SUN AND WILL BRING MORE RAIN AND WIND TO THE CHAIN FOR THE
WEEKEND.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 173 174 175 176 177 178 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...DS




000
FXAK68 PAFC 240723 AAA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
1021 PM AKST SUN NOV 23 2014

UPDATED SOUTHCENTRAL SHORT TERM DISCUSSION

ANALYSIS AND UPPER LEVELS...
A 980S MB LOW SE OF SAND POINT IS STACKED UNDER THE UPPER CENTER
AND IS SLOWLY DRIFTING EAST AND WEAKENING. WAVES EMBEDDED IN THE
BROAD UPPER LEVEL CYCLONIC FLOW PRODUCED RAIN SHOWERS ACROSS THE
GULF AND AK PEN WITH MIXED SHOWERS TO SNOW SHOWERS OVER BRISTOL
BAY AND THE REMAINDER OF SOUTHCENTRAL. AN ELEVATED WARM LAYER AND BELOW
FREEZING SURFACE TEMPS PRODUCED ISOLATED POCKETS OF LIGHT FREEZING
RAIN OVER THE EASTERN BRISTOL BAY ZONE THIS MORNING. THE KING
SALMON NEXRAD SHOWED ANOTHER BATCH OF MOISTURE MOVING NORTH THIS
AFTERNOON...SO THE THREAT OF FREEZING RAIN MAY CONTINUE UNTIL
SURFACE TEMPS RISE ABOVE FREEZING THIS AFTERNOON. GUSTY NORTHWEST
WINDS ON THE BACKSIDE OF LOW SOUTH OF THE AK PEN CONTINUE ALONG
THE WESTERN AK PEN AND EAST ALEUTIANS. GUSTY EAST WINDS CONTINUE
ACROSS THE NORTH GULF WITH NE WINDS OVER THE WESTERN GULF AND
NORTHERLY GAP FLOWS ACROSS THE MATANUSKA VALLEY.

MODEL DISCUSSION ...
THOUGH THERE ARE SOME MODEL DIFFERENCES THROUGH THE SHORT TERM
(TUE AFTERNOON) THE IMPACTS ARE FAIRLY SIMILAR. THE TIMING OF THE
FRONT ACROSS THE BERING SEA WITH ACCOMPANYING GALES AND RAIN ARE
SIMILAR AS WELL AS SHOWERS WITH WAVES MOVING NORTH ACROSS THE GULF
AND SOUTHCENTRAL. SIGNIFICANT DIFFERENCES DEVELOP OUT WEST WITH
THE TIMING OF THE NEXT WAVE WHICH APPROACHES THE EASTERN ALEUTIANS
TUE NIGHT. THE LAST 2 RUNS OF THE EC HAVE COME IN SIGNIFICANTLY
FURTHER SOUTH WITH THIS FEATURE...AND NOW KEEP IT ENTIRELY OUT OF
THE AOR. THE GFS/NAM/GEM ON THE OTHER HAND ARE IN GOOD AGREEMENT
WITH A GALE FORCE LOW APPROACHING THE EASTERN ALEUTIANS BY LATE
TUESDAY NIGHT. THIS FURTHER NORTH SOLUTION WAS PREFERRED FOR THE
AFTERNOON PACKAGE AS IT WAS CLOSER TO THE CURRENT FORECAST. LATER
RUNS WILL HOWEVER NEED TO BE MONITORED...AS AGREEMENT IN
SOUTHERLY SOLUTION WOULD RESULT IN A SIGNIFICANT CHANGE TO THE
FORECAST.

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A WEAK FRONT ALONG THE NORTH GULF COAST WILL KEEP SHOWER ACTIVITY
MOST ACTIVE ACROSS COASTAL LOCATIONS TONIGHT...WITH MUCH MORE
SPORADIC AND LIGHT SHOWER ACTIVITY INLAND. RAIN AND SNOW SHOWERS
WILL BE MOST ACTIVE FROM EASTERN PRINCE WILLIAM SOUND
EASTWARD...WITH ACCUMULATING SNOW ACROSS PORTIONS OF THOMPSON PASS
INTO THE SOUTHERN COPPER RIVER BASIN. EVENTUALLY THE LOW WILL
TRACK EAST TOMORROW...WITH SHOWERS GRADUALLY DIMINISHING THROUGH
TUESDAY NIGHT. MINOR ACCUMULATIONS WILL BE POSSIBLE ACROSS FAVORED
UPSLOPE REGIONS IN THE TALKEETNA MOUNTAINS AND NORTH OF TALKEETNA
THROUGH BROAD PASS INTO MONDAY NIGHT. HIGH PRESSURE BUILDS IN
WEDNESDAY AND THURSDAY...BRINGING DRY WEATHER TO ALL OF
SOUTHCENTRAL.

SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH WEDNESDAY)...
A WEAK SHORTWAVE ALOFT WILL BRING RAIN FROM THE ALASKA
PENINSULA...BECOMING SNOW MIXED WITH RAIN AS IT STRETCHES INTO
WESTERN BRISTOL BAY. THIS WILL BRING ACCUMULATING SNOW TO WESTERN
BRISTOL BAY THIS EVENING...ESPECIALLY IN THE DILLINGHAM
AREA...WHERE COLD AIR ALOFT STILL EXISTS. THERE IS A SLIGHT CHANCE
THAT ENOUGH WARM AIR ALOFT WILL REACH WESTERN BRISTOL BAY LATE
TONIGHT TO CREATE AREAS OF FREEZING RAIN...HOWEVER THIS SHOULD NOT
BE VERY WIDESPREAD. AREAS FURTHER EAST WILL REMAIN AS RAIN WITH
EASTERLY FLOW ALOFT.

THE ENTIRE AREA WILL THEN BEGIN TO CLEAR OUT ON MONDAY
MORNING AS THE STATIONARY UPPER TROUGH DISSIPATES AND WEAK
RIDGING CURRENTLY OVER THE BERING MOVES IN. THIS WILL KEEP SKIES
GENERALLY WITH PRECIPITATION LIMITED TO A FEW PASSING SHOWERS. A
WEAK FRONT WILL THEN APPROACH THE KUSKOKWIM DELTA ON
TUESDAY...BRINGING A CHANCE OF RAIN TO THE AREAS. RIDGING WILL
HOWEVER REMAIN OVER THE KUSKOKWIM VALLEY AND BRISTOL BAY...KEEPING
THE AREA DRY WITH LIGHT WINDS INTO MID WEEK.

SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH WEDNESDAY)...

AFTER A WEAKENING AREA OF RAIN AND SNOW SHOWERS FROM THE PRIBILOF
ISLANDS INTO THE AKPENN DISSIPATES LATE TONIGHT...THE WEATHER WILL
QUICKLY BECOME DOMINATED BY A FRONTAL SYSTEM CURRENTLY ENTERING
THE WESTERN ALEUTIANS. THIS SYSTEM WILL BECOME A LOW COMPLEX WITH
MULTIPLE CENTERS OVER THE WESTERN BERING BY MONDAY AFTERNOON. WITH
CONSIDERABLE MODEL DISAGREEMENT WITH BOTH THE LOCATION AND
INTENSITY OF THESE LOWS...FORECAST CONFIDENCE QUICKLY DIMINISHES
WITH A DEVELOPING LOW APPROACHING THE EASTERN ALEUTIANS TUESDAY.
IT DOES APPEAR THAT THIS SETUP WILL KEEP WET WEATHER OVER THE
BERING WITH A POTENTIAL FOR GALE FORCE WINDS IN THE EASTERN
ALEUTIANS BY WEDNESDAY.

LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE OUTCOME OF THE LONG TERM FORECAST REMAINS HIGHLY DEPENDENT
THE TRACK AND STRENGTH OF THE COMPLEX LOW AS IT BEGINS TO
CONSOLIDATE OVER THE BERING SEA WEDNESDAY. GLOBAL MODELS CONTINUE
TO STRUGGLE WITH THE DETAILS OF THIS SYSTEM...KEEPING FORECAST
CONFIDENCE LOW IN THE TIMING AND STRENGTH OF THE ASSOCIATED
FRONTAL SYSTEM AS IT PROGRESSES EASTWARD. THE MORE NORTHERLY GFS
SOLUTION IS SLOWER TO CONSOLIDATE THE LOW OVER THE NORTHERN
BERING...BUT QUICKEST WITH BRINGING FRONTAL WINDS AND
PRECIPITATION TO THE CENTRAL ALEUTIANS WEDNESDAY MORNING AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY MORNING. THE MORE
SOUTHERLY ECMWF SOLUTION CONSOLIDATES THE LOW QUICKER OVER THE
SOUTHERN BERING...BUT IS SLOWER TO BRING THE FRONTAL WINDS AND
PRECIPITATION INTO THE CENTRAL ALEUTIANS WEDNESDAY AFTERNOON AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY AFTERNOON.

GLOBAL GUIDANCE HAS BEEN SIGNALING THAT THIS ACTIVITY OUT WEST
WILL AMPLIFY A RIDGE OF HIGH PRESSURE IN THE GULF WHICH WILL ACT
TO SLOW THE PROGRESSION OF THIS PATTERN...AND WILL KEEP
SOUTHCENTRAL ALASKA DRY THROUGH THE END OF THE WEEK. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.
CONFIDENCE BEGINS TO DIMINISH INTO THE WEEKEND...WHERE THE
LONGEVITY OF THIS PATTERN BECOMES HIGHLY DEPENDENT ON WHICH MODEL
SOLUTION VERIFIES. A MORE SOUTHERLY SOLUTION (ECMWF) REGARDING
THE LOW OUT WEST WOULD FAVOR DRIER CONDITIONS PERSISTING THROUGH
MUCH OF THE WEEKEND....WHEREAS THE MORE NORTHERLY SOLUTION (GFS)
DEAMPLIFIES THE RIDGE QUICKER AND BRINGS A WEAK SHORTWAVE THROUGH
SOUTHCENTRAL ON SUNDAY.

