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000
FXAK67 PAJK 011333
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
533 AM AKDT WED APR 1 2015

.SHORT TERM...A VORTICITY SPINNER OFFSHORE OF CHICHAGOF ISLAND,
IS ENHANCING SHOWER ACTIVITY ACROSS SOUTHEAST ALASKA THIS MORNING.
AS OF 12Z, THE WEAK UPPER LOW IS ALREADY MOVING ONSHORE AND AS IT
DOES SHOWERS WILL REMAIN NUMEROUS THROUGH THE DAY ACROSS THE
NORTH WITH SOME ENHANCEMENT ALONG WEST-FACING SLOPES OF THE
CHUGACH AND COAST MOUNTAINS. DEPENDING ON THE SPEED OF THIS
FEATURE, LATE AFTERNOON SHOWERS MAY BEGIN TO DISSIPATE AND THERE
MAY BE A BRIEF PERIOD OF SOME CLEARING BEFORE THE CIRRUS SHIELD
FROM THE NEXT SYSTEM GREYS SKIES ONCE AGAIN THIS EVENING. DUE TO
A RIDGE BUILDING OVER THE EASTERN GULF, THIS UPPER LEVEL FEATURE
AND ITS WEAK SURFACE REFLECTION WILL WEAKEN THROUGH THE DAY AS IT
CANNOT COPE WITH THE MORE ANTICYCLONIC FLOW ALOFT.

AS A PARENT LOW IN THE FAR SOUTHWEST GULF TRACKS EASTWARD THROUGH
THURSDAY, ITS ASSOCIATED FRONT WILL HELP PROGRESS THE RIDGE OVER
THE EASTERN GULF EASTWARD INTO CANADA BY LATE TONIGHT. THE FRONT
WILL SPREAD RAIN INTO THE GULF TODAY, REACHING THE SOUTHEAST
ALASKA COAST TONIGHT WITH AMOUNTS GENERALLY LESS THAN A HALF INCH.
LOCALLY...AMOUNTS MAY STACK UP TO THREE QUARTERS INCH ACROSS
SOUTHERN BARANOF ISLAND. LIGHT RAIN WILL EXTEND DEEPER INLAND
DRIVEN BY THE 700 MB ONSHORE FLOW AS THE WARMER AND MORE MOIST
MARINE AIR MASS GENTLY RIDES OVER THE SLIGHTLY COOLER AIR MASS
OVER THE PANHANDLE. MODELS ARE ADVECTING OMEGA FIELDS ONSHORE AS
EARLY AS THIS EVENING SUPPORTING THE FORWARD ADVANCE OF THE PRECIP
SHIELD WELL EARLIER THAN FRONTAL ARRIVAL, BUT SOME INEVITABLE
OFFSHORE FLOW AT LOWER LEVELS WILL HELP LIMIT QPF ACROSS THE
INTERIOR ZONES WITH THE FRONT`S ORIENTATION.

THE FRONT WILL RAISE WIND SPEEDS TO 30 KT ACROSS THE 310 ZONE
TODAY, AND AS IT NEARS SHORE, A SOUTHEAST/EAST GALE FORCE BARRIER
JET WILL DEVELOP ALONG THE OUTSIDE WATERS TONIGHT. LOOKING INSIDE,
SOME ACCENTUATION OF SOUTHERLIES WILL EVOLVE THIS MORNING AS THE
WEAK CIRCULATION IN THE NORTHEAST GULF MOVES INTO THE NORTHERN
PANHANDLE BUT THESE WILL GENERALLY SLACKEN IN THE AFTERNOON.
HOWEVER, AS WEAK RIDGING SPRINGS NORTH ACROSS THE REGION BEHIND
THE SYSTEM, SOUTHERLIES WILL RE-ENHANCE THIS AFTERNOON THROUGH
LYNN CANAL AND SKAGWAY BEFORE GRADIENTS FLIP WINDS TO GENERALLY
LIGHT NORTHERLY IN ANTICIPATION OF THE FRONT TONIGHT. SOME WEAK
OUTFLOW WINDS ARE POSSIBLE DOWNTOWN JUNEAU LATE TONIGHT, AS WINDS
ALOFT BRIEFLY FORM A CRITICAL LEVEL BUT THE SETUP IS LESS THAN
IDEAL AS CROSS BARRIER FLOW NOT TOO STRONG, SO CONCERN IS MINIMAL.
WIND SPEEDS WILL STRENGTHEN TONIGHT OVER THE SOUTHERN AREAS AS A
LOW LEVEL SOUTHERLY JET IMPOSES SOUTHERLIES OVER CHATHAM STRAIT
AND SOUTHERN PARTS OF STEPHENS PASSAGE, EVEN IN VIOLATION OF A
SLIGHT NORTHERLY PRESSURE GRADIENT, ESPECIALLY LATE. LEFT 30 KT
FOR CLARENCE STRAIT AFTER MIDNIGHT TONIGHT, BUT A MINIMAL GALE IS
POSSIBLE WITH 6 MB OF GRADIENT BETWEEN SITKA AND KETCHIKAN. DID
NOT PLACE STRONG WIND HEADLINES FOR 27 AND 28 LATE TONIGHT, BUT DO
THINK 30 TO 35 MPH IS LIKELY FOR THESE AREAS, SO DEFINITELY EXPECT
BREEZY CONDITIONS ALONG WITH MODERATE BANDS OF RAIN AT TIMES.

BROAD-BRUSHED MODEL DIFFERENCES WITH THE FRONT AND ANY WAVES ALONG
IT BY USING A NAM/ECMWF/GFS BLEND. ONE CONCERN IS THAT THE ECMWF
STILL QUICKER WITH ALL TRANSITING FEATURES. 06Z NAM HAS SPED
THINGS UP AS WELL. THE FORECAST MAY BE A LITTLE TOO WET LATE THIS
AFTERNOON, EARLY THIS EVENING. IF OUTDOOR ACTIVITIES NEED TO BE
DONE, THIS MAY BE THE TIME TO DO THEM.

.LONG TERM...VERTICALLY STACKED LOW IN THE AK GULF THURSDAY WILL
BEGIN TO TRACK TO THE SOUTHEAST FRIDAY NIGHT INTO FRIDAY WHILE THE
ASSOCIATED WEATHER FRONT CROSSES OVER THE PANHANDLE. WINDS OVER
THE COASTAL WATERS WILL DROP OFF SHARPLY THURSDAY MORNING WITH
PANHANDLE AND INNER CHANNEL WINDS PICKING UP THEN DIMINISHING
LATER IN THE DAY AS THE FRONT MOVES OVER THE REGION. GALES FORCE
WINDS ALONG THE COASTAL WATERS WILL DROP OFF WITH BARRIER JET
REAMING A FEW HOURS LONGER IN THE NORTHERN AK GULF. 850 MB WINDS
IN THE 40 TO 45 KT RANGE ALONG THE FRONT AND WITH THE RELATIVELY
WEAK LOW CENTER NOT EXPECTING OVERLAND WINDS TO GET MUCH ABOVE 25
MPH WITH INNER CHANNEL MARINE WINDS JUT IN THE MAX SMALL CRAFT
LEVELS. NEW MODEL RUNS HAVE THE LOW CENTER FURTHER TO THE SOUTH
INITIALLY ON THURSDAY WHICH WOULD INDICATE LOWER POPS FOR THE
NORTHER COASTAL REGIONS, HOWEVER WHILE THE WAS FAIR AGREEMENT
BETWEEN THE ECMWF AND GFS FOR PRESSURE AND WINDS THERE IS MORE
SPREAD WITH POP FOR THAT REGION. DECIDED TO GO WITH RAIN LIKELY
FOR THE YAKUTAT REGION. EXPECT CATEGORICAL POPS FOR THE REMAINDER
OF THE PANHANDLE WITH PRECIP DIMINISHING FROM NORTH TO SOUTH AS
THE LOW PROGRESSES TOWARDS THE N PACIFIC. MOVING INTO THE WEEKEND
EXPECTING DRIER WEATHER FOR MOST OF THE REGION WITH BUILDING HIGH
PRESSURE, WITH THE EXCEPTION OF TWO POTENTIAL SHORT WAVES, ONE
HITTING THE YUKON AND FAR NORTHERN PANHANDLE SATURDAY EVENING AND
A SECOND WAVE IN ADVANCE OF NEXT WEEKS MORE DEFINED FEATURE SUNDAY
EVENING. LOW CONFIDENCE ON THE YUKON WAVE EFFECTING THE NORTHERN
PANHANDLE. THE NEXT LOW SHOULD TRACK FROM THE BERING SEA TO THE
SOUTHEAST, REFORMING IN THE WESTERN AK GULF SUNDAY. THIS IS
FOLLOWED BY A STRONGER, BROADER LOW FOLLOWING A SIMILAR TRACK
REACHING THE AK GULF TUESDAY INTO TUESDAY NIGHT. TEMPERATURES
BEGIN TO SHOW A LARGER DIURNAL RANGE BY THE WEEKEND DUE TO SOME
CLEARING SKIES AND OVERNIGHT RADIATIONAL COOLING IN ADDITION TO
NORTHWESTERLY FLOW WITH THE BUILDING RIDGE MOVING DOWN COLDER AIR
FROM THE INTERIOR. OVERNIGHT LOWS MAY BE LOW ENOUGH FOR A MIX OF
SNOW FOR THE NORTHERN THIRD OF THE PANHANDLE AND AT HIGHER
ELEVATIONS WITH THESE SHORTWAVES. HOWEVER THIS COLDER AIR WILL BE
TIMED WITH DRIER AIR SO NOT EXPECTING ANY SIGNIFICANT SNOW.
DAYTIME HIGHS WILL BE IN THE 40S SO ANY DAY TIME PRECIP WILL FALL
AS RAIN.

MODELS WERE IN FAIR AGREEMENT INITIALLY, BUT THESE NEW RUNS DID
SHIFT THE LOW FURTHER TO THE SOUTH. BY THE WEEKEND MODEL SPREAD
INCREASES SIGNIFICANTLY. USED A BLEND OF ECMWF/GEM/GFS WHICH DID
SHIFT POSITION OF THE INITIAL LOW BUT OTHERWISE CHANGES TO THE
FORECAST WERE MINIMAL THROUGH THE WEEKEND. STARTING SATURDAY BEGAN
TO TRANSITION TO INHERITED WPC ENSEMBLE GRIDS TO THE LARGE
OPERATIONAL MODEL SPREAD. FORECAST CONFIDENCE IS ABOVE AVERAGE
INITIALLY BUT DROP BELOW AVERAGE BY THE WEEKEND.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-022-033>036-053.

&&

$$

JWA/PRB

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








000
FXAK67 PAJK 011333
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
533 AM AKDT WED APR 1 2015

.SHORT TERM...A VORTICITY SPINNER OFFSHORE OF CHICHAGOF ISLAND,
IS ENHANCING SHOWER ACTIVITY ACROSS SOUTHEAST ALASKA THIS MORNING.
AS OF 12Z, THE WEAK UPPER LOW IS ALREADY MOVING ONSHORE AND AS IT
DOES SHOWERS WILL REMAIN NUMEROUS THROUGH THE DAY ACROSS THE
NORTH WITH SOME ENHANCEMENT ALONG WEST-FACING SLOPES OF THE
CHUGACH AND COAST MOUNTAINS. DEPENDING ON THE SPEED OF THIS
FEATURE, LATE AFTERNOON SHOWERS MAY BEGIN TO DISSIPATE AND THERE
MAY BE A BRIEF PERIOD OF SOME CLEARING BEFORE THE CIRRUS SHIELD
FROM THE NEXT SYSTEM GREYS SKIES ONCE AGAIN THIS EVENING. DUE TO
A RIDGE BUILDING OVER THE EASTERN GULF, THIS UPPER LEVEL FEATURE
AND ITS WEAK SURFACE REFLECTION WILL WEAKEN THROUGH THE DAY AS IT
CANNOT COPE WITH THE MORE ANTICYCLONIC FLOW ALOFT.

AS A PARENT LOW IN THE FAR SOUTHWEST GULF TRACKS EASTWARD THROUGH
THURSDAY, ITS ASSOCIATED FRONT WILL HELP PROGRESS THE RIDGE OVER
THE EASTERN GULF EASTWARD INTO CANADA BY LATE TONIGHT. THE FRONT
WILL SPREAD RAIN INTO THE GULF TODAY, REACHING THE SOUTHEAST
ALASKA COAST TONIGHT WITH AMOUNTS GENERALLY LESS THAN A HALF INCH.
LOCALLY...AMOUNTS MAY STACK UP TO THREE QUARTERS INCH ACROSS
SOUTHERN BARANOF ISLAND. LIGHT RAIN WILL EXTEND DEEPER INLAND
DRIVEN BY THE 700 MB ONSHORE FLOW AS THE WARMER AND MORE MOIST
MARINE AIR MASS GENTLY RIDES OVER THE SLIGHTLY COOLER AIR MASS
OVER THE PANHANDLE. MODELS ARE ADVECTING OMEGA FIELDS ONSHORE AS
EARLY AS THIS EVENING SUPPORTING THE FORWARD ADVANCE OF THE PRECIP
SHIELD WELL EARLIER THAN FRONTAL ARRIVAL, BUT SOME INEVITABLE
OFFSHORE FLOW AT LOWER LEVELS WILL HELP LIMIT QPF ACROSS THE
INTERIOR ZONES WITH THE FRONT`S ORIENTATION.

THE FRONT WILL RAISE WIND SPEEDS TO 30 KT ACROSS THE 310 ZONE
TODAY, AND AS IT NEARS SHORE, A SOUTHEAST/EAST GALE FORCE BARRIER
JET WILL DEVELOP ALONG THE OUTSIDE WATERS TONIGHT. LOOKING INSIDE,
SOME ACCENTUATION OF SOUTHERLIES WILL EVOLVE THIS MORNING AS THE
WEAK CIRCULATION IN THE NORTHEAST GULF MOVES INTO THE NORTHERN
PANHANDLE BUT THESE WILL GENERALLY SLACKEN IN THE AFTERNOON.
HOWEVER, AS WEAK RIDGING SPRINGS NORTH ACROSS THE REGION BEHIND
THE SYSTEM, SOUTHERLIES WILL RE-ENHANCE THIS AFTERNOON THROUGH
LYNN CANAL AND SKAGWAY BEFORE GRADIENTS FLIP WINDS TO GENERALLY
LIGHT NORTHERLY IN ANTICIPATION OF THE FRONT TONIGHT. SOME WEAK
OUTFLOW WINDS ARE POSSIBLE DOWNTOWN JUNEAU LATE TONIGHT, AS WINDS
ALOFT BRIEFLY FORM A CRITICAL LEVEL BUT THE SETUP IS LESS THAN
IDEAL AS CROSS BARRIER FLOW NOT TOO STRONG, SO CONCERN IS MINIMAL.
WIND SPEEDS WILL STRENGTHEN TONIGHT OVER THE SOUTHERN AREAS AS A
LOW LEVEL SOUTHERLY JET IMPOSES SOUTHERLIES OVER CHATHAM STRAIT
AND SOUTHERN PARTS OF STEPHENS PASSAGE, EVEN IN VIOLATION OF A
SLIGHT NORTHERLY PRESSURE GRADIENT, ESPECIALLY LATE. LEFT 30 KT
FOR CLARENCE STRAIT AFTER MIDNIGHT TONIGHT, BUT A MINIMAL GALE IS
POSSIBLE WITH 6 MB OF GRADIENT BETWEEN SITKA AND KETCHIKAN. DID
NOT PLACE STRONG WIND HEADLINES FOR 27 AND 28 LATE TONIGHT, BUT DO
THINK 30 TO 35 MPH IS LIKELY FOR THESE AREAS, SO DEFINITELY EXPECT
BREEZY CONDITIONS ALONG WITH MODERATE BANDS OF RAIN AT TIMES.

BROAD-BRUSHED MODEL DIFFERENCES WITH THE FRONT AND ANY WAVES ALONG
IT BY USING A NAM/ECMWF/GFS BLEND. ONE CONCERN IS THAT THE ECMWF
STILL QUICKER WITH ALL TRANSITING FEATURES. 06Z NAM HAS SPED
THINGS UP AS WELL. THE FORECAST MAY BE A LITTLE TOO WET LATE THIS
AFTERNOON, EARLY THIS EVENING. IF OUTDOOR ACTIVITIES NEED TO BE
DONE, THIS MAY BE THE TIME TO DO THEM.

.LONG TERM...VERTICALLY STACKED LOW IN THE AK GULF THURSDAY WILL
BEGIN TO TRACK TO THE SOUTHEAST FRIDAY NIGHT INTO FRIDAY WHILE THE
ASSOCIATED WEATHER FRONT CROSSES OVER THE PANHANDLE. WINDS OVER
THE COASTAL WATERS WILL DROP OFF SHARPLY THURSDAY MORNING WITH
PANHANDLE AND INNER CHANNEL WINDS PICKING UP THEN DIMINISHING
LATER IN THE DAY AS THE FRONT MOVES OVER THE REGION. GALES FORCE
WINDS ALONG THE COASTAL WATERS WILL DROP OFF WITH BARRIER JET
REAMING A FEW HOURS LONGER IN THE NORTHERN AK GULF. 850 MB WINDS
IN THE 40 TO 45 KT RANGE ALONG THE FRONT AND WITH THE RELATIVELY
WEAK LOW CENTER NOT EXPECTING OVERLAND WINDS TO GET MUCH ABOVE 25
MPH WITH INNER CHANNEL MARINE WINDS JUT IN THE MAX SMALL CRAFT
LEVELS. NEW MODEL RUNS HAVE THE LOW CENTER FURTHER TO THE SOUTH
INITIALLY ON THURSDAY WHICH WOULD INDICATE LOWER POPS FOR THE
NORTHER COASTAL REGIONS, HOWEVER WHILE THE WAS FAIR AGREEMENT
BETWEEN THE ECMWF AND GFS FOR PRESSURE AND WINDS THERE IS MORE
SPREAD WITH POP FOR THAT REGION. DECIDED TO GO WITH RAIN LIKELY
FOR THE YAKUTAT REGION. EXPECT CATEGORICAL POPS FOR THE REMAINDER
OF THE PANHANDLE WITH PRECIP DIMINISHING FROM NORTH TO SOUTH AS
THE LOW PROGRESSES TOWARDS THE N PACIFIC. MOVING INTO THE WEEKEND
EXPECTING DRIER WEATHER FOR MOST OF THE REGION WITH BUILDING HIGH
PRESSURE, WITH THE EXCEPTION OF TWO POTENTIAL SHORT WAVES, ONE
HITTING THE YUKON AND FAR NORTHERN PANHANDLE SATURDAY EVENING AND
A SECOND WAVE IN ADVANCE OF NEXT WEEKS MORE DEFINED FEATURE SUNDAY
EVENING. LOW CONFIDENCE ON THE YUKON WAVE EFFECTING THE NORTHERN
PANHANDLE. THE NEXT LOW SHOULD TRACK FROM THE BERING SEA TO THE
SOUTHEAST, REFORMING IN THE WESTERN AK GULF SUNDAY. THIS IS
FOLLOWED BY A STRONGER, BROADER LOW FOLLOWING A SIMILAR TRACK
REACHING THE AK GULF TUESDAY INTO TUESDAY NIGHT. TEMPERATURES
BEGIN TO SHOW A LARGER DIURNAL RANGE BY THE WEEKEND DUE TO SOME
CLEARING SKIES AND OVERNIGHT RADIATIONAL COOLING IN ADDITION TO
NORTHWESTERLY FLOW WITH THE BUILDING RIDGE MOVING DOWN COLDER AIR
FROM THE INTERIOR. OVERNIGHT LOWS MAY BE LOW ENOUGH FOR A MIX OF
SNOW FOR THE NORTHERN THIRD OF THE PANHANDLE AND AT HIGHER
ELEVATIONS WITH THESE SHORTWAVES. HOWEVER THIS COLDER AIR WILL BE
TIMED WITH DRIER AIR SO NOT EXPECTING ANY SIGNIFICANT SNOW.
DAYTIME HIGHS WILL BE IN THE 40S SO ANY DAY TIME PRECIP WILL FALL
AS RAIN.

MODELS WERE IN FAIR AGREEMENT INITIALLY, BUT THESE NEW RUNS DID
SHIFT THE LOW FURTHER TO THE SOUTH. BY THE WEEKEND MODEL SPREAD
INCREASES SIGNIFICANTLY. USED A BLEND OF ECMWF/GEM/GFS WHICH DID
SHIFT POSITION OF THE INITIAL LOW BUT OTHERWISE CHANGES TO THE
FORECAST WERE MINIMAL THROUGH THE WEEKEND. STARTING SATURDAY BEGAN
TO TRANSITION TO INHERITED WPC ENSEMBLE GRIDS TO THE LARGE
OPERATIONAL MODEL SPREAD. FORECAST CONFIDENCE IS ABOVE AVERAGE
INITIALLY BUT DROP BELOW AVERAGE BY THE WEEKEND.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-022-033>036-053.

&&

$$

JWA/PRB

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







000
FXAK67 PAJK 011333
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
533 AM AKDT WED APR 1 2015

.SHORT TERM...A VORTICITY SPINNER OFFSHORE OF CHICHAGOF ISLAND,
IS ENHANCING SHOWER ACTIVITY ACROSS SOUTHEAST ALASKA THIS MORNING.
AS OF 12Z, THE WEAK UPPER LOW IS ALREADY MOVING ONSHORE AND AS IT
DOES SHOWERS WILL REMAIN NUMEROUS THROUGH THE DAY ACROSS THE
NORTH WITH SOME ENHANCEMENT ALONG WEST-FACING SLOPES OF THE
CHUGACH AND COAST MOUNTAINS. DEPENDING ON THE SPEED OF THIS
FEATURE, LATE AFTERNOON SHOWERS MAY BEGIN TO DISSIPATE AND THERE
MAY BE A BRIEF PERIOD OF SOME CLEARING BEFORE THE CIRRUS SHIELD
FROM THE NEXT SYSTEM GREYS SKIES ONCE AGAIN THIS EVENING. DUE TO
A RIDGE BUILDING OVER THE EASTERN GULF, THIS UPPER LEVEL FEATURE
AND ITS WEAK SURFACE REFLECTION WILL WEAKEN THROUGH THE DAY AS IT
CANNOT COPE WITH THE MORE ANTICYCLONIC FLOW ALOFT.

AS A PARENT LOW IN THE FAR SOUTHWEST GULF TRACKS EASTWARD THROUGH
THURSDAY, ITS ASSOCIATED FRONT WILL HELP PROGRESS THE RIDGE OVER
THE EASTERN GULF EASTWARD INTO CANADA BY LATE TONIGHT. THE FRONT
WILL SPREAD RAIN INTO THE GULF TODAY, REACHING THE SOUTHEAST
ALASKA COAST TONIGHT WITH AMOUNTS GENERALLY LESS THAN A HALF INCH.
LOCALLY...AMOUNTS MAY STACK UP TO THREE QUARTERS INCH ACROSS
SOUTHERN BARANOF ISLAND. LIGHT RAIN WILL EXTEND DEEPER INLAND
DRIVEN BY THE 700 MB ONSHORE FLOW AS THE WARMER AND MORE MOIST
MARINE AIR MASS GENTLY RIDES OVER THE SLIGHTLY COOLER AIR MASS
OVER THE PANHANDLE. MODELS ARE ADVECTING OMEGA FIELDS ONSHORE AS
EARLY AS THIS EVENING SUPPORTING THE FORWARD ADVANCE OF THE PRECIP
SHIELD WELL EARLIER THAN FRONTAL ARRIVAL, BUT SOME INEVITABLE
OFFSHORE FLOW AT LOWER LEVELS WILL HELP LIMIT QPF ACROSS THE
INTERIOR ZONES WITH THE FRONT`S ORIENTATION.

THE FRONT WILL RAISE WIND SPEEDS TO 30 KT ACROSS THE 310 ZONE
TODAY, AND AS IT NEARS SHORE, A SOUTHEAST/EAST GALE FORCE BARRIER
JET WILL DEVELOP ALONG THE OUTSIDE WATERS TONIGHT. LOOKING INSIDE,
SOME ACCENTUATION OF SOUTHERLIES WILL EVOLVE THIS MORNING AS THE
WEAK CIRCULATION IN THE NORTHEAST GULF MOVES INTO THE NORTHERN
PANHANDLE BUT THESE WILL GENERALLY SLACKEN IN THE AFTERNOON.
HOWEVER, AS WEAK RIDGING SPRINGS NORTH ACROSS THE REGION BEHIND
THE SYSTEM, SOUTHERLIES WILL RE-ENHANCE THIS AFTERNOON THROUGH
LYNN CANAL AND SKAGWAY BEFORE GRADIENTS FLIP WINDS TO GENERALLY
LIGHT NORTHERLY IN ANTICIPATION OF THE FRONT TONIGHT. SOME WEAK
OUTFLOW WINDS ARE POSSIBLE DOWNTOWN JUNEAU LATE TONIGHT, AS WINDS
ALOFT BRIEFLY FORM A CRITICAL LEVEL BUT THE SETUP IS LESS THAN
IDEAL AS CROSS BARRIER FLOW NOT TOO STRONG, SO CONCERN IS MINIMAL.
WIND SPEEDS WILL STRENGTHEN TONIGHT OVER THE SOUTHERN AREAS AS A
LOW LEVEL SOUTHERLY JET IMPOSES SOUTHERLIES OVER CHATHAM STRAIT
AND SOUTHERN PARTS OF STEPHENS PASSAGE, EVEN IN VIOLATION OF A
SLIGHT NORTHERLY PRESSURE GRADIENT, ESPECIALLY LATE. LEFT 30 KT
FOR CLARENCE STRAIT AFTER MIDNIGHT TONIGHT, BUT A MINIMAL GALE IS
POSSIBLE WITH 6 MB OF GRADIENT BETWEEN SITKA AND KETCHIKAN. DID
NOT PLACE STRONG WIND HEADLINES FOR 27 AND 28 LATE TONIGHT, BUT DO
THINK 30 TO 35 MPH IS LIKELY FOR THESE AREAS, SO DEFINITELY EXPECT
BREEZY CONDITIONS ALONG WITH MODERATE BANDS OF RAIN AT TIMES.

BROAD-BRUSHED MODEL DIFFERENCES WITH THE FRONT AND ANY WAVES ALONG
IT BY USING A NAM/ECMWF/GFS BLEND. ONE CONCERN IS THAT THE ECMWF
STILL QUICKER WITH ALL TRANSITING FEATURES. 06Z NAM HAS SPED
THINGS UP AS WELL. THE FORECAST MAY BE A LITTLE TOO WET LATE THIS
AFTERNOON, EARLY THIS EVENING. IF OUTDOOR ACTIVITIES NEED TO BE
DONE, THIS MAY BE THE TIME TO DO THEM.

.LONG TERM...VERTICALLY STACKED LOW IN THE AK GULF THURSDAY WILL
BEGIN TO TRACK TO THE SOUTHEAST FRIDAY NIGHT INTO FRIDAY WHILE THE
ASSOCIATED WEATHER FRONT CROSSES OVER THE PANHANDLE. WINDS OVER
THE COASTAL WATERS WILL DROP OFF SHARPLY THURSDAY MORNING WITH
PANHANDLE AND INNER CHANNEL WINDS PICKING UP THEN DIMINISHING
LATER IN THE DAY AS THE FRONT MOVES OVER THE REGION. GALES FORCE
WINDS ALONG THE COASTAL WATERS WILL DROP OFF WITH BARRIER JET
REAMING A FEW HOURS LONGER IN THE NORTHERN AK GULF. 850 MB WINDS
IN THE 40 TO 45 KT RANGE ALONG THE FRONT AND WITH THE RELATIVELY
WEAK LOW CENTER NOT EXPECTING OVERLAND WINDS TO GET MUCH ABOVE 25
MPH WITH INNER CHANNEL MARINE WINDS JUT IN THE MAX SMALL CRAFT
LEVELS. NEW MODEL RUNS HAVE THE LOW CENTER FURTHER TO THE SOUTH
INITIALLY ON THURSDAY WHICH WOULD INDICATE LOWER POPS FOR THE
NORTHER COASTAL REGIONS, HOWEVER WHILE THE WAS FAIR AGREEMENT
BETWEEN THE ECMWF AND GFS FOR PRESSURE AND WINDS THERE IS MORE
SPREAD WITH POP FOR THAT REGION. DECIDED TO GO WITH RAIN LIKELY
FOR THE YAKUTAT REGION. EXPECT CATEGORICAL POPS FOR THE REMAINDER
OF THE PANHANDLE WITH PRECIP DIMINISHING FROM NORTH TO SOUTH AS
THE LOW PROGRESSES TOWARDS THE N PACIFIC. MOVING INTO THE WEEKEND
EXPECTING DRIER WEATHER FOR MOST OF THE REGION WITH BUILDING HIGH
PRESSURE, WITH THE EXCEPTION OF TWO POTENTIAL SHORT WAVES, ONE
HITTING THE YUKON AND FAR NORTHERN PANHANDLE SATURDAY EVENING AND
A SECOND WAVE IN ADVANCE OF NEXT WEEKS MORE DEFINED FEATURE SUNDAY
EVENING. LOW CONFIDENCE ON THE YUKON WAVE EFFECTING THE NORTHERN
PANHANDLE. THE NEXT LOW SHOULD TRACK FROM THE BERING SEA TO THE
SOUTHEAST, REFORMING IN THE WESTERN AK GULF SUNDAY. THIS IS
FOLLOWED BY A STRONGER, BROADER LOW FOLLOWING A SIMILAR TRACK
REACHING THE AK GULF TUESDAY INTO TUESDAY NIGHT. TEMPERATURES
BEGIN TO SHOW A LARGER DIURNAL RANGE BY THE WEEKEND DUE TO SOME
CLEARING SKIES AND OVERNIGHT RADIATIONAL COOLING IN ADDITION TO
NORTHWESTERLY FLOW WITH THE BUILDING RIDGE MOVING DOWN COLDER AIR
FROM THE INTERIOR. OVERNIGHT LOWS MAY BE LOW ENOUGH FOR A MIX OF
SNOW FOR THE NORTHERN THIRD OF THE PANHANDLE AND AT HIGHER
ELEVATIONS WITH THESE SHORTWAVES. HOWEVER THIS COLDER AIR WILL BE
TIMED WITH DRIER AIR SO NOT EXPECTING ANY SIGNIFICANT SNOW.
DAYTIME HIGHS WILL BE IN THE 40S SO ANY DAY TIME PRECIP WILL FALL
AS RAIN.

MODELS WERE IN FAIR AGREEMENT INITIALLY, BUT THESE NEW RUNS DID
SHIFT THE LOW FURTHER TO THE SOUTH. BY THE WEEKEND MODEL SPREAD
INCREASES SIGNIFICANTLY. USED A BLEND OF ECMWF/GEM/GFS WHICH DID
SHIFT POSITION OF THE INITIAL LOW BUT OTHERWISE CHANGES TO THE
FORECAST WERE MINIMAL THROUGH THE WEEKEND. STARTING SATURDAY BEGAN
TO TRANSITION TO INHERITED WPC ENSEMBLE GRIDS TO THE LARGE
OPERATIONAL MODEL SPREAD. FORECAST CONFIDENCE IS ABOVE AVERAGE
INITIALLY BUT DROP BELOW AVERAGE BY THE WEEKEND.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ021-022-033>036-053.

&&

$$

JWA/PRB

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






  [top]

000
FXAK68 PAFC 011323
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
523 AM AKDT WED APR 1 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS OVER THE REGION WITH A NEARLY ZONAL
SUBTROPICAL JET DRIVING SYSTEMS EASTWARD ACROSS THE NORTH PACIFIC
AND ALEUTIANS. A RIDGE CONTINUES TO BUILD OVER THE WESTERN BERING
...WITH A SECOND RIDGE OVER THE INTERIOR YUKON AND EASTERN
INTERIOR OF ALASKA SLIDING SLOWLY NORTH. THIS IS PARTLY IN
RESPONSE TO INCREASINGLY CYCLONIC FLOW IN ASSOCIATION WITH THE
CONSOLIDATING UPPER LEVEL LOW ALONG THE NORTHERN EDGE OF A STRONG
JET STREAK SOUTH OF THE AKPEN AND KODIAK ISLAND. AS THE TROUGH
CONTINUES TO CONSOLIDATE ALONG THE NORTHERN EDGE OF THE JET
STREAK...WITH PERIPHERAL EFFECTS BEING FELT ALONG THE SOUTHERN END
OF THE AKPEN AND LATER TODAY TOWARDS KODIAK ISLAND. DECENT
NORTHERLY COLD ADVECTION CAN BE EXPECTED ALONG THE BACK SIDE OF
THE LOW AND AHEAD OF THE BUILDING RIDGE OVER THE BERING WITH THE
BUILDING UPSTREAM RIDGE AS THE LOW CONTINUES TO EXIT STAGE EAST
TOWARD THE FAR SOUTHERN GULF.

NOT MUCH HAS CHANGED ACROSS SOUTHWEST AND SOUTHCENTRAL ALASKA AS A
SERIES OF MOSTLY VERY WEAK UPPER LEVEL WAVES TRACK IN FROM THE
GULF PRODUCING FAIRLY WIDESPREAD CLOUDS AND ISOLATED TO SCATTERED
CONVECTIVE SHOWERS. A WEAK AND ELONGATED TROUGH AXIS FROM THE
EASTERN BERING TO SOUTH OF KODIAK ISLAND IS PROGRESSING SLOWLY
NORTHEASTWARD TOWARD THE SOUTHERN MAINLAND...BUT THERE IS VERY
LITTLE VERTICAL MOTION OUT AHEAD OF IT. IF ANYTHING...THERE IS
IMPROVING CONDITIONS RIGHT OUT AHEAD OF THIS AS THE MORE
SIGNIFICANT UPPER WAVES MENTIONED REMAIN NORTH OF THE ALASKA RANGE AND
SOUTH TOWARD THE NORTH PACIFIC AND SOUTHERN GULF OF ALASKA.

&&

.MODEL DISCUSSION...
THERE CONTINUE TO BE SOME MINOR MODEL DIFFERENCES WITH TRACK OF
LOW SOUTH OF THE AKPEN AS IT HEADS INTO THE SOUTHERN GULF AS WELL
AS WITH WEAK TRIPLE POINT WHICH DEVELOPS OUT AHEAD OF IT. THIS
MAINLY AFFECTS WIND DIRECTIONS OVER THE SOUTHERN GULF WHICH WILL
GENERALLY BE ON THE LIGHT SIDE IN VICINITY OF THE MAIN LOW CENTER.
WILL CONTINUE TO USE AN AVERAGE POSITION OF THE VARIOUS MODELS
FOR THE UPDATED FORECAST. OVERALL THERE IS A TREND TOWARD A WEAKER
TRIPLE POINT LOW AND FARTHER SOUTH TRACK OF THE MAIN LOW.
THUS...THE OCCLUDED FRONT WILL MAKE LESS NORTH AND WEST PROGRESS
RESULTING IN LESS PRECIP FOR KODIAK ISLAND AND THE NORTH GULF
COAST. OUTSIDE OF THE DETAILS OF THE LOW TRACK FORECAST CONFIDENCE
IS GENERALLY ABOVE AVERAGE.

OVER SOUTHCENTRAL...MARGINALLY UNSTABLE CONDITIONS WILL CONTINUE
OVER THE REGION THROUGH TODAY BEFORE INCREASING STABILIZATION WITH
FLOW BACKING AND BECOMING OFFSHORE BY THURSDAY.

OUT OVER THE FAR WESTERN BERING...A GALE-FORCE FRONT OVER THE
WESTERN BERING ASSOCIATED WITH A KAMCHATKA LOW WILL HELP AMPLIFY
THE DOWNSTREAM RIDGE OVER THE CENTRAL AND EASTERN BERING AND
WESTERN MAINLAND OVER THE NEXT COUPLE OF DAYS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THERE ARE TWO MAIN SYSTEMS WHICH WILL INFLUENCE THE WEATHER
ACROSS THE GULF AND THE SOUTHCENTRAL MAINLAND OVER THE NEXT COUPLE
OF DAYS. THE FIRST FEATURE IS AN UPPER WAVE OVER THE NORTHERN GULF
OF ALASKA WHICH MOVES ACROSS SOUTHCENTRAL TODAY AND INTO THE
INTERIOR TONIGHT. THIS FEATURE WILL BE THE DRIVING FORCE FOR
CONTINUED SHOWER ACTIVITY ACROSS SOUTHCENTRAL TODAY AND THIS
EVENING. THE SECOND FEATURE/S IS THE LOW SOUTH OF THE AK PEN AND
ITS ASSOCIATED OCCLUDED FRONT APPROACHING KODIAK/SOUTHERN GULF
THIS MORNING. THE FRONTAL SYSTEM MOVES INTO THE NORTHERN GULF
ALASKA TONIGHT AND WILL BRING RAIN TO THE COASTS ALONG WITH GALES
OVER SELECTED MARINE AREAS. MEANWHILE...THE LOW WILL MOVE SOUTH OF
THE GULF OVER THE NEXT DAY OR SO WITH A COUPLE OF MINOR LOWS
DEVELOPING UNDER THE BROADENING UPPER TROUGH. THESE MINOR LOWS
WILL STAY IN THE GULF WITH THE MAIN INFLUENCE ON WIND FIELDS. BACK
TO THE FRONT...AS THE OVERALL LOW COMPLEX MOVES SOUTH AND EAST THE
FRONT WILL BE DRAGGED SOUTH AND EAST AND DRYING WILL OCCUR OVER
THE INLAND ON THU INTO FRI MORNING. THERE WILL ALSO BE BRISK
OUTFLOW WINDS ACROSS THE NORTH GULF COAST AND EASTERN LATE
TONIGHT/EARLY THU WHICH WILL CARRY INTO THE EARLY AFTERNOON HOURS.
WE MAY ALSO SEE FAIRLY WARM TEMPS IN THE OUTFLOW AREAS AS THE
GAP/KATABATIC FLOWS WILL KEEP THE SEABREEZES AT BAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE NORTH PACIFIC LOW POSITIONED SOUTH OF KODIAK ISLAND THIS
MORNING WILL BRING WRAP-AROUND SCATTERED RAIN SHOWERS ALONG THE
ALASKA RANGE AND THE ALEUTIAN RANGE THROUGH WEDNESDAY AFTERNOON.
BY THURSDAY THE LOW PRESSURE SYSTEM WILL MOVE INTO THE EASTERN
SIDE OF THE GULF. THIS WILL RESULT IN THE SOUTHWEST ALASKA REGION
WITH DRIER CONDITIONS ACCOMPANIED BY NORTHERLY WINDS AND COOLER
TEMPERATURES HEADING INTO THE WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
AS THE NORTH PACIFIC LOW CONTINUES TO MOVE EASTWARD TOWARD THE
GULF...THIS WILL BRING GUSTY NORTHWESTERLY GAP WINDS ALONG THE
EASTERN ALEUTIANS THIS MORNING THROUGH THURSDAY. THIS WILL BRING
COOLER TEMPERATURES TO THE EASTERN ALEUTIANS AND THE ALASKA
PENINSULA. THIS WILL BE ACCOMPANIED BY A MIXTURE OF RAIN/SNOW
ALONG THE ALEUTIANS AND SNOW FARTHER NORTH INTO THE EASTERN
BERING SEA THROUGH THURSDAY. AN UPPER LEVEL RIDGE WILL BUILD
INTO THE CENTRAL BERING OVERNIGHT TONIGHT WITH STRATUS AND PATCHY
FOG UNDER THE RIDGE. IN THE WESTERN ALEUTIANS...A GALE FORCE NORTH
PACIFIC LOW TRACKS ALONG THE KAMCHATKA PENINSULA AND WILL BE
ACCOMPANIED BY A FRONTAL SYSTEM MOVING THROUGH NEAR SHEMYA THIS
MORNING BEFORE ENTERING THE WESTERN BERING SEA. THIS WILL BRING
WARMER TEMPERATURES AND PRECIPITATION WITH GUSTY WINDS TO THE
WESTERN ALEUTIANS AND WESTERN BERING SEA THROUGH WEDNESDAY
EVENING. A SECOND LOW WILL FORM BY THURSDAY EVENING NEAR SHEMYA
AND WILL BRING WARMER TEMPERATURES AND PRECIPITATION IN THE FORM
OF ALL RAIN HEADING INTO THE WEEKEND FOR THE WESTERN
ALEUTIANS/BERING SEA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
A FRONTAL BOUNDARY WILL LINGER IN THE NORTH GULF AND ALONG THE
COAST ON THURSDAY. MOST OF THE STEADY PRECIPITATION WILL BE ALONG
THE COAST...HOWEVER...INCREASING CYCLONIC FLOW AND DEEP LAYER
MOISTURE ALONG WITH COLD UPPER LEVEL TEMPERATURES KEEPS THE CHANCE
FOR SHOWERS ALONG THE MOUNTAINS IN THE COOK INLET
REGION...ESPECIALLY IN THE COPPER RIVER BASIN. THIS SYSTEM EXITS
ON FRIDAY DRYING CONDITIONS OUT AGAIN. THE EXTENDED FORECAST THEN
REVOLVES AROUND A FRONT MOVING INTO THE BERING SEA LATE THIS WEEK.
THIS FRONT IS CURRENTLY PROGGED TO MOVE INTO THE GULF IN SOME
FASHION THROUGH EARLY NEXT WEEK...BUT GUIDANCE DOES NOT HAVE A
GOOD HANDLE ON THE EVOLUTION OF THE FLOW PATTERN ALOFT. THE BEST
AGREEMENT IN GUIDANCE THE PAST COUPLE DAYS HAS BEEN KEEPING THE
MAINLAND ON THE COOL SIDE OF THE JET WHILE ENERGY SLIDES TO THE
SOUTH. THIS WOULD RETURN THE AREA TO NORMAL OR SLIGHTLY ABOVE
NORMAL TEMPERATURE WITH THE BEST CHANCES FOR PRECIPITATION
REMAINING IN THE GULF AND ALONG THE COAST.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...119 120 131 132 136 138 150 155 172 176 178
         HEAVY FREEZING SPRAY 179 180.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...ML




000
FXAK68 PAFC 011323
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
523 AM AKDT WED APR 1 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS OVER THE REGION WITH A NEARLY ZONAL
SUBTROPICAL JET DRIVING SYSTEMS EASTWARD ACROSS THE NORTH PACIFIC
AND ALEUTIANS. A RIDGE CONTINUES TO BUILD OVER THE WESTERN BERING
...WITH A SECOND RIDGE OVER THE INTERIOR YUKON AND EASTERN
INTERIOR OF ALASKA SLIDING SLOWLY NORTH. THIS IS PARTLY IN
RESPONSE TO INCREASINGLY CYCLONIC FLOW IN ASSOCIATION WITH THE
CONSOLIDATING UPPER LEVEL LOW ALONG THE NORTHERN EDGE OF A STRONG
JET STREAK SOUTH OF THE AKPEN AND KODIAK ISLAND. AS THE TROUGH
CONTINUES TO CONSOLIDATE ALONG THE NORTHERN EDGE OF THE JET
STREAK...WITH PERIPHERAL EFFECTS BEING FELT ALONG THE SOUTHERN END
OF THE AKPEN AND LATER TODAY TOWARDS KODIAK ISLAND. DECENT
NORTHERLY COLD ADVECTION CAN BE EXPECTED ALONG THE BACK SIDE OF
THE LOW AND AHEAD OF THE BUILDING RIDGE OVER THE BERING WITH THE
BUILDING UPSTREAM RIDGE AS THE LOW CONTINUES TO EXIT STAGE EAST
TOWARD THE FAR SOUTHERN GULF.

NOT MUCH HAS CHANGED ACROSS SOUTHWEST AND SOUTHCENTRAL ALASKA AS A
SERIES OF MOSTLY VERY WEAK UPPER LEVEL WAVES TRACK IN FROM THE
GULF PRODUCING FAIRLY WIDESPREAD CLOUDS AND ISOLATED TO SCATTERED
CONVECTIVE SHOWERS. A WEAK AND ELONGATED TROUGH AXIS FROM THE
EASTERN BERING TO SOUTH OF KODIAK ISLAND IS PROGRESSING SLOWLY
NORTHEASTWARD TOWARD THE SOUTHERN MAINLAND...BUT THERE IS VERY
LITTLE VERTICAL MOTION OUT AHEAD OF IT. IF ANYTHING...THERE IS
IMPROVING CONDITIONS RIGHT OUT AHEAD OF THIS AS THE MORE
SIGNIFICANT UPPER WAVES MENTIONED REMAIN NORTH OF THE ALASKA RANGE AND
SOUTH TOWARD THE NORTH PACIFIC AND SOUTHERN GULF OF ALASKA.

&&

.MODEL DISCUSSION...
THERE CONTINUE TO BE SOME MINOR MODEL DIFFERENCES WITH TRACK OF
LOW SOUTH OF THE AKPEN AS IT HEADS INTO THE SOUTHERN GULF AS WELL
AS WITH WEAK TRIPLE POINT WHICH DEVELOPS OUT AHEAD OF IT. THIS
MAINLY AFFECTS WIND DIRECTIONS OVER THE SOUTHERN GULF WHICH WILL
GENERALLY BE ON THE LIGHT SIDE IN VICINITY OF THE MAIN LOW CENTER.
WILL CONTINUE TO USE AN AVERAGE POSITION OF THE VARIOUS MODELS
FOR THE UPDATED FORECAST. OVERALL THERE IS A TREND TOWARD A WEAKER
TRIPLE POINT LOW AND FARTHER SOUTH TRACK OF THE MAIN LOW.
THUS...THE OCCLUDED FRONT WILL MAKE LESS NORTH AND WEST PROGRESS
RESULTING IN LESS PRECIP FOR KODIAK ISLAND AND THE NORTH GULF
COAST. OUTSIDE OF THE DETAILS OF THE LOW TRACK FORECAST CONFIDENCE
IS GENERALLY ABOVE AVERAGE.

OVER SOUTHCENTRAL...MARGINALLY UNSTABLE CONDITIONS WILL CONTINUE
OVER THE REGION THROUGH TODAY BEFORE INCREASING STABILIZATION WITH
FLOW BACKING AND BECOMING OFFSHORE BY THURSDAY.

OUT OVER THE FAR WESTERN BERING...A GALE-FORCE FRONT OVER THE
WESTERN BERING ASSOCIATED WITH A KAMCHATKA LOW WILL HELP AMPLIFY
THE DOWNSTREAM RIDGE OVER THE CENTRAL AND EASTERN BERING AND
WESTERN MAINLAND OVER THE NEXT COUPLE OF DAYS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THERE ARE TWO MAIN SYSTEMS WHICH WILL INFLUENCE THE WEATHER
ACROSS THE GULF AND THE SOUTHCENTRAL MAINLAND OVER THE NEXT COUPLE
OF DAYS. THE FIRST FEATURE IS AN UPPER WAVE OVER THE NORTHERN GULF
OF ALASKA WHICH MOVES ACROSS SOUTHCENTRAL TODAY AND INTO THE
INTERIOR TONIGHT. THIS FEATURE WILL BE THE DRIVING FORCE FOR
CONTINUED SHOWER ACTIVITY ACROSS SOUTHCENTRAL TODAY AND THIS
EVENING. THE SECOND FEATURE/S IS THE LOW SOUTH OF THE AK PEN AND
ITS ASSOCIATED OCCLUDED FRONT APPROACHING KODIAK/SOUTHERN GULF
THIS MORNING. THE FRONTAL SYSTEM MOVES INTO THE NORTHERN GULF
ALASKA TONIGHT AND WILL BRING RAIN TO THE COASTS ALONG WITH GALES
OVER SELECTED MARINE AREAS. MEANWHILE...THE LOW WILL MOVE SOUTH OF
THE GULF OVER THE NEXT DAY OR SO WITH A COUPLE OF MINOR LOWS
DEVELOPING UNDER THE BROADENING UPPER TROUGH. THESE MINOR LOWS
WILL STAY IN THE GULF WITH THE MAIN INFLUENCE ON WIND FIELDS. BACK
TO THE FRONT...AS THE OVERALL LOW COMPLEX MOVES SOUTH AND EAST THE
FRONT WILL BE DRAGGED SOUTH AND EAST AND DRYING WILL OCCUR OVER
THE INLAND ON THU INTO FRI MORNING. THERE WILL ALSO BE BRISK
OUTFLOW WINDS ACROSS THE NORTH GULF COAST AND EASTERN LATE
TONIGHT/EARLY THU WHICH WILL CARRY INTO THE EARLY AFTERNOON HOURS.
WE MAY ALSO SEE FAIRLY WARM TEMPS IN THE OUTFLOW AREAS AS THE
GAP/KATABATIC FLOWS WILL KEEP THE SEABREEZES AT BAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE NORTH PACIFIC LOW POSITIONED SOUTH OF KODIAK ISLAND THIS
MORNING WILL BRING WRAP-AROUND SCATTERED RAIN SHOWERS ALONG THE
ALASKA RANGE AND THE ALEUTIAN RANGE THROUGH WEDNESDAY AFTERNOON.
BY THURSDAY THE LOW PRESSURE SYSTEM WILL MOVE INTO THE EASTERN
SIDE OF THE GULF. THIS WILL RESULT IN THE SOUTHWEST ALASKA REGION
WITH DRIER CONDITIONS ACCOMPANIED BY NORTHERLY WINDS AND COOLER
TEMPERATURES HEADING INTO THE WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
AS THE NORTH PACIFIC LOW CONTINUES TO MOVE EASTWARD TOWARD THE
GULF...THIS WILL BRING GUSTY NORTHWESTERLY GAP WINDS ALONG THE
EASTERN ALEUTIANS THIS MORNING THROUGH THURSDAY. THIS WILL BRING
COOLER TEMPERATURES TO THE EASTERN ALEUTIANS AND THE ALASKA
PENINSULA. THIS WILL BE ACCOMPANIED BY A MIXTURE OF RAIN/SNOW
ALONG THE ALEUTIANS AND SNOW FARTHER NORTH INTO THE EASTERN
BERING SEA THROUGH THURSDAY. AN UPPER LEVEL RIDGE WILL BUILD
INTO THE CENTRAL BERING OVERNIGHT TONIGHT WITH STRATUS AND PATCHY
FOG UNDER THE RIDGE. IN THE WESTERN ALEUTIANS...A GALE FORCE NORTH
PACIFIC LOW TRACKS ALONG THE KAMCHATKA PENINSULA AND WILL BE
ACCOMPANIED BY A FRONTAL SYSTEM MOVING THROUGH NEAR SHEMYA THIS
MORNING BEFORE ENTERING THE WESTERN BERING SEA. THIS WILL BRING
WARMER TEMPERATURES AND PRECIPITATION WITH GUSTY WINDS TO THE
WESTERN ALEUTIANS AND WESTERN BERING SEA THROUGH WEDNESDAY
EVENING. A SECOND LOW WILL FORM BY THURSDAY EVENING NEAR SHEMYA
AND WILL BRING WARMER TEMPERATURES AND PRECIPITATION IN THE FORM
OF ALL RAIN HEADING INTO THE WEEKEND FOR THE WESTERN
ALEUTIANS/BERING SEA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
A FRONTAL BOUNDARY WILL LINGER IN THE NORTH GULF AND ALONG THE
COAST ON THURSDAY. MOST OF THE STEADY PRECIPITATION WILL BE ALONG
THE COAST...HOWEVER...INCREASING CYCLONIC FLOW AND DEEP LAYER
MOISTURE ALONG WITH COLD UPPER LEVEL TEMPERATURES KEEPS THE CHANCE
FOR SHOWERS ALONG THE MOUNTAINS IN THE COOK INLET
REGION...ESPECIALLY IN THE COPPER RIVER BASIN. THIS SYSTEM EXITS
ON FRIDAY DRYING CONDITIONS OUT AGAIN. THE EXTENDED FORECAST THEN
REVOLVES AROUND A FRONT MOVING INTO THE BERING SEA LATE THIS WEEK.
THIS FRONT IS CURRENTLY PROGGED TO MOVE INTO THE GULF IN SOME
FASHION THROUGH EARLY NEXT WEEK...BUT GUIDANCE DOES NOT HAVE A
GOOD HANDLE ON THE EVOLUTION OF THE FLOW PATTERN ALOFT. THE BEST
AGREEMENT IN GUIDANCE THE PAST COUPLE DAYS HAS BEEN KEEPING THE
MAINLAND ON THE COOL SIDE OF THE JET WHILE ENERGY SLIDES TO THE
SOUTH. THIS WOULD RETURN THE AREA TO NORMAL OR SLIGHTLY ABOVE
NORMAL TEMPERATURE WITH THE BEST CHANCES FOR PRECIPITATION
REMAINING IN THE GULF AND ALONG THE COAST.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...119 120 131 132 136 138 150 155 172 176 178
         HEAVY FREEZING SPRAY 179 180.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...ML



000
FXAK68 PAFC 011323 CCA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
523 AM AKDT WED APR 1 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS OVER THE REGION WITH A NEARLY ZONAL SUBTROPICAL
JET DRIVING SYSTEMS EASTWARD ACROSS THE NORTH PACIFIC AND ALEUTIANS.
A RIDGE CONTINUES TO BUILD OVER THE WESTERN BERING...WITH A SECOND
RIDGE OVER THE INTERIOR YUKON AND EASTERN INTERIOR OF ALASKA SLIDING
SLOWLY NORTH. THIS IS PARTLY IN RESPONSE TO INCREASINGLY CYCLONIC
FLOW IN ASSOCIATION WITH THE CONSOLIDATING UPPER LEVEL LOW ALONG
THE NORTHERN EDGE OF A STRONG JET STREAK SOUTH OF THE AKPEN AND
KODIAK ISLAND. AS THE TROUGH CONTINUES TO CONSOLIDATE ALONG THE
NORTHERN EDGE OF THE JET STREAK...WITH PERIPHERAL EFFECTS BEING
FELT ALONG THE SOUTHERN END OF THE AKPEN AND LATER TODAY TOWARDS
KODIAK ISLAND. DECENT NORTHERLY COLD ADVECTION CAN BE EXPECTED
ALONG THE BACK SIDE OF THE LOW AND AHEAD OF THE BUILDING RIDGE
OVER THE BERING WITH THE BUILDING UPSTREAM RIDGE AS THE LOW
CONTINUES TO EXIT STAGE EAST TOWARD THE FAR SOUTHERN GULF.

NOT MUCH HAS CHANGED ACROSS SOUTHWEST AND SOUTHCENTRAL ALASKA AS A
SERIES OF MOSTLY VERY WEAK UPPER LEVEL WAVES TRACK IN FROM THE
GULF PRODUCING FAIRLY WIDESPREAD CLOUDS AND ISOLATED TO SCATTERED
CONVECTIVE SHOWERS. A WEAK AND ELONGATED TROUGH AXIS FROM THE
EASTERN BERING TO SOUTH OF KODIAK ISLAND IS PROGRESSING SLOWLY
NORTHEASTWARD TOWARD THE SOUTHERN MAINLAND...BUT THERE IS VERY
LITTLE VERTICAL MOTION OUT AHEAD OF IT. IF ANYTHING...THERE IS
IMPROVING CONDITIONS RIGHT OUT AHEAD OF THIS AS THE MORE
SIGNIFICANT UPPER WAVES MENTIONED REMAIN NORTH OF THE ALASKA RANGE AND
SOUTH TOWARD THE NORTH PACIFIC AND SOUTHERN GULF OF ALASKA.

&&

.MODEL DISCUSSION...
THERE CONTINUE TO BE SOME MINOR MODEL DIFFERENCES WITH TRACK OF
LOW SOUTH OF THE AKPEN AS IT HEADS INTO THE SOUTHERN GULF AS WELL
AS WITH WEAK TRIPLE POINT WHICH DEVELOPS OUT AHEAD OF IT. THIS
MAINLY AFFECTS WIND DIRECTIONS OVER THE SOUTHERN GULF WHICH WILL
GENERALLY BE ON THE LIGHT SIDE IN VICINITY OF THE MAIN LOW CENTER.
WILL CONTINUE TO USE AN AVERAGE POSITION OF THE VARIOUS MODELS
FOR THE UPDATED FORECAST. OVERALL THERE IS A TREND TOWARD A WEAKER
TRIPLE POINT LOW AND FARTHER SOUTH TRACK OF THE MAIN LOW.
THUS...THE OCCLUDED FRONT WILL MAKE LESS NORTH AND WEST PROGRESS
RESULTING IN LESS PRECIP FOR KODIAK ISLAND AND THE NORTH GULF
COAST. OUTSIDE OF THE DETAILS OF THE LOW TRACK FORECAST CONFIDENCE
IS GENERALLY ABOVE AVERAGE.

OVER SOUTHCENTRAL...MARGINALLY UNSTABLE CONDITIONS WILL CONTINUE
OVER THE REGION THROUGH TODAY BEFORE INCREASING STABILIZATION WITH
FLOW BACKING AND BECOMING OFFSHORE BY THURSDAY.

OUT OVER THE FAR WESTERN BERING...A GALE-FORCE FRONT OVER THE
WESTERN BERING ASSOCIATED WITH A KAMCHATKA LOW WILL HELP AMPLIFY
THE DOWNSTREAM RIDGE OVER THE CENTRAL AND EASTERN BERING AND
WESTERN MAINLAND OVER THE NEXT COUPLE OF DAYS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
THERE ARE TWO MAIN SYSTEMS WHICH WILL INFLUENCE THE WEATHER
ACROSS THE GULF AND THE SOUTHCENTRAL MAINLAND OVER THE NEXT COUPLE
OF DAYS. THE FIRST FEATURE IS AN UPPER WAVE OVER THE NORTHERN GULF
OF ALASKA WHICH MOVES ACROSS SOUTHCENTRAL TODAY AND INTO THE
INTERIOR TONIGHT. THIS FEATURE WILL BE THE DRIVING FORCE FOR
CONTINUED SHOWER ACTIVITY ACROSS SOUTHCENTRAL TODAY AND THIS
EVENING. THE SECOND FEATURE/S IS THE LOW SOUTH OF THE AK PEN AND
ITS ASSOCIATED OCCLUDED FRONT APPROACHING KODIAK/SOUTHERN GULF
THIS MORNING. THE FRONTAL SYSTEM MOVES INTO THE NORTHERN GULF
ALASKA TONIGHT AND WILL BRING RAIN TO THE COASTS ALONG WITH GALES
OVER SELECTED MARINE AREAS. MEANWHILE...THE LOW WILL MOVE SOUTH OF
THE GULF OVER THE NEXT DAY OR SO WITH A COUPLE OF MINOR LOWS
DEVELOPING UNDER THE BROADENING UPPER TROUGH. THESE MINOR LOWS
WILL STAY IN THE GULF WITH THE MAIN INFLUENCE ON WIND FIELDS. BACK
TO THE FRONT...AS THE OVERALL LOW COMPLEX MOVES SOUTH AND EAST THE
FRONT WILL BE DRAGGED SOUTH AND EAST AND DRYING WILL OCCUR OVER
THE INLAND ON THU INTO FRI MORNING. THERE WILL ALSO BE BRISK
OUTFLOW WINDS ACROSS THE NORTH GULF COAST AND EASTERN LATE
TONIGHT/EARLY THU WHICH WILL CARRY INTO THE EARLY AFTERNOON HOURS.
WE MAY ALSO SEE FAIRLY WARM TEMPS IN THE OUTFLOW AREAS AS THE
GAP/KATABATIC FLOWS WILL KEEP THE SEA BREEZES AT BAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE NORTH PACIFIC LOW POSITIONED SOUTH OF KODIAK ISLAND THIS
MORNING WILL BRING WRAP-AROUND SCATTERED RAIN SHOWERS ALONG THE
ALASKA RANGE AND THE ALEUTIAN RANGE THROUGH WEDNESDAY AFTERNOON.
BY THURSDAY THE LOW PRESSURE SYSTEM WILL MOVE INTO THE EASTERN
SIDE OF THE GULF. THIS WILL RESULT IN THE SOUTHWEST ALASKA REGION
WITH DRIER CONDITIONS ACCOMPANIED BY NORTHERLY WINDS AND COOLER
TEMPERATURES HEADING INTO THE WEEKEND.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
AS THE NORTH PACIFIC LOW CONTINUES TO MOVE EASTWARD TOWARD THE
GULF...THIS WILL BRING GUSTY NORTHWESTERLY GAP WINDS ALONG THE
EASTERN ALEUTIANS THIS MORNING THROUGH THURSDAY. THIS WILL BRING
COOLER TEMPERATURES TO THE EASTERN ALEUTIANS AND THE ALASKA
PENINSULA. THIS WILL BE ACCOMPANIED BY A MIXTURE OF RAIN/SNOW
ALONG THE ALEUTIANS AND SNOW FARTHER NORTH INTO THE EASTERN
BERING SEA THROUGH THURSDAY. AN UPPER LEVEL RIDGE WILL BUILD
INTO THE CENTRAL BERING OVERNIGHT TONIGHT WITH STRATUS AND PATCHY
FOG UNDER THE RIDGE. IN THE WESTERN ALEUTIANS...A GALE FORCE NORTH
PACIFIC LOW TRACKS ALONG THE KAMCHATKA PENINSULA AND WILL BE
ACCOMPANIED BY A FRONTAL SYSTEM MOVING THROUGH NEAR SHEMYA THIS
MORNING BEFORE ENTERING THE WESTERN BERING SEA. THIS WILL BRING
WARMER TEMPERATURES AND PRECIPITATION WITH GUSTY WINDS TO THE
WESTERN ALEUTIANS AND WESTERN BERING SEA THROUGH WEDNESDAY
EVENING. A SECOND LOW WILL FORM BY THURSDAY EVENING NEAR SHEMYA
AND WILL BRING WARMER TEMPERATURES AND PRECIPITATION IN THE FORM
OF ALL RAIN HEADING INTO THE WEEKEND FOR THE WESTERN
ALEUTIANS/BERING SEA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
A FRONTAL BOUNDARY WILL LINGER IN THE NORTH GULF AND ALONG THE
COAST ON THURSDAY. MOST OF THE STEADY PRECIPITATION WILL BE ALONG
THE COAST...HOWEVER...INCREASING CYCLONIC FLOW AND DEEP LAYER
MOISTURE ALONG WITH COLD UPPER LEVEL TEMPERATURES KEEPS THE CHANCE
FOR SHOWERS ALONG THE MOUNTAINS IN THE COOK INLET
REGION...ESPECIALLY IN THE COPPER RIVER BASIN. THIS SYSTEM EXITS
ON FRIDAY DRYING CONDITIONS OUT AGAIN. THE EXTENDED FORECAST THEN
REVOLVES AROUND A FRONT MOVING INTO THE BERING SEA LATE THIS WEEK.
THIS FRONT IS CURRENTLY PROGGED TO MOVE INTO THE GULF IN SOME
FASHION THROUGH EARLY NEXT WEEK...BUT GUIDANCE DOES NOT HAVE A
GOOD HANDLE ON THE EVOLUTION OF THE FLOW PATTERN ALOFT. THE BEST
AGREEMENT IN GUIDANCE THE PAST COUPLE DAYS HAS BEEN KEEPING THE
MAINLAND ON THE COOL SIDE OF THE JET WHILE ENERGY SLIDES TO THE
SOUTH. THIS WOULD RETURN THE AREA TO NORMAL OR SLIGHTLY ABOVE
NORMAL TEMPERATURE WITH THE BEST CHANCES FOR PRECIPITATION
REMAINING IN THE GULF AND ALONG THE COAST.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...119 120 131 132 136 138 150 155 172 176 178
         HEAVY FREEZING SPRAY 179 180.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...ML


  [top]

000
FXAK69 PAFG 010929
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
129 AM AKDT WED APR 1 2015

.DISCUSSION...
MODELS SIMILAR THROUGH 60 HOURS. LONG WAVE UPPER LEVEL TROUGH WILL
DEVELOP OVER MOST ALL OF NORTHERN ALASKA THROUGH WEDNESDAY. WEAK
UPPER LOW WITH MINOR SHORT WAVE TROUGH MOVING NORTH OVER CENTRAL
ALASKA. THIS WILL SPREAD SOME SCATTERED RAIN AND SNOW SHOWERS OVER
NORTHERN ALASKA.

TIGHT GRADIENT OVER THE ARCTIC COAST WILL CONTINUE THROUGH MOST OF
THE DAY ON WEDNESDAY. THIS WILL CONTINUE BLOWING SNOW OVER MOST
AREAS. THE GRADIENT WILL BEGIN TO RELAX BY EARLY WED AFTERNOON.

AN UPPER LEVEL TROUGH HANGS ON TO THE WEST COAST AND IS PROVIDING
SNOW LIGHT SNOW SHOWERS OVER THE AREA BEFORE IT MOVES EAST ON
THURSDAY.

LONGER TERM MODELS FOR INTO NEXT WEEK INDICATE A COOLER THAN
NORMAL PATTERN OVERALL FOR MUCH OF NORTHERN ALASKA.

&&

.FIRE WEATHER...NONE.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CF APR 15




000
FXAK69 PAFG 010929
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
129 AM AKDT WED APR 1 2015

.DISCUSSION...
MODELS SIMILAR THROUGH 60 HOURS. LONG WAVE UPPER LEVEL TROUGH WILL
DEVELOP OVER MOST ALL OF NORTHERN ALASKA THROUGH WEDNESDAY. WEAK
UPPER LOW WITH MINOR SHORT WAVE TROUGH MOVING NORTH OVER CENTRAL
ALASKA. THIS WILL SPREAD SOME SCATTERED RAIN AND SNOW SHOWERS OVER
NORTHERN ALASKA.

TIGHT GRADIENT OVER THE ARCTIC COAST WILL CONTINUE THROUGH MOST OF
THE DAY ON WEDNESDAY. THIS WILL CONTINUE BLOWING SNOW OVER MOST
AREAS. THE GRADIENT WILL BEGIN TO RELAX BY EARLY WED AFTERNOON.

AN UPPER LEVEL TROUGH HANGS ON TO THE WEST COAST AND IS PROVIDING
SNOW LIGHT SNOW SHOWERS OVER THE AREA BEFORE IT MOVES EAST ON
THURSDAY.

LONGER TERM MODELS FOR INTO NEXT WEEK INDICATE A COOLER THAN
NORMAL PATTERN OVERALL FOR MUCH OF NORTHERN ALASKA.

&&

.FIRE WEATHER...NONE.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CF APR 15




000
FXAK69 PAFG 010929
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
129 AM AKDT WED APR 1 2015

.DISCUSSION...
MODELS SIMILAR THROUGH 60 HOURS. LONG WAVE UPPER LEVEL TROUGH WILL
DEVELOP OVER MOST ALL OF NORTHERN ALASKA THROUGH WEDNESDAY. WEAK
UPPER LOW WITH MINOR SHORT WAVE TROUGH MOVING NORTH OVER CENTRAL
ALASKA. THIS WILL SPREAD SOME SCATTERED RAIN AND SNOW SHOWERS OVER
NORTHERN ALASKA.

TIGHT GRADIENT OVER THE ARCTIC COAST WILL CONTINUE THROUGH MOST OF
THE DAY ON WEDNESDAY. THIS WILL CONTINUE BLOWING SNOW OVER MOST
AREAS. THE GRADIENT WILL BEGIN TO RELAX BY EARLY WED AFTERNOON.

AN UPPER LEVEL TROUGH HANGS ON TO THE WEST COAST AND IS PROVIDING
SNOW LIGHT SNOW SHOWERS OVER THE AREA BEFORE IT MOVES EAST ON
THURSDAY.

LONGER TERM MODELS FOR INTO NEXT WEEK INDICATE A COOLER THAN
NORMAL PATTERN OVERALL FOR MUCH OF NORTHERN ALASKA.

&&

.FIRE WEATHER...NONE.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CF APR 15




000
FXAK69 PAFG 010929
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
129 AM AKDT WED APR 1 2015

.DISCUSSION...
MODELS SIMILAR THROUGH 60 HOURS. LONG WAVE UPPER LEVEL TROUGH WILL
DEVELOP OVER MOST ALL OF NORTHERN ALASKA THROUGH WEDNESDAY. WEAK
UPPER LOW WITH MINOR SHORT WAVE TROUGH MOVING NORTH OVER CENTRAL
ALASKA. THIS WILL SPREAD SOME SCATTERED RAIN AND SNOW SHOWERS OVER
NORTHERN ALASKA.

TIGHT GRADIENT OVER THE ARCTIC COAST WILL CONTINUE THROUGH MOST OF
THE DAY ON WEDNESDAY. THIS WILL CONTINUE BLOWING SNOW OVER MOST
AREAS. THE GRADIENT WILL BEGIN TO RELAX BY EARLY WED AFTERNOON.

AN UPPER LEVEL TROUGH HANGS ON TO THE WEST COAST AND IS PROVIDING
SNOW LIGHT SNOW SHOWERS OVER THE AREA BEFORE IT MOVES EAST ON
THURSDAY.

LONGER TERM MODELS FOR INTO NEXT WEEK INDICATE A COOLER THAN
NORMAL PATTERN OVERALL FOR MUCH OF NORTHERN ALASKA.

&&

.FIRE WEATHER...NONE.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CF APR 15




000
FXAK68 PAFC 010011
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
411 PM AKDT TUE MAR 31 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS OVER THE REGION WITH A NEARLY ZONAL
SUBTROPICAL JET DRIVING SYSTEMS EASTWARD ACROSS THE NORTH PACIFIC
AND ALEUTIANS. THE FLOW HAS BECOME MORE AMPLIFIED THE PAST 12
HOURS WITH A BUILDING RIDGE OVER THE WESTERN BERING OUT AHEAD OF
A SHORT-WAVE TROUGH DIGGING SOUTHEASTWARD OUT OF ASIA. THIS IS NOW
CAUSING DOWNSTREAM AMPLIFICATION WITH A LOW/TROUGH TRANSITING THE
ALEUTIANS/NORTH CENTRAL PACIFIC. A STRONG JET STREAK AND SHORT-
WAVE HAVE LED TO INTENSIFICATION OF THE LOW WHICH HAS NOW OCCLUDED
AND NEARLY STALLED SOUTH OF THE EASTERN ALEUTIANS. AS THE TROUGH
CONTINUES TO AMPLIFY THIS WILL CAUSE THE LOW TO TAKE A MORE
SOUTHERLY TRACK WITH THE EASTERN ALEUTIANS AND ALASKA PENINSULA ON
THE NORTHERN PERIPHERY OF THE STORM. THE AIR MASS OVER THE CENTRAL
BERING SEA IS QUITE COLD AS IS EVIDENT BY THE 12Z SOUNDING OUT OF
SAINT PAUL...WITH 850 TEMPS OF AROUND -14 DEGREES CELSIUS. WITH
THE BUILDING UPSTREAM RIDGE NORTHERLY FLOW IS JUST BEGINNING TO
STRENGTHEN AND WILL EVENTUALLY LEAD TO DECENT COLD ADVECTION AS
THE LOW EXITS.