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


&&

$$




000
FXAK68 PAFC 240723 AAA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
1021 PM AKST SUN NOV 23 2014

UPDATED SOUTHCENTRAL SHORT TERM DISCUSSION

ANALYSIS AND UPPER LEVELS...
A 980S MB LOW SE OF SAND POINT IS STACKED UNDER THE UPPER CENTER
AND IS SLOWLY DRIFTING EAST AND WEAKENING. WAVES EMBEDDED IN THE
BROAD UPPER LEVEL CYCLONIC FLOW PRODUCED RAIN SHOWERS ACROSS THE
GULF AND AK PEN WITH MIXED SHOWERS TO SNOW SHOWERS OVER BRISTOL
BAY AND THE REMAINDER OF SOUTHCENTRAL. AN ELEVATED WARM LAYER AND BELOW
FREEZING SURFACE TEMPS PRODUCED ISOLATED POCKETS OF LIGHT FREEZING
RAIN OVER THE EASTERN BRISTOL BAY ZONE THIS MORNING. THE KING
SALMON NEXRAD SHOWED ANOTHER BATCH OF MOISTURE MOVING NORTH THIS
AFTERNOON...SO THE THREAT OF FREEZING RAIN MAY CONTINUE UNTIL
SURFACE TEMPS RISE ABOVE FREEZING THIS AFTERNOON. GUSTY NORTHWEST
WINDS ON THE BACKSIDE OF LOW SOUTH OF THE AK PEN CONTINUE ALONG
THE WESTERN AK PEN AND EAST ALEUTIANS. GUSTY EAST WINDS CONTINUE
ACROSS THE NORTH GULF WITH NE WINDS OVER THE WESTERN GULF AND
NORTHERLY GAP FLOWS ACROSS THE MATANUSKA VALLEY.

MODEL DISCUSSION ...
THOUGH THERE ARE SOME MODEL DIFFERENCES THROUGH THE SHORT TERM
(TUE AFTERNOON) THE IMPACTS ARE FAIRLY SIMILAR. THE TIMING OF THE
FRONT ACROSS THE BERING SEA WITH ACCOMPANYING GALES AND RAIN ARE
SIMILAR AS WELL AS SHOWERS WITH WAVES MOVING NORTH ACROSS THE GULF
AND SOUTHCENTRAL. SIGNIFICANT DIFFERENCES DEVELOP OUT WEST WITH
THE TIMING OF THE NEXT WAVE WHICH APPROACHES THE EASTERN ALEUTIANS
TUE NIGHT. THE LAST 2 RUNS OF THE EC HAVE COME IN SIGNIFICANTLY
FURTHER SOUTH WITH THIS FEATURE...AND NOW KEEP IT ENTIRELY OUT OF
THE AOR. THE GFS/NAM/GEM ON THE OTHER HAND ARE IN GOOD AGREEMENT
WITH A GALE FORCE LOW APPROACHING THE EASTERN ALEUTIANS BY LATE
TUESDAY NIGHT. THIS FURTHER NORTH SOLUTION WAS PREFERRED FOR THE
AFTERNOON PACKAGE AS IT WAS CLOSER TO THE CURRENT FORECAST. LATER
RUNS WILL HOWEVER NEED TO BE MONITORED...AS AGREEMENT IN
SOUTHERLY SOLUTION WOULD RESULT IN A SIGNIFICANT CHANGE TO THE
FORECAST.

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A WEAK FRONT ALONG THE NORTH GULF COAST WILL KEEP SHOWER ACTIVITY
MOST ACTIVE ACROSS COASTAL LOCATIONS TONIGHT...WITH MUCH MORE
SPORADIC AND LIGHT SHOWER ACTIVITY INLAND. RAIN AND SNOW SHOWERS
WILL BE MOST ACTIVE FROM EASTERN PRINCE WILLIAM SOUND
EASTWARD...WITH ACCUMULATING SNOW ACROSS PORTIONS OF THOMPSON PASS
INTO THE SOUTHERN COPPER RIVER BASIN. EVENTUALLY THE LOW WILL
TRACK EAST TOMORROW...WITH SHOWERS GRADUALLY DIMINISHING THROUGH
TUESDAY NIGHT. MINOR ACCUMULATIONS WILL BE POSSIBLE ACROSS FAVORED
UPSLOPE REGIONS IN THE TALKEETNA MOUNTAINS AND NORTH OF TALKEETNA
THROUGH BROAD PASS INTO MONDAY NIGHT. HIGH PRESSURE BUILDS IN
WEDNESDAY AND THURSDAY...BRINGING DRY WEATHER TO ALL OF
SOUTHCENTRAL.

SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH WEDNESDAY)...
A WEAK SHORTWAVE ALOFT WILL BRING RAIN FROM THE ALASKA
PENINSULA...BECOMING SNOW MIXED WITH RAIN AS IT STRETCHES INTO
WESTERN BRISTOL BAY. THIS WILL BRING ACCUMULATING SNOW TO WESTERN
BRISTOL BAY THIS EVENING...ESPECIALLY IN THE DILLINGHAM
AREA...WHERE COLD AIR ALOFT STILL EXISTS. THERE IS A SLIGHT CHANCE
THAT ENOUGH WARM AIR ALOFT WILL REACH WESTERN BRISTOL BAY LATE
TONIGHT TO CREATE AREAS OF FREEZING RAIN...HOWEVER THIS SHOULD NOT
BE VERY WIDESPREAD. AREAS FURTHER EAST WILL REMAIN AS RAIN WITH
EASTERLY FLOW ALOFT.

THE ENTIRE AREA WILL THEN BEGIN TO CLEAR OUT ON MONDAY
MORNING AS THE STATIONARY UPPER TROUGH DISSIPATES AND WEAK
RIDGING CURRENTLY OVER THE BERING MOVES IN. THIS WILL KEEP SKIES
GENERALLY WITH PRECIPITATION LIMITED TO A FEW PASSING SHOWERS. A
WEAK FRONT WILL THEN APPROACH THE KUSKOKWIM DELTA ON
TUESDAY...BRINGING A CHANCE OF RAIN TO THE AREAS. RIDGING WILL
HOWEVER REMAIN OVER THE KUSKOKWIM VALLEY AND BRISTOL BAY...KEEPING
THE AREA DRY WITH LIGHT WINDS INTO MID WEEK.

SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH WEDNESDAY)...

AFTER A WEAKENING AREA OF RAIN AND SNOW SHOWERS FROM THE PRIBILOF
ISLANDS INTO THE AKPENN DISSIPATES LATE TONIGHT...THE WEATHER WILL
QUICKLY BECOME DOMINATED BY A FRONTAL SYSTEM CURRENTLY ENTERING
THE WESTERN ALEUTIANS. THIS SYSTEM WILL BECOME A LOW COMPLEX WITH
MULTIPLE CENTERS OVER THE WESTERN BERING BY MONDAY AFTERNOON. WITH
CONSIDERABLE MODEL DISAGREEMENT WITH BOTH THE LOCATION AND
INTENSITY OF THESE LOWS...FORECAST CONFIDENCE QUICKLY DIMINISHES
WITH A DEVELOPING LOW APPROACHING THE EASTERN ALEUTIANS TUESDAY.
IT DOES APPEAR THAT THIS SETUP WILL KEEP WET WEATHER OVER THE
BERING WITH A POTENTIAL FOR GALE FORCE WINDS IN THE EASTERN
ALEUTIANS BY WEDNESDAY.

LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE OUTCOME OF THE LONG TERM FORECAST REMAINS HIGHLY DEPENDENT
THE TRACK AND STRENGTH OF THE COMPLEX LOW AS IT BEGINS TO
CONSOLIDATE OVER THE BERING SEA WEDNESDAY. GLOBAL MODELS CONTINUE
TO STRUGGLE WITH THE DETAILS OF THIS SYSTEM...KEEPING FORECAST
CONFIDENCE LOW IN THE TIMING AND STRENGTH OF THE ASSOCIATED
FRONTAL SYSTEM AS IT PROGRESSES EASTWARD. THE MORE NORTHERLY GFS
SOLUTION IS SLOWER TO CONSOLIDATE THE LOW OVER THE NORTHERN
BERING...BUT QUICKEST WITH BRINGING FRONTAL WINDS AND
PRECIPITATION TO THE CENTRAL ALEUTIANS WEDNESDAY MORNING AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY MORNING. THE MORE
SOUTHERLY ECMWF SOLUTION CONSOLIDATES THE LOW QUICKER OVER THE
SOUTHERN BERING...BUT IS SLOWER TO BRING THE FRONTAL WINDS AND
PRECIPITATION INTO THE CENTRAL ALEUTIANS WEDNESDAY AFTERNOON AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY AFTERNOON.

GLOBAL GUIDANCE HAS BEEN SIGNALING THAT THIS ACTIVITY OUT WEST
WILL AMPLIFY A RIDGE OF HIGH PRESSURE IN THE GULF WHICH WILL ACT
TO SLOW THE PROGRESSION OF THIS PATTERN...AND WILL KEEP
SOUTHCENTRAL ALASKA DRY THROUGH THE END OF THE WEEK. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.
CONFIDENCE BEGINS TO DIMINISH INTO THE WEEKEND...WHERE THE
LONGEVITY OF THIS PATTERN BECOMES HIGHLY DEPENDENT ON WHICH MODEL
SOLUTION VERIFIES. A MORE SOUTHERLY SOLUTION (ECMWF) REGARDING
THE LOW OUT WEST WOULD FAVOR DRIER CONDITIONS PERSISTING THROUGH
MUCH OF THE WEEKEND....WHEREAS THE MORE NORTHERLY SOLUTION (GFS)
DEAMPLIFIES THE RIDGE QUICKER AND BRINGS A WEAK SHORTWAVE THROUGH
SOUTHCENTRAL ON SUNDAY.