NOT MUCH HAS CHANGED ACROSS SOUTHWEST AND SOUTHCENTRAL ALASKA AS A
SERIES OF MOSTLY VERY WEAK UPPER LEVEL WAVES TRACK IN FROM THE
GULF PRODUCING FAIRLY WIDESPREAD CLOUDS AND A FEW SHOWERS. A WEAK
AND ELONGATED TROUGH AXIS FROM THE EASTERN BERING TO SOUTH OF
KODIAK ISLAND IS PROGRESSING SLOWLY NORTHEASTWARD TOWARD THE
SOUTHERN MAINLAND...BUT THERE IS VERY LITTLE VERTICAL MOTION OUT
AHEAD OF IT. IF ANYTHING...THERE IS IMPROVING CONDITIONS RIGHT OUT
AHEAD OF THIS AS THE MORE SIGNIFICANT UPPER WAVES MENTIONED ABOVE
ARE PUSHED OFF TO THE NORTH.

&&

.MODEL DISCUSSION...
THERE CONTINUE TO BE SOME MINOR MODEL DIFFERENCES WITH TRACK OF
LOW SOUTH OF THE EASTERN ALEUTIANS AS IT HEADS INTO THE SOUTHERN
GULF AS WELL AS WITH WEAK TRIPLE POINT WHICH DEVELOPS OUT AHEAD
OF IT. THIS MAINLY AFFECTS WIND DIRECTIONS OVER THE SOUTHERN GULF
WHICH WILL GENERALLY BE ON THE LIGHT SIDE IN VICINITY OF THE MAIN
LOW CENTER. WILL USE AN AVERAGE POSITION OF THE VARIOUS MODELS FOR
THE UPDATED FORECAST. OVERALL THERE IS A TREND TOWARD A WEAKER
TRIPLE POINT LOW AND FARTHER SOUTH TRACK OF THE MAIN LOW.
THUS...THE OCCLUDED FRONT WILL MAKE LESS NORTH AND WEST PROGRESS
RESULTING IN LESS PRECIP FOR KODIAK ISLAND AND THE NORTH GULF
COAST. OUTSIDE OF THE DETAILS OF THE LOW TRACK FORECAST CONFIDENCE
IS GENERALLY ABOVE AVERAGE.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH THU NIGHT)...

AFTER A FEW NOTICEABLE BREAKS IN CLOUDS ACROSS THE REGION THIS
AFTERNOON...CLOUDS WILL BEGIN BUILDING BACK ACROSS THE REGION THIS
EVENING. WATER VAPOR IMAGERY DEPICTS A WEAK AND DISORGANIZED
SHORT WAVE PUSHING ACROSS THE WESTERN COPPER RIVER BASIN...THAT
HAS AIDED IN THE DEVELOPMENT OF SHOWER ACTIVITY ACROSS THE KENAI
PENINSULA AND PARTS OF THE MAT-SU VALLEY DURING THE DAY. THE 00Z
RAOB FROM PANC SHOWS THAT THE THERMAL PROFILE HAS COOLED (NOTED
MAINLY BY 850 AND 500 MB TEMPERATURES)...WHICH INDICATED SOME
ELEVATED INSTABILITY PRESENT ACROSS SOUTHCENTRAL ALASKA. WHILE THE
TEMP/DEW POINT DEPRESSION ACROSS ANCHORAGE AND THE MATSU VALLEY
RANGES FROM 10-15 DEGREES...ONCE TEMPERATURES BEGIN TO COOL THIS
EVENING AND THE COLUMN BEGINS TO SATURATE...SCATTERED RAIN AND
SNOW SHOWERS WILL BE SEEN ACROSS THE AREA. GREATEST CHANCES FOR
PRECIPITATION REMAIN ALONG THE EASTERN HALF OF THE KENAI PENINSULA
AS A DECAYING LOW IN PRICE WILLIAM SOUND PUSHES INLAND.

AN AREA OF LOW PRESSURE SKIRTING SOUTH OF THE ALASKA PENINSULA
WILL PUSH INTO THE WESTERN GULF TOMORROW AFTERNOON AND PUSH A
FRONT TOWARD THE NORTHERN GULF COAST. GUSTY WINDS WILL DEVELOP
THROUGH PORTAGE VALLEY AND TURNAGAIN ARM AS WELL AS THE KNIK
RIVER VALLEY. AS WINDS ACROSS TURNAGAIN ARM BEGIN TO INCREASE ON
WEDNESDAY...IT SHOULD HELP DIMINISH RAIN CHANCES ACROSS THE
ANCHORAGE BOWL. THIS LOW WILL QUICKLY PUSH INTO THE EASTERN GULF
ON THURSDAY AND ALLOW FOR PRECIPITATION CHANCES ACROSS THE GULF
COAST TO BEGIN TO DIMINISH. CLEARING SKIES ACROSS THE INTERIOR OR
SOUTHCENTRAL WILL BE SEEN THURSDAY AND CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LINGERING SCATTERED RAIN AND SNOW SHOWERS AROUND THE SOUTHWEST
MAINLAND HAVE QUICKLY TAPERED OFF THIS AFTERNOON...WITH SOME
REMAINING SCATTERED SHOWERS ALONG THE ALASKA PENINSULA AND
ALEUTIAN RANGE. THESE SHOWERS WILL PERSIST THROUGH THIS
EVENING...AS A WEAK WAVE TRACKS OVER BRISTOL BAY WHILE FURTHER
WEAKENING OVERNIGHT. MUCH OF THE MAINLAND WILL REMAIN DRY THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF PARTS OF THE BRISTOL
BAY ZONE. THE NEXT ROUND OF PRECIPITATION AND GUSTY WINDS WILL
CLIP THE ALASKA PENINSULA TOMORROW MORNING AND PERSIST THROUGH
THURSDAY MORNING...AS THE NORTH PACIFIC LOW TRACKS FURTHER
EASTWARD. AS THE SYSTEM ENTERS THE GULF EARLY THURSDAY
MORNING...SHOWERS WILL TAPER OFF AND COOLER TEMPERATURES WILL MOVE
IN OVER THE MAINLAND AS THE RIDGE OVER THE EASTERN BERING PUSHES
INTO THE SOUTHWEST COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A NORTH PACIFIC LOW SOUTH OF DUTCH HARBOR WILL BRING A MIX OF RAIN
AND SNOW TO THE EASTERN ALEUTIANS AND ALASKA PENINSULA THIS
EVENING...ALONG WITH SOME LOCALIZED GUSTY WINDS OVER THE AREA.
THIS SYSTEM WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE
ALEUTIAN CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY
TOMORROW AFTERNOON. AN AREA OF COLD AIR ADVECTION BEHIND THE
PASSING LOW WILL HELP GENERATE SOME STRONGER GUSTS AND SNOW
SHOWERS BEHIND THE SYSTEM...WHICH WILL BE REINFORCED BY A RIDGE
BUILDING INTO THE CENTRAL BERING OVERNIGHT TONIGHT. FURTHER
WEST...A STRONGER FRONTAL SYSTEM ASSOCIATED WITH A GALE FORCE LOW
OFF THE COAST OF THE KAMCHATKA PENINSULA WILL BRING THE NEXT ROUND
OF PRECIPITATION AND GUSTY WINDS TO THE WESTERN ALEUTIANS BY
TOMORROW AFTERNOON. GUSTY SOUTHERLY WINDS ASSOCIATED WITH THIS
SYSTEM WILL BRING IN SOME WARMER TEMPERATURES FROM THE NORTHERN
PACIFIC...CAUSING THE PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS
THE WARM FRONT PASSES THROUGH THE AREA...THIS SHOT OF WARMER AIR
WILL BE REINFORCED BY ANOTHER SYSTEM FORMING SOUTHWEST OF SHEMYA
THURSDAY AFTERNOON.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
A FRONTAL BOUNDARY WILL LINGER IN THE NORTH GULF AND ALONG THE
COAST ON THURSDAY. MOST OF THE STEADY PRECIPITATION WILL BE ALONG
THE COAST...HOWEVER...INCREASING CYCLONIC FLOW AND DEEP LAYER
MOISTURE ALONG WITH COLD UPPER LEVEL TEMPERATURES KEEPS THE CHANCE
FOR SHOWERS ALONG THE MOUNTAINS IN THE COOK INLET
REGION...ESPECIALLY IN THE COPPER RIVER BASIN. THIS SYSTEM EXITS
ON FRIDAY DRYING CONDITIONS OUT AGAIN. THE EXTENDED FORECAST THEN
REVOLVES AROUND A FRONT MOVING INTO THE BERING SEA LATE THIS WEEK.
THIS FRONT IS CURRENTLY PROGGED TO MOVE INTO THE GULF IN SOME
FASHION THROUGH EARLY NEXT WEEK...BUT GUIDANCE DOES NOT HAVE A
GOOD HANDLE ON THE EVOLUTION OF THE FLOW PATTERN ALOFT. THE BEST
AGREEMENT IN GUIDANCE THE PAST COUPLE DAYS HAS BEEN KEEPING THE
MAINLAND ON THE COOL SIDE OF THE JET WHILE ENERGY SLIDES TO THE
SOUTH. THIS WOULD RETURN THE AREA TO NORMAL OR SLIGHTLY ABOVE
NORMAL TEMPERATURE WITH THE BEST CHANCES FOR PRECIPITATION
REMAINING IN THE GULF AND ALONG THE COAST.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 120 131 132 150 155 172 178.
 HEAVY FREEZING SPRAY 179 180.
FIRE WEATHER...NONE.

&&

$$

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




000
FXAK68 PAFC 010011
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
411 PM AKDT TUE MAR 31 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS OVER THE REGION WITH A NEARLY ZONAL
SUBTROPICAL JET DRIVING SYSTEMS EASTWARD ACROSS THE NORTH PACIFIC
AND ALEUTIANS. THE FLOW HAS BECOME MORE AMPLIFIED THE PAST 12
HOURS WITH A BUILDING RIDGE OVER THE WESTERN BERING OUT AHEAD OF
A SHORT-WAVE TROUGH DIGGING SOUTHEASTWARD OUT OF ASIA. THIS IS NOW
CAUSING DOWNSTREAM AMPLIFICATION WITH A LOW/TROUGH TRANSITING THE
ALEUTIANS/NORTH CENTRAL PACIFIC. A STRONG JET STREAK AND SHORT-
WAVE HAVE LED TO INTENSIFICATION OF THE LOW WHICH HAS NOW OCCLUDED
AND NEARLY STALLED SOUTH OF THE EASTERN ALEUTIANS. AS THE TROUGH
CONTINUES TO AMPLIFY THIS WILL CAUSE THE LOW TO TAKE A MORE
SOUTHERLY TRACK WITH THE EASTERN ALEUTIANS AND ALASKA PENINSULA ON
THE NORTHERN PERIPHERY OF THE STORM. THE AIR MASS OVER THE CENTRAL
BERING SEA IS QUITE COLD AS IS EVIDENT BY THE 12Z SOUNDING OUT OF
SAINT PAUL...WITH 850 TEMPS OF AROUND -14 DEGREES CELSIUS. WITH
THE BUILDING UPSTREAM RIDGE NORTHERLY FLOW IS JUST BEGINNING TO
STRENGTHEN AND WILL EVENTUALLY LEAD TO DECENT COLD ADVECTION AS
THE LOW EXITS.

NOT MUCH HAS CHANGED ACROSS SOUTHWEST AND SOUTHCENTRAL ALASKA AS A
SERIES OF MOSTLY VERY WEAK UPPER LEVEL WAVES TRACK IN FROM THE
GULF PRODUCING FAIRLY WIDESPREAD CLOUDS AND A FEW SHOWERS. A WEAK
AND ELONGATED TROUGH AXIS FROM THE EASTERN BERING TO SOUTH OF
KODIAK ISLAND IS PROGRESSING SLOWLY NORTHEASTWARD TOWARD THE
SOUTHERN MAINLAND...BUT THERE IS VERY LITTLE VERTICAL MOTION OUT
AHEAD OF IT. IF ANYTHING...THERE IS IMPROVING CONDITIONS RIGHT OUT
AHEAD OF THIS AS THE MORE SIGNIFICANT UPPER WAVES MENTIONED ABOVE
ARE PUSHED OFF TO THE NORTH.

&&

.MODEL DISCUSSION...
THERE CONTINUE TO BE SOME MINOR MODEL DIFFERENCES WITH TRACK OF
LOW SOUTH OF THE EASTERN ALEUTIANS AS IT HEADS INTO THE SOUTHERN
GULF AS WELL AS WITH WEAK TRIPLE POINT WHICH DEVELOPS OUT AHEAD
OF IT. THIS MAINLY AFFECTS WIND DIRECTIONS OVER THE SOUTHERN GULF
WHICH WILL GENERALLY BE ON THE LIGHT SIDE IN VICINITY OF THE MAIN
LOW CENTER. WILL USE AN AVERAGE POSITION OF THE VARIOUS MODELS FOR
THE UPDATED FORECAST. OVERALL THERE IS A TREND TOWARD A WEAKER
TRIPLE POINT LOW AND FARTHER SOUTH TRACK OF THE MAIN LOW.
THUS...THE OCCLUDED FRONT WILL MAKE LESS NORTH AND WEST PROGRESS
RESULTING IN LESS PRECIP FOR KODIAK ISLAND AND THE NORTH GULF
COAST. OUTSIDE OF THE DETAILS OF THE LOW TRACK FORECAST CONFIDENCE
IS GENERALLY ABOVE AVERAGE.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH THU NIGHT)...

AFTER A FEW NOTICEABLE BREAKS IN CLOUDS ACROSS THE REGION THIS
AFTERNOON...CLOUDS WILL BEGIN BUILDING BACK ACROSS THE REGION THIS
EVENING. WATER VAPOR IMAGERY DEPICTS A WEAK AND DISORGANIZED
SHORT WAVE PUSHING ACROSS THE WESTERN COPPER RIVER BASIN...THAT
HAS AIDED IN THE DEVELOPMENT OF SHOWER ACTIVITY ACROSS THE KENAI
PENINSULA AND PARTS OF THE MAT-SU VALLEY DURING THE DAY. THE 00Z
RAOB FROM PANC SHOWS THAT THE THERMAL PROFILE HAS COOLED (NOTED
MAINLY BY 850 AND 500 MB TEMPERATURES)...WHICH INDICATED SOME
ELEVATED INSTABILITY PRESENT ACROSS SOUTHCENTRAL ALASKA. WHILE THE
TEMP/DEW POINT DEPRESSION ACROSS ANCHORAGE AND THE MATSU VALLEY
RANGES FROM 10-15 DEGREES...ONCE TEMPERATURES BEGIN TO COOL THIS
EVENING AND THE COLUMN BEGINS TO SATURATE...SCATTERED RAIN AND
SNOW SHOWERS WILL BE SEEN ACROSS THE AREA. GREATEST CHANCES FOR
PRECIPITATION REMAIN ALONG THE EASTERN HALF OF THE KENAI PENINSULA
AS A DECAYING LOW IN PRICE WILLIAM SOUND PUSHES INLAND.

AN AREA OF LOW PRESSURE SKIRTING SOUTH OF THE ALASKA PENINSULA
WILL PUSH INTO THE WESTERN GULF TOMORROW AFTERNOON AND PUSH A
FRONT TOWARD THE NORTHERN GULF COAST. GUSTY WINDS WILL DEVELOP
THROUGH PORTAGE VALLEY AND TURNAGAIN ARM AS WELL AS THE KNIK
RIVER VALLEY. AS WINDS ACROSS TURNAGAIN ARM BEGIN TO INCREASE ON
WEDNESDAY...IT SHOULD HELP DIMINISH RAIN CHANCES ACROSS THE
ANCHORAGE BOWL. THIS LOW WILL QUICKLY PUSH INTO THE EASTERN GULF
ON THURSDAY AND ALLOW FOR PRECIPITATION CHANCES ACROSS THE GULF
COAST TO BEGIN TO DIMINISH. CLEARING SKIES ACROSS THE INTERIOR OR
SOUTHCENTRAL WILL BE SEEN THURSDAY AND CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LINGERING SCATTERED RAIN AND SNOW SHOWERS AROUND THE SOUTHWEST
MAINLAND HAVE QUICKLY TAPERED OFF THIS AFTERNOON...WITH SOME
REMAINING SCATTERED SHOWERS ALONG THE ALASKA PENINSULA AND
ALEUTIAN RANGE. THESE SHOWERS WILL PERSIST THROUGH THIS
EVENING...AS A WEAK WAVE TRACKS OVER BRISTOL BAY WHILE FURTHER
WEAKENING OVERNIGHT. MUCH OF THE MAINLAND WILL REMAIN DRY THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF PARTS OF THE BRISTOL
BAY ZONE. THE NEXT ROUND OF PRECIPITATION AND GUSTY WINDS WILL
CLIP THE ALASKA PENINSULA TOMORROW MORNING AND PERSIST THROUGH
THURSDAY MORNING...AS THE NORTH PACIFIC LOW TRACKS FURTHER
EASTWARD. AS THE SYSTEM ENTERS THE GULF EARLY THURSDAY
MORNING...SHOWERS WILL TAPER OFF AND COOLER TEMPERATURES WILL MOVE
IN OVER THE MAINLAND AS THE RIDGE OVER THE EASTERN BERING PUSHES
INTO THE SOUTHWEST COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A NORTH PACIFIC LOW SOUTH OF DUTCH HARBOR WILL BRING A MIX OF RAIN
AND SNOW TO THE EASTERN ALEUTIANS AND ALASKA PENINSULA THIS
EVENING...ALONG WITH SOME LOCALIZED GUSTY WINDS OVER THE AREA.
THIS SYSTEM WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE
ALEUTIAN CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY
TOMORROW AFTERNOON. AN AREA OF COLD AIR ADVECTION BEHIND THE
PASSING LOW WILL HELP GENERATE SOME STRONGER GUSTS AND SNOW
SHOWERS BEHIND THE SYSTEM...WHICH WILL BE REINFORCED BY A RIDGE
BUILDING INTO THE CENTRAL BERING OVERNIGHT TONIGHT. FURTHER
WEST...A STRONGER FRONTAL SYSTEM ASSOCIATED WITH A GALE FORCE LOW
OFF THE COAST OF THE KAMCHATKA PENINSULA WILL BRING THE NEXT ROUND
OF PRECIPITATION AND GUSTY WINDS TO THE WESTERN ALEUTIANS BY
TOMORROW AFTERNOON. GUSTY SOUTHERLY WINDS ASSOCIATED WITH THIS
SYSTEM WILL BRING IN SOME WARMER TEMPERATURES FROM THE NORTHERN
PACIFIC...CAUSING THE PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS
THE WARM FRONT PASSES THROUGH THE AREA...THIS SHOT OF WARMER AIR
WILL BE REINFORCED BY ANOTHER SYSTEM FORMING SOUTHWEST OF SHEMYA
THURSDAY AFTERNOON.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
A FRONTAL BOUNDARY WILL LINGER IN THE NORTH GULF AND ALONG THE
COAST ON THURSDAY. MOST OF THE STEADY PRECIPITATION WILL BE ALONG
THE COAST...HOWEVER...INCREASING CYCLONIC FLOW AND DEEP LAYER
MOISTURE ALONG WITH COLD UPPER LEVEL TEMPERATURES KEEPS THE CHANCE
FOR SHOWERS ALONG THE MOUNTAINS IN THE COOK INLET
REGION...ESPECIALLY IN THE COPPER RIVER BASIN. THIS SYSTEM EXITS
ON FRIDAY DRYING CONDITIONS OUT AGAIN. THE EXTENDED FORECAST THEN
REVOLVES AROUND A FRONT MOVING INTO THE BERING SEA LATE THIS WEEK.
THIS FRONT IS CURRENTLY PROGGED TO MOVE INTO THE GULF IN SOME
FASHION THROUGH EARLY NEXT WEEK...BUT GUIDANCE DOES NOT HAVE A
GOOD HANDLE ON THE EVOLUTION OF THE FLOW PATTERN ALOFT. THE BEST
AGREEMENT IN GUIDANCE THE PAST COUPLE DAYS HAS BEEN KEEPING THE
MAINLAND ON THE COOL SIDE OF THE JET WHILE ENERGY SLIDES TO THE
SOUTH. THIS WOULD RETURN THE AREA TO NORMAL OR SLIGHTLY ABOVE
NORMAL TEMPERATURE WITH THE BEST CHANCES FOR PRECIPITATION
REMAINING IN THE GULF AND ALONG THE COAST.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 120 131 132 150 155 172 178.
 HEAVY FREEZING SPRAY 179 180.
FIRE WEATHER...NONE.

&&

$$

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



000
FXAK68 PAFC 010011
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
411 PM AKDT TUE MAR 31 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS OVER THE REGION WITH A NEARLY ZONAL
SUBTROPICAL JET DRIVING SYSTEMS EASTWARD ACROSS THE NORTH PACIFIC
AND ALEUTIANS. THE FLOW HAS BECOME MORE AMPLIFIED THE PAST 12
HOURS WITH A BUILDING RIDGE OVER THE WESTERN BERING OUT AHEAD OF
A SHORT-WAVE TROUGH DIGGING SOUTHEASTWARD OUT OF ASIA. THIS IS NOW
CAUSING DOWNSTREAM AMPLIFICATION WITH A LOW/TROUGH TRANSITING THE
ALEUTIANS/NORTH CENTRAL PACIFIC. A STRONG JET STREAK AND SHORT-
WAVE HAVE LED TO INTENSIFICATION OF THE LOW WHICH HAS NOW OCCLUDED
AND NEARLY STALLED SOUTH OF THE EASTERN ALEUTIANS. AS THE TROUGH
CONTINUES TO AMPLIFY THIS WILL CAUSE THE LOW TO TAKE A MORE
SOUTHERLY TRACK WITH THE EASTERN ALEUTIANS AND ALASKA PENINSULA ON
THE NORTHERN PERIPHERY OF THE STORM. THE AIR MASS OVER THE CENTRAL
BERING SEA IS QUITE COLD AS IS EVIDENT BY THE 12Z SOUNDING OUT OF
SAINT PAUL...WITH 850 TEMPS OF AROUND -14 DEGREES CELSIUS. WITH
THE BUILDING UPSTREAM RIDGE NORTHERLY FLOW IS JUST BEGINNING TO
STRENGTHEN AND WILL EVENTUALLY LEAD TO DECENT COLD ADVECTION AS
THE LOW EXITS.

NOT MUCH HAS CHANGED ACROSS SOUTHWEST AND SOUTHCENTRAL ALASKA AS A
SERIES OF MOSTLY VERY WEAK UPPER LEVEL WAVES TRACK IN FROM THE
GULF PRODUCING FAIRLY WIDESPREAD CLOUDS AND A FEW SHOWERS. A WEAK
AND ELONGATED TROUGH AXIS FROM THE EASTERN BERING TO SOUTH OF
KODIAK ISLAND IS PROGRESSING SLOWLY NORTHEASTWARD TOWARD THE
SOUTHERN MAINLAND...BUT THERE IS VERY LITTLE VERTICAL MOTION OUT
AHEAD OF IT. IF ANYTHING...THERE IS IMPROVING CONDITIONS RIGHT OUT
AHEAD OF THIS AS THE MORE SIGNIFICANT UPPER WAVES MENTIONED ABOVE
ARE PUSHED OFF TO THE NORTH.

&&

.MODEL DISCUSSION...
THERE CONTINUE TO BE SOME MINOR MODEL DIFFERENCES WITH TRACK OF
LOW SOUTH OF THE EASTERN ALEUTIANS AS IT HEADS INTO THE SOUTHERN
GULF AS WELL AS WITH WEAK TRIPLE POINT WHICH DEVELOPS OUT AHEAD
OF IT. THIS MAINLY AFFECTS WIND DIRECTIONS OVER THE SOUTHERN GULF
WHICH WILL GENERALLY BE ON THE LIGHT SIDE IN VICINITY OF THE MAIN
LOW CENTER. WILL USE AN AVERAGE POSITION OF THE VARIOUS MODELS FOR
THE UPDATED FORECAST. OVERALL THERE IS A TREND TOWARD A WEAKER
TRIPLE POINT LOW AND FARTHER SOUTH TRACK OF THE MAIN LOW.
THUS...THE OCCLUDED FRONT WILL MAKE LESS NORTH AND WEST PROGRESS
RESULTING IN LESS PRECIP FOR KODIAK ISLAND AND THE NORTH GULF
COAST. OUTSIDE OF THE DETAILS OF THE LOW TRACK FORECAST CONFIDENCE
IS GENERALLY ABOVE AVERAGE.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH THU NIGHT)...

AFTER A FEW NOTICEABLE BREAKS IN CLOUDS ACROSS THE REGION THIS
AFTERNOON...CLOUDS WILL BEGIN BUILDING BACK ACROSS THE REGION THIS
EVENING. WATER VAPOR IMAGERY DEPICTS A WEAK AND DISORGANIZED
SHORT WAVE PUSHING ACROSS THE WESTERN COPPER RIVER BASIN...THAT
HAS AIDED IN THE DEVELOPMENT OF SHOWER ACTIVITY ACROSS THE KENAI
PENINSULA AND PARTS OF THE MAT-SU VALLEY DURING THE DAY. THE 00Z
RAOB FROM PANC SHOWS THAT THE THERMAL PROFILE HAS COOLED (NOTED
MAINLY BY 850 AND 500 MB TEMPERATURES)...WHICH INDICATED SOME
ELEVATED INSTABILITY PRESENT ACROSS SOUTHCENTRAL ALASKA. WHILE THE
TEMP/DEW POINT DEPRESSION ACROSS ANCHORAGE AND THE MATSU VALLEY
RANGES FROM 10-15 DEGREES...ONCE TEMPERATURES BEGIN TO COOL THIS
EVENING AND THE COLUMN BEGINS TO SATURATE...SCATTERED RAIN AND
SNOW SHOWERS WILL BE SEEN ACROSS THE AREA. GREATEST CHANCES FOR
PRECIPITATION REMAIN ALONG THE EASTERN HALF OF THE KENAI PENINSULA
AS A DECAYING LOW IN PRICE WILLIAM SOUND PUSHES INLAND.

AN AREA OF LOW PRESSURE SKIRTING SOUTH OF THE ALASKA PENINSULA
WILL PUSH INTO THE WESTERN GULF TOMORROW AFTERNOON AND PUSH A
FRONT TOWARD THE NORTHERN GULF COAST. GUSTY WINDS WILL DEVELOP
THROUGH PORTAGE VALLEY AND TURNAGAIN ARM AS WELL AS THE KNIK
RIVER VALLEY. AS WINDS ACROSS TURNAGAIN ARM BEGIN TO INCREASE ON
WEDNESDAY...IT SHOULD HELP DIMINISH RAIN CHANCES ACROSS THE
ANCHORAGE BOWL. THIS LOW WILL QUICKLY PUSH INTO THE EASTERN GULF
ON THURSDAY AND ALLOW FOR PRECIPITATION CHANCES ACROSS THE GULF
COAST TO BEGIN TO DIMINISH. CLEARING SKIES ACROSS THE INTERIOR OR
SOUTHCENTRAL WILL BE SEEN THURSDAY AND CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LINGERING SCATTERED RAIN AND SNOW SHOWERS AROUND THE SOUTHWEST
MAINLAND HAVE QUICKLY TAPERED OFF THIS AFTERNOON...WITH SOME
REMAINING SCATTERED SHOWERS ALONG THE ALASKA PENINSULA AND
ALEUTIAN RANGE. THESE SHOWERS WILL PERSIST THROUGH THIS
EVENING...AS A WEAK WAVE TRACKS OVER BRISTOL BAY WHILE FURTHER
WEAKENING OVERNIGHT. MUCH OF THE MAINLAND WILL REMAIN DRY THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF PARTS OF THE BRISTOL
BAY ZONE. THE NEXT ROUND OF PRECIPITATION AND GUSTY WINDS WILL
CLIP THE ALASKA PENINSULA TOMORROW MORNING AND PERSIST THROUGH
THURSDAY MORNING...AS THE NORTH PACIFIC LOW TRACKS FURTHER
EASTWARD. AS THE SYSTEM ENTERS THE GULF EARLY THURSDAY
MORNING...SHOWERS WILL TAPER OFF AND COOLER TEMPERATURES WILL MOVE
IN OVER THE MAINLAND AS THE RIDGE OVER THE EASTERN BERING PUSHES
INTO THE SOUTHWEST COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A NORTH PACIFIC LOW SOUTH OF DUTCH HARBOR WILL BRING A MIX OF RAIN
AND SNOW TO THE EASTERN ALEUTIANS AND ALASKA PENINSULA THIS
EVENING...ALONG WITH SOME LOCALIZED GUSTY WINDS OVER THE AREA.
THIS SYSTEM WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE
ALEUTIAN CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY
TOMORROW AFTERNOON. AN AREA OF COLD AIR ADVECTION BEHIND THE
PASSING LOW WILL HELP GENERATE SOME STRONGER GUSTS AND SNOW
SHOWERS BEHIND THE SYSTEM...WHICH WILL BE REINFORCED BY A RIDGE
BUILDING INTO THE CENTRAL BERING OVERNIGHT TONIGHT. FURTHER
WEST...A STRONGER FRONTAL SYSTEM ASSOCIATED WITH A GALE FORCE LOW
OFF THE COAST OF THE KAMCHATKA PENINSULA WILL BRING THE NEXT ROUND
OF PRECIPITATION AND GUSTY WINDS TO THE WESTERN ALEUTIANS BY
TOMORROW AFTERNOON. GUSTY SOUTHERLY WINDS ASSOCIATED WITH THIS
SYSTEM WILL BRING IN SOME WARMER TEMPERATURES FROM THE NORTHERN
PACIFIC...CAUSING THE PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS
THE WARM FRONT PASSES THROUGH THE AREA...THIS SHOT OF WARMER AIR
WILL BE REINFORCED BY ANOTHER SYSTEM FORMING SOUTHWEST OF SHEMYA
THURSDAY AFTERNOON.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
A FRONTAL BOUNDARY WILL LINGER IN THE NORTH GULF AND ALONG THE
COAST ON THURSDAY. MOST OF THE STEADY PRECIPITATION WILL BE ALONG
THE COAST...HOWEVER...INCREASING CYCLONIC FLOW AND DEEP LAYER
MOISTURE ALONG WITH COLD UPPER LEVEL TEMPERATURES KEEPS THE CHANCE
FOR SHOWERS ALONG THE MOUNTAINS IN THE COOK INLET
REGION...ESPECIALLY IN THE COPPER RIVER BASIN. THIS SYSTEM EXITS
ON FRIDAY DRYING CONDITIONS OUT AGAIN. THE EXTENDED FORECAST THEN
REVOLVES AROUND A FRONT MOVING INTO THE BERING SEA LATE THIS WEEK.
THIS FRONT IS CURRENTLY PROGGED TO MOVE INTO THE GULF IN SOME
FASHION THROUGH EARLY NEXT WEEK...BUT GUIDANCE DOES NOT HAVE A
GOOD HANDLE ON THE EVOLUTION OF THE FLOW PATTERN ALOFT. THE BEST
AGREEMENT IN GUIDANCE THE PAST COUPLE DAYS HAS BEEN KEEPING THE
MAINLAND ON THE COOL SIDE OF THE JET WHILE ENERGY SLIDES TO THE
SOUTH. THIS WOULD RETURN THE AREA TO NORMAL OR SLIGHTLY ABOVE
NORMAL TEMPERATURE WITH THE BEST CHANCES FOR PRECIPITATION
REMAINING IN THE GULF AND ALONG THE COAST.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 120 131 132 150 155 172 178.
 HEAVY FREEZING SPRAY 179 180.
FIRE WEATHER...NONE.

&&

$$

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




000
FXAK67 PAJK 312327
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
327 PM AKDT TUE MAR 31 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE REVEALS A WEAKENING
LOW...ABOUT 1001 MB...OVER THE EASTERN GULF WITH A TROUGH
STRETCHING SOUTHEASTWARD FROM THE LOW CENTER TO NEAR HAIDA GWAII AND
A WEAK RIDGE OF HIGH PRESSURE BUILDS ACROSS THE SOUTHERN
PANHANDLE. LARGE AREA OF RAIN SHOWERS WRAPPING AROUND THE LOW
OVER THE OPEN OCEAN. BETWEEN THE RIDGE AND THE LOW...SOUTHERLY
ONSHORE FLOW 10 TO 15 MPH PREVAIL OVER THE PANHANDLE WITH SMALL
CRAFT LEVEL WINDS ACROSS NORTHERN LYNN CANAL. ACROSS THE OUTER
WATERS...SOUTH TO SOUTHWEST WINDS AROUND 15 KNOTS PREVAIL WITH
ROUGH SMALL CRAFT LEVEL SEAS 8 TO 12 FEET DUE TO LONG PERIOD
SOUTHWEST SWELLS. AFTERNOON TEMPERATURES RANGE IN THE LOWER TO MID
40S.

MODELS REMAIN IN GENERAL AGREEMENT FOR THE WEAKENING LOW IN THE
EASTERN GULF THIS EVENING DISSIPATES BY EARLY WEDNESDAY MORNING AS
THE RIDGE OF HIGH PRESSURE CONTINUES TO BUILD OVER THE PANHANDLE
THROUGH LATE WEDNESDAY. A DEVELOPING LOW IN THE WESTERN GULF ON
WEDNESDAY AFTERNOON WILL MOVE EASTWARD AND PUSH THE RIDGE A LITTLE
TO THE EAST. REFRESHED THE INHERITED FORECAST WITH THE GFS AND NAM
FOR THEIR GOOD CONSENSUS.

AS THE RIDGE CONTINUES TO BUILD...THE SMALL CRAFT LEVEL SOUTHERLY
WINDS LATE THIS AFTERNOON OVER NORTHERN LYNN CANAL WILL DIMINISH
THIS EVENING. EXPECT NO SMALL CRAFT LEVEL WINDS ACROSS THE OUTER
WATERS...BUT THE ROUGH SEAS WILL REMAIN THROUGH WEDNESDAY DUE TO
SWELLS. A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS SOUTHEAST
ALASKA WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS RAIN SHOWERS
ON AND OFF BASES TONIGHT AND WEDNESDAY. DUE TO ONGOING RAIN
SHOWERS AND CLOUD COVER...EXPECT SMALL DIURNAL TEMPERATURE
FLUCTUATIONS WITH OVERNIGHT LOWS MOSTLY IN THE MID TO UPPER 30S
AND WEDNESDAY HIGHS IN THE MID 40S.

.LONG TERM...AFTER A DAY OF RELATIVE AGREEMENT IN THE LONG RANGE
IN YESTERDAY`S AM PACKAGE...WE RETURN TO GENERAL MODEL
DISAGREEMENT AFTER 4-5 DAYS IN TODAY`S PACKAGE. MODERATE FRONT
APPROACHING THE COASTLINE AT 03Z THURS IS BEING PUSHED BY UPPER
CLOSED LOW BARGING INTO THE CENTRAL GULF WITH 1000 MB LOW SURFACE
REFLECTION. THE SURFACE LOW...A TWEAK FASTER ON THE NEW MODEL
UPDATES...SLOWS RAPIDLY AFTER ABOUT 09Z AND THEN TAKES A TURN TO
THE SOUTHEAST AS IT BEGINS TO SLOWLY WEAKEN LATE ON THU. FRONT`S
MAIN IMPACT WILL BE A MODERATE EAST-WEST PRESSURE GRADIENT AND SCA-
LEVEL SE WINDS OVER MOSTLY THE SOUTHERN INNER CHANNELS DURING THE
DAY ON FRI WHILE MUCH OF THE ADJACENT OUTER WATERS WILL HAVE WINDS
IN VICINITY OF 30KT SUSTAINED FOR A PERIOD EARLY ON THURSDAY
BEFORE THE WEAKENING TAKES OVER. THIS INCLUDES A BRIEF BARRIER JET
ENHANCEMENT OVER THE NORTHWESTERN MARINE AREA. INLAND/COASTAL WINDS
WILL LIKELY BE SUB- STRONG WIND LEVEL THROUGH THE EVENT. MEANWHILE ON
THU MODERATE RAIN WILL SPREAD INTO THE SOUTHERN HALF OF THE
PANHANDLE WHILE LIGHTER PRECIP WILL COVER MUCH OF THE NORTH. WITH
THE NAM AMOUNTS APPEARING TO BE OVERDONE STILL HAVE TOTAL VALUES
WELL OVER AN INCH TO 2 INCHES OVER FAVORABLE AREAS OF THE SOUTH.
EC/NAM COMBO UTILIZED FOR MUCH OF THESE EARLY UPDATES THOUGH MODEL
DIFFERENCES WERE MINOR. THESE INCLUDED BUMPING HI TEMPS UPWARDS ON
THU BY A COUPLE DEGREES F. THE LOW IS SLOW TO MOVE OUT TO THE
SOUTHEAST ON FRI AND SHOWERS APPEAR LIKELY TO LINGER OVER MOSTLY
THE SOUTHERN HALF OF THE PANHANDLE...ESPECIALLY IF THE PERSISTENT
RETENTION OF ENERGY TO THE SOUTH ADVERTISED BY THE GFS VERIFIES.

SATURDAY APPEARS TO BE POTENTIALLY MOSTLY DRY FOR ALL BUT SOUTHERN
AREAS ON THE CURRENT GUIDANCE AS UPPER RIDGING GENERALLY TAKES
OVER THE GULF...HOWEVER THIS IS WHERE MODEL GUIDANCE BEGINS TO
DIVERGE  SIGNIFICANTLY. THE EC BRINGS A MODERATE WAVE
SOUTHEASTWARD THROUGH THE PANHANDLE WITHIN THE NW FLOW
ALOFT SUN/SUN PM...ALTHOUGH WEAKER THAN PREVIOUS RUNS. THE GEM
SOLUTION IS FOR A TRACK SOUTHEASTWARD THROUGH THE CENTRAL GULF
WITH A STRONGER WAVE. YET ANOTHER SOLUTION IS THE GFS...WHICH
SHOWS A WEAKENING WAVE AND FRONT MOVING INTO THE PANHANDLE FROM
THE WNW BY SUNDAY NIGHT AS STRONG TROUGHING BUILDS INTO THE
ALEUTIANS. THE LATTER IS THE ONE COMMON GENERAL THREAD AMONGST ALL
OF THE GUIDANCE... THE TIMING IS MODEL DEPENDENT BUT GENERALLY
FASTER THAN PREVIOUS RUNS. AN ENTRENCHED TROUGH SEEMS LIKELY BY
MON PM/TUES. ANYWAYS, THE DETAILS OF THE LATE WEEKEND/MONDAY WAVE
ARE THUS STILL UP IN THE AIR. GIVEN THE MODEL TEMPS PREDICTED FOR
LATE WEEKEND...SNOW IS STILL A THREAT OVER THE NORTHERN 1/3 OF THE
PANHANDLE OR SO ALTHOUGH THE POTENTIAL OF AN INTERIOR AIR SOURCE
SEEMS TO BE WANING AT THIS POINT. THUS ANY SNOW THAT DOES OCCUR
WOULD LIKELY BE BRIEF, ESPECIALLY WITH THE CONTINUING LACK OF SNOW
COVER INLAND BELOW A COUPLE THOUSAND FEET IN ELEVATION. WENT WITH
WPC GRIDS FROM DAY 5 ONWARDS WITH THE AMOUNT OF UNCERTAINTY
PRESENT. THESE GRIDS WERE BASED ON A NAEFS/GEM COMBO WITH NO INPUT
FROM THE EC UPDATES.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

AHN/WESLEY

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













000
FXAK67 PAJK 312327
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
327 PM AKDT TUE MAR 31 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE REVEALS A WEAKENING
LOW...ABOUT 1001 MB...OVER THE EASTERN GULF WITH A TROUGH
STRETCHING SOUTHEASTWARD FROM THE LOW CENTER TO NEAR HAIDA GWAII AND
A WEAK RIDGE OF HIGH PRESSURE BUILDS ACROSS THE SOUTHERN
PANHANDLE. LARGE AREA OF RAIN SHOWERS WRAPPING AROUND THE LOW
OVER THE OPEN OCEAN. BETWEEN THE RIDGE AND THE LOW...SOUTHERLY
ONSHORE FLOW 10 TO 15 MPH PREVAIL OVER THE PANHANDLE WITH SMALL
CRAFT LEVEL WINDS ACROSS NORTHERN LYNN CANAL. ACROSS THE OUTER
WATERS...SOUTH TO SOUTHWEST WINDS AROUND 15 KNOTS PREVAIL WITH
ROUGH SMALL CRAFT LEVEL SEAS 8 TO 12 FEET DUE TO LONG PERIOD
SOUTHWEST SWELLS. AFTERNOON TEMPERATURES RANGE IN THE LOWER TO MID
40S.

MODELS REMAIN IN GENERAL AGREEMENT FOR THE WEAKENING LOW IN THE
EASTERN GULF THIS EVENING DISSIPATES BY EARLY WEDNESDAY MORNING AS
THE RIDGE OF HIGH PRESSURE CONTINUES TO BUILD OVER THE PANHANDLE
THROUGH LATE WEDNESDAY. A DEVELOPING LOW IN THE WESTERN GULF ON
WEDNESDAY AFTERNOON WILL MOVE EASTWARD AND PUSH THE RIDGE A LITTLE
TO THE EAST. REFRESHED THE INHERITED FORECAST WITH THE GFS AND NAM
FOR THEIR GOOD CONSENSUS.

AS THE RIDGE CONTINUES TO BUILD...THE SMALL CRAFT LEVEL SOUTHERLY
WINDS LATE THIS AFTERNOON OVER NORTHERN LYNN CANAL WILL DIMINISH
THIS EVENING. EXPECT NO SMALL CRAFT LEVEL WINDS ACROSS THE OUTER
WATERS...BUT THE ROUGH SEAS WILL REMAIN THROUGH WEDNESDAY DUE TO
SWELLS. A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS SOUTHEAST
ALASKA WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS RAIN SHOWERS
ON AND OFF BASES TONIGHT AND WEDNESDAY. DUE TO ONGOING RAIN
SHOWERS AND CLOUD COVER...EXPECT SMALL DIURNAL TEMPERATURE
FLUCTUATIONS WITH OVERNIGHT LOWS MOSTLY IN THE MID TO UPPER 30S
AND WEDNESDAY HIGHS IN THE MID 40S.

.LONG TERM...AFTER A DAY OF RELATIVE AGREEMENT IN THE LONG RANGE
IN YESTERDAY`S AM PACKAGE...WE RETURN TO GENERAL MODEL
DISAGREEMENT AFTER 4-5 DAYS IN TODAY`S PACKAGE. MODERATE FRONT
APPROACHING THE COASTLINE AT 03Z THURS IS BEING PUSHED BY UPPER
CLOSED LOW BARGING INTO THE CENTRAL GULF WITH 1000 MB LOW SURFACE
REFLECTION. THE SURFACE LOW...A TWEAK FASTER ON THE NEW MODEL
UPDATES...SLOWS RAPIDLY AFTER ABOUT 09Z AND THEN TAKES A TURN TO
THE SOUTHEAST AS IT BEGINS TO SLOWLY WEAKEN LATE ON THU. FRONT`S
MAIN IMPACT WILL BE A MODERATE EAST-WEST PRESSURE GRADIENT AND SCA-
LEVEL SE WINDS OVER MOSTLY THE SOUTHERN INNER CHANNELS DURING THE
DAY ON FRI WHILE MUCH OF THE ADJACENT OUTER WATERS WILL HAVE WINDS
IN VICINITY OF 30KT SUSTAINED FOR A PERIOD EARLY ON THURSDAY
BEFORE THE WEAKENING TAKES OVER. THIS INCLUDES A BRIEF BARRIER JET
ENHANCEMENT OVER THE NORTHWESTERN MARINE AREA. INLAND/COASTAL WINDS
WILL LIKELY BE SUB- STRONG WIND LEVEL THROUGH THE EVENT. MEANWHILE ON
THU MODERATE RAIN WILL SPREAD INTO THE SOUTHERN HALF OF THE
PANHANDLE WHILE LIGHTER PRECIP WILL COVER MUCH OF THE NORTH. WITH
THE NAM AMOUNTS APPEARING TO BE OVERDONE STILL HAVE TOTAL VALUES
WELL OVER AN INCH TO 2 INCHES OVER FAVORABLE AREAS OF THE SOUTH.
EC/NAM COMBO UTILIZED FOR MUCH OF THESE EARLY UPDATES THOUGH MODEL
DIFFERENCES WERE MINOR. THESE INCLUDED BUMPING HI TEMPS UPWARDS ON
THU BY A COUPLE DEGREES F. THE LOW IS SLOW TO MOVE OUT TO THE
SOUTHEAST ON FRI AND SHOWERS APPEAR LIKELY TO LINGER OVER MOSTLY
THE SOUTHERN HALF OF THE PANHANDLE...ESPECIALLY IF THE PERSISTENT
RETENTION OF ENERGY TO THE SOUTH ADVERTISED BY THE GFS VERIFIES.

SATURDAY APPEARS TO BE POTENTIALLY MOSTLY DRY FOR ALL BUT SOUTHERN
AREAS ON THE CURRENT GUIDANCE AS UPPER RIDGING GENERALLY TAKES
OVER THE GULF...HOWEVER THIS IS WHERE MODEL GUIDANCE BEGINS TO
DIVERGE  SIGNIFICANTLY. THE EC BRINGS A MODERATE WAVE
SOUTHEASTWARD THROUGH THE PANHANDLE WITHIN THE NW FLOW
ALOFT SUN/SUN PM...ALTHOUGH WEAKER THAN PREVIOUS RUNS. THE GEM
SOLUTION IS FOR A TRACK SOUTHEASTWARD THROUGH THE CENTRAL GULF
WITH A STRONGER WAVE. YET ANOTHER SOLUTION IS THE GFS...WHICH
SHOWS A WEAKENING WAVE AND FRONT MOVING INTO THE PANHANDLE FROM
THE WNW BY SUNDAY NIGHT AS STRONG TROUGHING BUILDS INTO THE
ALEUTIANS. THE LATTER IS THE ONE COMMON GENERAL THREAD AMONGST ALL
OF THE GUIDANCE... THE TIMING IS MODEL DEPENDENT BUT GENERALLY
FASTER THAN PREVIOUS RUNS. AN ENTRENCHED TROUGH SEEMS LIKELY BY
MON PM/TUES. ANYWAYS, THE DETAILS OF THE LATE WEEKEND/MONDAY WAVE
ARE THUS STILL UP IN THE AIR. GIVEN THE MODEL TEMPS PREDICTED FOR
LATE WEEKEND...SNOW IS STILL A THREAT OVER THE NORTHERN 1/3 OF THE
PANHANDLE OR SO ALTHOUGH THE POTENTIAL OF AN INTERIOR AIR SOURCE
SEEMS TO BE WANING AT THIS POINT. THUS ANY SNOW THAT DOES OCCUR
WOULD LIKELY BE BRIEF, ESPECIALLY WITH THE CONTINUING LACK OF SNOW
COVER INLAND BELOW A COUPLE THOUSAND FEET IN ELEVATION. WENT WITH
WPC GRIDS FROM DAY 5 ONWARDS WITH THE AMOUNT OF UNCERTAINTY
PRESENT. THESE GRIDS WERE BASED ON A NAEFS/GEM COMBO WITH NO INPUT
FROM THE EC UPDATES.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

AHN/WESLEY

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













000
FXAK67 PAJK 312327
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
327 PM AKDT TUE MAR 31 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE REVEALS A WEAKENING
LOW...ABOUT 1001 MB...OVER THE EASTERN GULF WITH A TROUGH
STRETCHING SOUTHEASTWARD FROM THE LOW CENTER TO NEAR HAIDA GWAII AND
A WEAK RIDGE OF HIGH PRESSURE BUILDS ACROSS THE SOUTHERN
PANHANDLE. LARGE AREA OF RAIN SHOWERS WRAPPING AROUND THE LOW
OVER THE OPEN OCEAN. BETWEEN THE RIDGE AND THE LOW...SOUTHERLY
ONSHORE FLOW 10 TO 15 MPH PREVAIL OVER THE PANHANDLE WITH SMALL
CRAFT LEVEL WINDS ACROSS NORTHERN LYNN CANAL. ACROSS THE OUTER
WATERS...SOUTH TO SOUTHWEST WINDS AROUND 15 KNOTS PREVAIL WITH
ROUGH SMALL CRAFT LEVEL SEAS 8 TO 12 FEET DUE TO LONG PERIOD
SOUTHWEST SWELLS. AFTERNOON TEMPERATURES RANGE IN THE LOWER TO MID
40S.

MODELS REMAIN IN GENERAL AGREEMENT FOR THE WEAKENING LOW IN THE
EASTERN GULF THIS EVENING DISSIPATES BY EARLY WEDNESDAY MORNING AS
THE RIDGE OF HIGH PRESSURE CONTINUES TO BUILD OVER THE PANHANDLE
THROUGH LATE WEDNESDAY. A DEVELOPING LOW IN THE WESTERN GULF ON
WEDNESDAY AFTERNOON WILL MOVE EASTWARD AND PUSH THE RIDGE A LITTLE
TO THE EAST. REFRESHED THE INHERITED FORECAST WITH THE GFS AND NAM
FOR THEIR GOOD CONSENSUS.

AS THE RIDGE CONTINUES TO BUILD...THE SMALL CRAFT LEVEL SOUTHERLY
WINDS LATE THIS AFTERNOON OVER NORTHERN LYNN CANAL WILL DIMINISH
THIS EVENING. EXPECT NO SMALL CRAFT LEVEL WINDS ACROSS THE OUTER
WATERS...BUT THE ROUGH SEAS WILL REMAIN THROUGH WEDNESDAY DUE TO
SWELLS. A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS SOUTHEAST
ALASKA WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS RAIN SHOWERS
ON AND OFF BASES TONIGHT AND WEDNESDAY. DUE TO ONGOING RAIN
SHOWERS AND CLOUD COVER...EXPECT SMALL DIURNAL TEMPERATURE
FLUCTUATIONS WITH OVERNIGHT LOWS MOSTLY IN THE MID TO UPPER 30S
AND WEDNESDAY HIGHS IN THE MID 40S.

.LONG TERM...AFTER A DAY OF RELATIVE AGREEMENT IN THE LONG RANGE
IN YESTERDAY`S AM PACKAGE...WE RETURN TO GENERAL MODEL
DISAGREEMENT AFTER 4-5 DAYS IN TODAY`S PACKAGE. MODERATE FRONT
APPROACHING THE COASTLINE AT 03Z THURS IS BEING PUSHED BY UPPER
CLOSED LOW BARGING INTO THE CENTRAL GULF WITH 1000 MB LOW SURFACE
REFLECTION. THE SURFACE LOW...A TWEAK FASTER ON THE NEW MODEL
UPDATES...SLOWS RAPIDLY AFTER ABOUT 09Z AND THEN TAKES A TURN TO
THE SOUTHEAST AS IT BEGINS TO SLOWLY WEAKEN LATE ON THU. FRONT`S
MAIN IMPACT WILL BE A MODERATE EAST-WEST PRESSURE GRADIENT AND SCA-
LEVEL SE WINDS OVER MOSTLY THE SOUTHERN INNER CHANNELS DURING THE
DAY ON FRI WHILE MUCH OF THE ADJACENT OUTER WATERS WILL HAVE WINDS
IN VICINITY OF 30KT SUSTAINED FOR A PERIOD EARLY ON THURSDAY
BEFORE THE WEAKENING TAKES OVER. THIS INCLUDES A BRIEF BARRIER JET
ENHANCEMENT OVER THE NORTHWESTERN MARINE AREA. INLAND/COASTAL WINDS
WILL LIKELY BE SUB- STRONG WIND LEVEL THROUGH THE EVENT. MEANWHILE ON
THU MODERATE RAIN WILL SPREAD INTO THE SOUTHERN HALF OF THE
PANHANDLE WHILE LIGHTER PRECIP WILL COVER MUCH OF THE NORTH. WITH
THE NAM AMOUNTS APPEARING TO BE OVERDONE STILL HAVE TOTAL VALUES
WELL OVER AN INCH TO 2 INCHES OVER FAVORABLE AREAS OF THE SOUTH.
EC/NAM COMBO UTILIZED FOR MUCH OF THESE EARLY UPDATES THOUGH MODEL
DIFFERENCES WERE MINOR. THESE INCLUDED BUMPING HI TEMPS UPWARDS ON
THU BY A COUPLE DEGREES F. THE LOW IS SLOW TO MOVE OUT TO THE
SOUTHEAST ON FRI AND SHOWERS APPEAR LIKELY TO LINGER OVER MOSTLY
THE SOUTHERN HALF OF THE PANHANDLE...ESPECIALLY IF THE PERSISTENT
RETENTION OF ENERGY TO THE SOUTH ADVERTISED BY THE GFS VERIFIES.

SATURDAY APPEARS TO BE POTENTIALLY MOSTLY DRY FOR ALL BUT SOUTHERN
AREAS ON THE CURRENT GUIDANCE AS UPPER RIDGING GENERALLY TAKES
OVER THE GULF...HOWEVER THIS IS WHERE MODEL GUIDANCE BEGINS TO
DIVERGE  SIGNIFICANTLY. THE EC BRINGS A MODERATE WAVE
SOUTHEASTWARD THROUGH THE PANHANDLE WITHIN THE NW FLOW
ALOFT SUN/SUN PM...ALTHOUGH WEAKER THAN PREVIOUS RUNS. THE GEM
SOLUTION IS FOR A TRACK SOUTHEASTWARD THROUGH THE CENTRAL GULF
WITH A STRONGER WAVE. YET ANOTHER SOLUTION IS THE GFS...WHICH
SHOWS A WEAKENING WAVE AND FRONT MOVING INTO THE PANHANDLE FROM
THE WNW BY SUNDAY NIGHT AS STRONG TROUGHING BUILDS INTO THE
ALEUTIANS. THE LATTER IS THE ONE COMMON GENERAL THREAD AMONGST ALL
OF THE GUIDANCE... THE TIMING IS MODEL DEPENDENT BUT GENERALLY
FASTER THAN PREVIOUS RUNS. AN ENTRENCHED TROUGH SEEMS LIKELY BY
MON PM/TUES. ANYWAYS, THE DETAILS OF THE LATE WEEKEND/MONDAY WAVE
ARE THUS STILL UP IN THE AIR. GIVEN THE MODEL TEMPS PREDICTED FOR
LATE WEEKEND...SNOW IS STILL A THREAT OVER THE NORTHERN 1/3 OF THE
PANHANDLE OR SO ALTHOUGH THE POTENTIAL OF AN INTERIOR AIR SOURCE
SEEMS TO BE WANING AT THIS POINT. THUS ANY SNOW THAT DOES OCCUR
WOULD LIKELY BE BRIEF, ESPECIALLY WITH THE CONTINUING LACK OF SNOW
COVER INLAND BELOW A COUPLE THOUSAND FEET IN ELEVATION. WENT WITH
WPC GRIDS FROM DAY 5 ONWARDS WITH THE AMOUNT OF UNCERTAINTY
PRESENT. THESE GRIDS WERE BASED ON A NAEFS/GEM COMBO WITH NO INPUT
FROM THE EC UPDATES.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

AHN/WESLEY

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













000
FXAK67 PAJK 312327
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
327 PM AKDT TUE MAR 31 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE REVEALS A WEAKENING
LOW...ABOUT 1001 MB...OVER THE EASTERN GULF WITH A TROUGH
STRETCHING SOUTHEASTWARD FROM THE LOW CENTER TO NEAR HAIDA GWAII AND
A WEAK RIDGE OF HIGH PRESSURE BUILDS ACROSS THE SOUTHERN
PANHANDLE. LARGE AREA OF RAIN SHOWERS WRAPPING AROUND THE LOW
OVER THE OPEN OCEAN. BETWEEN THE RIDGE AND THE LOW...SOUTHERLY
ONSHORE FLOW 10 TO 15 MPH PREVAIL OVER THE PANHANDLE WITH SMALL
CRAFT LEVEL WINDS ACROSS NORTHERN LYNN CANAL. ACROSS THE OUTER
WATERS...SOUTH TO SOUTHWEST WINDS AROUND 15 KNOTS PREVAIL WITH
ROUGH SMALL CRAFT LEVEL SEAS 8 TO 12 FEET DUE TO LONG PERIOD
SOUTHWEST SWELLS. AFTERNOON TEMPERATURES RANGE IN THE LOWER TO MID
40S.

MODELS REMAIN IN GENERAL AGREEMENT FOR THE WEAKENING LOW IN THE
EASTERN GULF THIS EVENING DISSIPATES BY EARLY WEDNESDAY MORNING AS
THE RIDGE OF HIGH PRESSURE CONTINUES TO BUILD OVER THE PANHANDLE
THROUGH LATE WEDNESDAY. A DEVELOPING LOW IN THE WESTERN GULF ON
WEDNESDAY AFTERNOON WILL MOVE EASTWARD AND PUSH THE RIDGE A LITTLE
TO THE EAST. REFRESHED THE INHERITED FORECAST WITH THE GFS AND NAM
FOR THEIR GOOD CONSENSUS.

AS THE RIDGE CONTINUES TO BUILD...THE SMALL CRAFT LEVEL SOUTHERLY
WINDS LATE THIS AFTERNOON OVER NORTHERN LYNN CANAL WILL DIMINISH
THIS EVENING. EXPECT NO SMALL CRAFT LEVEL WINDS ACROSS THE OUTER
WATERS...BUT THE ROUGH SEAS WILL REMAIN THROUGH WEDNESDAY DUE TO
SWELLS. A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS SOUTHEAST
ALASKA WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS RAIN SHOWERS
ON AND OFF BASES TONIGHT AND WEDNESDAY. DUE TO ONGOING RAIN
SHOWERS AND CLOUD COVER...EXPECT SMALL DIURNAL TEMPERATURE
FLUCTUATIONS WITH OVERNIGHT LOWS MOSTLY IN THE MID TO UPPER 30S
AND WEDNESDAY HIGHS IN THE MID 40S.

.LONG TERM...AFTER A DAY OF RELATIVE AGREEMENT IN THE LONG RANGE
IN YESTERDAY`S AM PACKAGE...WE RETURN TO GENERAL MODEL
DISAGREEMENT AFTER 4-5 DAYS IN TODAY`S PACKAGE. MODERATE FRONT
APPROACHING THE COASTLINE AT 03Z THURS IS BEING PUSHED BY UPPER
CLOSED LOW BARGING INTO THE CENTRAL GULF WITH 1000 MB LOW SURFACE
REFLECTION. THE SURFACE LOW...A TWEAK FASTER ON THE NEW MODEL
UPDATES...SLOWS RAPIDLY AFTER ABOUT 09Z AND THEN TAKES A TURN TO
THE SOUTHEAST AS IT BEGINS TO SLOWLY WEAKEN LATE ON THU. FRONT`S
MAIN IMPACT WILL BE A MODERATE EAST-WEST PRESSURE GRADIENT AND SCA-
LEVEL SE WINDS OVER MOSTLY THE SOUTHERN INNER CHANNELS DURING THE
DAY ON FRI WHILE MUCH OF THE ADJACENT OUTER WATERS WILL HAVE WINDS
IN VICINITY OF 30KT SUSTAINED FOR A PERIOD EARLY ON THURSDAY
BEFORE THE WEAKENING TAKES OVER. THIS INCLUDES A BRIEF BARRIER JET
ENHANCEMENT OVER THE NORTHWESTERN MARINE AREA. INLAND/COASTAL WINDS
WILL LIKELY BE SUB- STRONG WIND LEVEL THROUGH THE EVENT. MEANWHILE ON
THU MODERATE RAIN WILL SPREAD INTO THE SOUTHERN HALF OF THE
PANHANDLE WHILE LIGHTER PRECIP WILL COVER MUCH OF THE NORTH. WITH
THE NAM AMOUNTS APPEARING TO BE OVERDONE STILL HAVE TOTAL VALUES
WELL OVER AN INCH TO 2 INCHES OVER FAVORABLE AREAS OF THE SOUTH.
EC/NAM COMBO UTILIZED FOR MUCH OF THESE EARLY UPDATES THOUGH MODEL
DIFFERENCES WERE MINOR. THESE INCLUDED BUMPING HI TEMPS UPWARDS ON
THU BY A COUPLE DEGREES F. THE LOW IS SLOW TO MOVE OUT TO THE
SOUTHEAST ON FRI AND SHOWERS APPEAR LIKELY TO LINGER OVER MOSTLY
THE SOUTHERN HALF OF THE PANHANDLE...ESPECIALLY IF THE PERSISTENT
RETENTION OF ENERGY TO THE SOUTH ADVERTISED BY THE GFS VERIFIES.

SATURDAY APPEARS TO BE POTENTIALLY MOSTLY DRY FOR ALL BUT SOUTHERN
AREAS ON THE CURRENT GUIDANCE AS UPPER RIDGING GENERALLY TAKES
OVER THE GULF...HOWEVER THIS IS WHERE MODEL GUIDANCE BEGINS TO
DIVERGE  SIGNIFICANTLY. THE EC BRINGS A MODERATE WAVE
SOUTHEASTWARD THROUGH THE PANHANDLE WITHIN THE NW FLOW
ALOFT SUN/SUN PM...ALTHOUGH WEAKER THAN PREVIOUS RUNS. THE GEM
SOLUTION IS FOR A TRACK SOUTHEASTWARD THROUGH THE CENTRAL GULF
WITH A STRONGER WAVE. YET ANOTHER SOLUTION IS THE GFS...WHICH
SHOWS A WEAKENING WAVE AND FRONT MOVING INTO THE PANHANDLE FROM
THE WNW BY SUNDAY NIGHT AS STRONG TROUGHING BUILDS INTO THE
ALEUTIANS. THE LATTER IS THE ONE COMMON GENERAL THREAD AMONGST ALL
OF THE GUIDANCE... THE TIMING IS MODEL DEPENDENT BUT GENERALLY
FASTER THAN PREVIOUS RUNS. AN ENTRENCHED TROUGH SEEMS LIKELY BY
MON PM/TUES. ANYWAYS, THE DETAILS OF THE LATE WEEKEND/MONDAY WAVE
ARE THUS STILL UP IN THE AIR. GIVEN THE MODEL TEMPS PREDICTED FOR
LATE WEEKEND...SNOW IS STILL A THREAT OVER THE NORTHERN 1/3 OF THE
PANHANDLE OR SO ALTHOUGH THE POTENTIAL OF AN INTERIOR AIR SOURCE
SEEMS TO BE WANING AT THIS POINT. THUS ANY SNOW THAT DOES OCCUR
WOULD LIKELY BE BRIEF, ESPECIALLY WITH THE CONTINUING LACK OF SNOW
COVER INLAND BELOW A COUPLE THOUSAND FEET IN ELEVATION. WENT WITH
WPC GRIDS FROM DAY 5 ONWARDS WITH THE AMOUNT OF UNCERTAINTY
PRESENT. THESE GRIDS WERE BASED ON A NAEFS/GEM COMBO WITH NO INPUT
FROM THE EC UPDATES.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

AHN/WESLEY

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













000
FXAK67 PAJK 312327
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
327 PM AKDT TUE MAR 31 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE REVEALS A WEAKENING
LOW...ABOUT 1001 MB...OVER THE EASTERN GULF WITH A TROUGH
STRETCHING SOUTHEASTWARD FROM THE LOW CENTER TO NEAR HAIDA GWAII AND
A WEAK RIDGE OF HIGH PRESSURE BUILDS ACROSS THE SOUTHERN
PANHANDLE. LARGE AREA OF RAIN SHOWERS WRAPPING AROUND THE LOW
OVER THE OPEN OCEAN. BETWEEN THE RIDGE AND THE LOW...SOUTHERLY
ONSHORE FLOW 10 TO 15 MPH PREVAIL OVER THE PANHANDLE WITH SMALL
CRAFT LEVEL WINDS ACROSS NORTHERN LYNN CANAL. ACROSS THE OUTER
WATERS...SOUTH TO SOUTHWEST WINDS AROUND 15 KNOTS PREVAIL WITH
ROUGH SMALL CRAFT LEVEL SEAS 8 TO 12 FEET DUE TO LONG PERIOD
SOUTHWEST SWELLS. AFTERNOON TEMPERATURES RANGE IN THE LOWER TO MID
40S.

MODELS REMAIN IN GENERAL AGREEMENT FOR THE WEAKENING LOW IN THE
EASTERN GULF THIS EVENING DISSIPATES BY EARLY WEDNESDAY MORNING AS
THE RIDGE OF HIGH PRESSURE CONTINUES TO BUILD OVER THE PANHANDLE
THROUGH LATE WEDNESDAY. A DEVELOPING LOW IN THE WESTERN GULF ON
WEDNESDAY AFTERNOON WILL MOVE EASTWARD AND PUSH THE RIDGE A LITTLE
TO THE EAST. REFRESHED THE INHERITED FORECAST WITH THE GFS AND NAM
FOR THEIR GOOD CONSENSUS.

AS THE RIDGE CONTINUES TO BUILD...THE SMALL CRAFT LEVEL SOUTHERLY
WINDS LATE THIS AFTERNOON OVER NORTHERN LYNN CANAL WILL DIMINISH
THIS EVENING. EXPECT NO SMALL CRAFT LEVEL WINDS ACROSS THE OUTER
WATERS...BUT THE ROUGH SEAS WILL REMAIN THROUGH WEDNESDAY DUE TO
SWELLS. A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS SOUTHEAST
ALASKA WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS RAIN SHOWERS
ON AND OFF BASES TONIGHT AND WEDNESDAY. DUE TO ONGOING RAIN
SHOWERS AND CLOUD COVER...EXPECT SMALL DIURNAL TEMPERATURE
FLUCTUATIONS WITH OVERNIGHT LOWS MOSTLY IN THE MID TO UPPER 30S
AND WEDNESDAY HIGHS IN THE MID 40S.

.LONG TERM...AFTER A DAY OF RELATIVE AGREEMENT IN THE LONG RANGE
IN YESTERDAY`S AM PACKAGE...WE RETURN TO GENERAL MODEL
DISAGREEMENT AFTER 4-5 DAYS IN TODAY`S PACKAGE. MODERATE FRONT
APPROACHING THE COASTLINE AT 03Z THURS IS BEING PUSHED BY UPPER
CLOSED LOW BARGING INTO THE CENTRAL GULF WITH 1000 MB LOW SURFACE
REFLECTION. THE SURFACE LOW...A TWEAK FASTER ON THE NEW MODEL
UPDATES...SLOWS RAPIDLY AFTER ABOUT 09Z AND THEN TAKES A TURN TO
THE SOUTHEAST AS IT BEGINS TO SLOWLY WEAKEN LATE ON THU. FRONT`S
MAIN IMPACT WILL BE A MODERATE EAST-WEST PRESSURE GRADIENT AND SCA-
LEVEL SE WINDS OVER MOSTLY THE SOUTHERN INNER CHANNELS DURING THE
DAY ON FRI WHILE MUCH OF THE ADJACENT OUTER WATERS WILL HAVE WINDS
IN VICINITY OF 30KT SUSTAINED FOR A PERIOD EARLY ON THURSDAY
BEFORE THE WEAKENING TAKES OVER. THIS INCLUDES A BRIEF BARRIER JET
ENHANCEMENT OVER THE NORTHWESTERN MARINE AREA. INLAND/COASTAL WINDS
WILL LIKELY BE SUB- STRONG WIND LEVEL THROUGH THE EVENT. MEANWHILE ON
THU MODERATE RAIN WILL SPREAD INTO THE SOUTHERN HALF OF THE
PANHANDLE WHILE LIGHTER PRECIP WILL COVER MUCH OF THE NORTH. WITH
THE NAM AMOUNTS APPEARING TO BE OVERDONE STILL HAVE TOTAL VALUES
WELL OVER AN INCH TO 2 INCHES OVER FAVORABLE AREAS OF THE SOUTH.
EC/NAM COMBO UTILIZED FOR MUCH OF THESE EARLY UPDATES THOUGH MODEL
DIFFERENCES WERE MINOR. THESE INCLUDED BUMPING HI TEMPS UPWARDS ON
THU BY A COUPLE DEGREES F. THE LOW IS SLOW TO MOVE OUT TO THE
SOUTHEAST ON FRI AND SHOWERS APPEAR LIKELY TO LINGER OVER MOSTLY
THE SOUTHERN HALF OF THE PANHANDLE...ESPECIALLY IF THE PERSISTENT
RETENTION OF ENERGY TO THE SOUTH ADVERTISED BY THE GFS VERIFIES.

SATURDAY APPEARS TO BE POTENTIALLY MOSTLY DRY FOR ALL BUT SOUTHERN
AREAS ON THE CURRENT GUIDANCE AS UPPER RIDGING GENERALLY TAKES
OVER THE GULF...HOWEVER THIS IS WHERE MODEL GUIDANCE BEGINS TO
DIVERGE  SIGNIFICANTLY. THE EC BRINGS A MODERATE WAVE
SOUTHEASTWARD THROUGH THE PANHANDLE WITHIN THE NW FLOW
ALOFT SUN/SUN PM...ALTHOUGH WEAKER THAN PREVIOUS RUNS. THE GEM
SOLUTION IS FOR A TRACK SOUTHEASTWARD THROUGH THE CENTRAL GULF
WITH A STRONGER WAVE. YET ANOTHER SOLUTION IS THE GFS...WHICH
SHOWS A WEAKENING WAVE AND FRONT MOVING INTO THE PANHANDLE FROM
THE WNW BY SUNDAY NIGHT AS STRONG TROUGHING BUILDS INTO THE
ALEUTIANS. THE LATTER IS THE ONE COMMON GENERAL THREAD AMONGST ALL
OF THE GUIDANCE... THE TIMING IS MODEL DEPENDENT BUT GENERALLY
FASTER THAN PREVIOUS RUNS. AN ENTRENCHED TROUGH SEEMS LIKELY BY
MON PM/TUES. ANYWAYS, THE DETAILS OF THE LATE WEEKEND/MONDAY WAVE
ARE THUS STILL UP IN THE AIR. GIVEN THE MODEL TEMPS PREDICTED FOR
LATE WEEKEND...SNOW IS STILL A THREAT OVER THE NORTHERN 1/3 OF THE
PANHANDLE OR SO ALTHOUGH THE POTENTIAL OF AN INTERIOR AIR SOURCE
SEEMS TO BE WANING AT THIS POINT. THUS ANY SNOW THAT DOES OCCUR
WOULD LIKELY BE BRIEF, ESPECIALLY WITH THE CONTINUING LACK OF SNOW
COVER INLAND BELOW A COUPLE THOUSAND FEET IN ELEVATION. WENT WITH
WPC GRIDS FROM DAY 5 ONWARDS WITH THE AMOUNT OF UNCERTAINTY
PRESENT. THESE GRIDS WERE BASED ON A NAEFS/GEM COMBO WITH NO INPUT
FROM THE EC UPDATES.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

AHN/WESLEY

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














000
FXAK67 PAJK 312327
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
327 PM AKDT TUE MAR 31 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE REVEALS A WEAKENING
LOW...ABOUT 1001 MB...OVER THE EASTERN GULF WITH A TROUGH
STRETCHING SOUTHEASTWARD FROM THE LOW CENTER TO NEAR HAIDA GWAII AND
A WEAK RIDGE OF HIGH PRESSURE BUILDS ACROSS THE SOUTHERN
PANHANDLE. LARGE AREA OF RAIN SHOWERS WRAPPING AROUND THE LOW
OVER THE OPEN OCEAN. BETWEEN THE RIDGE AND THE LOW...SOUTHERLY
ONSHORE FLOW 10 TO 15 MPH PREVAIL OVER THE PANHANDLE WITH SMALL
CRAFT LEVEL WINDS ACROSS NORTHERN LYNN CANAL. ACROSS THE OUTER
WATERS...SOUTH TO SOUTHWEST WINDS AROUND 15 KNOTS PREVAIL WITH
ROUGH SMALL CRAFT LEVEL SEAS 8 TO 12 FEET DUE TO LONG PERIOD
SOUTHWEST SWELLS. AFTERNOON TEMPERATURES RANGE IN THE LOWER TO MID
40S.