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


&&

$$





000
FXAK68 PAFC 240721 AAA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
1021 PM AKST SUN NOV 23 2014

UPDATED SOUTHCENTRAL SHORT TERM DISCUSSION

ANALYSIS AND UPPER LEVELS...
A 980S MB LOW SE OF SAND POINT IS STACKED UNDER THE UPPER CENTER
AND IS SLOWLY DRIFTING EAST AND WEAKENING. WAVES EMBEDDED IN THE
BROAD UPPER LEVEL CYCLONIC FLOW PRODUCED RAIN SHOWERS ACROSS THE
GULF AND AK PEN WITH MIXED SHOWERS TO SNOW SHOWERS OVER BRISTOL
BAY AND THE REMAINDER OF SOUTHCENTRAL. AN ELEVATED WARM LAYER AND BELOW
FREEZING SURFACE TEMPS PRODUCED ISOLATED POCKETS OF LIGHT FREEZING
RAIN OVER THE EASTERN BRISTOL BAY ZONE THIS MORNING. THE KING
SALMON NEXRAD SHOWED ANOTHER BATCH OF MOISTURE MOVING NORTH THIS
AFTERNOON...SO THE THREAT OF FREEZING RAIN MAY CONTINUE UNTIL
SURFACE TEMPS RISE ABOVE FREEZING THIS AFTERNOON. GUSTY NORTHWEST
WINDS ON THE BACKSIDE OF LOW SOUTH OF THE AK PEN CONTINUE ALONG
THE WESTERN AK PEN AND EAST ALEUTIANS. GUSTY EAST WINDS CONTINUE
ACROSS THE NORTH GULF WITH NE WINDS OVER THE WESTERN GULF AND
NORTHERLY GAP FLOWS ACROSS THE MATANUSKA VALLEY.

MODEL DISCUSSION ...
THOUGH THERE ARE SOME MODEL DIFFERENCES THROUGH THE SHORT TERM
(TUE AFTERNOON) THE IMPACTS ARE FAIRLY SIMILAR. THE TIMING OF THE
FRONT ACROSS THE BERING SEA WITH ACCOMPANYING GALES AND RAIN ARE
SIMILAR AS WELL AS SHOWERS WITH WAVES MOVING NORTH ACROSS THE GULF
AND SOUTHCENTRAL. SIGNIFICANT DIFFERENCES DEVELOP OUT WEST WITH
THE TIMING OF THE NEXT WAVE WHICH APPROACHES THE EASTERN ALEUTIANS
TUE NIGHT. THE LAST 2 RUNS OF THE EC HAVE COME IN SIGNIFICANTLY
FURTHER SOUTH WITH THIS FEATURE...AND NOW KEEP IT ENTIRELY OUT OF
THE AOR. THE GFS/NAM/GEM ON THE OTHER HAND ARE IN GOOD AGREEMENT
WITH A GALE FORCE LOW APPROACHING THE EASTERN ALEUTIANS BY LATE
TUESDAY NIGHT. THIS FURTHER NORTH SOLUTION WAS PREFERRED FOR THE
AFTERNOON PACKAGE AS IT WAS CLOSER TO THE CURRENT FORECAST. LATER
RUNS WILL HOWEVER NEED TO BE MONITORED...AS AGREEMENT IN
SOUTHERLY SOLUTION WOULD RESULT IN A SIGNIFICANT CHANGE TO THE
FORECAST.

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A WEAK FRONT ALONG THE NORTH GULF COAST WILL KEEP SHOWER ACTIVITY
MOST ACTIVE ACROSS COASTAL LOCATIONS TONIGHT...WITH MUCH MORE
SPORADIC AND LIGHT SHOWER ACTIVITY INLAND. RAIN AND SNOW SHOWERS
WILL BE MOST ACTIVE FROM EASTERN PRINCE WILLIAM SOUND
EASTWARD...WITH ACCUMULATING SNOW ACROSS PORTIONS OF THOMPSON PASS
INTO THE SOUTHERN COPPER RIVER BASIN. EVENTUALLY THE LOW WILL
TRACK EAST TOMORROW...WITH SHOWERS GRADUALLY DIMINISHING THROUGH
TUESDAY NIGHT. MINOR ACCUMULATIONS WILL BE POSSIBLE ACROSS FAVORED
UPSLOPE REGIONS IN THE TALKEETNA MOUNTAINS AND NORTH OF TALKEETNA
THROUGH BROAD PASS INTO MONDAY NIGHT. HIGH PRESSURE BUILDS IN
WEDNESDAY AND THURSDAY...BRINGING DRY WEATHER TO ALL OF
SOUTHCENTRAL.

SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH WEDNESDAY)...
A WEAK SHORTWAVE ALOFT WILL BRING RAIN FROM THE ALASKA
PENINSULA...BECOMING SNOW MIXED WITH RAIN AS IT STRETCHES INTO
WESTERN BRISTOL BAY. THIS WILL BRING ACCUMULATING SNOW TO WESTERN
BRISTOL BAY THIS EVENING...ESPECIALLY IN THE DILLINGHAM
AREA...WHERE COLD AIR ALOFT STILL EXISTS. THERE IS A SLIGHT CHANCE
THAT ENOUGH WARM AIR ALOFT WILL REACH WESTERN BRISTOL BAY LATE
TONIGHT TO CREATE AREAS OF FREEZING RAIN...HOWEVER THIS SHOULD NOT
BE VERY WIDESPREAD. AREAS FURTHER EAST WILL REMAIN AS RAIN WITH
EASTERLY FLOW ALOFT.

THE ENTIRE AREA WILL THEN BEGIN TO CLEAR OUT ON MONDAY
MORNING AS THE STATIONARY UPPER TROUGH DISSIPATES AND WEAK
RIDGING CURRENTLY OVER THE BERING MOVES IN. THIS WILL KEEP SKIES
GENERALLY WITH PRECIPITATION LIMITED TO A FEW PASSING SHOWERS. A
WEAK FRONT WILL THEN APPROACH THE KUSKOKWIM DELTA ON
TUESDAY...BRINGING A CHANCE OF RAIN TO THE AREAS. RIDGING WILL
HOWEVER REMAIN OVER THE KUSKOKWIM VALLEY AND BRISTOL BAY...KEEPING
THE AREA DRY WITH LIGHT WINDS INTO MID WEEK.

SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH WEDNESDAY)...

AFTER A WEAKENING AREA OF RAIN AND SNOW SHOWERS FROM THE PRIBILOF
ISLANDS INTO THE AKPENN DISSIPATES LATE TONIGHT...THE WEATHER WILL
QUICKLY BECOME DOMINATED BY A FRONTAL SYSTEM CURRENTLY ENTERING
THE WESTERN ALEUTIANS. THIS SYSTEM WILL BECOME A LOW COMPLEX WITH
MULTIPLE CENTERS OVER THE WESTERN BERING BY MONDAY AFTERNOON. WITH
CONSIDERABLE MODEL DISAGREEMENT WITH BOTH THE LOCATION AND
INTENSITY OF THESE LOWS...FORECAST CONFIDENCE QUICKLY DIMINISHES
WITH A DEVELOPING LOW APPROACHING THE EASTERN ALEUTIANS TUESDAY.
IT DOES APPEAR THAT THIS SETUP WILL KEEP WET WEATHER OVER THE
BERING WITH A POTENTIAL FOR GALE FORCE WINDS IN THE EASTERN
ALEUTIANS BY WEDNESDAY.

LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE OUTCOME OF THE LONG TERM FORECAST REMAINS HIGHLY DEPENDENT
THE TRACK AND STRENGTH OF THE COMPLEX LOW AS IT BEGINS TO
CONSOLIDATE OVER THE BERING SEA WEDNESDAY. GLOBAL MODELS CONTINUE
TO STRUGGLE WITH THE DETAILS OF THIS SYSTEM...KEEPING FORECAST
CONFIDENCE LOW IN THE TIMING AND STRENGTH OF THE ASSOCIATED
FRONTAL SYSTEM AS IT PROGRESSES EASTWARD. THE MORE NORTHERLY GFS
SOLUTION IS SLOWER TO CONSOLIDATE THE LOW OVER THE NORTHERN
BERING...BUT QUICKEST WITH BRINGING FRONTAL WINDS AND
PRECIPITATION TO THE CENTRAL ALEUTIANS WEDNESDAY MORNING AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY MORNING. THE MORE
SOUTHERLY ECMWF SOLUTION CONSOLIDATES THE LOW QUICKER OVER THE
SOUTHERN BERING...BUT IS SLOWER TO BRING THE FRONTAL WINDS AND
PRECIPITATION INTO THE CENTRAL ALEUTIANS WEDNESDAY AFTERNOON AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY AFTERNOON.

GLOBAL GUIDANCE HAS BEEN SIGNALING THAT THIS ACTIVITY OUT WEST
WILL AMPLIFY A RIDGE OF HIGH PRESSURE IN THE GULF WHICH WILL ACT
TO SLOW THE PROGRESSION OF THIS PATTERN...AND WILL KEEP
SOUTHCENTRAL ALASKA DRY THROUGH THE END OF THE WEEK. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.
CONFIDENCE BEGINS TO DIMINISH INTO THE WEEKEND...WHERE THE
LONGEVITY OF THIS PATTERN BECOMES HIGHLY DEPENDENT ON WHICH MODEL
SOLUTION VERIFIES. A MORE SOUTHERLY SOLUTION (ECMWF) REGARDING
THE LOW OUT WEST WOULD FAVOR DRIER CONDITIONS PERSISTING THROUGH
MUCH OF THE WEEKEND....WHEREAS THE MORE NORTHERLY SOLUTION (GFS)
DEAMPLIFIES THE RIDGE QUICKER AND BRINGS A WEAK SHORTWAVE THROUGH
SOUTHCENTRAL ON SUNDAY.

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


&&

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

&&

$$

SYNOPSIS AND MODEL DISCUSSION...
SOUTHCENTRAL ALASKA...
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...
LONG TERM...