MODELS REMAIN IN GENERAL AGREEMENT FOR THE WEAKENING LOW IN THE
EASTERN GULF THIS EVENING DISSIPATES BY EARLY WEDNESDAY MORNING AS
THE RIDGE OF HIGH PRESSURE CONTINUES TO BUILD OVER THE PANHANDLE
THROUGH LATE WEDNESDAY. A DEVELOPING LOW IN THE WESTERN GULF ON
WEDNESDAY AFTERNOON WILL MOVE EASTWARD AND PUSH THE RIDGE A LITTLE
TO THE EAST. REFRESHED THE INHERITED FORECAST WITH THE GFS AND NAM
FOR THEIR GOOD CONSENSUS.

AS THE RIDGE CONTINUES TO BUILD...THE SMALL CRAFT LEVEL SOUTHERLY
WINDS LATE THIS AFTERNOON OVER NORTHERN LYNN CANAL WILL DIMINISH
THIS EVENING. EXPECT NO SMALL CRAFT LEVEL WINDS ACROSS THE OUTER
WATERS...BUT THE ROUGH SEAS WILL REMAIN THROUGH WEDNESDAY DUE TO
SWELLS. A WEAK UPPER LEVEL SHORTWAVE TROUGH ACROSS SOUTHEAST
ALASKA WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS RAIN SHOWERS
ON AND OFF BASES TONIGHT AND WEDNESDAY. DUE TO ONGOING RAIN
SHOWERS AND CLOUD COVER...EXPECT SMALL DIURNAL TEMPERATURE
FLUCTUATIONS WITH OVERNIGHT LOWS MOSTLY IN THE MID TO UPPER 30S
AND WEDNESDAY HIGHS IN THE MID 40S.

.LONG TERM...AFTER A DAY OF RELATIVE AGREEMENT IN THE LONG RANGE
IN YESTERDAY`S AM PACKAGE...WE RETURN TO GENERAL MODEL
DISAGREEMENT AFTER 4-5 DAYS IN TODAY`S PACKAGE. MODERATE FRONT
APPROACHING THE COASTLINE AT 03Z THURS IS BEING PUSHED BY UPPER
CLOSED LOW BARGING INTO THE CENTRAL GULF WITH 1000 MB LOW SURFACE
REFLECTION. THE SURFACE LOW...A TWEAK FASTER ON THE NEW MODEL
UPDATES...SLOWS RAPIDLY AFTER ABOUT 09Z AND THEN TAKES A TURN TO
THE SOUTHEAST AS IT BEGINS TO SLOWLY WEAKEN LATE ON THU. FRONT`S
MAIN IMPACT WILL BE A MODERATE EAST-WEST PRESSURE GRADIENT AND SCA-
LEVEL SE WINDS OVER MOSTLY THE SOUTHERN INNER CHANNELS DURING THE
DAY ON FRI WHILE MUCH OF THE ADJACENT OUTER WATERS WILL HAVE WINDS
IN VICINITY OF 30KT SUSTAINED FOR A PERIOD EARLY ON THURSDAY
BEFORE THE WEAKENING TAKES OVER. THIS INCLUDES A BRIEF BARRIER JET
ENHANCEMENT OVER THE NORTHWESTERN MARINE AREA. INLAND/COASTAL WINDS
WILL LIKELY BE SUB- STRONG WIND LEVEL THROUGH THE EVENT. MEANWHILE ON
THU MODERATE RAIN WILL SPREAD INTO THE SOUTHERN HALF OF THE
PANHANDLE WHILE LIGHTER PRECIP WILL COVER MUCH OF THE NORTH. WITH
THE NAM AMOUNTS APPEARING TO BE OVERDONE STILL HAVE TOTAL VALUES
WELL OVER AN INCH TO 2 INCHES OVER FAVORABLE AREAS OF THE SOUTH.
EC/NAM COMBO UTILIZED FOR MUCH OF THESE EARLY UPDATES THOUGH MODEL
DIFFERENCES WERE MINOR. THESE INCLUDED BUMPING HI TEMPS UPWARDS ON
THU BY A COUPLE DEGREES F. THE LOW IS SLOW TO MOVE OUT TO THE
SOUTHEAST ON FRI AND SHOWERS APPEAR LIKELY TO LINGER OVER MOSTLY
THE SOUTHERN HALF OF THE PANHANDLE...ESPECIALLY IF THE PERSISTENT
RETENTION OF ENERGY TO THE SOUTH ADVERTISED BY THE GFS VERIFIES.

SATURDAY APPEARS TO BE POTENTIALLY MOSTLY DRY FOR ALL BUT SOUTHERN
AREAS ON THE CURRENT GUIDANCE AS UPPER RIDGING GENERALLY TAKES
OVER THE GULF...HOWEVER THIS IS WHERE MODEL GUIDANCE BEGINS TO
DIVERGE  SIGNIFICANTLY. THE EC BRINGS A MODERATE WAVE
SOUTHEASTWARD THROUGH THE PANHANDLE WITHIN THE NW FLOW
ALOFT SUN/SUN PM...ALTHOUGH WEAKER THAN PREVIOUS RUNS. THE GEM
SOLUTION IS FOR A TRACK SOUTHEASTWARD THROUGH THE CENTRAL GULF
WITH A STRONGER WAVE. YET ANOTHER SOLUTION IS THE GFS...WHICH
SHOWS A WEAKENING WAVE AND FRONT MOVING INTO THE PANHANDLE FROM
THE WNW BY SUNDAY NIGHT AS STRONG TROUGHING BUILDS INTO THE
ALEUTIANS. THE LATTER IS THE ONE COMMON GENERAL THREAD AMONGST ALL
OF THE GUIDANCE... THE TIMING IS MODEL DEPENDENT BUT GENERALLY
FASTER THAN PREVIOUS RUNS. AN ENTRENCHED TROUGH SEEMS LIKELY BY
MON PM/TUES. ANYWAYS, THE DETAILS OF THE LATE WEEKEND/MONDAY WAVE
ARE THUS STILL UP IN THE AIR. GIVEN THE MODEL TEMPS PREDICTED FOR
LATE WEEKEND...SNOW IS STILL A THREAT OVER THE NORTHERN 1/3 OF THE
PANHANDLE OR SO ALTHOUGH THE POTENTIAL OF AN INTERIOR AIR SOURCE
SEEMS TO BE WANING AT THIS POINT. THUS ANY SNOW THAT DOES OCCUR
WOULD LIKELY BE BRIEF, ESPECIALLY WITH THE CONTINUING LACK OF SNOW
COVER INLAND BELOW A COUPLE THOUSAND FEET IN ELEVATION. WENT WITH
WPC GRIDS FROM DAY 5 ONWARDS WITH THE AMOUNT OF UNCERTAINTY
PRESENT. THESE GRIDS WERE BASED ON A NAEFS/GEM COMBO WITH NO INPUT
FROM THE EC UPDATES.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043.

&&

$$

AHN/WESLEY

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













000
FXAK69 PAFG 312015
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1215 PM AKDT TUE MAR 31 2015

.DISCUSSION...
CURRENT OPERATIONAL MODEL RUNS ARE IN GOOD AGREEMENT THROUGH THU
NIGHT...THEN BEGIN TO DIVERGE WIDELY OVER THE BERING SEA FRI AND
OVER THE ALASKA WEST COAST BY SAT. EXTENDED OUTLOOK CONFIDENCE
REMAINS LOW DUE TO WIDELY DIFFERING OPERATIONAL RUNS AND ENSEMBLE
MEANS.

A WEAK UPPER FLOW PATTERN WILL CONTINUE OVER THE NORTHERN ALASKA
MAINLAND THROUGH THU NIGHT. AN UPPER LEVEL RIDGE WILL BEGIN TO
BUILD OVER THE BERING SEA TUE NIGHT. THE RIDGE WILL CONTINUE TO
BUILD SLOWLY THROUGH FRI AS IT APPROACHES THE ALASKA WEST
COAST...THEN BREAK DOWN AS AN UPPER LOW APPROACHES FROM THE WEST.
HOWEVER...FORECAST UNCERTAINTY BEGINS TO INCREASE OVER THE BERING
SEA FRI AS THE GFS/NAM BRING AN UPPER LOW AND AN ASSOCIATED
SURFACE SYSTEM EASTWARD...ECMWF SOLUTION CARRIES ONLY AN UPPER
LEVEL TROUGH WITH A MUCH WEAKER SURFACE SYSTEM. AT THIS TIME
WE ARE LEANING TOWARDS THE GFS/NAM SOLUTIONS.

MODERATELY STRONG EAST WINDS ARE EXPECTED TO CONTINUE ALONG
THE ARCTIC COAST THROUGH THIS EVENING...THEN DIMINISH ONLY
VERY SLOWLY THROUGH WED EVENING.

A WEAK UPPER LEVEL DISTURBANCE OVER THE SOUTH CENTRAL INTERIOR
EAST WILL TRACK NORTHWARD ACROSS THE INTERIOR TONIGHT INTO WED.
ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED OVER MUCH OF THE
CENTRAL AND WESTERN INTERIOR TONIGHT THROUGH WED...CONTINUING OVER
THE MUCH OF THE WESTERN INTERIOR THROUGH WED NIGHT. A LOW PRESSURE
SYSTEM PROGGED TO MOVE INTO THE EASTERN GULF OF ALASKA THU NIGHT
MAY PUMP SOME MOISTURE INTO THE EASTERN ALASKA RANGE AND SOUTHEAST
INTERIOR THU NIGHT AND FRI...SO WILL INTRODUCE A CHANCE OF SNOW
FOR THOSE AREAS.

ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED TO CONTINUE
OVER MUCH OF NORTHWEST ALASKA TONIGHT AND WED...GRADUALLY
TAPERING OFF WED NIGHT.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ201-AKZ202-AKZ203.

GALE WARNING FOR PKZ230-PKZ235-PKZ240-PKZ245.

&&

$$

RF MAR 15



000
FXAK69 PAFG 312015
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1215 PM AKDT TUE MAR 31 2015

.DISCUSSION...
CURRENT OPERATIONAL MODEL RUNS ARE IN GOOD AGREEMENT THROUGH THU
NIGHT...THEN BEGIN TO DIVERGE WIDELY OVER THE BERING SEA FRI AND
OVER THE ALASKA WEST COAST BY SAT. EXTENDED OUTLOOK CONFIDENCE
REMAINS LOW DUE TO WIDELY DIFFERING OPERATIONAL RUNS AND ENSEMBLE
MEANS.

A WEAK UPPER FLOW PATTERN WILL CONTINUE OVER THE NORTHERN ALASKA
MAINLAND THROUGH THU NIGHT. AN UPPER LEVEL RIDGE WILL BEGIN TO
BUILD OVER THE BERING SEA TUE NIGHT. THE RIDGE WILL CONTINUE TO
BUILD SLOWLY THROUGH FRI AS IT APPROACHES THE ALASKA WEST
COAST...THEN BREAK DOWN AS AN UPPER LOW APPROACHES FROM THE WEST.
HOWEVER...FORECAST UNCERTAINTY BEGINS TO INCREASE OVER THE BERING
SEA FRI AS THE GFS/NAM BRING AN UPPER LOW AND AN ASSOCIATED
SURFACE SYSTEM EASTWARD...ECMWF SOLUTION CARRIES ONLY AN UPPER
LEVEL TROUGH WITH A MUCH WEAKER SURFACE SYSTEM. AT THIS TIME
WE ARE LEANING TOWARDS THE GFS/NAM SOLUTIONS.

MODERATELY STRONG EAST WINDS ARE EXPECTED TO CONTINUE ALONG
THE ARCTIC COAST THROUGH THIS EVENING...THEN DIMINISH ONLY
VERY SLOWLY THROUGH WED EVENING.

A WEAK UPPER LEVEL DISTURBANCE OVER THE SOUTH CENTRAL INTERIOR
EAST WILL TRACK NORTHWARD ACROSS THE INTERIOR TONIGHT INTO WED.
ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED OVER MUCH OF THE
CENTRAL AND WESTERN INTERIOR TONIGHT THROUGH WED...CONTINUING OVER
THE MUCH OF THE WESTERN INTERIOR THROUGH WED NIGHT. A LOW PRESSURE
SYSTEM PROGGED TO MOVE INTO THE EASTERN GULF OF ALASKA THU NIGHT
MAY PUMP SOME MOISTURE INTO THE EASTERN ALASKA RANGE AND SOUTHEAST
INTERIOR THU NIGHT AND FRI...SO WILL INTRODUCE A CHANCE OF SNOW
FOR THOSE AREAS.

ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED TO CONTINUE
OVER MUCH OF NORTHWEST ALASKA TONIGHT AND WED...GRADUALLY
TAPERING OFF WED NIGHT.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ201-AKZ202-AKZ203.

GALE WARNING FOR PKZ230-PKZ235-PKZ240-PKZ245.

&&

$$

RF MAR 15




000
FXAK69 PAFG 312015
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1215 PM AKDT TUE MAR 31 2015

.DISCUSSION...
CURRENT OPERATIONAL MODEL RUNS ARE IN GOOD AGREEMENT THROUGH THU
NIGHT...THEN BEGIN TO DIVERGE WIDELY OVER THE BERING SEA FRI AND
OVER THE ALASKA WEST COAST BY SAT. EXTENDED OUTLOOK CONFIDENCE
REMAINS LOW DUE TO WIDELY DIFFERING OPERATIONAL RUNS AND ENSEMBLE
MEANS.

A WEAK UPPER FLOW PATTERN WILL CONTINUE OVER THE NORTHERN ALASKA
MAINLAND THROUGH THU NIGHT. AN UPPER LEVEL RIDGE WILL BEGIN TO
BUILD OVER THE BERING SEA TUE NIGHT. THE RIDGE WILL CONTINUE TO
BUILD SLOWLY THROUGH FRI AS IT APPROACHES THE ALASKA WEST
COAST...THEN BREAK DOWN AS AN UPPER LOW APPROACHES FROM THE WEST.
HOWEVER...FORECAST UNCERTAINTY BEGINS TO INCREASE OVER THE BERING
SEA FRI AS THE GFS/NAM BRING AN UPPER LOW AND AN ASSOCIATED
SURFACE SYSTEM EASTWARD...ECMWF SOLUTION CARRIES ONLY AN UPPER
LEVEL TROUGH WITH A MUCH WEAKER SURFACE SYSTEM. AT THIS TIME
WE ARE LEANING TOWARDS THE GFS/NAM SOLUTIONS.

MODERATELY STRONG EAST WINDS ARE EXPECTED TO CONTINUE ALONG
THE ARCTIC COAST THROUGH THIS EVENING...THEN DIMINISH ONLY
VERY SLOWLY THROUGH WED EVENING.

A WEAK UPPER LEVEL DISTURBANCE OVER THE SOUTH CENTRAL INTERIOR
EAST WILL TRACK NORTHWARD ACROSS THE INTERIOR TONIGHT INTO WED.
ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED OVER MUCH OF THE
CENTRAL AND WESTERN INTERIOR TONIGHT THROUGH WED...CONTINUING OVER
THE MUCH OF THE WESTERN INTERIOR THROUGH WED NIGHT. A LOW PRESSURE
SYSTEM PROGGED TO MOVE INTO THE EASTERN GULF OF ALASKA THU NIGHT
MAY PUMP SOME MOISTURE INTO THE EASTERN ALASKA RANGE AND SOUTHEAST
INTERIOR THU NIGHT AND FRI...SO WILL INTRODUCE A CHANCE OF SNOW
FOR THOSE AREAS.

ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED TO CONTINUE
OVER MUCH OF NORTHWEST ALASKA TONIGHT AND WED...GRADUALLY
TAPERING OFF WED NIGHT.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ201-AKZ202-AKZ203.

GALE WARNING FOR PKZ230-PKZ235-PKZ240-PKZ245.

&&

$$

RF MAR 15




000
FXAK67 PAJK 311353
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
553 AM AKDT TUE MAR 31 2015

.SHORT TERM...AT 09Z TUE MORNING...WV IMAGERY SHOWED AN UPPER LOW
POSITIONED OVER THE SCNTRL GULF. UPPER RIDGE WAS LOCATED
DOWNSTREAM FROM THIS FEATURE OVER NWRN CANADA...WHILE A WEAKENING
SHORTWAVE TROUGH WAS LIFTING N OVER THE PANHANDLE. MODEL GUIDANCE
SHOWS THE UPPER LOW OVER THE GULF WILL MOVE E TOWARD THE COAST OF
SERN AK BY 12Z WED...WITH ONLY MINOR DIFFERENCES IN POSITION NOTED
AMONGST SUITE OF SOLUTIONS DUE TO VARIATIONS IN HOW THE LOW
PHASES WITH A VORTICITY STREAMER APPROACHING IT FROM THE W. AT THE
SURFACE...LOW PRESSURE WILL ENTER THE ERN GULF BY
AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS NNW OVER THE
SRN/CNTRL PANHANDLE. THIS WILL RESULT IN A TIGHTENING PRESSURE
GRADIENT OVER LYNN CANAL AND CAUSE SLY WINDS TO STRENGTHEN TO
SMALL CRAFT. ELSEWHERE...SMALL CRAFT SEAS WILL CONTINUE OVER THE
OUTSIDE WATERS...AND WSWLY WINDS TO 30 KT WILL EVENTUALLY DEVELOP
OVER MARINE ZONE 41 ALONG THE SRN PERIPHERY OF THE GULF LOW.

OTHERWISE...STRATIFORM PRECIPITATION WILL DIMINISH OVER THE NRN
PANHANDLE AS THE DAY PROGRESSES...WHILE BANDS OF SHOWERS SPREAD
INLAND AHEAD OF THE UPPER DISTURBANCE DURING THE AFTERNOON AND
NIGHT...WITH THE HIGHEST PROBABILITY OF PRECIPITATION EXPECTED TO
OCCUR OVER THE SRN HALF OF THE PANHANDLE. SUFFICIENT CAPE WILL
EXIST FOR THUNDERSTORMS FROM THE SRN OUTSIDE WATERS INTO THE SRN
PANHANDLE TODAY/TONIGHT. THIS HAS APPARENTLY BEEN CONFIRMED BY AN
ISOLATED LIGHTNING STRIKE LOCATED NEAR ANNETTE AT 1230Z.
HOWEVER...THE OVERALL THUNDERSTORM ENVIRONMENT IS FORECAST TO BE
MARGINAL DUE TO WEAKENING ASCENT ASSOCIATED WITH THE UPPER
LOW...AND COLD BOUNDARY LAYER TEMPERATURE PROFILES /LCL
TEMPERATURE AOB 3C...WARM CLOUD DEPTH LESS THAN 500 METERS/.
THUS...WILL CONTINUE TO MONITOR SHORT TERM TRENDS AND UPDATE THE
FORECAST FOR THUNDERSTORM POTENTIAL IF CONFIDENCE IN ADDITIONAL
OCCURRENCE INCREASES.

NO CHANGE WAS MADE TO PRESSURE GRIDS. POP AND QPF WERE UPDATED
USING A COMBINATION OF GFS/ECMWF/ARW/NMM.

.LONG TERM...THE PHASING OF THE UPPER LEVEL LOW AND THE VORTICITY
STREAMER DESCRIBED ABOVE WILL BE COMPLETE WEDNESDAY MORNING
EXTENDING SHOWERS FOR SOUTHEAST INTO WEDNESDAY. HOWEVER, RAINFALL
AMOUNTS WILL BEGIN TO LIGHTEN AS THE DAY WEARS ON, IN PART, DUE TO
MORE ANTICYCLONIC CURVATURE BUILDING WITH THE BUILDING RIDGE OVER
THE EASTERN GULF. POPS WILL BE HIGHER INLAND AS THE INSTABILITY IS
ACCENTUATED BY THE ACCENT OVER THE COAST MOUNTAINS.

ALL EYES WILL THEN FOCUS ON THE STORM SOUTH OF DUTCH HARBOR THIS
MORNING. THIS STORM SWINGS A FRONT ACROSS THE GULF
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AND INTO THE PANHANDLE
THURSDAY WITH WIDESPREAD 30 KT WINDS AND STEADY RAINS MOVING
NORTHEAST, EVENTUALLY INTO THE PANHANDLE. NEW RUNS OF THE ECMWF
LEFT THE PACK OF MODELS BY ADVANCING IT FASTER. WITH THE
UNCERTAINTY ON SPEED, KEPT THE FORECAST AS IS, BUT WE MUST
COMMUNICATE SOME UNCERTAINTY HERE. THE INHERITED PRECIPITATION
FIELD WAS BLENDED WITH THE 00Z GFS AND 00Z ECWMF TO ADVANCE IT
FARTHER EAST A LITTLE. WEDNESDAY NIGHT, ALL MODELS WITH THE
EXCEPTION OF THE NAM SHOWING PRECIPITATION OVER EVEN THE THE
INTERIOR PANHANDLE. CONFIDENCE NOT GREAT ON THIS WITH THE
ORIENTATION OF THE ADVANCING FRONT, AND TRIED TO COUNTER THIS
INCORPORATING A LITTLE OF THE NAM. HOWEVER, THE 700 MB FLOW STILL
CARRYING MORE ONSHORE COMPONENT, AND THUS WITH GRADUAL UPGLIDE,
FELT WE HAD TO LEAVE IT IN. THE GFS SUGGESTING RAIN BANDS MAY BE
HEAVY AT TIMES ON BARANOF ISLAND LATE WEDNESDAY NIGHT AND THROUGH
THE SOUTHERN INNER CHANNELS THURSDAY. WINDS WILL STRENGTHEN IN
TURN TO SMALL CRAFT FROM THE CENTRAL PANHANDLE SOUTHWARD LATE
WEDNESDAY NIGHT/EARLY THURSDAY MORNING. BUT PARALLEL GRADIENTS
SHOULD KEEP THE FAR NORTHERN PASSAGES RELATIVELY LIGHT FROM THE
NORTH.

THE LOW BEGINS TO SLIDE TO THE SOUTHEAST INTO FRIDAY, THUS DRYING
OUT THE NORTHERN PANHANDLE. RESIDUAL INSTABILITY WILL PERSIST OVER
THE SOUTH ENOUGH TO EXTEND SHOWER ACTIVITY INTO THE EARLY WEEKEND.
SOME COLDER AIR WILL SLIDE SOUTH OF THE ALASKA RANGE IN NORTHWEST
FLOW BEHIND THE LOW WHICH MAY BE ENOUGH TO REINTRODUCE SOME SNOW
MIXING IN WITH THE DISSIPATING SHOWERS ON THE NORTHWEST EDGE OF
THE PRECIPITATION FIELD. THE ECMWF IS SUGGESTING A HEALTHY SHORT-
WAVE RIDING EASTWARD FROM THE BERING SEA INTO THE NORTHERN GULF
LATE INTO THE WEEKEND BRINGING THE POSSIBILITY OF SOME SNOW MIXED
WITH THE RAIN FOR THE NORTHERN PANHANDLE SUNDAY NIGHT. GFS NOT AS
KEEN. THUS WAS CAREFUL TO BOTH RAISE POPS AND MODERATE TEMPERATURES
JUST A TAD. STILL LEFT THE CHANCE OF SNOW WITH RAIN FOR JUNEAU AND
POINTS NORTH AND NORTHWEST.

GFS AND ECMWF USED TO UPDATE FROM LATE WEDNESDAY NIGHT INTO
FRIDAY. ONLY MINOR TWEAKS MADE FOR WEDNESDAY INTO WEDNESDAY
EVENING. FORECAST CONFIDENCE AVERAGE FOR PERIOD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-041.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ042-043-052.

&&

$$

GARNER/ADKINS

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









000
FXAK67 PAJK 311353
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
553 AM AKDT TUE MAR 31 2015

.SHORT TERM...AT 09Z TUE MORNING...WV IMAGERY SHOWED AN UPPER LOW
POSITIONED OVER THE SCNTRL GULF. UPPER RIDGE WAS LOCATED
DOWNSTREAM FROM THIS FEATURE OVER NWRN CANADA...WHILE A WEAKENING
SHORTWAVE TROUGH WAS LIFTING N OVER THE PANHANDLE. MODEL GUIDANCE
SHOWS THE UPPER LOW OVER THE GULF WILL MOVE E TOWARD THE COAST OF
SERN AK BY 12Z WED...WITH ONLY MINOR DIFFERENCES IN POSITION NOTED
AMONGST SUITE OF SOLUTIONS DUE TO VARIATIONS IN HOW THE LOW
PHASES WITH A VORTICITY STREAMER APPROACHING IT FROM THE W. AT THE
SURFACE...LOW PRESSURE WILL ENTER THE ERN GULF BY
AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS NNW OVER THE
SRN/CNTRL PANHANDLE. THIS WILL RESULT IN A TIGHTENING PRESSURE
GRADIENT OVER LYNN CANAL AND CAUSE SLY WINDS TO STRENGTHEN TO
SMALL CRAFT. ELSEWHERE...SMALL CRAFT SEAS WILL CONTINUE OVER THE
OUTSIDE WATERS...AND WSWLY WINDS TO 30 KT WILL EVENTUALLY DEVELOP
OVER MARINE ZONE 41 ALONG THE SRN PERIPHERY OF THE GULF LOW.

OTHERWISE...STRATIFORM PRECIPITATION WILL DIMINISH OVER THE NRN
PANHANDLE AS THE DAY PROGRESSES...WHILE BANDS OF SHOWERS SPREAD
INLAND AHEAD OF THE UPPER DISTURBANCE DURING THE AFTERNOON AND
NIGHT...WITH THE HIGHEST PROBABILITY OF PRECIPITATION EXPECTED TO
OCCUR OVER THE SRN HALF OF THE PANHANDLE. SUFFICIENT CAPE WILL
EXIST FOR THUNDERSTORMS FROM THE SRN OUTSIDE WATERS INTO THE SRN
PANHANDLE TODAY/TONIGHT. THIS HAS APPARENTLY BEEN CONFIRMED BY AN
ISOLATED LIGHTNING STRIKE LOCATED NEAR ANNETTE AT 1230Z.
HOWEVER...THE OVERALL THUNDERSTORM ENVIRONMENT IS FORECAST TO BE
MARGINAL DUE TO WEAKENING ASCENT ASSOCIATED WITH THE UPPER
LOW...AND COLD BOUNDARY LAYER TEMPERATURE PROFILES /LCL
TEMPERATURE AOB 3C...WARM CLOUD DEPTH LESS THAN 500 METERS/.
THUS...WILL CONTINUE TO MONITOR SHORT TERM TRENDS AND UPDATE THE
FORECAST FOR THUNDERSTORM POTENTIAL IF CONFIDENCE IN ADDITIONAL
OCCURRENCE INCREASES.

NO CHANGE WAS MADE TO PRESSURE GRIDS. POP AND QPF WERE UPDATED
USING A COMBINATION OF GFS/ECMWF/ARW/NMM.

.LONG TERM...THE PHASING OF THE UPPER LEVEL LOW AND THE VORTICITY
STREAMER DESCRIBED ABOVE WILL BE COMPLETE WEDNESDAY MORNING
EXTENDING SHOWERS FOR SOUTHEAST INTO WEDNESDAY. HOWEVER, RAINFALL
AMOUNTS WILL BEGIN TO LIGHTEN AS THE DAY WEARS ON, IN PART, DUE TO
MORE ANTICYCLONIC CURVATURE BUILDING WITH THE BUILDING RIDGE OVER
THE EASTERN GULF. POPS WILL BE HIGHER INLAND AS THE INSTABILITY IS
ACCENTUATED BY THE ACCENT OVER THE COAST MOUNTAINS.

ALL EYES WILL THEN FOCUS ON THE STORM SOUTH OF DUTCH HARBOR THIS
MORNING. THIS STORM SWINGS A FRONT ACROSS THE GULF
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AND INTO THE PANHANDLE
THURSDAY WITH WIDESPREAD 30 KT WINDS AND STEADY RAINS MOVING
NORTHEAST, EVENTUALLY INTO THE PANHANDLE. NEW RUNS OF THE ECMWF
LEFT THE PACK OF MODELS BY ADVANCING IT FASTER. WITH THE
UNCERTAINTY ON SPEED, KEPT THE FORECAST AS IS, BUT WE MUST
COMMUNICATE SOME UNCERTAINTY HERE. THE INHERITED PRECIPITATION
FIELD WAS BLENDED WITH THE 00Z GFS AND 00Z ECWMF TO ADVANCE IT
FARTHER EAST A LITTLE. WEDNESDAY NIGHT, ALL MODELS WITH THE
EXCEPTION OF THE NAM SHOWING PRECIPITATION OVER EVEN THE THE
INTERIOR PANHANDLE. CONFIDENCE NOT GREAT ON THIS WITH THE
ORIENTATION OF THE ADVANCING FRONT, AND TRIED TO COUNTER THIS
INCORPORATING A LITTLE OF THE NAM. HOWEVER, THE 700 MB FLOW STILL
CARRYING MORE ONSHORE COMPONENT, AND THUS WITH GRADUAL UPGLIDE,
FELT WE HAD TO LEAVE IT IN. THE GFS SUGGESTING RAIN BANDS MAY BE
HEAVY AT TIMES ON BARANOF ISLAND LATE WEDNESDAY NIGHT AND THROUGH
THE SOUTHERN INNER CHANNELS THURSDAY. WINDS WILL STRENGTHEN IN
TURN TO SMALL CRAFT FROM THE CENTRAL PANHANDLE SOUTHWARD LATE
WEDNESDAY NIGHT/EARLY THURSDAY MORNING. BUT PARALLEL GRADIENTS
SHOULD KEEP THE FAR NORTHERN PASSAGES RELATIVELY LIGHT FROM THE
NORTH.

THE LOW BEGINS TO SLIDE TO THE SOUTHEAST INTO FRIDAY, THUS DRYING
OUT THE NORTHERN PANHANDLE. RESIDUAL INSTABILITY WILL PERSIST OVER
THE SOUTH ENOUGH TO EXTEND SHOWER ACTIVITY INTO THE EARLY WEEKEND.
SOME COLDER AIR WILL SLIDE SOUTH OF THE ALASKA RANGE IN NORTHWEST
FLOW BEHIND THE LOW WHICH MAY BE ENOUGH TO REINTRODUCE SOME SNOW
MIXING IN WITH THE DISSIPATING SHOWERS ON THE NORTHWEST EDGE OF
THE PRECIPITATION FIELD. THE ECMWF IS SUGGESTING A HEALTHY SHORT-
WAVE RIDING EASTWARD FROM THE BERING SEA INTO THE NORTHERN GULF
LATE INTO THE WEEKEND BRINGING THE POSSIBILITY OF SOME SNOW MIXED
WITH THE RAIN FOR THE NORTHERN PANHANDLE SUNDAY NIGHT. GFS NOT AS
KEEN. THUS WAS CAREFUL TO BOTH RAISE POPS AND MODERATE TEMPERATURES
JUST A TAD. STILL LEFT THE CHANCE OF SNOW WITH RAIN FOR JUNEAU AND
POINTS NORTH AND NORTHWEST.

GFS AND ECMWF USED TO UPDATE FROM LATE WEDNESDAY NIGHT INTO
FRIDAY. ONLY MINOR TWEAKS MADE FOR WEDNESDAY INTO WEDNESDAY
EVENING. FORECAST CONFIDENCE AVERAGE FOR PERIOD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-041.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ042-043-052.

&&

$$

GARNER/ADKINS

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










000
FXAK67 PAJK 311353
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
553 AM AKDT TUE MAR 31 2015

.SHORT TERM...AT 09Z TUE MORNING...WV IMAGERY SHOWED AN UPPER LOW
POSITIONED OVER THE SCNTRL GULF. UPPER RIDGE WAS LOCATED
DOWNSTREAM FROM THIS FEATURE OVER NWRN CANADA...WHILE A WEAKENING
SHORTWAVE TROUGH WAS LIFTING N OVER THE PANHANDLE. MODEL GUIDANCE
SHOWS THE UPPER LOW OVER THE GULF WILL MOVE E TOWARD THE COAST OF
SERN AK BY 12Z WED...WITH ONLY MINOR DIFFERENCES IN POSITION NOTED
AMONGST SUITE OF SOLUTIONS DUE TO VARIATIONS IN HOW THE LOW
PHASES WITH A VORTICITY STREAMER APPROACHING IT FROM THE W. AT THE
SURFACE...LOW PRESSURE WILL ENTER THE ERN GULF BY
AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS NNW OVER THE
SRN/CNTRL PANHANDLE. THIS WILL RESULT IN A TIGHTENING PRESSURE
GRADIENT OVER LYNN CANAL AND CAUSE SLY WINDS TO STRENGTHEN TO
SMALL CRAFT. ELSEWHERE...SMALL CRAFT SEAS WILL CONTINUE OVER THE
OUTSIDE WATERS...AND WSWLY WINDS TO 30 KT WILL EVENTUALLY DEVELOP
OVER MARINE ZONE 41 ALONG THE SRN PERIPHERY OF THE GULF LOW.

OTHERWISE...STRATIFORM PRECIPITATION WILL DIMINISH OVER THE NRN
PANHANDLE AS THE DAY PROGRESSES...WHILE BANDS OF SHOWERS SPREAD
INLAND AHEAD OF THE UPPER DISTURBANCE DURING THE AFTERNOON AND
NIGHT...WITH THE HIGHEST PROBABILITY OF PRECIPITATION EXPECTED TO
OCCUR OVER THE SRN HALF OF THE PANHANDLE. SUFFICIENT CAPE WILL
EXIST FOR THUNDERSTORMS FROM THE SRN OUTSIDE WATERS INTO THE SRN
PANHANDLE TODAY/TONIGHT. THIS HAS APPARENTLY BEEN CONFIRMED BY AN
ISOLATED LIGHTNING STRIKE LOCATED NEAR ANNETTE AT 1230Z.
HOWEVER...THE OVERALL THUNDERSTORM ENVIRONMENT IS FORECAST TO BE
MARGINAL DUE TO WEAKENING ASCENT ASSOCIATED WITH THE UPPER
LOW...AND COLD BOUNDARY LAYER TEMPERATURE PROFILES /LCL
TEMPERATURE AOB 3C...WARM CLOUD DEPTH LESS THAN 500 METERS/.
THUS...WILL CONTINUE TO MONITOR SHORT TERM TRENDS AND UPDATE THE
FORECAST FOR THUNDERSTORM POTENTIAL IF CONFIDENCE IN ADDITIONAL
OCCURRENCE INCREASES.

NO CHANGE WAS MADE TO PRESSURE GRIDS. POP AND QPF WERE UPDATED
USING A COMBINATION OF GFS/ECMWF/ARW/NMM.

.LONG TERM...THE PHASING OF THE UPPER LEVEL LOW AND THE VORTICITY
STREAMER DESCRIBED ABOVE WILL BE COMPLETE WEDNESDAY MORNING
EXTENDING SHOWERS FOR SOUTHEAST INTO WEDNESDAY. HOWEVER, RAINFALL
AMOUNTS WILL BEGIN TO LIGHTEN AS THE DAY WEARS ON, IN PART, DUE TO
MORE ANTICYCLONIC CURVATURE BUILDING WITH THE BUILDING RIDGE OVER
THE EASTERN GULF. POPS WILL BE HIGHER INLAND AS THE INSTABILITY IS
ACCENTUATED BY THE ACCENT OVER THE COAST MOUNTAINS.

ALL EYES WILL THEN FOCUS ON THE STORM SOUTH OF DUTCH HARBOR THIS
MORNING. THIS STORM SWINGS A FRONT ACROSS THE GULF
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AND INTO THE PANHANDLE
THURSDAY WITH WIDESPREAD 30 KT WINDS AND STEADY RAINS MOVING
NORTHEAST, EVENTUALLY INTO THE PANHANDLE. NEW RUNS OF THE ECMWF
LEFT THE PACK OF MODELS BY ADVANCING IT FASTER. WITH THE
UNCERTAINTY ON SPEED, KEPT THE FORECAST AS IS, BUT WE MUST
COMMUNICATE SOME UNCERTAINTY HERE. THE INHERITED PRECIPITATION
FIELD WAS BLENDED WITH THE 00Z GFS AND 00Z ECWMF TO ADVANCE IT
FARTHER EAST A LITTLE. WEDNESDAY NIGHT, ALL MODELS WITH THE
EXCEPTION OF THE NAM SHOWING PRECIPITATION OVER EVEN THE THE
INTERIOR PANHANDLE. CONFIDENCE NOT GREAT ON THIS WITH THE
ORIENTATION OF THE ADVANCING FRONT, AND TRIED TO COUNTER THIS
INCORPORATING A LITTLE OF THE NAM. HOWEVER, THE 700 MB FLOW STILL
CARRYING MORE ONSHORE COMPONENT, AND THUS WITH GRADUAL UPGLIDE,
FELT WE HAD TO LEAVE IT IN. THE GFS SUGGESTING RAIN BANDS MAY BE
HEAVY AT TIMES ON BARANOF ISLAND LATE WEDNESDAY NIGHT AND THROUGH
THE SOUTHERN INNER CHANNELS THURSDAY. WINDS WILL STRENGTHEN IN
TURN TO SMALL CRAFT FROM THE CENTRAL PANHANDLE SOUTHWARD LATE
WEDNESDAY NIGHT/EARLY THURSDAY MORNING. BUT PARALLEL GRADIENTS
SHOULD KEEP THE FAR NORTHERN PASSAGES RELATIVELY LIGHT FROM THE
NORTH.

THE LOW BEGINS TO SLIDE TO THE SOUTHEAST INTO FRIDAY, THUS DRYING
OUT THE NORTHERN PANHANDLE. RESIDUAL INSTABILITY WILL PERSIST OVER
THE SOUTH ENOUGH TO EXTEND SHOWER ACTIVITY INTO THE EARLY WEEKEND.
SOME COLDER AIR WILL SLIDE SOUTH OF THE ALASKA RANGE IN NORTHWEST
FLOW BEHIND THE LOW WHICH MAY BE ENOUGH TO REINTRODUCE SOME SNOW
MIXING IN WITH THE DISSIPATING SHOWERS ON THE NORTHWEST EDGE OF
THE PRECIPITATION FIELD. THE ECMWF IS SUGGESTING A HEALTHY SHORT-
WAVE RIDING EASTWARD FROM THE BERING SEA INTO THE NORTHERN GULF
LATE INTO THE WEEKEND BRINGING THE POSSIBILITY OF SOME SNOW MIXED
WITH THE RAIN FOR THE NORTHERN PANHANDLE SUNDAY NIGHT. GFS NOT AS
KEEN. THUS WAS CAREFUL TO BOTH RAISE POPS AND MODERATE TEMPERATURES
JUST A TAD. STILL LEFT THE CHANCE OF SNOW WITH RAIN FOR JUNEAU AND
POINTS NORTH AND NORTHWEST.

GFS AND ECMWF USED TO UPDATE FROM LATE WEDNESDAY NIGHT INTO
FRIDAY. ONLY MINOR TWEAKS MADE FOR WEDNESDAY INTO WEDNESDAY
EVENING. FORECAST CONFIDENCE AVERAGE FOR PERIOD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-041.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ042-043-052.

&&

$$

GARNER/ADKINS

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









000
FXAK67 PAJK 311353
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
553 AM AKDT TUE MAR 31 2015

.SHORT TERM...AT 09Z TUE MORNING...WV IMAGERY SHOWED AN UPPER LOW
POSITIONED OVER THE SCNTRL GULF. UPPER RIDGE WAS LOCATED
DOWNSTREAM FROM THIS FEATURE OVER NWRN CANADA...WHILE A WEAKENING
SHORTWAVE TROUGH WAS LIFTING N OVER THE PANHANDLE. MODEL GUIDANCE
SHOWS THE UPPER LOW OVER THE GULF WILL MOVE E TOWARD THE COAST OF
SERN AK BY 12Z WED...WITH ONLY MINOR DIFFERENCES IN POSITION NOTED
AMONGST SUITE OF SOLUTIONS DUE TO VARIATIONS IN HOW THE LOW
PHASES WITH A VORTICITY STREAMER APPROACHING IT FROM THE W. AT THE
SURFACE...LOW PRESSURE WILL ENTER THE ERN GULF BY
AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS NNW OVER THE
SRN/CNTRL PANHANDLE. THIS WILL RESULT IN A TIGHTENING PRESSURE
GRADIENT OVER LYNN CANAL AND CAUSE SLY WINDS TO STRENGTHEN TO
SMALL CRAFT. ELSEWHERE...SMALL CRAFT SEAS WILL CONTINUE OVER THE
OUTSIDE WATERS...AND WSWLY WINDS TO 30 KT WILL EVENTUALLY DEVELOP
OVER MARINE ZONE 41 ALONG THE SRN PERIPHERY OF THE GULF LOW.

OTHERWISE...STRATIFORM PRECIPITATION WILL DIMINISH OVER THE NRN
PANHANDLE AS THE DAY PROGRESSES...WHILE BANDS OF SHOWERS SPREAD
INLAND AHEAD OF THE UPPER DISTURBANCE DURING THE AFTERNOON AND
NIGHT...WITH THE HIGHEST PROBABILITY OF PRECIPITATION EXPECTED TO
OCCUR OVER THE SRN HALF OF THE PANHANDLE. SUFFICIENT CAPE WILL
EXIST FOR THUNDERSTORMS FROM THE SRN OUTSIDE WATERS INTO THE SRN
PANHANDLE TODAY/TONIGHT. THIS HAS APPARENTLY BEEN CONFIRMED BY AN
ISOLATED LIGHTNING STRIKE LOCATED NEAR ANNETTE AT 1230Z.
HOWEVER...THE OVERALL THUNDERSTORM ENVIRONMENT IS FORECAST TO BE
MARGINAL DUE TO WEAKENING ASCENT ASSOCIATED WITH THE UPPER
LOW...AND COLD BOUNDARY LAYER TEMPERATURE PROFILES /LCL
TEMPERATURE AOB 3C...WARM CLOUD DEPTH LESS THAN 500 METERS/.
THUS...WILL CONTINUE TO MONITOR SHORT TERM TRENDS AND UPDATE THE
FORECAST FOR THUNDERSTORM POTENTIAL IF CONFIDENCE IN ADDITIONAL
OCCURRENCE INCREASES.

NO CHANGE WAS MADE TO PRESSURE GRIDS. POP AND QPF WERE UPDATED
USING A COMBINATION OF GFS/ECMWF/ARW/NMM.

.LONG TERM...THE PHASING OF THE UPPER LEVEL LOW AND THE VORTICITY
STREAMER DESCRIBED ABOVE WILL BE COMPLETE WEDNESDAY MORNING
EXTENDING SHOWERS FOR SOUTHEAST INTO WEDNESDAY. HOWEVER, RAINFALL
AMOUNTS WILL BEGIN TO LIGHTEN AS THE DAY WEARS ON, IN PART, DUE TO
MORE ANTICYCLONIC CURVATURE BUILDING WITH THE BUILDING RIDGE OVER
THE EASTERN GULF. POPS WILL BE HIGHER INLAND AS THE INSTABILITY IS
ACCENTUATED BY THE ACCENT OVER THE COAST MOUNTAINS.

ALL EYES WILL THEN FOCUS ON THE STORM SOUTH OF DUTCH HARBOR THIS
MORNING. THIS STORM SWINGS A FRONT ACROSS THE GULF
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT AND INTO THE PANHANDLE
THURSDAY WITH WIDESPREAD 30 KT WINDS AND STEADY RAINS MOVING
NORTHEAST, EVENTUALLY INTO THE PANHANDLE. NEW RUNS OF THE ECMWF
LEFT THE PACK OF MODELS BY ADVANCING IT FASTER. WITH THE
UNCERTAINTY ON SPEED, KEPT THE FORECAST AS IS, BUT WE MUST
COMMUNICATE SOME UNCERTAINTY HERE. THE INHERITED PRECIPITATION
FIELD WAS BLENDED WITH THE 00Z GFS AND 00Z ECWMF TO ADVANCE IT
FARTHER EAST A LITTLE. WEDNESDAY NIGHT, ALL MODELS WITH THE
EXCEPTION OF THE NAM SHOWING PRECIPITATION OVER EVEN THE THE
INTERIOR PANHANDLE. CONFIDENCE NOT GREAT ON THIS WITH THE
ORIENTATION OF THE ADVANCING FRONT, AND TRIED TO COUNTER THIS
INCORPORATING A LITTLE OF THE NAM. HOWEVER, THE 700 MB FLOW STILL
CARRYING MORE ONSHORE COMPONENT, AND THUS WITH GRADUAL UPGLIDE,
FELT WE HAD TO LEAVE IT IN. THE GFS SUGGESTING RAIN BANDS MAY BE
HEAVY AT TIMES ON BARANOF ISLAND LATE WEDNESDAY NIGHT AND THROUGH
THE SOUTHERN INNER CHANNELS THURSDAY. WINDS WILL STRENGTHEN IN
TURN TO SMALL CRAFT FROM THE CENTRAL PANHANDLE SOUTHWARD LATE
WEDNESDAY NIGHT/EARLY THURSDAY MORNING. BUT PARALLEL GRADIENTS
SHOULD KEEP THE FAR NORTHERN PASSAGES RELATIVELY LIGHT FROM THE
NORTH.

THE LOW BEGINS TO SLIDE TO THE SOUTHEAST INTO FRIDAY, THUS DRYING
OUT THE NORTHERN PANHANDLE. RESIDUAL INSTABILITY WILL PERSIST OVER
THE SOUTH ENOUGH TO EXTEND SHOWER ACTIVITY INTO THE EARLY WEEKEND.
SOME COLDER AIR WILL SLIDE SOUTH OF THE ALASKA RANGE IN NORTHWEST
FLOW BEHIND THE LOW WHICH MAY BE ENOUGH TO REINTRODUCE SOME SNOW
MIXING IN WITH THE DISSIPATING SHOWERS ON THE NORTHWEST EDGE OF
THE PRECIPITATION FIELD. THE ECMWF IS SUGGESTING A HEALTHY SHORT-
WAVE RIDING EASTWARD FROM THE BERING SEA INTO THE NORTHERN GULF
LATE INTO THE WEEKEND BRINGING THE POSSIBILITY OF SOME SNOW MIXED
WITH THE RAIN FOR THE NORTHERN PANHANDLE SUNDAY NIGHT. GFS NOT AS
KEEN. THUS WAS CAREFUL TO BOTH RAISE POPS AND MODERATE TEMPERATURES
JUST A TAD. STILL LEFT THE CHANCE OF SNOW WITH RAIN FOR JUNEAU AND
POINTS NORTH AND NORTHWEST.

GFS AND ECMWF USED TO UPDATE FROM LATE WEDNESDAY NIGHT INTO
FRIDAY. ONLY MINOR TWEAKS MADE FOR WEDNESDAY INTO WEDNESDAY
EVENING. FORECAST CONFIDENCE AVERAGE FOR PERIOD.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-041.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ042-043-052.

&&

$$

GARNER/ADKINS

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










000
FXAK68 PAFC 311318
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
518 AM AKDT TUE MAR 31 2015

.ANALYSIS AND UPPER LEVELS...
LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND THE
NORTH PACIFIC...WITH HIGH PRESSURE RIDGES REMAINING OVER THE FAR
WESTERN BERING AND ALSO OVER THE NORTHEASTERN INTERIOR OF THE
STATE. THE SUBTROPICAL JET IS NEARLY ZONAL SOUTH OF THE ALEUTIAN
CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH PACIFIC. THIS IS
RESULTING IN A PERSISTENT STORM TRACK ALONG THE SOUTHERN TIER OF
THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK LOWS AFFECTING
THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND ANOTHER JUST
SOUTH OF THE EASTERN ALEUTIANS. AS HAS BEEN THE CASE OVER THE
PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE TRACKING
NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. ISOLATED
CONVECTIVE SHOWERS DEVELOPED OFF OF THE TALKEETNA MOUNTAINS AND
MOVED ACROSS THE SUSITNA VALLEY LAST (SUN) EVENING AS THE 00Z
ANCHORAGE SOUNDING DEPICTED LIFTED INDICES NEAR OR SLIGHTLY BELOW
ZERO (MORE TYPICAL OF LATE MAY OR EARLY JUNE)...BUT THESE SHOWERS
HAVE DISSIPATED WITH THE LOSS OF DAYTIME HEATING. THE BULK OF
PRECIP HAS BEEN OVER THE NORTHERN GULF WITH A WEAK VORTICITY
MAXIMUM MOVING MOVING SLOWLY WEST TO NORTHWEST TOWARD THE EASTERN
KENAI PENINSULA. ISOLATED TO SCATTERED SHOWERS ALSO CONTINUE OVER
SOUTHWEST ALASKA EAST OF BETHEL WITH THE REMNANTS OF A WEAK
DEFORMATION BAND THAT HAS BEEN NEARLY STATIONARY IN WEAK UPPER
FLOW ACROSS THE AREA.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH WEAK FLOW OUTSIDE OF THE MAIN LOW PRESSURE
SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND DIURNAL CLOUDS AND SHOWER
ACTIVITY. MODELS DO BEGIN TO DIVERGE A BIT AS THE SYSTEM TRACKING
SOUTH OF THE AKPEN MOVES TO THE SOUTH OF KODIAK ISLAND TUESDAY
NIGHT INTO WEDNESDAY. THEY ALL HINT AT SOME DEVELOPMENT OF A
TRIPLE POINT LOW...BUT RIGHT NOW ALMOST ALL MODELS DEPICT THE
INITIAL PARENT LOW REMAINING THE PRIMARY LOW OVER THE FAR SOUTHERN
GULF. IN ANY CASE THESE DIFFERENCES ONLY AFFECT THE AREA IN THE
DIRECT VICINITY OF THE SYSTEM. THE GFS WAS LARGELY PREFERRED IN
THE SHORT TERM...WITH SOME DEFERENCE TO THE NAM EARLY FOR LOCAL
EFFECTS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (THROUGH WED NIGHT)...
SOUTHCENTRAL MAINLAND
UNSETTLED WEATHER WILL CONTINUE ACROSS SOUTHCENTRAL THROUGH WED.
AN UPPER TROUGH COUPLED WITH A WEAK SURFACE TROUGH MOVES NORTH
AND WEST ACROSS SOUTHCENTRAL TODAY. THE UPPER TROUGH MOVES INTO
THE INTERIOR TONIGHT AND WILL BE FOLLOWED BY A SECONDARY TROUGH
PUSHING NORTH ACROSS THE GULF OF WED. THIS SECONDARY THROUGH WILL
BE SOMEWHAT WEAKER THEN ITS PREDECESSOR. AVAILABLE SOUNDING AND
MODEL GUIDANCE INDICATE THAT SHOWERS WILL BE THE DOMINATE
CHARACTER OF PRECIPITATION WITH THESE FEATURES. FREEZING LEVELS
THROUGH WED WILL BE HIGH ENOUGH THAT OF THE PRECIPITATION WILL
FALL AS RAIN DURING THE AFTERNOON HOURS...THEN BECOMING MORE MIXED
OR SNOW DURING THE OVERNIGHT AND EARLY MORNING HOURS. DRIER
CONDITIONS ARE EXPECTED OVERNIGHT WED AS THE LOW MOVING INTO THE
GULF CREATES NORTHERLY OFFSHORE FLOW.

KODIAK AND GULF
AN OCCLUDED FRONT MOVING INTO THE SW GULF EARLY WED WILL BRING
SNOW AND RAIN TO KODIAK ISLAND BEGINNING EARLY WED MORNING.
THICKNESS VALUES AND 850MB WIND DIRECTIONS (SE) WOULD INDICATE
THAT PRECIPITATION WILL START INITIALLY AS SNOW OR MIX AND RAPIDLY
TRANSITION TOWARD RAIN. GALES ARE EXPECTED TO ACCOMPANY THE FRONT
ACROSS THE GULF.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE BRISTOL BAY THROUGH THE LOWER KUSKOKWIM VALLEY WILL HAVE
NUMEROUS SNOW SHOWERS WITH A WEAK DISTURBANCE PUSHING THROUGH THE
AREA THIS MORNING. WHILE...THE KUSKOKWIM DELTA REGION WILL HAVE
LOW STRATUS/PATCHY FOG WITH SCATTERED SNOW SHOWERS ALONG THE COAST
IN THE MORNING TODAY. THE WINDS WILL SHIFT TO OFFSHORE FLOW AND
WILL BRING DRIER CONDITIONS BY TUESDAY EVENING. THIS WILL RESULT
IN THE DIMINISHING OF THE STRATUS AND FOG GOING INTO WEDNESDAY.
THERE IS A GALE FORCE NORTH PACIFIC LOW JUST SOUTH THE EASTERN
ALEUTIANS. THIS SYSTEM WILL TRACK SOUTH OF THE KODIAK ISLAND BY
WEDNESDAY. THIS WILL GIVE WRAP-AROUND MOISTURE SPILLING OVER THE
ALASKA PENINSULA INTO THE BRISTOL BAY AREA WITH CONTINUED WARMER
TEMPERATURES THROUGH WEDNESDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THERE IS A GALE FORCE NORTH PACIFIC LOW JUST SOUTH OF CENTRAL
ALEUTIANS NEAR NIKOLSKI THIS MORNING. THIS SYSTEM WILL BRING
WARMER TEMPERATURES ALONG THE CENTRAL TO EASTERN ALEUTIANS AS THE
LOW TRACKS EASTWARD ALONG THE CHAIN...BEFORE TRACKING INTO THE
GULF OF ALASKA BY THURSDAY MORNING. THIS WILL BRING WET AND
SOUTHERLY WINDY CONDITIONS AND NORTHEASTERLY WINDS WITH SNOW
SHOWERS ON THE BACKSIDE OF THE LOW AS THIS SYSTEM TRACKS EASTWARD
THROUGH MIDWEEK. AN UPPER LEVEL RIDGE WILL BUILD INTO THE WESTERN
BERING BY TUESDAY AFTERNOON. BY WEDNESDAY...THE AKPEN AND EASTERN
ALEUTIANS WILL HAVE GUSTY NORTHWESTERLY GAP FLOW AS THE LOW
PRESSURE SYSTEM CONTINUES TO TRACK INTO THE WESTERN GULF. THE
WESTERN ALEUTAINS WILL HAVE A GALE FORCE LOW DROPPING DOWN FROM
KAMCHATKA PENINSULA WITH AN ASSOCIATED WEATHER FRONT BRINGING THE
NEXT ROUND OF PRECIPITATION BY WEDNESDAY. THIS WILL RESULT IN
STRONG SOUTHERLY WINDS BRINGING IN WARMER TEMPERATURES FROM THE
NORTHERN PACIFIC...WHICH WILL CAUSE THE PRECIPITATION TYPE TO
TRANSITION OVER TO RAIN AS THE WARM FRONT PASSES THROUGH THE
AREA BY WEDNESDAY AFTERNOON.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 132 138 155 172 173 174 178
         HEAVY FREEZING SPRAY 179 180 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...ML



000
FXAK68 PAFC 311318
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
518 AM AKDT TUE MAR 31 2015

.ANALYSIS AND UPPER LEVELS...
LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND THE
NORTH PACIFIC...WITH HIGH PRESSURE RIDGES REMAINING OVER THE FAR
WESTERN BERING AND ALSO OVER THE NORTHEASTERN INTERIOR OF THE
STATE. THE SUBTROPICAL JET IS NEARLY ZONAL SOUTH OF THE ALEUTIAN
CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH PACIFIC. THIS IS
RESULTING IN A PERSISTENT STORM TRACK ALONG THE SOUTHERN TIER OF
THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK LOWS AFFECTING
THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND ANOTHER JUST
SOUTH OF THE EASTERN ALEUTIANS. AS HAS BEEN THE CASE OVER THE
PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE TRACKING
NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. ISOLATED
CONVECTIVE SHOWERS DEVELOPED OFF OF THE TALKEETNA MOUNTAINS AND
MOVED ACROSS THE SUSITNA VALLEY LAST (SUN) EVENING AS THE 00Z
ANCHORAGE SOUNDING DEPICTED LIFTED INDICES NEAR OR SLIGHTLY BELOW
ZERO (MORE TYPICAL OF LATE MAY OR EARLY JUNE)...BUT THESE SHOWERS
HAVE DISSIPATED WITH THE LOSS OF DAYTIME HEATING. THE BULK OF
PRECIP HAS BEEN OVER THE NORTHERN GULF WITH A WEAK VORTICITY
MAXIMUM MOVING MOVING SLOWLY WEST TO NORTHWEST TOWARD THE EASTERN
KENAI PENINSULA. ISOLATED TO SCATTERED SHOWERS ALSO CONTINUE OVER
SOUTHWEST ALASKA EAST OF BETHEL WITH THE REMNANTS OF A WEAK
DEFORMATION BAND THAT HAS BEEN NEARLY STATIONARY IN WEAK UPPER
FLOW ACROSS THE AREA.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH WEAK FLOW OUTSIDE OF THE MAIN LOW PRESSURE
SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND DIURNAL CLOUDS AND SHOWER
ACTIVITY. MODELS DO BEGIN TO DIVERGE A BIT AS THE SYSTEM TRACKING
SOUTH OF THE AKPEN MOVES TO THE SOUTH OF KODIAK ISLAND TUESDAY
NIGHT INTO WEDNESDAY. THEY ALL HINT AT SOME DEVELOPMENT OF A
TRIPLE POINT LOW...BUT RIGHT NOW ALMOST ALL MODELS DEPICT THE
INITIAL PARENT LOW REMAINING THE PRIMARY LOW OVER THE FAR SOUTHERN
GULF. IN ANY CASE THESE DIFFERENCES ONLY AFFECT THE AREA IN THE
DIRECT VICINITY OF THE SYSTEM. THE GFS WAS LARGELY PREFERRED IN
THE SHORT TERM...WITH SOME DEFERENCE TO THE NAM EARLY FOR LOCAL
EFFECTS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (THROUGH WED NIGHT)...
SOUTHCENTRAL MAINLAND
UNSETTLED WEATHER WILL CONTINUE ACROSS SOUTHCENTRAL THROUGH WED.
AN UPPER TROUGH COUPLED WITH A WEAK SURFACE TROUGH MOVES NORTH
AND WEST ACROSS SOUTHCENTRAL TODAY. THE UPPER TROUGH MOVES INTO
THE INTERIOR TONIGHT AND WILL BE FOLLOWED BY A SECONDARY TROUGH
PUSHING NORTH ACROSS THE GULF OF WED. THIS SECONDARY THROUGH WILL
BE SOMEWHAT WEAKER THEN ITS PREDECESSOR. AVAILABLE SOUNDING AND
MODEL GUIDANCE INDICATE THAT SHOWERS WILL BE THE DOMINATE
CHARACTER OF PRECIPITATION WITH THESE FEATURES. FREEZING LEVELS
THROUGH WED WILL BE HIGH ENOUGH THAT OF THE PRECIPITATION WILL
FALL AS RAIN DURING THE AFTERNOON HOURS...THEN BECOMING MORE MIXED
OR SNOW DURING THE OVERNIGHT AND EARLY MORNING HOURS. DRIER
CONDITIONS ARE EXPECTED OVERNIGHT WED AS THE LOW MOVING INTO THE
GULF CREATES NORTHERLY OFFSHORE FLOW.

KODIAK AND GULF
AN OCCLUDED FRONT MOVING INTO THE SW GULF EARLY WED WILL BRING
SNOW AND RAIN TO KODIAK ISLAND BEGINNING EARLY WED MORNING.
THICKNESS VALUES AND 850MB WIND DIRECTIONS (SE) WOULD INDICATE
THAT PRECIPITATION WILL START INITIALLY AS SNOW OR MIX AND RAPIDLY
TRANSITION TOWARD RAIN. GALES ARE EXPECTED TO ACCOMPANY THE FRONT
ACROSS THE GULF.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE BRISTOL BAY THROUGH THE LOWER KUSKOKWIM VALLEY WILL HAVE
NUMEROUS SNOW SHOWERS WITH A WEAK DISTURBANCE PUSHING THROUGH THE
AREA THIS MORNING. WHILE...THE KUSKOKWIM DELTA REGION WILL HAVE
LOW STRATUS/PATCHY FOG WITH SCATTERED SNOW SHOWERS ALONG THE COAST
IN THE MORNING TODAY. THE WINDS WILL SHIFT TO OFFSHORE FLOW AND
WILL BRING DRIER CONDITIONS BY TUESDAY EVENING. THIS WILL RESULT
IN THE DIMINISHING OF THE STRATUS AND FOG GOING INTO WEDNESDAY.
THERE IS A GALE FORCE NORTH PACIFIC LOW JUST SOUTH THE EASTERN
ALEUTIANS. THIS SYSTEM WILL TRACK SOUTH OF THE KODIAK ISLAND BY
WEDNESDAY. THIS WILL GIVE WRAP-AROUND MOISTURE SPILLING OVER THE
ALASKA PENINSULA INTO THE BRISTOL BAY AREA WITH CONTINUED WARMER
TEMPERATURES THROUGH WEDNESDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THERE IS A GALE FORCE NORTH PACIFIC LOW JUST SOUTH OF CENTRAL
ALEUTIANS NEAR NIKOLSKI THIS MORNING. THIS SYSTEM WILL BRING
WARMER TEMPERATURES ALONG THE CENTRAL TO EASTERN ALEUTIANS AS THE
LOW TRACKS EASTWARD ALONG THE CHAIN...BEFORE TRACKING INTO THE
GULF OF ALASKA BY THURSDAY MORNING. THIS WILL BRING WET AND
SOUTHERLY WINDY CONDITIONS AND NORTHEASTERLY WINDS WITH SNOW
SHOWERS ON THE BACKSIDE OF THE LOW AS THIS SYSTEM TRACKS EASTWARD
THROUGH MIDWEEK. AN UPPER LEVEL RIDGE WILL BUILD INTO THE WESTERN
BERING BY TUESDAY AFTERNOON. BY WEDNESDAY...THE AKPEN AND EASTERN
ALEUTIANS WILL HAVE GUSTY NORTHWESTERLY GAP FLOW AS THE LOW
PRESSURE SYSTEM CONTINUES TO TRACK INTO THE WESTERN GULF. THE
WESTERN ALEUTAINS WILL HAVE A GALE FORCE LOW DROPPING DOWN FROM
KAMCHATKA PENINSULA WITH AN ASSOCIATED WEATHER FRONT BRINGING THE
NEXT ROUND OF PRECIPITATION BY WEDNESDAY. THIS WILL RESULT IN
STRONG SOUTHERLY WINDS BRINGING IN WARMER TEMPERATURES FROM THE
NORTHERN PACIFIC...WHICH WILL CAUSE THE PRECIPITATION TYPE TO
TRANSITION OVER TO RAIN AS THE WARM FRONT PASSES THROUGH THE
AREA BY WEDNESDAY AFTERNOON.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 132 138 155 172 173 174 178
         HEAVY FREEZING SPRAY 179 180 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...ML




000
FXAK68 PAFC 311318
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
518 AM AKDT TUE MAR 31 2015

.ANALYSIS AND UPPER LEVELS...
LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND THE
NORTH PACIFIC...WITH HIGH PRESSURE RIDGES REMAINING OVER THE FAR
WESTERN BERING AND ALSO OVER THE NORTHEASTERN INTERIOR OF THE
STATE. THE SUBTROPICAL JET IS NEARLY ZONAL SOUTH OF THE ALEUTIAN
CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH PACIFIC. THIS IS
RESULTING IN A PERSISTENT STORM TRACK ALONG THE SOUTHERN TIER OF
THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK LOWS AFFECTING
THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND ANOTHER JUST
SOUTH OF THE EASTERN ALEUTIANS. AS HAS BEEN THE CASE OVER THE
PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE TRACKING
NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. ISOLATED
CONVECTIVE SHOWERS DEVELOPED OFF OF THE TALKEETNA MOUNTAINS AND
MOVED ACROSS THE SUSITNA VALLEY LAST (SUN) EVENING AS THE 00Z
ANCHORAGE SOUNDING DEPICTED LIFTED INDICES NEAR OR SLIGHTLY BELOW
ZERO (MORE TYPICAL OF LATE MAY OR EARLY JUNE)...BUT THESE SHOWERS
HAVE DISSIPATED WITH THE LOSS OF DAYTIME HEATING. THE BULK OF
PRECIP HAS BEEN OVER THE NORTHERN GULF WITH A WEAK VORTICITY
MAXIMUM MOVING MOVING SLOWLY WEST TO NORTHWEST TOWARD THE EASTERN
KENAI PENINSULA. ISOLATED TO SCATTERED SHOWERS ALSO CONTINUE OVER
SOUTHWEST ALASKA EAST OF BETHEL WITH THE REMNANTS OF A WEAK
DEFORMATION BAND THAT HAS BEEN NEARLY STATIONARY IN WEAK UPPER
FLOW ACROSS THE AREA.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH WEAK FLOW OUTSIDE OF THE MAIN LOW PRESSURE
SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND DIURNAL CLOUDS AND SHOWER
ACTIVITY. MODELS DO BEGIN TO DIVERGE A BIT AS THE SYSTEM TRACKING
SOUTH OF THE AKPEN MOVES TO THE SOUTH OF KODIAK ISLAND TUESDAY
NIGHT INTO WEDNESDAY. THEY ALL HINT AT SOME DEVELOPMENT OF A
TRIPLE POINT LOW...BUT RIGHT NOW ALMOST ALL MODELS DEPICT THE
INITIAL PARENT LOW REMAINING THE PRIMARY LOW OVER THE FAR SOUTHERN
GULF. IN ANY CASE THESE DIFFERENCES ONLY AFFECT THE AREA IN THE
DIRECT VICINITY OF THE SYSTEM. THE GFS WAS LARGELY PREFERRED IN
THE SHORT TERM...WITH SOME DEFERENCE TO THE NAM EARLY FOR LOCAL
EFFECTS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (THROUGH WED NIGHT)...
SOUTHCENTRAL MAINLAND
UNSETTLED WEATHER WILL CONTINUE ACROSS SOUTHCENTRAL THROUGH WED.
AN UPPER TROUGH COUPLED WITH A WEAK SURFACE TROUGH MOVES NORTH
AND WEST ACROSS SOUTHCENTRAL TODAY. THE UPPER TROUGH MOVES INTO
THE INTERIOR TONIGHT AND WILL BE FOLLOWED BY A SECONDARY TROUGH
PUSHING NORTH ACROSS THE GULF OF WED. THIS SECONDARY THROUGH WILL
BE SOMEWHAT WEAKER THEN ITS PREDECESSOR. AVAILABLE SOUNDING AND
MODEL GUIDANCE INDICATE THAT SHOWERS WILL BE THE DOMINATE
CHARACTER OF PRECIPITATION WITH THESE FEATURES. FREEZING LEVELS
THROUGH WED WILL BE HIGH ENOUGH THAT OF THE PRECIPITATION WILL
FALL AS RAIN DURING THE AFTERNOON HOURS...THEN BECOMING MORE MIXED
OR SNOW DURING THE OVERNIGHT AND EARLY MORNING HOURS. DRIER
CONDITIONS ARE EXPECTED OVERNIGHT WED AS THE LOW MOVING INTO THE
GULF CREATES NORTHERLY OFFSHORE FLOW.

KODIAK AND GULF
AN OCCLUDED FRONT MOVING INTO THE SW GULF EARLY WED WILL BRING
SNOW AND RAIN TO KODIAK ISLAND BEGINNING EARLY WED MORNING.
THICKNESS VALUES AND 850MB WIND DIRECTIONS (SE) WOULD INDICATE
THAT PRECIPITATION WILL START INITIALLY AS SNOW OR MIX AND RAPIDLY
TRANSITION TOWARD RAIN. GALES ARE EXPECTED TO ACCOMPANY THE FRONT
ACROSS THE GULF.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
THE BRISTOL BAY THROUGH THE LOWER KUSKOKWIM VALLEY WILL HAVE
NUMEROUS SNOW SHOWERS WITH A WEAK DISTURBANCE PUSHING THROUGH THE
AREA THIS MORNING. WHILE...THE KUSKOKWIM DELTA REGION WILL HAVE
LOW STRATUS/PATCHY FOG WITH SCATTERED SNOW SHOWERS ALONG THE COAST
IN THE MORNING TODAY. THE WINDS WILL SHIFT TO OFFSHORE FLOW AND
WILL BRING DRIER CONDITIONS BY TUESDAY EVENING. THIS WILL RESULT
IN THE DIMINISHING OF THE STRATUS AND FOG GOING INTO WEDNESDAY.
THERE IS A GALE FORCE NORTH PACIFIC LOW JUST SOUTH THE EASTERN
ALEUTIANS. THIS SYSTEM WILL TRACK SOUTH OF THE KODIAK ISLAND BY
WEDNESDAY. THIS WILL GIVE WRAP-AROUND MOISTURE SPILLING OVER THE
ALASKA PENINSULA INTO THE BRISTOL BAY AREA WITH CONTINUED WARMER
TEMPERATURES THROUGH WEDNESDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THERE IS A GALE FORCE NORTH PACIFIC LOW JUST SOUTH OF CENTRAL
ALEUTIANS NEAR NIKOLSKI THIS MORNING. THIS SYSTEM WILL BRING
WARMER TEMPERATURES ALONG THE CENTRAL TO EASTERN ALEUTIANS AS THE
LOW TRACKS EASTWARD ALONG THE CHAIN...BEFORE TRACKING INTO THE
GULF OF ALASKA BY THURSDAY MORNING. THIS WILL BRING WET AND
SOUTHERLY WINDY CONDITIONS AND NORTHEASTERLY WINDS WITH SNOW
SHOWERS ON THE BACKSIDE OF THE LOW AS THIS SYSTEM TRACKS EASTWARD
THROUGH MIDWEEK. AN UPPER LEVEL RIDGE WILL BUILD INTO THE WESTERN
BERING BY TUESDAY AFTERNOON. BY WEDNESDAY...THE AKPEN AND EASTERN
ALEUTIANS WILL HAVE GUSTY NORTHWESTERLY GAP FLOW AS THE LOW
PRESSURE SYSTEM CONTINUES TO TRACK INTO THE WESTERN GULF. THE
WESTERN ALEUTAINS WILL HAVE A GALE FORCE LOW DROPPING DOWN FROM
KAMCHATKA PENINSULA WITH AN ASSOCIATED WEATHER FRONT BRINGING THE
NEXT ROUND OF PRECIPITATION BY WEDNESDAY. THIS WILL RESULT IN
STRONG SOUTHERLY WINDS BRINGING IN WARMER TEMPERATURES FROM THE
NORTHERN PACIFIC...WHICH WILL CAUSE THE PRECIPITATION TYPE TO
TRANSITION OVER TO RAIN AS THE WARM FRONT PASSES THROUGH THE
AREA BY WEDNESDAY AFTERNOON.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALES 132 138 155 172 173 174 178
         HEAVY FREEZING SPRAY 179 180 185.
FIRE WEATHER...NONE.