000
FXAK68 PAFC 240721 AAA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
1021 PM AKST SUN NOV 23 2014

UPDATED SOUTHCENTRAL SHORT TERM DISCUSSION

ANALYSIS AND UPPER LEVELS...
A 980S MB LOW SE OF SAND POINT IS STACKED UNDER THE UPPER CENTER
AND IS SLOWLY DRIFTING EAST AND WEAKENING. WAVES EMBEDDED IN THE
BROAD UPPER LEVEL CYCLONIC FLOW PRODUCED RAIN SHOWERS ACROSS THE
GULF AND AK PEN WITH MIXED SHOWERS TO SNOW SHOWERS OVER BRISTOL
BAY AND THE REMAINDER OF SOUTHCENTRAL. AN ELEVATED WARM LAYER AND BELOW
FREEZING SURFACE TEMPS PRODUCED ISOLATED POCKETS OF LIGHT FREEZING
RAIN OVER THE EASTERN BRISTOL BAY ZONE THIS MORNING. THE KING
SALMON NEXRAD SHOWED ANOTHER BATCH OF MOISTURE MOVING NORTH THIS
AFTERNOON...SO THE THREAT OF FREEZING RAIN MAY CONTINUE UNTIL
SURFACE TEMPS RISE ABOVE FREEZING THIS AFTERNOON. GUSTY NORTHWEST
WINDS ON THE BACKSIDE OF LOW SOUTH OF THE AK PEN CONTINUE ALONG
THE WESTERN AK PEN AND EAST ALEUTIANS. GUSTY EAST WINDS CONTINUE
ACROSS THE NORTH GULF WITH NE WINDS OVER THE WESTERN GULF AND
NORTHERLY GAP FLOWS ACROSS THE MATANUSKA VALLEY.

MODEL DISCUSSION ...
THOUGH THERE ARE SOME MODEL DIFFERENCES THROUGH THE SHORT TERM
(TUE AFTERNOON) THE IMPACTS ARE FAIRLY SIMILAR. THE TIMING OF THE
FRONT ACROSS THE BERING SEA WITH ACCOMPANYING GALES AND RAIN ARE
SIMILAR AS WELL AS SHOWERS WITH WAVES MOVING NORTH ACROSS THE GULF
AND SOUTHCENTRAL. SIGNIFICANT DIFFERENCES DEVELOP OUT WEST WITH
THE TIMING OF THE NEXT WAVE WHICH APPROACHES THE EASTERN ALEUTIANS
TUE NIGHT. THE LAST 2 RUNS OF THE EC HAVE COME IN SIGNIFICANTLY
FURTHER SOUTH WITH THIS FEATURE...AND NOW KEEP IT ENTIRELY OUT OF
THE AOR. THE GFS/NAM/GEM ON THE OTHER HAND ARE IN GOOD AGREEMENT
WITH A GALE FORCE LOW APPROACHING THE EASTERN ALEUTIANS BY LATE
TUESDAY NIGHT. THIS FURTHER NORTH SOLUTION WAS PREFERRED FOR THE
AFTERNOON PACKAGE AS IT WAS CLOSER TO THE CURRENT FORECAST. LATER
RUNS WILL HOWEVER NEED TO BE MONITORED...AS AGREEMENT IN
SOUTHERLY SOLUTION WOULD RESULT IN A SIGNIFICANT CHANGE TO THE
FORECAST.

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A WEAK FRONT ALONG THE NORTH GULF COAST WILL KEEP SHOWER ACTIVITY
MOST ACTIVE ACROSS COASTAL LOCATIONS TONIGHT...WITH MUCH MORE
SPORADIC AND LIGHT SHOWER ACTIVITY INLAND. RAIN AND SNOW SHOWERS
WILL BE MOST ACTIVE FROM EASTERN PRINCE WILLIAM SOUND
EASTWARD...WITH ACCUMULATING SNOW ACROSS PORTIONS OF THOMPSON PASS
INTO THE SOUTHERN COPPER RIVER BASIN. EVENTUALLY THE LOW WILL
TRACK EAST TOMORROW...WITH SHOWERS GRADUALLY DIMINISHING THROUGH
TUESDAY NIGHT. MINOR ACCUMULATIONS WILL BE POSSIBLE ACROSS FAVORED
UPSLOPE REGIONS IN THE TALKEETNA MOUNTAINS AND NORTH OF TALKEETNA
THROUGH BROAD PASS INTO MONDAY NIGHT. HIGH PRESSURE BUILDS IN
WEDNESDAY AND THURSDAY...BRINGING DRY WEATHER TO ALL OF
SOUTHCENTRAL.

SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH WEDNESDAY)...
A WEAK SHORTWAVE ALOFT WILL BRING RAIN FROM THE ALASKA
PENINSULA...BECOMING SNOW MIXED WITH RAIN AS IT STRETCHES INTO
WESTERN BRISTOL BAY. THIS WILL BRING ACCUMULATING SNOW TO WESTERN
BRISTOL BAY THIS EVENING...ESPECIALLY IN THE DILLINGHAM
AREA...WHERE COLD AIR ALOFT STILL EXISTS. THERE IS A SLIGHT CHANCE
THAT ENOUGH WARM AIR ALOFT WILL REACH WESTERN BRISTOL BAY LATE
TONIGHT TO CREATE AREAS OF FREEZING RAIN...HOWEVER THIS SHOULD NOT
BE VERY WIDESPREAD. AREAS FURTHER EAST WILL REMAIN AS RAIN WITH
EASTERLY FLOW ALOFT.

THE ENTIRE AREA WILL THEN BEGIN TO CLEAR OUT ON MONDAY
MORNING AS THE STATIONARY UPPER TROUGH DISSIPATES AND WEAK
RIDGING CURRENTLY OVER THE BERING MOVES IN. THIS WILL KEEP SKIES
GENERALLY WITH PRECIPITATION LIMITED TO A FEW PASSING SHOWERS. A
WEAK FRONT WILL THEN APPROACH THE KUSKOKWIM DELTA ON
TUESDAY...BRINGING A CHANCE OF RAIN TO THE AREAS. RIDGING WILL
HOWEVER REMAIN OVER THE KUSKOKWIM VALLEY AND BRISTOL BAY...KEEPING
THE AREA DRY WITH LIGHT WINDS INTO MID WEEK.

SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH WEDNESDAY)...

AFTER A WEAKENING AREA OF RAIN AND SNOW SHOWERS FROM THE PRIBILOF
ISLANDS INTO THE AKPENN DISSIPATES LATE TONIGHT...THE WEATHER WILL
QUICKLY BECOME DOMINATED BY A FRONTAL SYSTEM CURRENTLY ENTERING
THE WESTERN ALEUTIANS. THIS SYSTEM WILL BECOME A LOW COMPLEX WITH
MULTIPLE CENTERS OVER THE WESTERN BERING BY MONDAY AFTERNOON. WITH
CONSIDERABLE MODEL DISAGREEMENT WITH BOTH THE LOCATION AND
INTENSITY OF THESE LOWS...FORECAST CONFIDENCE QUICKLY DIMINISHES
WITH A DEVELOPING LOW APPROACHING THE EASTERN ALEUTIANS TUESDAY.
IT DOES APPEAR THAT THIS SETUP WILL KEEP WET WEATHER OVER THE
BERING WITH A POTENTIAL FOR GALE FORCE WINDS IN THE EASTERN
ALEUTIANS BY WEDNESDAY.

LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE OUTCOME OF THE LONG TERM FORECAST REMAINS HIGHLY DEPENDENT
THE TRACK AND STRENGTH OF THE COMPLEX LOW AS IT BEGINS TO
CONSOLIDATE OVER THE BERING SEA WEDNESDAY. GLOBAL MODELS CONTINUE
TO STRUGGLE WITH THE DETAILS OF THIS SYSTEM...KEEPING FORECAST
CONFIDENCE LOW IN THE TIMING AND STRENGTH OF THE ASSOCIATED
FRONTAL SYSTEM AS IT PROGRESSES EASTWARD. THE MORE NORTHERLY GFS
SOLUTION IS SLOWER TO CONSOLIDATE THE LOW OVER THE NORTHERN
BERING...BUT QUICKEST WITH BRINGING FRONTAL WINDS AND
PRECIPITATION TO THE CENTRAL ALEUTIANS WEDNESDAY MORNING AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY MORNING. THE MORE
SOUTHERLY ECMWF SOLUTION CONSOLIDATES THE LOW QUICKER OVER THE
SOUTHERN BERING...BUT IS SLOWER TO BRING THE FRONTAL WINDS AND
PRECIPITATION INTO THE CENTRAL ALEUTIANS WEDNESDAY AFTERNOON AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY AFTERNOON.

GLOBAL GUIDANCE HAS BEEN SIGNALING THAT THIS ACTIVITY OUT WEST
WILL AMPLIFY A RIDGE OF HIGH PRESSURE IN THE GULF WHICH WILL ACT
TO SLOW THE PROGRESSION OF THIS PATTERN...AND WILL KEEP
SOUTHCENTRAL ALASKA DRY THROUGH THE END OF THE WEEK. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.
CONFIDENCE BEGINS TO DIMINISH INTO THE WEEKEND...WHERE THE
LONGEVITY OF THIS PATTERN BECOMES HIGHLY DEPENDENT ON WHICH MODEL
SOLUTION VERIFIES. A MORE SOUTHERLY SOLUTION (ECMWF) REGARDING
THE LOW OUT WEST WOULD FAVOR DRIER CONDITIONS PERSISTING THROUGH
MUCH OF THE WEEKEND....WHEREAS THE MORE NORTHERLY SOLUTION (GFS)
DEAMPLIFIES THE RIDGE QUICKER AND BRINGS A WEAK SHORTWAVE THROUGH
SOUTHCENTRAL ON SUNDAY.

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


&&

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

&&

$$

SYNOPSIS AND MODEL DISCUSSION...
SOUTHCENTRAL ALASKA...
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...
LONG TERM...





000
FXAK68 PAFC 240131
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
431 PM AKST SUN NOV 23 2014

.ANALYSIS AND UPPER LEVELS...
A 980S MB LOW SE OF SAND POINT IS STACKED UNDER THE UPPER CENTER
AND IS SLOWLY DRIFTING EAST AND WEAKENING. WAVES EMBEDDED IN THE
BROAD UPPER LEVEL CYCLONIC FLOW PRODUCED RAIN SHOWERS ACROSS THE
GULF AND AK PEN WITH MIXED SHOWERS TO SNOW SHOWERS OVER BRISTOL
BAY AND THE REMAINDER OF SOUTHCENTRAL. AN ELEVATED WARM LAYER AND BELOW
FREEZING SURFACE TEMPS PRODUCED ISOLATED POCKETS OF LIGHT FREEZING
RAIN OVER THE EASTERN BRISTOL BAY ZONE THIS MORNING. THE KING
SALMON NEXRAD SHOWED ANOTHER BATCH OF MOISTURE MOVING NORTH THIS
AFTERNOON...SO THE THREAT OF FREEZING RAIN MAY CONTINUE UNTIL
SURFACE TEMPS RISE ABOVE FREEZING THIS AFTERNOON. GUSTY NORTHWEST
WINDS ON THE BACKSIDE OF LOW SOUTH OF THE AK PEN CONTINUE ALONG
THE WESTERN AK PEN AND EAST ALEUTIANS. GUSTY EAST WINDS CONTINUE
ACROSS THE NORTH GULF WITH NE WINDS OVER THE WESTERN GULF AND
NORTHERLY GAP FLOWS ACROSS THE MATANUSKA VALLEY.

&&

.MODEL DISCUSSION ...
THOUGH THERE ARE SOME MODEL DIFFERENCES THROUGH THE SHORT TERM
(TUE AFTERNOON) THE IMPACTS ARE FAIRLY SIMILAR. THE TIMING OF THE
FRONT ACROSS THE BERING SEA WITH ACCOMPANYING GALES AND RAIN ARE
SIMILAR AS WELL AS SHOWERS WITH WAVES MOVING NORTH ACROSS THE GULF
AND SOUTHCENTRAL. SIGNIFICANT DIFFERENCES DEVELOP OUT WEST WITH
THE TIMING OF THE NEXT WAVE WHICH APPROACHES THE EASTERN ALEUTIANS
TUE NIGHT. THE LAST 2 RUNS OF THE EC HAVE COME IN SIGNIFICANTLY
FURTHER SOUTH WITH THIS FEATURE...AND NOW KEEP IT ENTIRELY OUT OF
THE AOR. THE GFS/NAM/GEM ON THE OTHER HAND ARE IN GOOD AGREEMENT
WITH A GALE FORCE LOW APPROACHING THE EASTERN ALEUTIANS BY LATE
TUESDAY NIGHT. THIS FURTHER NORTH SOLUTION WAS PREFERRED FOR THE
AFTERNOON PACKAGE AS IT WAS CLOSER TO THE CURRENT FORECAST. LATER
RUNS WILL HOWEVER NEED TO BE MONITORED...AS AGREEMENT IN
SOUTHERLY SOLUTION WOULD RESULT IN A SIGNIFICANT CHANGE TO THE
FORECAST.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES MOVING NORTHWARD ACROSS THE
GULF OF ALASKA TO SOUTHCENTRAL CONTINUE TO PROVIDE QUITE THE
CHALLENGE FOR THE PRECIPITATION FORECAST. FOR THE MOST PART SHOWERS
ASSOCIATED WITH THESE DISTURBANCES HAVE BEEN CONFINED TO THE GULF
COASTAL REGION WITH VERY FEW SHOWERS MAKING IT OVER THE COASTAL
MOUNTAINS. THIS IS DUE TO WEAK DOWNSLOPE FLOW AND LOW LEVEL DRY
AIR SUPPORTED BY OFFSHORE FLOW AT THE SURFACE. HOWEVER...THERE
HAVE BEEN A FEW STRONGER UPPER WAVES (ONE OF WHICH IS MOVING
THROUGH THIS MORNING) WHICH TEMPORARILY MODIFY THE LOW LEVEL FLOW
(TO WEAKEN DOWNSLOPING). PINPOINTING THE LOCATION AND AMOUNT OF
PRECIP IS VERY DIFFICULT...ESPECIALLY SINCE NONE OF THE MODELS
HAVE A GREAT HANDLE ON THE PLACEMENT AND TIMING OF INDIVIDUAL
FEATURES. SATELLITE AND RADAR TRENDS ARE THE MOST USEFUL TOOL IN
THIS SITUATION. BECAUSE OF THIS...FORECAST CONFIDENCE IN THE
PRECIP FORECAST BEYOND THE FIRST SIX HOURS IS LOW.

THE AIR MASS ACROSS THE REGION HAS CONTINUED A STEADY COOLING
TREND. THE IMMEDIATE COAST REMAINS ALL RAIN...BUT INTERIOR
PORTIONS OF WESTERN PRINCE WILLIAM SOUND HAVE SEEN SOME PERIODS OF
SNOW OR RAIN AND SNOW MIXED WITH VERY MINOR SNOW ACCUMULATIONS.
AS PER THE ANCHORAGE SOUNDING ANYTHING ON THE LEE SIDE OF THE
COASTAL RANGE WILL FALL AS SNOW.

UPPER LEVEL FLOW WILL SHIFT SUNDAY NIGHT INTO MONDAY AS THE LOW
ALONG THE ALASKA PENINSULA EXITS EASTWARD ACROSS THE GULF AND
UPPER FLOW OVER SOUTHCENTRAL BECOMES WESTERLY. PRECIP WILL THEN
BECOME FAVORED ALONG THE WEST SLOPES OF MOUNTAINS WHILE PRECIP IN
WESTERN PRINCE WILLIAM SOUND WILL DIMINISH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH WEDNESDAY)...
A WEAK SHORTWAVE ALOFT WILL BRING RAIN FROM THE ALASKA
PENINSULA...BECOMING SNOW MIXED WITH RAIN AS IT STRETCHES INTO
WESTERN BRISTOL BAY. THIS WILL BRING ACCUMULATING SNOW TO WESTERN
BRISTOL BAY THIS EVENING...ESPECIALLY IN THE DILLINGHAM
AREA...WHERE COLD AIR ALOFT STILL EXISTS. THERE IS A SLIGHT CHANCE
THAT ENOUGH WARM AIR ALOFT WILL REACH WESTERN BRISTOL BAY LATE
TONIGHT TO CREATE AREAS OF FREEZING RAIN...HOWEVER THIS SHOULD NOT
BE VERY WIDESPREAD. AREAS FURTHER EAST WILL REMAIN AS RAIN WITH
EASTERLY FLOW ALOFT.

THE ENTIRE AREA WILL THEN BEGIN TO CLEAR OUT ON MONDAY
MORNING AS THE STATIONARY UPPER TROUGH DISSIPATES AND WEAK
RIDGING CURRENTLY OVER THE BERING MOVES IN. THIS WILL KEEP SKIES
GENERALLY WITH PRECIPITATION LIMITED TO A FEW PASSING SHOWERS. A
WEAK FRONT WILL THEN APPROACH THE KUSKOKWIM DELTA ON
TUESDAY...BRINGING A CHANCE OF RAIN TO THE AREAS. RIDGING WILL
HOWEVER REMAIN OVER THE KUSKOKWIM VALLEY AND BRISTOL BAY...KEEPING
THE AREA DRY WITH LIGHT WINDS INTO MID WEEK.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH WEDNESDAY)...

AFTER A WEAKENING AREA OF RAIN AND SNOW SHOWERS FROM THE PRIBILOF
ISLANDS INTO THE AKPENN DISSIPATES LATE TONIGHT...THE WEATHER WILL
QUICKLY BECOME DOMINATED BY A FRONTAL SYSTEM CURRENTLY ENTERING
THE WESTERN ALEUTIANS. THIS SYSTEM WILL BECOME A LOW COMPLEX WITH
MULTIPLE CENTERS OVER THE WESTERN BERING BY MONDAY AFTERNOON. WITH
CONSIDERABLE MODEL DISAGREEMENT WITH BOTH THE LOCATION AND
INTENSITY OF THESE LOWS...FORECAST CONFIDENCE QUICKLY DIMINISHES
WITH A DEVELOPING LOW APPROACHING THE EASTERN ALEUTIANS TUESDAY.
IT DOES APPEAR THAT THIS SETUP WILL KEEP WET WEATHER OVER THE
BERING WITH A POTENTIAL FOR GALE FORCE WINDS IN THE EASTERN
ALEUTIANS BY WEDNESDAY.


&&

.LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE OUTCOME OF THE LONG TERM FORECAST REMAINS HIGHLY DEPENDENT
THE TRACK AND STRENGTH OF THE COMPLEX LOW AS IT BEGINS TO
CONSOLIDATE OVER THE BERING SEA WEDNESDAY. GLOBAL MODELS CONTINUE
TO STRUGGLE WITH THE DETAILS OF THIS SYSTEM...KEEPING FORECAST
CONFIDENCE LOW IN THE TIMING AND STRENGTH OF THE ASSOCIATED
FRONTAL SYSTEM AS IT PROGRESSES EASTWARD. THE MORE NORTHERLY GFS
SOLUTION IS SLOWER TO CONSOLIDATE THE LOW OVER THE NORTHERN
BERING...BUT QUICKEST WITH BRINGING FRONTAL WINDS AND
PRECIPITATION TO THE CENTRAL ALEUTIANS WEDNESDAY MORNING AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY MORNING. THE MORE
SOUTHERLY ECMWF SOLUTION CONSOLIDATES THE LOW QUICKER OVER THE
SOUTHERN BERING...BUT IS SLOWER TO BRING THE FRONTAL WINDS AND
PRECIPITATION INTO THE CENTRAL ALEUTIANS WEDNESDAY AFTERNOON AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY AFTERNOON.