&&

$$

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...BC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...ML



000
FXAK69 PAFG 311053
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
253 AM AKDT TUE MAR 31 2015

.DISCUSSION...
00Z SYNOPTIC MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST
THE 06Z ANALYSIS. THE MODELS CONTINUE TO PERFORM REASONABLY AS
FAR AS FEATURE POSITION AND STRENGTH HOWEVER 06Z AND 09Z
TEMPERATURE VERIFICATION OVER THE INTERIOR CONTINUES TO PERFORM
POORLY. RUN TO RUN CONTINUITY AS WELL SPREAD BETWEEN MODEL
FAMILIES REMAIN REASONABLE THROUGH FRIDAY....HOWEVER BY THE
WEEKEND SIGNIFICANT MODEL SPREAD ERUPTS AND RELATIVE MEASURES OF
PREDICTABILITY PLUMMET LEADING TO LOW CONFIDENCE IN THE LONG
RANGE GUIDANCE. RELIED HEAVILY AGAIN ON INHERITED FORECAST FOR
TEMPERATURES AND A BLEND OF ECMWF AND NAM FOR PRECIPITATION FIELDS.

ALOFT AT 500 HPA...A 514 DAM LOW OVER WESTERN KOTZEBUE SOUND
LIFTS NORTHWEST IN TO THE SOUTHERN CHUKCHI SEA WEDNESDAY. A 515
DAM LOW OVER THE CENTRAL ALEUTIANS WILL MOVE RAPIDLY EAST TO BE
LOCATED 200 NM SOUTH OF DUTCH HARBOR WEDNESDAY MORNING AND IN THE
CENTRAL GULF OF ALASKA THURSDAY MORNING. THE LOW CONTINUES TO MOVE
TO THE EAST INTO THE EASTERN GULF OF ALASKA FRIDAY MORNING. AN
UPPER LEVEL RIDGE BUILDS RAPIDLY NORTH INTO THE EASTERN BERING
SEA AND WESTERN ALASKA WEDNESDAY AND THURSDAY AND WILL BE CENTERED
ALONG A ST LAWRENCE ISLAND TO COLD BAY AXIS FRIDAY MORNING AS THE
UPPER LEVEL TROUGH SLIPS EAST TO BE LOCATED OVER A BARROW TO SITKA
AXIS BY FRIDAY MORNING.

ON THE SURFACE...A 1003 MB LOW CURRENTLY OVER WESTERN KOTZEBUE
SOUND WILL PUSH NORTHWEST AND WEAKEN TO 1008 MB AS IT MOVES INTO
THE SOUTHERN CHUKCHI SEA. TRAILING FRONT OVER THE WESTERN BROOKS
RANGE EXTENDING SOUTH MERGES WITH THE ARCTIC FRONT THAT EXTENDS
SOUTH OVER THE WESTERN INTERIOR AND WEST COAST. THIS AREA WILL BE
THE FOCAL POINT FOR SNOW SHOWERS TODAY NORTH OF THE SEWARD
PENINSULA AND RAIN AND SNOW SHOWERS SOUTH OF THE SEWARD PENINSULA.
A WEAK FRONT MOVING NORTHWEST AROUND A WEAK LOW MOVING INTO THE
NORTHEAST GULF OF ALASKA TUESDAY NIGHT AND WEDNESDAY WILL BRING
MOSTLY CLOUDY SKIES SOUTH AND EAST OF FAIRBANKS AND MOSTLY CLOUDY
SKIES WITH SCATTERED SNOW SHOWERS OR FLURRIES NORTH AND WEST OF
FAIRBANKS TUESDAY NIGHT AND WEDNESDAY.

1037 MB HIGH PRESSURE APPROXIMATELY 400 NM NORTH OF DEMARCATION
POINT COMBINED WITH COMPLEX SET OF LOW PRESSURE TROUGHS OVER THE
INTERIOR CREATING STRONG GRADIENT OVER THE NORTH SLOPE COAST.
ONGOING BLIZZARD WARNING OVER EASTERN BEAUFORT SEA COAST ALLOWED
TO CONTINUE AS WINDS BRIEFLY DIMINISH EARLY THIS MORNING BUT ARE
EXPECTED TO INCREASE AGAIN LATER THIS MORNING AND AFTERNOON WITH
BLIZZARD CONDITIONS EXPECTED TO DEVELOP AGAIN BY LATE MORNING.
WINTER WEATHER ADVISORIES FOR CENTRAL BEAUFORT SEA COAST AND
NORTHERN COAST FOR BLOWING SNOW ALLOWED TO CONTINUE THROUGH THIS
EVENING WITH WINDS AGAIN EXPECTED TO PICK UP BY LATE MORNING AND
CONTINUE TROUGH THIS AFTERNOON.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ230.
&&

$$

CCC MAR 15



000
FXAK69 PAFG 311053
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
253 AM AKDT TUE MAR 31 2015

.DISCUSSION...
00Z SYNOPTIC MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST
THE 06Z ANALYSIS. THE MODELS CONTINUE TO PERFORM REASONABLY AS
FAR AS FEATURE POSITION AND STRENGTH HOWEVER 06Z AND 09Z
TEMPERATURE VERIFICATION OVER THE INTERIOR CONTINUES TO PERFORM
POORLY. RUN TO RUN CONTINUITY AS WELL SPREAD BETWEEN MODEL
FAMILIES REMAIN REASONABLE THROUGH FRIDAY....HOWEVER BY THE
WEEKEND SIGNIFICANT MODEL SPREAD ERUPTS AND RELATIVE MEASURES OF
PREDICTABILITY PLUMMET LEADING TO LOW CONFIDENCE IN THE LONG
RANGE GUIDANCE. RELIED HEAVILY AGAIN ON INHERITED FORECAST FOR
TEMPERATURES AND A BLEND OF ECMWF AND NAM FOR PRECIPITATION FIELDS.

ALOFT AT 500 HPA...A 514 DAM LOW OVER WESTERN KOTZEBUE SOUND
LIFTS NORTHWEST IN TO THE SOUTHERN CHUKCHI SEA WEDNESDAY. A 515
DAM LOW OVER THE CENTRAL ALEUTIANS WILL MOVE RAPIDLY EAST TO BE
LOCATED 200 NM SOUTH OF DUTCH HARBOR WEDNESDAY MORNING AND IN THE
CENTRAL GULF OF ALASKA THURSDAY MORNING. THE LOW CONTINUES TO MOVE
TO THE EAST INTO THE EASTERN GULF OF ALASKA FRIDAY MORNING. AN
UPPER LEVEL RIDGE BUILDS RAPIDLY NORTH INTO THE EASTERN BERING
SEA AND WESTERN ALASKA WEDNESDAY AND THURSDAY AND WILL BE CENTERED
ALONG A ST LAWRENCE ISLAND TO COLD BAY AXIS FRIDAY MORNING AS THE
UPPER LEVEL TROUGH SLIPS EAST TO BE LOCATED OVER A BARROW TO SITKA
AXIS BY FRIDAY MORNING.

ON THE SURFACE...A 1003 MB LOW CURRENTLY OVER WESTERN KOTZEBUE
SOUND WILL PUSH NORTHWEST AND WEAKEN TO 1008 MB AS IT MOVES INTO
THE SOUTHERN CHUKCHI SEA. TRAILING FRONT OVER THE WESTERN BROOKS
RANGE EXTENDING SOUTH MERGES WITH THE ARCTIC FRONT THAT EXTENDS
SOUTH OVER THE WESTERN INTERIOR AND WEST COAST. THIS AREA WILL BE
THE FOCAL POINT FOR SNOW SHOWERS TODAY NORTH OF THE SEWARD
PENINSULA AND RAIN AND SNOW SHOWERS SOUTH OF THE SEWARD PENINSULA.
A WEAK FRONT MOVING NORTHWEST AROUND A WEAK LOW MOVING INTO THE
NORTHEAST GULF OF ALASKA TUESDAY NIGHT AND WEDNESDAY WILL BRING
MOSTLY CLOUDY SKIES SOUTH AND EAST OF FAIRBANKS AND MOSTLY CLOUDY
SKIES WITH SCATTERED SNOW SHOWERS OR FLURRIES NORTH AND WEST OF
FAIRBANKS TUESDAY NIGHT AND WEDNESDAY.

1037 MB HIGH PRESSURE APPROXIMATELY 400 NM NORTH OF DEMARCATION
POINT COMBINED WITH COMPLEX SET OF LOW PRESSURE TROUGHS OVER THE
INTERIOR CREATING STRONG GRADIENT OVER THE NORTH SLOPE COAST.
ONGOING BLIZZARD WARNING OVER EASTERN BEAUFORT SEA COAST ALLOWED
TO CONTINUE AS WINDS BRIEFLY DIMINISH EARLY THIS MORNING BUT ARE
EXPECTED TO INCREASE AGAIN LATER THIS MORNING AND AFTERNOON WITH
BLIZZARD CONDITIONS EXPECTED TO DEVELOP AGAIN BY LATE MORNING.
WINTER WEATHER ADVISORIES FOR CENTRAL BEAUFORT SEA COAST AND
NORTHERN COAST FOR BLOWING SNOW ALLOWED TO CONTINUE THROUGH THIS
EVENING WITH WINDS AGAIN EXPECTED TO PICK UP BY LATE MORNING AND
CONTINUE TROUGH THIS AFTERNOON.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ230.
&&

$$

CCC MAR 15




000
FXAK69 PAFG 311053
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
253 AM AKDT TUE MAR 31 2015

.DISCUSSION...
00Z SYNOPTIC MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST
THE 06Z ANALYSIS. THE MODELS CONTINUE TO PERFORM REASONABLY AS
FAR AS FEATURE POSITION AND STRENGTH HOWEVER 06Z AND 09Z
TEMPERATURE VERIFICATION OVER THE INTERIOR CONTINUES TO PERFORM
POORLY. RUN TO RUN CONTINUITY AS WELL SPREAD BETWEEN MODEL
FAMILIES REMAIN REASONABLE THROUGH FRIDAY....HOWEVER BY THE
WEEKEND SIGNIFICANT MODEL SPREAD ERUPTS AND RELATIVE MEASURES OF
PREDICTABILITY PLUMMET LEADING TO LOW CONFIDENCE IN THE LONG
RANGE GUIDANCE. RELIED HEAVILY AGAIN ON INHERITED FORECAST FOR
TEMPERATURES AND A BLEND OF ECMWF AND NAM FOR PRECIPITATION FIELDS.

ALOFT AT 500 HPA...A 514 DAM LOW OVER WESTERN KOTZEBUE SOUND
LIFTS NORTHWEST IN TO THE SOUTHERN CHUKCHI SEA WEDNESDAY. A 515
DAM LOW OVER THE CENTRAL ALEUTIANS WILL MOVE RAPIDLY EAST TO BE
LOCATED 200 NM SOUTH OF DUTCH HARBOR WEDNESDAY MORNING AND IN THE
CENTRAL GULF OF ALASKA THURSDAY MORNING. THE LOW CONTINUES TO MOVE
TO THE EAST INTO THE EASTERN GULF OF ALASKA FRIDAY MORNING. AN
UPPER LEVEL RIDGE BUILDS RAPIDLY NORTH INTO THE EASTERN BERING
SEA AND WESTERN ALASKA WEDNESDAY AND THURSDAY AND WILL BE CENTERED
ALONG A ST LAWRENCE ISLAND TO COLD BAY AXIS FRIDAY MORNING AS THE
UPPER LEVEL TROUGH SLIPS EAST TO BE LOCATED OVER A BARROW TO SITKA
AXIS BY FRIDAY MORNING.

ON THE SURFACE...A 1003 MB LOW CURRENTLY OVER WESTERN KOTZEBUE
SOUND WILL PUSH NORTHWEST AND WEAKEN TO 1008 MB AS IT MOVES INTO
THE SOUTHERN CHUKCHI SEA. TRAILING FRONT OVER THE WESTERN BROOKS
RANGE EXTENDING SOUTH MERGES WITH THE ARCTIC FRONT THAT EXTENDS
SOUTH OVER THE WESTERN INTERIOR AND WEST COAST. THIS AREA WILL BE
THE FOCAL POINT FOR SNOW SHOWERS TODAY NORTH OF THE SEWARD
PENINSULA AND RAIN AND SNOW SHOWERS SOUTH OF THE SEWARD PENINSULA.
A WEAK FRONT MOVING NORTHWEST AROUND A WEAK LOW MOVING INTO THE
NORTHEAST GULF OF ALASKA TUESDAY NIGHT AND WEDNESDAY WILL BRING
MOSTLY CLOUDY SKIES SOUTH AND EAST OF FAIRBANKS AND MOSTLY CLOUDY
SKIES WITH SCATTERED SNOW SHOWERS OR FLURRIES NORTH AND WEST OF
FAIRBANKS TUESDAY NIGHT AND WEDNESDAY.

1037 MB HIGH PRESSURE APPROXIMATELY 400 NM NORTH OF DEMARCATION
POINT COMBINED WITH COMPLEX SET OF LOW PRESSURE TROUGHS OVER THE
INTERIOR CREATING STRONG GRADIENT OVER THE NORTH SLOPE COAST.
ONGOING BLIZZARD WARNING OVER EASTERN BEAUFORT SEA COAST ALLOWED
TO CONTINUE AS WINDS BRIEFLY DIMINISH EARLY THIS MORNING BUT ARE
EXPECTED TO INCREASE AGAIN LATER THIS MORNING AND AFTERNOON WITH
BLIZZARD CONDITIONS EXPECTED TO DEVELOP AGAIN BY LATE MORNING.
WINTER WEATHER ADVISORIES FOR CENTRAL BEAUFORT SEA COAST AND
NORTHERN COAST FOR BLOWING SNOW ALLOWED TO CONTINUE THROUGH THIS
EVENING WITH WINDS AGAIN EXPECTED TO PICK UP BY LATE MORNING AND
CONTINUE TROUGH THIS AFTERNOON.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ230.
&&

$$

CCC MAR 15




000
FXAK69 PAFG 311053
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
253 AM AKDT TUE MAR 31 2015

.DISCUSSION...
00Z SYNOPTIC MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST
THE 06Z ANALYSIS. THE MODELS CONTINUE TO PERFORM REASONABLY AS
FAR AS FEATURE POSITION AND STRENGTH HOWEVER 06Z AND 09Z
TEMPERATURE VERIFICATION OVER THE INTERIOR CONTINUES TO PERFORM
POORLY. RUN TO RUN CONTINUITY AS WELL SPREAD BETWEEN MODEL
FAMILIES REMAIN REASONABLE THROUGH FRIDAY....HOWEVER BY THE
WEEKEND SIGNIFICANT MODEL SPREAD ERUPTS AND RELATIVE MEASURES OF
PREDICTABILITY PLUMMET LEADING TO LOW CONFIDENCE IN THE LONG
RANGE GUIDANCE. RELIED HEAVILY AGAIN ON INHERITED FORECAST FOR
TEMPERATURES AND A BLEND OF ECMWF AND NAM FOR PRECIPITATION FIELDS.

ALOFT AT 500 HPA...A 514 DAM LOW OVER WESTERN KOTZEBUE SOUND
LIFTS NORTHWEST IN TO THE SOUTHERN CHUKCHI SEA WEDNESDAY. A 515
DAM LOW OVER THE CENTRAL ALEUTIANS WILL MOVE RAPIDLY EAST TO BE
LOCATED 200 NM SOUTH OF DUTCH HARBOR WEDNESDAY MORNING AND IN THE
CENTRAL GULF OF ALASKA THURSDAY MORNING. THE LOW CONTINUES TO MOVE
TO THE EAST INTO THE EASTERN GULF OF ALASKA FRIDAY MORNING. AN
UPPER LEVEL RIDGE BUILDS RAPIDLY NORTH INTO THE EASTERN BERING
SEA AND WESTERN ALASKA WEDNESDAY AND THURSDAY AND WILL BE CENTERED
ALONG A ST LAWRENCE ISLAND TO COLD BAY AXIS FRIDAY MORNING AS THE
UPPER LEVEL TROUGH SLIPS EAST TO BE LOCATED OVER A BARROW TO SITKA
AXIS BY FRIDAY MORNING.

ON THE SURFACE...A 1003 MB LOW CURRENTLY OVER WESTERN KOTZEBUE
SOUND WILL PUSH NORTHWEST AND WEAKEN TO 1008 MB AS IT MOVES INTO
THE SOUTHERN CHUKCHI SEA. TRAILING FRONT OVER THE WESTERN BROOKS
RANGE EXTENDING SOUTH MERGES WITH THE ARCTIC FRONT THAT EXTENDS
SOUTH OVER THE WESTERN INTERIOR AND WEST COAST. THIS AREA WILL BE
THE FOCAL POINT FOR SNOW SHOWERS TODAY NORTH OF THE SEWARD
PENINSULA AND RAIN AND SNOW SHOWERS SOUTH OF THE SEWARD PENINSULA.
A WEAK FRONT MOVING NORTHWEST AROUND A WEAK LOW MOVING INTO THE
NORTHEAST GULF OF ALASKA TUESDAY NIGHT AND WEDNESDAY WILL BRING
MOSTLY CLOUDY SKIES SOUTH AND EAST OF FAIRBANKS AND MOSTLY CLOUDY
SKIES WITH SCATTERED SNOW SHOWERS OR FLURRIES NORTH AND WEST OF
FAIRBANKS TUESDAY NIGHT AND WEDNESDAY.

1037 MB HIGH PRESSURE APPROXIMATELY 400 NM NORTH OF DEMARCATION
POINT COMBINED WITH COMPLEX SET OF LOW PRESSURE TROUGHS OVER THE
INTERIOR CREATING STRONG GRADIENT OVER THE NORTH SLOPE COAST.
ONGOING BLIZZARD WARNING OVER EASTERN BEAUFORT SEA COAST ALLOWED
TO CONTINUE AS WINDS BRIEFLY DIMINISH EARLY THIS MORNING BUT ARE
EXPECTED TO INCREASE AGAIN LATER THIS MORNING AND AFTERNOON WITH
BLIZZARD CONDITIONS EXPECTED TO DEVELOP AGAIN BY LATE MORNING.
WINTER WEATHER ADVISORIES FOR CENTRAL BEAUFORT SEA COAST AND
NORTHERN COAST FOR BLOWING SNOW ALLOWED TO CONTINUE THROUGH THIS
EVENING WITH WINDS AGAIN EXPECTED TO PICK UP BY LATE MORNING AND
CONTINUE TROUGH THIS AFTERNOON.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ230.
&&

$$

CCC MAR 15




000
FXAK69 PAFG 311053
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
253 AM AKDT TUE MAR 31 2015

.DISCUSSION...
00Z SYNOPTIC MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST
THE 06Z ANALYSIS. THE MODELS CONTINUE TO PERFORM REASONABLY AS
FAR AS FEATURE POSITION AND STRENGTH HOWEVER 06Z AND 09Z
TEMPERATURE VERIFICATION OVER THE INTERIOR CONTINUES TO PERFORM
POORLY. RUN TO RUN CONTINUITY AS WELL SPREAD BETWEEN MODEL
FAMILIES REMAIN REASONABLE THROUGH FRIDAY....HOWEVER BY THE
WEEKEND SIGNIFICANT MODEL SPREAD ERUPTS AND RELATIVE MEASURES OF
PREDICTABILITY PLUMMET LEADING TO LOW CONFIDENCE IN THE LONG
RANGE GUIDANCE. RELIED HEAVILY AGAIN ON INHERITED FORECAST FOR
TEMPERATURES AND A BLEND OF ECMWF AND NAM FOR PRECIPITATION FIELDS.

ALOFT AT 500 HPA...A 514 DAM LOW OVER WESTERN KOTZEBUE SOUND
LIFTS NORTHWEST IN TO THE SOUTHERN CHUKCHI SEA WEDNESDAY. A 515
DAM LOW OVER THE CENTRAL ALEUTIANS WILL MOVE RAPIDLY EAST TO BE
LOCATED 200 NM SOUTH OF DUTCH HARBOR WEDNESDAY MORNING AND IN THE
CENTRAL GULF OF ALASKA THURSDAY MORNING. THE LOW CONTINUES TO MOVE
TO THE EAST INTO THE EASTERN GULF OF ALASKA FRIDAY MORNING. AN
UPPER LEVEL RIDGE BUILDS RAPIDLY NORTH INTO THE EASTERN BERING
SEA AND WESTERN ALASKA WEDNESDAY AND THURSDAY AND WILL BE CENTERED
ALONG A ST LAWRENCE ISLAND TO COLD BAY AXIS FRIDAY MORNING AS THE
UPPER LEVEL TROUGH SLIPS EAST TO BE LOCATED OVER A BARROW TO SITKA
AXIS BY FRIDAY MORNING.

ON THE SURFACE...A 1003 MB LOW CURRENTLY OVER WESTERN KOTZEBUE
SOUND WILL PUSH NORTHWEST AND WEAKEN TO 1008 MB AS IT MOVES INTO
THE SOUTHERN CHUKCHI SEA. TRAILING FRONT OVER THE WESTERN BROOKS
RANGE EXTENDING SOUTH MERGES WITH THE ARCTIC FRONT THAT EXTENDS
SOUTH OVER THE WESTERN INTERIOR AND WEST COAST. THIS AREA WILL BE
THE FOCAL POINT FOR SNOW SHOWERS TODAY NORTH OF THE SEWARD
PENINSULA AND RAIN AND SNOW SHOWERS SOUTH OF THE SEWARD PENINSULA.
A WEAK FRONT MOVING NORTHWEST AROUND A WEAK LOW MOVING INTO THE
NORTHEAST GULF OF ALASKA TUESDAY NIGHT AND WEDNESDAY WILL BRING
MOSTLY CLOUDY SKIES SOUTH AND EAST OF FAIRBANKS AND MOSTLY CLOUDY
SKIES WITH SCATTERED SNOW SHOWERS OR FLURRIES NORTH AND WEST OF
FAIRBANKS TUESDAY NIGHT AND WEDNESDAY.

1037 MB HIGH PRESSURE APPROXIMATELY 400 NM NORTH OF DEMARCATION
POINT COMBINED WITH COMPLEX SET OF LOW PRESSURE TROUGHS OVER THE
INTERIOR CREATING STRONG GRADIENT OVER THE NORTH SLOPE COAST.
ONGOING BLIZZARD WARNING OVER EASTERN BEAUFORT SEA COAST ALLOWED
TO CONTINUE AS WINDS BRIEFLY DIMINISH EARLY THIS MORNING BUT ARE
EXPECTED TO INCREASE AGAIN LATER THIS MORNING AND AFTERNOON WITH
BLIZZARD CONDITIONS EXPECTED TO DEVELOP AGAIN BY LATE MORNING.
WINTER WEATHER ADVISORIES FOR CENTRAL BEAUFORT SEA COAST AND
NORTHERN COAST FOR BLOWING SNOW ALLOWED TO CONTINUE THROUGH THIS
EVENING WITH WINDS AGAIN EXPECTED TO PICK UP BY LATE MORNING AND
CONTINUE TROUGH THIS AFTERNOON.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ230.
&&

$$

CCC MAR 15




000
FXAK69 PAFG 311053
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
253 AM AKDT TUE MAR 31 2015

.DISCUSSION...
00Z SYNOPTIC MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST
THE 06Z ANALYSIS. THE MODELS CONTINUE TO PERFORM REASONABLY AS
FAR AS FEATURE POSITION AND STRENGTH HOWEVER 06Z AND 09Z
TEMPERATURE VERIFICATION OVER THE INTERIOR CONTINUES TO PERFORM
POORLY. RUN TO RUN CONTINUITY AS WELL SPREAD BETWEEN MODEL
FAMILIES REMAIN REASONABLE THROUGH FRIDAY....HOWEVER BY THE
WEEKEND SIGNIFICANT MODEL SPREAD ERUPTS AND RELATIVE MEASURES OF
PREDICTABILITY PLUMMET LEADING TO LOW CONFIDENCE IN THE LONG
RANGE GUIDANCE. RELIED HEAVILY AGAIN ON INHERITED FORECAST FOR
TEMPERATURES AND A BLEND OF ECMWF AND NAM FOR PRECIPITATION FIELDS.

ALOFT AT 500 HPA...A 514 DAM LOW OVER WESTERN KOTZEBUE SOUND
LIFTS NORTHWEST IN TO THE SOUTHERN CHUKCHI SEA WEDNESDAY. A 515
DAM LOW OVER THE CENTRAL ALEUTIANS WILL MOVE RAPIDLY EAST TO BE
LOCATED 200 NM SOUTH OF DUTCH HARBOR WEDNESDAY MORNING AND IN THE
CENTRAL GULF OF ALASKA THURSDAY MORNING. THE LOW CONTINUES TO MOVE
TO THE EAST INTO THE EASTERN GULF OF ALASKA FRIDAY MORNING. AN
UPPER LEVEL RIDGE BUILDS RAPIDLY NORTH INTO THE EASTERN BERING
SEA AND WESTERN ALASKA WEDNESDAY AND THURSDAY AND WILL BE CENTERED
ALONG A ST LAWRENCE ISLAND TO COLD BAY AXIS FRIDAY MORNING AS THE
UPPER LEVEL TROUGH SLIPS EAST TO BE LOCATED OVER A BARROW TO SITKA
AXIS BY FRIDAY MORNING.

ON THE SURFACE...A 1003 MB LOW CURRENTLY OVER WESTERN KOTZEBUE
SOUND WILL PUSH NORTHWEST AND WEAKEN TO 1008 MB AS IT MOVES INTO
THE SOUTHERN CHUKCHI SEA. TRAILING FRONT OVER THE WESTERN BROOKS
RANGE EXTENDING SOUTH MERGES WITH THE ARCTIC FRONT THAT EXTENDS
SOUTH OVER THE WESTERN INTERIOR AND WEST COAST. THIS AREA WILL BE
THE FOCAL POINT FOR SNOW SHOWERS TODAY NORTH OF THE SEWARD
PENINSULA AND RAIN AND SNOW SHOWERS SOUTH OF THE SEWARD PENINSULA.
A WEAK FRONT MOVING NORTHWEST AROUND A WEAK LOW MOVING INTO THE
NORTHEAST GULF OF ALASKA TUESDAY NIGHT AND WEDNESDAY WILL BRING
MOSTLY CLOUDY SKIES SOUTH AND EAST OF FAIRBANKS AND MOSTLY CLOUDY
SKIES WITH SCATTERED SNOW SHOWERS OR FLURRIES NORTH AND WEST OF
FAIRBANKS TUESDAY NIGHT AND WEDNESDAY.

1037 MB HIGH PRESSURE APPROXIMATELY 400 NM NORTH OF DEMARCATION
POINT COMBINED WITH COMPLEX SET OF LOW PRESSURE TROUGHS OVER THE
INTERIOR CREATING STRONG GRADIENT OVER THE NORTH SLOPE COAST.
ONGOING BLIZZARD WARNING OVER EASTERN BEAUFORT SEA COAST ALLOWED
TO CONTINUE AS WINDS BRIEFLY DIMINISH EARLY THIS MORNING BUT ARE
EXPECTED TO INCREASE AGAIN LATER THIS MORNING AND AFTERNOON WITH
BLIZZARD CONDITIONS EXPECTED TO DEVELOP AGAIN BY LATE MORNING.
WINTER WEATHER ADVISORIES FOR CENTRAL BEAUFORT SEA COAST AND
NORTHERN COAST FOR BLOWING SNOW ALLOWED TO CONTINUE THROUGH THIS
EVENING WITH WINDS AGAIN EXPECTED TO PICK UP BY LATE MORNING AND
CONTINUE TROUGH THIS AFTERNOON.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ230.
&&

$$

CCC MAR 15




000
FXAK68 PAFC 310006
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
406 PM AKDT MON MAR 30 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND
THE NORTH PACIFIC. THE SUBTROPICAL JET IS NEARLY ZONAL JUST SOUTH
OF THE ALEUTIAN CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH
PACIFIC. THIS IS RESULTING IN A PERSISTENT STORM TRACK ALONG THE
SOUTHERN TIER OF THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK
LOWS AFFECTING THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND
ANOTHER OVER THE FAR WESTERN ALEUTIANS. SATELLITE IMAGERY SHOWS
CONVECTIVE CLOUDS ACROSS MUCH OF THE FORECAST AREA WHICH IS
INDICATIVE OF A GENERALLY UNSTABLE ATMOSPHERE. AS HAS BEEN THE
CASE OVER THE PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE
TRACKING NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. THE BULK
OF PRECIP HAS BEEN ALONG THE COAST THANKS TO PERSISTENT
DOWN-SLOPING OFF THE COASTAL MOUNTAINS...THOUGH THE LOW LEVEL
SOUTHEASTERLY FLOW IS BEGINNING TO WEAKEN AND BACK TOWARD THE
NORTH.

AS THE UPPER WAVES CONTINUE WESTWARD TO SOUTHWEST ALASKA THEY RUN
INTO SOME WEAK RIDGING WHICH HAS LED TO FORMATION OF A DEFORMATION
BAND. KING SALMON RADAR SHOWS A NORTH-SOUTH ORIENTED BAND OF
PRECIP ALIGNED DIRECTLY OVER KING SALMON. A SEPARATE UPPER LEVEL
WAVE IS LIFTING NORTHWARD ACROSS THE KUSKOKWIM DELTA PRODUCING
AREAS OF LIGHT SNOW.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH MUCH WEAKER FLOW OUTSIDE OF THE MAIN LOW
PRESSURE SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND CLOUD COVER. MODELS DO BEGIN
TO DIVERGE A BIT AS SYSTEM TRACKING SOUTH OF THE ALEUTIANS PASSES
SOUTH OF KODIAK ISLAND TUESDAY NIGHT INTO WEDNESDAY. THEY ALL HINT
AS DEVELOPMENT OF A TRIPLE POINT LOW...BUT DIFFER AS TO WHETHER
THIS BECOMES THE PRIMARY LOW CENTER. IN ANY CASE THESE DIFFERENCES
ONLY AFFECT THE AREA IN THE DIRECT VICINITY OF THE SYSTEM. WITH
A DECENT JET STREAK ALONG THE SOUTH TO EAST SIDE OF THIS SYSTEM
AND GOOD UPPER LEVEL DIFFLUENCE OUT AHEAD OF IT...PREFER THE MORE
AGGRESSIVE TRIPLE POINT DEVELOPMENT AS SEEN IN THE NAM.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH WED NIGHT)...

AN AREA OF LOW PRESSURE OVER THE SOUTHERN GULF OF ALASKA WILL
PHASE WITH A LOW PUSHING ACROSS THE ALASKA PENINSULA TONIGHT. RAIN
SHOWER ACTIVITY IS EXPECTED TO CONTINUE ALONG THE NORTHERN GULF
COAST WITH THE ENHANCED LIFT ASSOCIATED WITH THE PHASING LOWS AND
AND UPPER LEVEL SHORTWAVE ROTATING AROUND A PARENT LOW ALSO
LOCATED IN THE SOUTHERN GULF. DOWN-SLOPING HAS BEEN EATING AWAY
AT A MAJORITY OF THE PRECIPITATION THAT HAS TRIED TO MOVE INLAND
DURING THE DAY BUT 00Z RAOB DATA SUPPORTS THE MODEL DATA IN THAT
THE LOW LEVEL FLOW IS WEAKENING AND SHIFTING TO A MORE SOUTHERLY
ORIENTATION. THIS WILL ALLOW AN ISOLATED SHOWER OR TWO TO MOVE
INLAND DURING THE EVENING HOURS IF DEW POINT DEPRESSIONS IN EXCESS
OF 10 DEGREES ARE ABLE TO BE OVERCOME.

THE PATTERN BEGINS TO SHIFT TUESDAY AFTERNOON/EVENING AS AN AREA
OF LOW PRESSURE MOVES INTO THE WESTERN GULF. A SHORTWAVE PRECEDING
THIS FRONT WILL PUSH ACROSS SOUTHCENTRAL ALASKA AND BRING A DECENT
CHANCE FOR RAIN/SNOW (DEPENDING ON TIMING OF THE PRECIPITATION) TO
ANCHORAGE/KENAI AND THE MAT-SU VALLEY. AS THE LOW MOVES INTO THE
WESTERN GULF...THE PRESSURE GRADIENT WILL BECOME FAVORABLE FOR
SOUTHEASTERLY GAPS (TURNAGAIN ARM...PORTAGE VALLEY AND KNIK RIVER
VALLEY) TO HAVE SOME GUSTY WINDS. HOWEVER...THERE IS STILL SOME
UNCERTAINTY TO THE LOW TRACK WHICH WILL DIRECTLY IMPACT THE
PRESSURE GRADIENT AND WIND GUST STRENGTH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LOW STRATUS AND PATCHY FOG WILL BECOME PROMINENT OVER PARTS OF
THE KUSKOKWIM DELTA AND BRISTOL BAY ZONE OVERNIGHT...AS LINGERING
SHOWERS OVER THE MAINLAND TODAY HELPED TO REPLENISH LOW LEVEL
MOISTURE OVER THE AREA. AS THE UPPER LEVEL WAVE OVER THE KUSKOKWIM
DELTA EXITS TO THE NORTH TOMORROW MORNING...PRECIPITATION OVER THE
MAINLAND WILL TAPER OFF THROUGH WEDNESDAY MORNING. WET AND WARMER
CONDITIONS WILL THEN BUILD BACK MAINLY OVER THE ALASKA PENINSULA
WEDNESDAY...AS A GALE FORCE NORTH PACIFIC LOW TRACKS JUST SOUTH OF
KODIAK ISLAND. PRECIPITATION OVER THE BRISTOL BAY ZONE WILL TAPER
OFF BY THURSDAY MORNING...AS THE AFOREMENTIONED LOW TRACKS
FURTHER EASTWARD AND INTO THE GULF OF ALASKA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A VERTICALLY STACKED SYSTEM OVER THE WESTERN ALEUTIANS WILL CROSS
INTO THE NORTHERN PACIFIC...BEFORE REFORMING INTO A GALE FORCE
LOW SOUTH OF THE CENTRAL ALEUTIANS OVERNIGHT TONIGHT. THIS SYSTEM
WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE ALEUTIAN
CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY THURSDAY
MORNING. WET AND WINDY CONDITIONS ARE EXPECTED TO ACCOMPANY THIS
SYSTEM AS IT PROGRESSES EASTWARD THROUGH MIDWEEK. AN AREA OF COLD
AIR ADVECTION BEHIND THE PASSING LOW WILL HELP GENERATE SOME
STRONGER GUSTS AND SNOW SHOWERS BEHIND THE SYSTEM...WHICH WILL BE
REINFORCED BY A RIDGE BUILDING INTO THE WESTERN BERING TUESDAY
AFTERNOON. AREAS THAT ARE PRONE TO EXPERIENCING GAP WINDS...SUCH
AS AREAS AROUND THE AKPEN AND EASTERN ALEUTIANS...ARE LIKELY TO
EXPERIENCE STRONGER GAP FLOW AS THIS SYSTEM TRACKS THROUGH THEIR
AREA. A GALE FORCE LOW DROPPING DOWN FROM KAMCHATKA PENINSULA WITH
AN ASSOCIATED WEATHER FRONT WILL BRING THE NEXT ROUND OF
PRECIPITATION TO THE WESTERN ALEUTIANS BY WEDNESDAY. GUSTY
SOUTHERLY WINDS ASSOCIATED WITH THIS SYSTEM WILL BRING IN SOME
WARMER TEMPERATURES FROM THE NORTHERN PACIFIC...CAUSING THE
PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS THE WARM FRONT
PASSES THROUGH THE AREA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 173 174.
 HEAVY FREEZING SPRAY 179 185.
FIRE WEATHER...NONE.