GLOBAL GUIDANCE HAS BEEN SIGNALING THAT THIS ACTIVITY OUT WEST
WILL AMPLIFY A RIDGE OF HIGH PRESSURE IN THE GULF WHICH WILL ACT
TO SLOW THE PROGRESSION OF THIS PATTERN...AND WILL KEEP
SOUTHCENTRAL ALASKA DRY THROUGH THE END OF THE WEEK. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.
CONFIDENCE BEGINS TO DIMINISH INTO THE WEEKEND...WHERE THE
LONGEVITY OF THIS PATTERN BECOMES HIGHLY DEPENDENT ON WHICH MODEL
SOLUTION VERIFIES. A MORE SOUTHERLY SOLUTION (ECMWF) REGARDING
THE LOW OUT WEST WOULD FAVOR DRIER CONDITIONS PERSISTING THROUGH
MUCH OF THE WEEKEND....WHEREAS THE MORE NORTHERLY SOLUTION (GFS)
DEAMPLIFIES THE RIDGE QUICKER AND BRINGS A WEAK SHORTWAVE THROUGH
SOUTHCENTRAL ON SUNDAY.

&&

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

&&

$$





000
FXAK68 PAFC 240131
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
431 PM AKST SUN NOV 23 2014

.ANALYSIS AND UPPER LEVELS...
A 980S MB LOW SE OF SAND POINT IS STACKED UNDER THE UPPER CENTER
AND IS SLOWLY DRIFTING EAST AND WEAKENING. WAVES EMBEDDED IN THE
BROAD UPPER LEVEL CYCLONIC FLOW PRODUCED RAIN SHOWERS ACROSS THE
GULF AND AK PEN WITH MIXED SHOWERS TO SNOW SHOWERS OVER BRISTOL
BAY AND THE REMAINDER OF SOUTHCENTRAL. AN ELEVATED WARM LAYER AND BELOW
FREEZING SURFACE TEMPS PRODUCED ISOLATED POCKETS OF LIGHT FREEZING
RAIN OVER THE EASTERN BRISTOL BAY ZONE THIS MORNING. THE KING
SALMON NEXRAD SHOWED ANOTHER BATCH OF MOISTURE MOVING NORTH THIS
AFTERNOON...SO THE THREAT OF FREEZING RAIN MAY CONTINUE UNTIL
SURFACE TEMPS RISE ABOVE FREEZING THIS AFTERNOON. GUSTY NORTHWEST
WINDS ON THE BACKSIDE OF LOW SOUTH OF THE AK PEN CONTINUE ALONG
THE WESTERN AK PEN AND EAST ALEUTIANS. GUSTY EAST WINDS CONTINUE
ACROSS THE NORTH GULF WITH NE WINDS OVER THE WESTERN GULF AND
NORTHERLY GAP FLOWS ACROSS THE MATANUSKA VALLEY.

&&

.MODEL DISCUSSION ...
THOUGH THERE ARE SOME MODEL DIFFERENCES THROUGH THE SHORT TERM
(TUE AFTERNOON) THE IMPACTS ARE FAIRLY SIMILAR. THE TIMING OF THE
FRONT ACROSS THE BERING SEA WITH ACCOMPANYING GALES AND RAIN ARE
SIMILAR AS WELL AS SHOWERS WITH WAVES MOVING NORTH ACROSS THE GULF
AND SOUTHCENTRAL. SIGNIFICANT DIFFERENCES DEVELOP OUT WEST WITH
THE TIMING OF THE NEXT WAVE WHICH APPROACHES THE EASTERN ALEUTIANS
TUE NIGHT. THE LAST 2 RUNS OF THE EC HAVE COME IN SIGNIFICANTLY
FURTHER SOUTH WITH THIS FEATURE...AND NOW KEEP IT ENTIRELY OUT OF
THE AOR. THE GFS/NAM/GEM ON THE OTHER HAND ARE IN GOOD AGREEMENT
WITH A GALE FORCE LOW APPROACHING THE EASTERN ALEUTIANS BY LATE
TUESDAY NIGHT. THIS FURTHER NORTH SOLUTION WAS PREFERRED FOR THE
AFTERNOON PACKAGE AS IT WAS CLOSER TO THE CURRENT FORECAST. LATER
RUNS WILL HOWEVER NEED TO BE MONITORED...AS AGREEMENT IN
SOUTHERLY SOLUTION WOULD RESULT IN A SIGNIFICANT CHANGE TO THE
FORECAST.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES MOVING NORTHWARD ACROSS THE
GULF OF ALASKA TO SOUTHCENTRAL CONTINUE TO PROVIDE QUITE THE
CHALLENGE FOR THE PRECIPITATION FORECAST. FOR THE MOST PART SHOWERS
ASSOCIATED WITH THESE DISTURBANCES HAVE BEEN CONFINED TO THE GULF
COASTAL REGION WITH VERY FEW SHOWERS MAKING IT OVER THE COASTAL
MOUNTAINS. THIS IS DUE TO WEAK DOWNSLOPE FLOW AND LOW LEVEL DRY
AIR SUPPORTED BY OFFSHORE FLOW AT THE SURFACE. HOWEVER...THERE
HAVE BEEN A FEW STRONGER UPPER WAVES (ONE OF WHICH IS MOVING
THROUGH THIS MORNING) WHICH TEMPORARILY MODIFY THE LOW LEVEL FLOW
(TO WEAKEN DOWNSLOPING). PINPOINTING THE LOCATION AND AMOUNT OF
PRECIP IS VERY DIFFICULT...ESPECIALLY SINCE NONE OF THE MODELS
HAVE A GREAT HANDLE ON THE PLACEMENT AND TIMING OF INDIVIDUAL
FEATURES. SATELLITE AND RADAR TRENDS ARE THE MOST USEFUL TOOL IN
THIS SITUATION. BECAUSE OF THIS...FORECAST CONFIDENCE IN THE
PRECIP FORECAST BEYOND THE FIRST SIX HOURS IS LOW.

THE AIR MASS ACROSS THE REGION HAS CONTINUED A STEADY COOLING
TREND. THE IMMEDIATE COAST REMAINS ALL RAIN...BUT INTERIOR
PORTIONS OF WESTERN PRINCE WILLIAM SOUND HAVE SEEN SOME PERIODS OF
SNOW OR RAIN AND SNOW MIXED WITH VERY MINOR SNOW ACCUMULATIONS.
AS PER THE ANCHORAGE SOUNDING ANYTHING ON THE LEE SIDE OF THE
COASTAL RANGE WILL FALL AS SNOW.

UPPER LEVEL FLOW WILL SHIFT SUNDAY NIGHT INTO MONDAY AS THE LOW
ALONG THE ALASKA PENINSULA EXITS EASTWARD ACROSS THE GULF AND
UPPER FLOW OVER SOUTHCENTRAL BECOMES WESTERLY. PRECIP WILL THEN
BECOME FAVORED ALONG THE WEST SLOPES OF MOUNTAINS WHILE PRECIP IN
WESTERN PRINCE WILLIAM SOUND WILL DIMINISH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (TONIGHT THROUGH WEDNESDAY)...
A WEAK SHORTWAVE ALOFT WILL BRING RAIN FROM THE ALASKA
PENINSULA...BECOMING SNOW MIXED WITH RAIN AS IT STRETCHES INTO
WESTERN BRISTOL BAY. THIS WILL BRING ACCUMULATING SNOW TO WESTERN
BRISTOL BAY THIS EVENING...ESPECIALLY IN THE DILLINGHAM
AREA...WHERE COLD AIR ALOFT STILL EXISTS. THERE IS A SLIGHT CHANCE
THAT ENOUGH WARM AIR ALOFT WILL REACH WESTERN BRISTOL BAY LATE
TONIGHT TO CREATE AREAS OF FREEZING RAIN...HOWEVER THIS SHOULD NOT
BE VERY WIDESPREAD. AREAS FURTHER EAST WILL REMAIN AS RAIN WITH
EASTERLY FLOW ALOFT.

THE ENTIRE AREA WILL THEN BEGIN TO CLEAR OUT ON MONDAY
MORNING AS THE STATIONARY UPPER TROUGH DISSIPATES AND WEAK
RIDGING CURRENTLY OVER THE BERING MOVES IN. THIS WILL KEEP SKIES
GENERALLY WITH PRECIPITATION LIMITED TO A FEW PASSING SHOWERS. A
WEAK FRONT WILL THEN APPROACH THE KUSKOKWIM DELTA ON
TUESDAY...BRINGING A CHANCE OF RAIN TO THE AREAS. RIDGING WILL
HOWEVER REMAIN OVER THE KUSKOKWIM VALLEY AND BRISTOL BAY...KEEPING
THE AREA DRY WITH LIGHT WINDS INTO MID WEEK.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (TONIGHT THROUGH WEDNESDAY)...

AFTER A WEAKENING AREA OF RAIN AND SNOW SHOWERS FROM THE PRIBILOF
ISLANDS INTO THE AKPENN DISSIPATES LATE TONIGHT...THE WEATHER WILL
QUICKLY BECOME DOMINATED BY A FRONTAL SYSTEM CURRENTLY ENTERING
THE WESTERN ALEUTIANS. THIS SYSTEM WILL BECOME A LOW COMPLEX WITH
MULTIPLE CENTERS OVER THE WESTERN BERING BY MONDAY AFTERNOON. WITH
CONSIDERABLE MODEL DISAGREEMENT WITH BOTH THE LOCATION AND
INTENSITY OF THESE LOWS...FORECAST CONFIDENCE QUICKLY DIMINISHES
WITH A DEVELOPING LOW APPROACHING THE EASTERN ALEUTIANS TUESDAY.
IT DOES APPEAR THAT THIS SETUP WILL KEEP WET WEATHER OVER THE
BERING WITH A POTENTIAL FOR GALE FORCE WINDS IN THE EASTERN
ALEUTIANS BY WEDNESDAY.


&&

.LONG TERM FORECAST (DAYS 4 THROUGH 7)...
THE OUTCOME OF THE LONG TERM FORECAST REMAINS HIGHLY DEPENDENT
THE TRACK AND STRENGTH OF THE COMPLEX LOW AS IT BEGINS TO
CONSOLIDATE OVER THE BERING SEA WEDNESDAY. GLOBAL MODELS CONTINUE
TO STRUGGLE WITH THE DETAILS OF THIS SYSTEM...KEEPING FORECAST
CONFIDENCE LOW IN THE TIMING AND STRENGTH OF THE ASSOCIATED
FRONTAL SYSTEM AS IT PROGRESSES EASTWARD. THE MORE NORTHERLY GFS
SOLUTION IS SLOWER TO CONSOLIDATE THE LOW OVER THE NORTHERN
BERING...BUT QUICKEST WITH BRINGING FRONTAL WINDS AND
PRECIPITATION TO THE CENTRAL ALEUTIANS WEDNESDAY MORNING AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY MORNING. THE MORE
SOUTHERLY ECMWF SOLUTION CONSOLIDATES THE LOW QUICKER OVER THE
SOUTHERN BERING...BUT IS SLOWER TO BRING THE FRONTAL WINDS AND
PRECIPITATION INTO THE CENTRAL ALEUTIANS WEDNESDAY AFTERNOON AND
EVENTUALLY INTO THE SOUTHWEST COAST THURSDAY AFTERNOON.

GLOBAL GUIDANCE HAS BEEN SIGNALING THAT THIS ACTIVITY OUT WEST
WILL AMPLIFY A RIDGE OF HIGH PRESSURE IN THE GULF WHICH WILL ACT
TO SLOW THE PROGRESSION OF THIS PATTERN...AND WILL KEEP
SOUTHCENTRAL ALASKA DRY THROUGH THE END OF THE WEEK. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.
CONFIDENCE BEGINS TO DIMINISH INTO THE WEEKEND...WHERE THE
LONGEVITY OF THIS PATTERN BECOMES HIGHLY DEPENDENT ON WHICH MODEL
SOLUTION VERIFIES. A MORE SOUTHERLY SOLUTION (ECMWF) REGARDING
THE LOW OUT WEST WOULD FAVOR DRIER CONDITIONS PERSISTING THROUGH
MUCH OF THE WEEKEND....WHEREAS THE MORE NORTHERLY SOLUTION (GFS)
DEAMPLIFIES THE RIDGE QUICKER AND BRINGS A WEAK SHORTWAVE THROUGH
SOUTHCENTRAL ON SUNDAY.

&&

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

&&

$$




000
FXAK68 PAFC 231324
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
424 AM AKST SUN NOV 23 2014

.ANALYSIS AND UPPER LEVELS...

A LARGE STACKED UPPER LEVEL LOW CONTINUES TO SPIN IN VICINITY OF
THE SHUMAGIN ISLANDS THIS MORNING JUST TO THE SOUTH OF THE ALASKA
PENINSULA. WATER VAPOR AND INFRARED IMAGERY INDICATE A FAIRLY
UNSTABLE REGIME TO THE NORTHEAST THROUGH SOUTH OF THE LOW PRESSURE
CIRCULATION FROM SOUTHCENTRAL THROUGH THE GULF OF ALASKA
GENERATING SCATTERED TO NUMEROUS SNOW SHOWERS.

OUT WEST...A PAIR OF SHORTWAVE RIDGES MAKE UP THE GENERAL
RIDGINESS OVER THE NORTHERN AND WESTERN BERING SEA. A STRONG LOW
PRESSURE SYSTEM NEAR KAMCHATKA IS BEGINNING TO STRENGTHEN AS IT
BEGINS TO SLOWLY MOVE EAST TOWARD THE WESTERN BERING SEA.

&&

.MODEL DISCUSSION...

MODELS ARE IN GENERALLY GOOD AGREEMENT SYNOPTICALLY. THEY ALL TAKE
THE SHUMAGIN ISLANDS OCCLUDED LOW AND DRIFT IT EAST INTO THE
CENTRAL GULF BY LATE MONDAY INTO TUESDAY...MAKING IT BROAD AND
DIFFUSE IN THE PROCESS. MODELS DIFFER SOMEWHAT IN ITS DEPICTION IN
THE GULF BUT WITH NO SIGNIFICANT IMPACT ON THE FORECAST.

OUT IN THE FAR WEST...THE KAMCHATKA LOW CONTINUES TO STRENGTHEN
AND MATURE INTO A STRONG CYCLONE CENTERED NORTH AND WEST OF ATTU
THROUGH MON NIGHT. A LOW PRESSURE SYSTEM WILL STRENGTHEN ALONG ITS
ASSOCIATED FRONT AS IT MOVES INTO THE WESTERN ALEUTIANS LATE
SUNDAY INTO MONDAY...THEN CIRCLE BACK TOWARD BACK TOWARD THE
PARENT LOW AND MERGE WITH IT LATE MONDAY INTO TUESDAY NORTH AND
WEST OF ATTU.

THE IMPACT OF THE STRONG LOW PRESSURE SYSTEM BECOMING STATIONARY
OVER THE FAR WESTERN BERING LATE MONDAY INTO MID-WEEK WILL RESULT
IN HIGH PRESSURE RIDGING STRENGTHENING ALOFT OVER THE MAINLAND
TUESDAY INTO WEDNESDAY.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES MOVING NORTHWARD ACROSS THE
GULF OF ALASKA TO SOUTHCENTRAL CONTINUE TO PROVIDE QUITE THE
CHALLENGE FOR THE PRECIPITATION FORECAST. FOR THE MOST PART SHOWERS
ASSOCIATED WITH THESE DISTURBANCES HAVE BEEN CONFINED TO THE GULF
COASTAL REGION WITH VERY FEW SHOWERS MAKING IT OVER THE COASTAL
MOUNTAINS. THIS IS DUE TO WEAK DOWNSLOPE FLOW AND LOW LEVEL DRY
AIR SUPPORTED BY OFFSHORE FLOW AT THE SURFACE. HOWEVER...THERE
HAVE BEEN A FEW STRONGER UPPER WAVES (ONE OF WHICH IS MOVING
THROUGH THIS MORNING) WHICH TEMPORARILY MODIFY THE LOW LEVEL FLOW
(TO WEAKEN DOWNSLOPING). PINPOINTING THE LOCATION AND AMOUNT OF
PRECIP IS VERY DIFFICULT...ESPECIALLY SINCE NONE OF THE MODELS
HAVE A GREAT HANDLE ON THE PLACEMENT AND TIMING OF INDIVIDUAL
FEATURES. SATELLITE AND RADAR TRENDS ARE THE MOST USEFUL TOOL IN
THIS SITUATION. BECAUSE OF THIS...FORECAST CONFIDENCE IN THE
PRECIP FORECAST BEYOND THE FIRST SIX HOURS IS LOW.

THE AIR MASS ACROSS THE REGION HAS CONTINUED A STEADY COOLING
TREND. THE IMMEDIATE COAST REMAINS ALL RAIN...BUT INTERIOR
PORTIONS OF WESTERN PRINCE WILLIAM SOUND HAVE SEEN SOME PERIODS OF
SNOW OR RAIN AND SNOW MIXED WITH VERY MINOR SNOW ACCUMULATIONS.
AS PER THE ANCHORAGE SOUNDING ANYTHING ON THE LEE SIDE OF THE
COASTAL RANGE WILL FALL AS SNOW.

UPPER LEVEL FLOW WILL SHIFT SUNDAY NIGHT INTO MONDAY AS THE LOW
ALONG THE ALASKA PENINSULA EXITS EASTWARD ACROSS THE GULF AND
UPPER FLOW OVER SOUTHCENTRAL BECOMES WESTERLY. PRECIP WILL THEN
BECOME FAVORED ALONG THE WEST SLOPES OF MOUNTAINS WHILE PRECIP IN
WESTERN PRINCE WILLIAM SOUND WILL DIMINISH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 THROUGH 3)...
ISOLATED TO SCATTERED SNOW SHOWERS WILL CONTINUE TO DEVELOP TODAY ALONG
A WEAK STATIONARY BOUNDARY ACROSS BRISTOL BAY. WITH TEMPERATURES
NEAR FREEZING ALONG THE EASTERN ALASKA PENINSULA AND ALEUTIAN
RANGE AND BELOW FREEZING TEMPERATURES TO THE NORTH...ISOLATED
POCKETS OF FREEZING RAIN ARE POSSIBLE MAINLY SOUTH AND EAST OF
DILLINGHAM. SCATTERED SNOW SHOWERS WILL MAKE IT INTO THE ALASKA
RANGE TODAY AS THE BROAD AREA OF LOW PRESSURE PUSHES A SHORTWAVE
WESTWARD. ISOLATED TO SCATTERED PRECIPITATION DIMINISHES MONDAY
NIGHT AS THE MAIN LOW CENTER SHIFTS EAST. THE NEXT FRONT PUSHES
INTO THE EASTERN BERING ON TUESDAY BRINGING INCREASED RAIN CHANCES
FOR RAIN AND GUSTY WINDS ALONG THE ALASKA PENINSULA AND WESTERN
COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 THROUGH 3)...
NORTHERLY FLOW WITH ISOLATED TO SCATTERED SHOWERS CONTINUE ACROSS
THE BERING TODAY. LOW PRESSURE EAST OF THE KAMCHATKA PENINSULA
WILL PUSH A WARM FRONT INTO THE WESTERN ALEUTIANS THIS AFTERNOON
BRINGING STRONG WINDS AND RAIN THROUGH TONIGHT. THE BOUNDARY MOVES
INTO CENTRAL BERING/EASTERN ALEUTIANS BY TUESDAY MORNING AND THEN
REMAINS STATIONARY AS THE LOW FILLS. ANOTHER LOW WILL MOVE UP FROM
THE NORTH PACIFIC WITH ANOTHER ROUND OF PRECIPITATION MID WEEK.


&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE EXTENDED FORECAST LOOKS MUCH THE SAME TODAY AND WILL STILL BE
DEPENDENT ON A COMPLEX LOW SETTING UP SHOP IN THE WESTERN/CENTRAL
BERING SEA. A CURRENTLY DEVELOPING KAMCHATKA LOW WILL ANCHOR THE
LONGWAVE PATTERN WHILE SEVERAL COMPACT SHORTWAVE TROUGHS WILL
DEVELOP AND JOIN THE LARGE SCALE CIRCULATION. THE FIRST WILL
STRENGTHEN ALONG THE FRONTAL BOUNDARY PROGRESSING EASTWARD ACROSS
THE CHAIN IN THE VICINITY OF THE CENTRAL/EASTERN ALEUTIANS
BRINGING RAIN AND GALE FORCE WINDS. ANOTHER WAVE QUICKLY FOLLOWS
BY WEDNESDAY REINFORCING THE CIRCULATION AND BRINGING MORE RAIN
AND WIND TO THE CENTRAL ALEUTIANS WHILE SENDING THE FRONT FURTHER
EAST IN THE BERING SEA. GLOBAL GUIDANCE HAS BEEN SIGNALING THAT
THIS ACTIVITY OUT WEST WILL PUMP UP A RIDGE OF HIGH PRESSURE IN
THE GULF WHICH WILL ACT TO SLOW THE PROGRESSION OF THE PATTERN AND
KEEP THE SOUTHCENTRAL DRY FOR THE FORESEEABLE FUTURE. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...HEAVY FREEZING SPRAY 181.
         GALE 175 176 177 178 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...MTL




000
FXAK68 PAFC 231324
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
424 AM AKST SUN NOV 23 2014

.ANALYSIS AND UPPER LEVELS...

A LARGE STACKED UPPER LEVEL LOW CONTINUES TO SPIN IN VICINITY OF
THE SHUMAGIN ISLANDS THIS MORNING JUST TO THE SOUTH OF THE ALASKA
PENINSULA. WATER VAPOR AND INFRARED IMAGERY INDICATE A FAIRLY
UNSTABLE REGIME TO THE NORTHEAST THROUGH SOUTH OF THE LOW PRESSURE
CIRCULATION FROM SOUTHCENTRAL THROUGH THE GULF OF ALASKA
GENERATING SCATTERED TO NUMEROUS SNOW SHOWERS.

OUT WEST...A PAIR OF SHORTWAVE RIDGES MAKE UP THE GENERAL
RIDGINESS OVER THE NORTHERN AND WESTERN BERING SEA. A STRONG LOW
PRESSURE SYSTEM NEAR KAMCHATKA IS BEGINNING TO STRENGTHEN AS IT
BEGINS TO SLOWLY MOVE EAST TOWARD THE WESTERN BERING SEA.

&&

.MODEL DISCUSSION...

MODELS ARE IN GENERALLY GOOD AGREEMENT SYNOPTICALLY. THEY ALL TAKE
THE SHUMAGIN ISLANDS OCCLUDED LOW AND DRIFT IT EAST INTO THE
CENTRAL GULF BY LATE MONDAY INTO TUESDAY...MAKING IT BROAD AND
DIFFUSE IN THE PROCESS. MODELS DIFFER SOMEWHAT IN ITS DEPICTION IN
THE GULF BUT WITH NO SIGNIFICANT IMPACT ON THE FORECAST.

OUT IN THE FAR WEST...THE KAMCHATKA LOW CONTINUES TO STRENGTHEN
AND MATURE INTO A STRONG CYCLONE CENTERED NORTH AND WEST OF ATTU
THROUGH MON NIGHT. A LOW PRESSURE SYSTEM WILL STRENGTHEN ALONG ITS
ASSOCIATED FRONT AS IT MOVES INTO THE WESTERN ALEUTIANS LATE
SUNDAY INTO MONDAY...THEN CIRCLE BACK TOWARD BACK TOWARD THE
PARENT LOW AND MERGE WITH IT LATE MONDAY INTO TUESDAY NORTH AND
WEST OF ATTU.

THE IMPACT OF THE STRONG LOW PRESSURE SYSTEM BECOMING STATIONARY
OVER THE FAR WESTERN BERING LATE MONDAY INTO MID-WEEK WILL RESULT
IN HIGH PRESSURE RIDGING STRENGTHENING ALOFT OVER THE MAINLAND
TUESDAY INTO WEDNESDAY.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A SERIES OF UPPER LEVEL DISTURBANCES MOVING NORTHWARD ACROSS THE
GULF OF ALASKA TO SOUTHCENTRAL CONTINUE TO PROVIDE QUITE THE
CHALLENGE FOR THE PRECIPITATION FORECAST. FOR THE MOST PART SHOWERS
ASSOCIATED WITH THESE DISTURBANCES HAVE BEEN CONFINED TO THE GULF
COASTAL REGION WITH VERY FEW SHOWERS MAKING IT OVER THE COASTAL
MOUNTAINS. THIS IS DUE TO WEAK DOWNSLOPE FLOW AND LOW LEVEL DRY
AIR SUPPORTED BY OFFSHORE FLOW AT THE SURFACE. HOWEVER...THERE
HAVE BEEN A FEW STRONGER UPPER WAVES (ONE OF WHICH IS MOVING
THROUGH THIS MORNING) WHICH TEMPORARILY MODIFY THE LOW LEVEL FLOW
(TO WEAKEN DOWNSLOPING). PINPOINTING THE LOCATION AND AMOUNT OF
PRECIP IS VERY DIFFICULT...ESPECIALLY SINCE NONE OF THE MODELS
HAVE A GREAT HANDLE ON THE PLACEMENT AND TIMING OF INDIVIDUAL
FEATURES. SATELLITE AND RADAR TRENDS ARE THE MOST USEFUL TOOL IN
THIS SITUATION. BECAUSE OF THIS...FORECAST CONFIDENCE IN THE
PRECIP FORECAST BEYOND THE FIRST SIX HOURS IS LOW.

THE AIR MASS ACROSS THE REGION HAS CONTINUED A STEADY COOLING
TREND. THE IMMEDIATE COAST REMAINS ALL RAIN...BUT INTERIOR
PORTIONS OF WESTERN PRINCE WILLIAM SOUND HAVE SEEN SOME PERIODS OF
SNOW OR RAIN AND SNOW MIXED WITH VERY MINOR SNOW ACCUMULATIONS.
AS PER THE ANCHORAGE SOUNDING ANYTHING ON THE LEE SIDE OF THE
COASTAL RANGE WILL FALL AS SNOW.

UPPER LEVEL FLOW WILL SHIFT SUNDAY NIGHT INTO MONDAY AS THE LOW
ALONG THE ALASKA PENINSULA EXITS EASTWARD ACROSS THE GULF AND
UPPER FLOW OVER SOUTHCENTRAL BECOMES WESTERLY. PRECIP WILL THEN
BECOME FAVORED ALONG THE WEST SLOPES OF MOUNTAINS WHILE PRECIP IN
WESTERN PRINCE WILLIAM SOUND WILL DIMINISH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 THROUGH 3)...
ISOLATED TO SCATTERED SNOW SHOWERS WILL CONTINUE TO DEVELOP TODAY ALONG
A WEAK STATIONARY BOUNDARY ACROSS BRISTOL BAY. WITH TEMPERATURES
NEAR FREEZING ALONG THE EASTERN ALASKA PENINSULA AND ALEUTIAN
RANGE AND BELOW FREEZING TEMPERATURES TO THE NORTH...ISOLATED
POCKETS OF FREEZING RAIN ARE POSSIBLE MAINLY SOUTH AND EAST OF
DILLINGHAM. SCATTERED SNOW SHOWERS WILL MAKE IT INTO THE ALASKA
RANGE TODAY AS THE BROAD AREA OF LOW PRESSURE PUSHES A SHORTWAVE
WESTWARD. ISOLATED TO SCATTERED PRECIPITATION DIMINISHES MONDAY
NIGHT AS THE MAIN LOW CENTER SHIFTS EAST. THE NEXT FRONT PUSHES
INTO THE EASTERN BERING ON TUESDAY BRINGING INCREASED RAIN CHANCES
FOR RAIN AND GUSTY WINDS ALONG THE ALASKA PENINSULA AND WESTERN
COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 THROUGH 3)...
NORTHERLY FLOW WITH ISOLATED TO SCATTERED SHOWERS CONTINUE ACROSS
THE BERING TODAY. LOW PRESSURE EAST OF THE KAMCHATKA PENINSULA
WILL PUSH A WARM FRONT INTO THE WESTERN ALEUTIANS THIS AFTERNOON
BRINGING STRONG WINDS AND RAIN THROUGH TONIGHT. THE BOUNDARY MOVES
INTO CENTRAL BERING/EASTERN ALEUTIANS BY TUESDAY MORNING AND THEN
REMAINS STATIONARY AS THE LOW FILLS. ANOTHER LOW WILL MOVE UP FROM
THE NORTH PACIFIC WITH ANOTHER ROUND OF PRECIPITATION MID WEEK.


&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE EXTENDED FORECAST LOOKS MUCH THE SAME TODAY AND WILL STILL BE
DEPENDENT ON A COMPLEX LOW SETTING UP SHOP IN THE WESTERN/CENTRAL
BERING SEA. A CURRENTLY DEVELOPING KAMCHATKA LOW WILL ANCHOR THE
LONGWAVE PATTERN WHILE SEVERAL COMPACT SHORTWAVE TROUGHS WILL
DEVELOP AND JOIN THE LARGE SCALE CIRCULATION. THE FIRST WILL
STRENGTHEN ALONG THE FRONTAL BOUNDARY PROGRESSING EASTWARD ACROSS
THE CHAIN IN THE VICINITY OF THE CENTRAL/EASTERN ALEUTIANS
BRINGING RAIN AND GALE FORCE WINDS. ANOTHER WAVE QUICKLY FOLLOWS
BY WEDNESDAY REINFORCING THE CIRCULATION AND BRINGING MORE RAIN
AND WIND TO THE CENTRAL ALEUTIANS WHILE SENDING THE FRONT FURTHER
EAST IN THE BERING SEA. GLOBAL GUIDANCE HAS BEEN SIGNALING THAT
THIS ACTIVITY OUT WEST WILL PUMP UP A RIDGE OF HIGH PRESSURE IN
THE GULF WHICH WILL ACT TO SLOW THE PROGRESSION OF THE PATTERN AND
KEEP THE SOUTHCENTRAL DRY FOR THE FORESEEABLE FUTURE. EXPECT
SLIGHTLY ABOVE NORMAL TEMPERATURES AND LIGHT WINDS FOR THE WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...HEAVY FREEZING SPRAY 181.
         GALE 175 176 177 178 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...MTL





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