&&

$$

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



000
FXAK68 PAFC 310006
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
406 PM AKDT MON MAR 30 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND
THE NORTH PACIFIC. THE SUBTROPICAL JET IS NEARLY ZONAL JUST SOUTH
OF THE ALEUTIAN CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH
PACIFIC. THIS IS RESULTING IN A PERSISTENT STORM TRACK ALONG THE
SOUTHERN TIER OF THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK
LOWS AFFECTING THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND
ANOTHER OVER THE FAR WESTERN ALEUTIANS. SATELLITE IMAGERY SHOWS
CONVECTIVE CLOUDS ACROSS MUCH OF THE FORECAST AREA WHICH IS
INDICATIVE OF A GENERALLY UNSTABLE ATMOSPHERE. AS HAS BEEN THE
CASE OVER THE PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE
TRACKING NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. THE BULK
OF PRECIP HAS BEEN ALONG THE COAST THANKS TO PERSISTENT
DOWN-SLOPING OFF THE COASTAL MOUNTAINS...THOUGH THE LOW LEVEL
SOUTHEASTERLY FLOW IS BEGINNING TO WEAKEN AND BACK TOWARD THE
NORTH.

AS THE UPPER WAVES CONTINUE WESTWARD TO SOUTHWEST ALASKA THEY RUN
INTO SOME WEAK RIDGING WHICH HAS LED TO FORMATION OF A DEFORMATION
BAND. KING SALMON RADAR SHOWS A NORTH-SOUTH ORIENTED BAND OF
PRECIP ALIGNED DIRECTLY OVER KING SALMON. A SEPARATE UPPER LEVEL
WAVE IS LIFTING NORTHWARD ACROSS THE KUSKOKWIM DELTA PRODUCING
AREAS OF LIGHT SNOW.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH MUCH WEAKER FLOW OUTSIDE OF THE MAIN LOW
PRESSURE SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND CLOUD COVER. MODELS DO BEGIN
TO DIVERGE A BIT AS SYSTEM TRACKING SOUTH OF THE ALEUTIANS PASSES
SOUTH OF KODIAK ISLAND TUESDAY NIGHT INTO WEDNESDAY. THEY ALL HINT
AS DEVELOPMENT OF A TRIPLE POINT LOW...BUT DIFFER AS TO WHETHER
THIS BECOMES THE PRIMARY LOW CENTER. IN ANY CASE THESE DIFFERENCES
ONLY AFFECT THE AREA IN THE DIRECT VICINITY OF THE SYSTEM. WITH
A DECENT JET STREAK ALONG THE SOUTH TO EAST SIDE OF THIS SYSTEM
AND GOOD UPPER LEVEL DIFFLUENCE OUT AHEAD OF IT...PREFER THE MORE
AGGRESSIVE TRIPLE POINT DEVELOPMENT AS SEEN IN THE NAM.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH WED NIGHT)...

AN AREA OF LOW PRESSURE OVER THE SOUTHERN GULF OF ALASKA WILL
PHASE WITH A LOW PUSHING ACROSS THE ALASKA PENINSULA TONIGHT. RAIN
SHOWER ACTIVITY IS EXPECTED TO CONTINUE ALONG THE NORTHERN GULF
COAST WITH THE ENHANCED LIFT ASSOCIATED WITH THE PHASING LOWS AND
AND UPPER LEVEL SHORTWAVE ROTATING AROUND A PARENT LOW ALSO
LOCATED IN THE SOUTHERN GULF. DOWN-SLOPING HAS BEEN EATING AWAY
AT A MAJORITY OF THE PRECIPITATION THAT HAS TRIED TO MOVE INLAND
DURING THE DAY BUT 00Z RAOB DATA SUPPORTS THE MODEL DATA IN THAT
THE LOW LEVEL FLOW IS WEAKENING AND SHIFTING TO A MORE SOUTHERLY
ORIENTATION. THIS WILL ALLOW AN ISOLATED SHOWER OR TWO TO MOVE
INLAND DURING THE EVENING HOURS IF DEW POINT DEPRESSIONS IN EXCESS
OF 10 DEGREES ARE ABLE TO BE OVERCOME.

THE PATTERN BEGINS TO SHIFT TUESDAY AFTERNOON/EVENING AS AN AREA
OF LOW PRESSURE MOVES INTO THE WESTERN GULF. A SHORTWAVE PRECEDING
THIS FRONT WILL PUSH ACROSS SOUTHCENTRAL ALASKA AND BRING A DECENT
CHANCE FOR RAIN/SNOW (DEPENDING ON TIMING OF THE PRECIPITATION) TO
ANCHORAGE/KENAI AND THE MAT-SU VALLEY. AS THE LOW MOVES INTO THE
WESTERN GULF...THE PRESSURE GRADIENT WILL BECOME FAVORABLE FOR
SOUTHEASTERLY GAPS (TURNAGAIN ARM...PORTAGE VALLEY AND KNIK RIVER
VALLEY) TO HAVE SOME GUSTY WINDS. HOWEVER...THERE IS STILL SOME
UNCERTAINTY TO THE LOW TRACK WHICH WILL DIRECTLY IMPACT THE
PRESSURE GRADIENT AND WIND GUST STRENGTH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LOW STRATUS AND PATCHY FOG WILL BECOME PROMINENT OVER PARTS OF
THE KUSKOKWIM DELTA AND BRISTOL BAY ZONE OVERNIGHT...AS LINGERING
SHOWERS OVER THE MAINLAND TODAY HELPED TO REPLENISH LOW LEVEL
MOISTURE OVER THE AREA. AS THE UPPER LEVEL WAVE OVER THE KUSKOKWIM
DELTA EXITS TO THE NORTH TOMORROW MORNING...PRECIPITATION OVER THE
MAINLAND WILL TAPER OFF THROUGH WEDNESDAY MORNING. WET AND WARMER
CONDITIONS WILL THEN BUILD BACK MAINLY OVER THE ALASKA PENINSULA
WEDNESDAY...AS A GALE FORCE NORTH PACIFIC LOW TRACKS JUST SOUTH OF
KODIAK ISLAND. PRECIPITATION OVER THE BRISTOL BAY ZONE WILL TAPER
OFF BY THURSDAY MORNING...AS THE AFOREMENTIONED LOW TRACKS
FURTHER EASTWARD AND INTO THE GULF OF ALASKA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A VERTICALLY STACKED SYSTEM OVER THE WESTERN ALEUTIANS WILL CROSS
INTO THE NORTHERN PACIFIC...BEFORE REFORMING INTO A GALE FORCE
LOW SOUTH OF THE CENTRAL ALEUTIANS OVERNIGHT TONIGHT. THIS SYSTEM
WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE ALEUTIAN
CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY THURSDAY
MORNING. WET AND WINDY CONDITIONS ARE EXPECTED TO ACCOMPANY THIS
SYSTEM AS IT PROGRESSES EASTWARD THROUGH MIDWEEK. AN AREA OF COLD
AIR ADVECTION BEHIND THE PASSING LOW WILL HELP GENERATE SOME
STRONGER GUSTS AND SNOW SHOWERS BEHIND THE SYSTEM...WHICH WILL BE
REINFORCED BY A RIDGE BUILDING INTO THE WESTERN BERING TUESDAY
AFTERNOON. AREAS THAT ARE PRONE TO EXPERIENCING GAP WINDS...SUCH
AS AREAS AROUND THE AKPEN AND EASTERN ALEUTIANS...ARE LIKELY TO
EXPERIENCE STRONGER GAP FLOW AS THIS SYSTEM TRACKS THROUGH THEIR
AREA. A GALE FORCE LOW DROPPING DOWN FROM KAMCHATKA PENINSULA WITH
AN ASSOCIATED WEATHER FRONT WILL BRING THE NEXT ROUND OF
PRECIPITATION TO THE WESTERN ALEUTIANS BY WEDNESDAY. GUSTY
SOUTHERLY WINDS ASSOCIATED WITH THIS SYSTEM WILL BRING IN SOME
WARMER TEMPERATURES FROM THE NORTHERN PACIFIC...CAUSING THE
PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS THE WARM FRONT
PASSES THROUGH THE AREA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 173 174.
 HEAVY FREEZING SPRAY 179 185.
FIRE WEATHER...NONE.

&&

$$

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




000
FXAK68 PAFC 310006
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
406 PM AKDT MON MAR 30 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND
THE NORTH PACIFIC. THE SUBTROPICAL JET IS NEARLY ZONAL JUST SOUTH
OF THE ALEUTIAN CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH
PACIFIC. THIS IS RESULTING IN A PERSISTENT STORM TRACK ALONG THE
SOUTHERN TIER OF THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK
LOWS AFFECTING THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND
ANOTHER OVER THE FAR WESTERN ALEUTIANS. SATELLITE IMAGERY SHOWS
CONVECTIVE CLOUDS ACROSS MUCH OF THE FORECAST AREA WHICH IS
INDICATIVE OF A GENERALLY UNSTABLE ATMOSPHERE. AS HAS BEEN THE
CASE OVER THE PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE
TRACKING NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. THE BULK
OF PRECIP HAS BEEN ALONG THE COAST THANKS TO PERSISTENT
DOWN-SLOPING OFF THE COASTAL MOUNTAINS...THOUGH THE LOW LEVEL
SOUTHEASTERLY FLOW IS BEGINNING TO WEAKEN AND BACK TOWARD THE
NORTH.

AS THE UPPER WAVES CONTINUE WESTWARD TO SOUTHWEST ALASKA THEY RUN
INTO SOME WEAK RIDGING WHICH HAS LED TO FORMATION OF A DEFORMATION
BAND. KING SALMON RADAR SHOWS A NORTH-SOUTH ORIENTED BAND OF
PRECIP ALIGNED DIRECTLY OVER KING SALMON. A SEPARATE UPPER LEVEL
WAVE IS LIFTING NORTHWARD ACROSS THE KUSKOKWIM DELTA PRODUCING
AREAS OF LIGHT SNOW.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH MUCH WEAKER FLOW OUTSIDE OF THE MAIN LOW
PRESSURE SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND CLOUD COVER. MODELS DO BEGIN
TO DIVERGE A BIT AS SYSTEM TRACKING SOUTH OF THE ALEUTIANS PASSES
SOUTH OF KODIAK ISLAND TUESDAY NIGHT INTO WEDNESDAY. THEY ALL HINT
AS DEVELOPMENT OF A TRIPLE POINT LOW...BUT DIFFER AS TO WHETHER
THIS BECOMES THE PRIMARY LOW CENTER. IN ANY CASE THESE DIFFERENCES
ONLY AFFECT THE AREA IN THE DIRECT VICINITY OF THE SYSTEM. WITH
A DECENT JET STREAK ALONG THE SOUTH TO EAST SIDE OF THIS SYSTEM
AND GOOD UPPER LEVEL DIFFLUENCE OUT AHEAD OF IT...PREFER THE MORE
AGGRESSIVE TRIPLE POINT DEVELOPMENT AS SEEN IN THE NAM.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH WED NIGHT)...

AN AREA OF LOW PRESSURE OVER THE SOUTHERN GULF OF ALASKA WILL
PHASE WITH A LOW PUSHING ACROSS THE ALASKA PENINSULA TONIGHT. RAIN
SHOWER ACTIVITY IS EXPECTED TO CONTINUE ALONG THE NORTHERN GULF
COAST WITH THE ENHANCED LIFT ASSOCIATED WITH THE PHASING LOWS AND
AND UPPER LEVEL SHORTWAVE ROTATING AROUND A PARENT LOW ALSO
LOCATED IN THE SOUTHERN GULF. DOWN-SLOPING HAS BEEN EATING AWAY
AT A MAJORITY OF THE PRECIPITATION THAT HAS TRIED TO MOVE INLAND
DURING THE DAY BUT 00Z RAOB DATA SUPPORTS THE MODEL DATA IN THAT
THE LOW LEVEL FLOW IS WEAKENING AND SHIFTING TO A MORE SOUTHERLY
ORIENTATION. THIS WILL ALLOW AN ISOLATED SHOWER OR TWO TO MOVE
INLAND DURING THE EVENING HOURS IF DEW POINT DEPRESSIONS IN EXCESS
OF 10 DEGREES ARE ABLE TO BE OVERCOME.

THE PATTERN BEGINS TO SHIFT TUESDAY AFTERNOON/EVENING AS AN AREA
OF LOW PRESSURE MOVES INTO THE WESTERN GULF. A SHORTWAVE PRECEDING
THIS FRONT WILL PUSH ACROSS SOUTHCENTRAL ALASKA AND BRING A DECENT
CHANCE FOR RAIN/SNOW (DEPENDING ON TIMING OF THE PRECIPITATION) TO
ANCHORAGE/KENAI AND THE MAT-SU VALLEY. AS THE LOW MOVES INTO THE
WESTERN GULF...THE PRESSURE GRADIENT WILL BECOME FAVORABLE FOR
SOUTHEASTERLY GAPS (TURNAGAIN ARM...PORTAGE VALLEY AND KNIK RIVER
VALLEY) TO HAVE SOME GUSTY WINDS. HOWEVER...THERE IS STILL SOME
UNCERTAINTY TO THE LOW TRACK WHICH WILL DIRECTLY IMPACT THE
PRESSURE GRADIENT AND WIND GUST STRENGTH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LOW STRATUS AND PATCHY FOG WILL BECOME PROMINENT OVER PARTS OF
THE KUSKOKWIM DELTA AND BRISTOL BAY ZONE OVERNIGHT...AS LINGERING
SHOWERS OVER THE MAINLAND TODAY HELPED TO REPLENISH LOW LEVEL
MOISTURE OVER THE AREA. AS THE UPPER LEVEL WAVE OVER THE KUSKOKWIM
DELTA EXITS TO THE NORTH TOMORROW MORNING...PRECIPITATION OVER THE
MAINLAND WILL TAPER OFF THROUGH WEDNESDAY MORNING. WET AND WARMER
CONDITIONS WILL THEN BUILD BACK MAINLY OVER THE ALASKA PENINSULA
WEDNESDAY...AS A GALE FORCE NORTH PACIFIC LOW TRACKS JUST SOUTH OF
KODIAK ISLAND. PRECIPITATION OVER THE BRISTOL BAY ZONE WILL TAPER
OFF BY THURSDAY MORNING...AS THE AFOREMENTIONED LOW TRACKS
FURTHER EASTWARD AND INTO THE GULF OF ALASKA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A VERTICALLY STACKED SYSTEM OVER THE WESTERN ALEUTIANS WILL CROSS
INTO THE NORTHERN PACIFIC...BEFORE REFORMING INTO A GALE FORCE
LOW SOUTH OF THE CENTRAL ALEUTIANS OVERNIGHT TONIGHT. THIS SYSTEM
WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE ALEUTIAN
CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY THURSDAY
MORNING. WET AND WINDY CONDITIONS ARE EXPECTED TO ACCOMPANY THIS
SYSTEM AS IT PROGRESSES EASTWARD THROUGH MIDWEEK. AN AREA OF COLD
AIR ADVECTION BEHIND THE PASSING LOW WILL HELP GENERATE SOME
STRONGER GUSTS AND SNOW SHOWERS BEHIND THE SYSTEM...WHICH WILL BE
REINFORCED BY A RIDGE BUILDING INTO THE WESTERN BERING TUESDAY
AFTERNOON. AREAS THAT ARE PRONE TO EXPERIENCING GAP WINDS...SUCH
AS AREAS AROUND THE AKPEN AND EASTERN ALEUTIANS...ARE LIKELY TO
EXPERIENCE STRONGER GAP FLOW AS THIS SYSTEM TRACKS THROUGH THEIR
AREA. A GALE FORCE LOW DROPPING DOWN FROM KAMCHATKA PENINSULA WITH
AN ASSOCIATED WEATHER FRONT WILL BRING THE NEXT ROUND OF
PRECIPITATION TO THE WESTERN ALEUTIANS BY WEDNESDAY. GUSTY
SOUTHERLY WINDS ASSOCIATED WITH THIS SYSTEM WILL BRING IN SOME
WARMER TEMPERATURES FROM THE NORTHERN PACIFIC...CAUSING THE
PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS THE WARM FRONT
PASSES THROUGH THE AREA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 173 174.
 HEAVY FREEZING SPRAY 179 185.
FIRE WEATHER...NONE.

&&

$$

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




000
FXAK68 PAFC 310006
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
406 PM AKDT MON MAR 30 2015

.ANALYSIS AND UPPER LEVELS...
A LONG-WAVE TROUGH REMAINS FIRMLY ENTRENCHED ACROSS ALASKA AND
THE NORTH PACIFIC. THE SUBTROPICAL JET IS NEARLY ZONAL JUST SOUTH
OF THE ALEUTIAN CHAIN THEN DIVES SOUTHEASTWARD INTO THE NORTH
PACIFIC. THIS IS RESULTING IN A PERSISTENT STORM TRACK ALONG THE
SOUTHERN TIER OF THE FORECAST AREA. THERE ARE TWO RELATIVELY WEAK
LOWS AFFECTING THE FORECAST AREA...ONE JUST SOUTH OF THE GULF AND
ANOTHER OVER THE FAR WESTERN ALEUTIANS. SATELLITE IMAGERY SHOWS
CONVECTIVE CLOUDS ACROSS MUCH OF THE FORECAST AREA WHICH IS
INDICATIVE OF A GENERALLY UNSTABLE ATMOSPHERE. AS HAS BEEN THE
CASE OVER THE PAST FEW DAYS A SERIES OF UPPER LEVEL WAVES ARE
TRACKING NORTHWESTWARD ACROSS THE GULF AND SOUTHCENTRAL. THE BULK
OF PRECIP HAS BEEN ALONG THE COAST THANKS TO PERSISTENT
DOWN-SLOPING OFF THE COASTAL MOUNTAINS...THOUGH THE LOW LEVEL
SOUTHEASTERLY FLOW IS BEGINNING TO WEAKEN AND BACK TOWARD THE
NORTH.

AS THE UPPER WAVES CONTINUE WESTWARD TO SOUTHWEST ALASKA THEY RUN
INTO SOME WEAK RIDGING WHICH HAS LED TO FORMATION OF A DEFORMATION
BAND. KING SALMON RADAR SHOWS A NORTH-SOUTH ORIENTED BAND OF
PRECIP ALIGNED DIRECTLY OVER KING SALMON. A SEPARATE UPPER LEVEL
WAVE IS LIFTING NORTHWARD ACROSS THE KUSKOKWIM DELTA PRODUCING
AREAS OF LIGHT SNOW.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN VERY GOOD AGREEMENT WITH HANDLING OF LARGE SCALE
FEATURES OVER THE NEXT COUPLE DAYS. THUS FORECAST CONFIDENCE IS
GENERALLY HIGH. WITH MUCH WEAKER FLOW OUTSIDE OF THE MAIN LOW
PRESSURE SYSTEMS THE BIGGEST FORECAST CHALLENGES ARE ON THE LOCAL
SCALE...WITH ELEMENTS SUCH AS FOG AND CLOUD COVER. MODELS DO BEGIN
TO DIVERGE A BIT AS SYSTEM TRACKING SOUTH OF THE ALEUTIANS PASSES
SOUTH OF KODIAK ISLAND TUESDAY NIGHT INTO WEDNESDAY. THEY ALL HINT
AS DEVELOPMENT OF A TRIPLE POINT LOW...BUT DIFFER AS TO WHETHER
THIS BECOMES THE PRIMARY LOW CENTER. IN ANY CASE THESE DIFFERENCES
ONLY AFFECT THE AREA IN THE DIRECT VICINITY OF THE SYSTEM. WITH
A DECENT JET STREAK ALONG THE SOUTH TO EAST SIDE OF THIS SYSTEM
AND GOOD UPPER LEVEL DIFFLUENCE OUT AHEAD OF IT...PREFER THE MORE
AGGRESSIVE TRIPLE POINT DEVELOPMENT AS SEEN IN THE NAM.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (TONIGHT THROUGH WED NIGHT)...

AN AREA OF LOW PRESSURE OVER THE SOUTHERN GULF OF ALASKA WILL
PHASE WITH A LOW PUSHING ACROSS THE ALASKA PENINSULA TONIGHT. RAIN
SHOWER ACTIVITY IS EXPECTED TO CONTINUE ALONG THE NORTHERN GULF
COAST WITH THE ENHANCED LIFT ASSOCIATED WITH THE PHASING LOWS AND
AND UPPER LEVEL SHORTWAVE ROTATING AROUND A PARENT LOW ALSO
LOCATED IN THE SOUTHERN GULF. DOWN-SLOPING HAS BEEN EATING AWAY
AT A MAJORITY OF THE PRECIPITATION THAT HAS TRIED TO MOVE INLAND
DURING THE DAY BUT 00Z RAOB DATA SUPPORTS THE MODEL DATA IN THAT
THE LOW LEVEL FLOW IS WEAKENING AND SHIFTING TO A MORE SOUTHERLY
ORIENTATION. THIS WILL ALLOW AN ISOLATED SHOWER OR TWO TO MOVE
INLAND DURING THE EVENING HOURS IF DEW POINT DEPRESSIONS IN EXCESS
OF 10 DEGREES ARE ABLE TO BE OVERCOME.

THE PATTERN BEGINS TO SHIFT TUESDAY AFTERNOON/EVENING AS AN AREA
OF LOW PRESSURE MOVES INTO THE WESTERN GULF. A SHORTWAVE PRECEDING
THIS FRONT WILL PUSH ACROSS SOUTHCENTRAL ALASKA AND BRING A DECENT
CHANCE FOR RAIN/SNOW (DEPENDING ON TIMING OF THE PRECIPITATION) TO
ANCHORAGE/KENAI AND THE MAT-SU VALLEY. AS THE LOW MOVES INTO THE
WESTERN GULF...THE PRESSURE GRADIENT WILL BECOME FAVORABLE FOR
SOUTHEASTERLY GAPS (TURNAGAIN ARM...PORTAGE VALLEY AND KNIK RIVER
VALLEY) TO HAVE SOME GUSTY WINDS. HOWEVER...THERE IS STILL SOME
UNCERTAINTY TO THE LOW TRACK WHICH WILL DIRECTLY IMPACT THE
PRESSURE GRADIENT AND WIND GUST STRENGTH.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
LOW STRATUS AND PATCHY FOG WILL BECOME PROMINENT OVER PARTS OF
THE KUSKOKWIM DELTA AND BRISTOL BAY ZONE OVERNIGHT...AS LINGERING
SHOWERS OVER THE MAINLAND TODAY HELPED TO REPLENISH LOW LEVEL
MOISTURE OVER THE AREA. AS THE UPPER LEVEL WAVE OVER THE KUSKOKWIM
DELTA EXITS TO THE NORTH TOMORROW MORNING...PRECIPITATION OVER THE
MAINLAND WILL TAPER OFF THROUGH WEDNESDAY MORNING. WET AND WARMER
CONDITIONS WILL THEN BUILD BACK MAINLY OVER THE ALASKA PENINSULA
WEDNESDAY...AS A GALE FORCE NORTH PACIFIC LOW TRACKS JUST SOUTH OF
KODIAK ISLAND. PRECIPITATION OVER THE BRISTOL BAY ZONE WILL TAPER
OFF BY THURSDAY MORNING...AS THE AFOREMENTIONED LOW TRACKS
FURTHER EASTWARD AND INTO THE GULF OF ALASKA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A VERTICALLY STACKED SYSTEM OVER THE WESTERN ALEUTIANS WILL CROSS
INTO THE NORTHERN PACIFIC...BEFORE REFORMING INTO A GALE FORCE
LOW SOUTH OF THE CENTRAL ALEUTIANS OVERNIGHT TONIGHT. THIS SYSTEM
WILL CONTINUE AN EASTWARD TRACK JUST SOUTH OF THE ALEUTIAN
CHAIN...BEFORE TRACKING INTO THE GULF OF ALASKA BY THURSDAY
MORNING. WET AND WINDY CONDITIONS ARE EXPECTED TO ACCOMPANY THIS
SYSTEM AS IT PROGRESSES EASTWARD THROUGH MIDWEEK. AN AREA OF COLD
AIR ADVECTION BEHIND THE PASSING LOW WILL HELP GENERATE SOME
STRONGER GUSTS AND SNOW SHOWERS BEHIND THE SYSTEM...WHICH WILL BE
REINFORCED BY A RIDGE BUILDING INTO THE WESTERN BERING TUESDAY
AFTERNOON. AREAS THAT ARE PRONE TO EXPERIENCING GAP WINDS...SUCH
AS AREAS AROUND THE AKPEN AND EASTERN ALEUTIANS...ARE LIKELY TO
EXPERIENCE STRONGER GAP FLOW AS THIS SYSTEM TRACKS THROUGH THEIR
AREA. A GALE FORCE LOW DROPPING DOWN FROM KAMCHATKA PENINSULA WITH
AN ASSOCIATED WEATHER FRONT WILL BRING THE NEXT ROUND OF
PRECIPITATION TO THE WESTERN ALEUTIANS BY WEDNESDAY. GUSTY
SOUTHERLY WINDS ASSOCIATED WITH THIS SYSTEM WILL BRING IN SOME
WARMER TEMPERATURES FROM THE NORTHERN PACIFIC...CAUSING THE
PRECIPITATION TYPE TO SWITCH OVER TO RAIN AS THE WARM FRONT
PASSES THROUGH THE AREA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE LATTER PART OF THE WEEK WILL BE CHARACTERIZED FAIRLY QUIET
WEATHER ACROSS THE SOUTHERN MAINLAND. THERE WILL BE A NEAR GALE
FORCE FRONT MOVING UP TOWARD THE NORTHERN GULF THURSDAY BEFORE
WEAKENING LATE THURSDAY INTO FRIDAY. THIS WILL KEEP RAIN AND RAIN
SHOWERS...MAINLY OVER THE WATER BUT WESTERN PRINCE WILLIAM SOUND
COULD SEE NUMEROUS SHOWERS WITH THIS FEATURES. COLDER UPPER LEVEL
TEMPERATURES ALOFT COULD SUPPORT INSTABILITY SHOWERS OVER THE
COASTAL MOUNTAINS WITH INCREASING CYCLONIC FLOW. THIS SYSTEM WILL
WEAKEN IN THE GULF AND MOVE TOWARD THE PANHANDLE FRIDAY. AT THIS
POINT THE PATTERN TURNS MORE AMPLIFIED OUT WEST...BUT IT IS
UNCLEAR HOW MUCH THIS WILL AFFECT THE PATTERN OVER THE MAINLAND.
EXPECT A CONTINUATION OF ABOVE NORMAL TEMPERATURES AND DRIER
CONDITIONS THROUGH EARLY NEXT WEEK.

&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 173 174.
 HEAVY FREEZING SPRAY 179 185.
FIRE WEATHER...NONE.

&&

$$

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



000
FXAK67 PAJK 302339
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
323 PM AKDT MON MAR 30 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE SHOWS A 991 MB LOW NEAR
DIXON ENTRANCE MOVING NORTH TOWARD THE SOUTHERN PANHANDLE WITH
STRONG WINDS WRAPPING AROUND THE LOW AND MODERATE RAINFALL ACROSS
THE SOUTHERN ZONES. CLOUDS OUT-SKIRTING FROM THE LOW CENTRAL SPREAD
NORTH. OFFSHORE FLOW CONTINUES OVER THE NORTHERN PANHANDLE WITH A
PLENTY OF SUNSHINE...BUT CLOUDS SLOWLY INCREASE FROM THE SOUTH.
TEMPERATURES SOAR UP TO THE MID 40S. SCATTERED TO NUMEROUS RAIN
SHOWERS WILL CONTINUE ACROSS THE PANHANDLE THROUGH TUESDAY.

MODELS REMAIN IN FAIR AGREEMENT FOR THE LOW OVER THE SOUTHERN
PANHANDLE THIS AFTERNOON WEAKENS AND MOVES NORTHWESTWARD TO THE
NORTHERN GULF TONIGHT...THEN CONSOLIDATES WITH A LOW IN THE
CENTRAL GULF THROUGH TUESDAY AFTERNOON. REFRESHED THE INHERITED
FORECAST WITH THE GFS AND NAM FOR THEIR GOOD CONSENSUS. SOLID SMALL
CRAFT LEVEL WINDS ACROSS THE SOUTHERN OUTER WATERS AND SOUTHERN
INNER CHANNELS THIS EVENING WILL DIMINISH...BUT ROUGH SEAS DUE TO
LONG PERIOD OF SOUTHWEST SWELLS WILL REMAIN OVER THE OUTSIDE
WATERS THROUGH TUESDAY. NOT MUCH DIURNAL TEMPERATURE FLUCTUATION
IS EXPECTED AND OVERNIGHT LOWS WILL BE MOSTLY IN THE MID TO UPPER
30S WITH TUESDAY HIGHS BACK TO MID 40S.

AS THE LOW MOVES NORTH...STRONG WINDS OVER THE SOUTHERN PANHANDLE
WILL DECREASE BEHIND THE LOW...BUT BRIEFLY INCREASE ACROSS THE
SOUTH CENTRAL PANHANDLE THIS EVENING. A WEAK RIDGE OF HIGH
PRESSURE WILL BUILD OVER BRITISH COLUMBIA COAST TUESDAY AND
BETWEEN THE RIDGE AND THE LOW IN THE CENTRAL GULF WILL PRODUCE
WARM MOIST SUBTROPICAL AIR FEEDING INTO DIXON ENTRANCE EAST.

.LONG TERM...EXTENDED GRIDS A BIT DIFFICULT OBTAIN CONFIDENCE IN
INITIALLY DUE TO LACK OF EC DATA FROM LAST NIGHT...BUT FORTUITOUSLY
THAT RUN WAS AN OUTLIER PER HPC COORD. NEW RUN CAME MORE INLINE
WITH GEM AND GFS RUNS SO DESPITE THE SLOW START REASONABLE
CONFIDENCE FOR DAYS 4 ONWARD WAS ATTAINED. WEAK LOW OVER THE
EASTERN GULF ON TUES NIGHT WEAKENS FURTHER AND MOVES SLOWLY
INLAND...LIKELY WILL CONTINUE TO PRODUCE SCATTERED SHOWERS OVER THE
PANHANDLE INTO WED AFTERNOON. IN THE MEANTIME THE MORE SIGNIFICANT
LOW PRESSURE TAKES OVER THE EASTERN GULF FROM THE WEST BY WED
MORNING AND GENERATES SCA-LEVEL WINDS OFFSHORE AND OVER ALL INNER
CHANNELS EXCEPT FOR LYNN CANAL AND GLACIER BAY BY WED
AFTERNOON/EVENING... AND INTO THURS FOR SOME CHANNELS AND OFFSHORE
ZONES. UTILIZED NAM/EC COMBO FOR THIS PORTION OF THE FORECAST AS
AGREEMENT WAS STRONG...WIND FIELD NEEDED TWEAKING OVER A FEW
SOUTHERN/CENTRAL CHANNELS AS WELL AS OFFSHORE CONTINUING A BIT OF
AN UPWARD TREND. ALSO A SIGNIFICANT BARRIER JET IS PROGGED OVER THE
NORTHWEST PORTION AND GIVEN THE LONGEVITY OF THE LOW SEE NO REASON
NOT TO BELIEVE THIS. THE LOW STALLS OVER THE GULF ON GUIDANCE AND
EVENTUALLY WEAKENS ON THE MODELS BUT WILL LEAD TO WIDESPREAD
INSTABILITY- DOMINATED AREAS OF RAIN SHOWERS POTENTIALLY THROUGH
THE END OF THE WEEK.

AFTER THIS LOW MOVES OFF TO THE SOUTHEAST THERE IS WEAK UPPER
RIDGING ON THE MODELS OVER THE GULF BUT THE PANHANDLE REMAINS IN
ENOUGH NORTHWESTERLY FLOW ALOFT...MOIST ON THE GEM, EC AND GFS
GUIDANCE UPDATES...THAT PRECIP ALONG WITH COOLER CONDITIONS ARE ON
TAP FOR THIS WEEKEND. EVEN COOL ENOUGH FOR A CHANCE OF MIXED PRECIP
AT SEA LEVEL OVER THE NORTHERN FRINGE AND THE STRONGER EC IS
POINTING TOWARDS EVEN JUNEAU FOR THE LATE WEEKEND. BRIEF PERIOD OF
STRATIFORM PRECIP IS POSSIBLE FOR LATE SUNDAY OVER AT LEAST THE
NORTHERN PANHANDLE AND THIS WILL NEED TO BE MONITORED ON UPCOMING
MODEL UPDATES FOR THE POTENTIAL OF SOME SNOW. AFTER THIS
PERIOD..MODEL GUIDANCE VARIES TO SOME DEGREE BUT APPEARS THAT
THERE IS A BETTER-THAN-EVEN CHANCE THAT TROUGHING WILL AMPLIFY
SOMEWHERE NEAR THE ALEUTIANS AND FRONTS WILL CONTINUE TO ENTER THE
GULF IN THE MON-WED PERIOD. WITH THE GENERAL AGREEMENT IN THE 3
MAJOR MODELS WENT WITH WPC GUIDANCE FOR THIS PERIOD...ALTHOUGH DO
NOT LIKE THE WAY THE POP FIELDS ARE SMEARED ACROSS THE PANHANDLE.
CANNOT REASONABLY RULE OUT ANY PERIOD FOR PRECIP CHANCES SO NO
CHOICE BUT TO GO WITH THE ENSEMBLE AT THIS POINT. THIS SCENARIO
WOULD BE A WARM MOIST ONE FOR ALL OF THE PANHANDLE UNLIKE WHAT IS
LIKELY ON TAP FOR THE WEEKEND. OVERALL...FOR THE WEEKEND AND NEXT
WEEK...POSITION/STRENGTH OF THE GULF FRONTS WILL DEPEND ON THE
STRENGTH OF THE LATE-WEEKEND UPPER TROUGH OVER THE NORTHERN
PANHANDLE AND THE SAME FOR THE DEEP TROUGHING WELL TO THE WEST
EARLY NEXT WEEK. JUST TOO EARLY TO TELL AT THIS POINT. MODEL
CONFIDENCE A BIT ABOVE AVERAGE FOR THE EXTENDED AFTER THE GAPS IN
EC AND WPC GUIDANCE WERE FILLED.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 7 PM AKDT THIS EVENING FOR AKZ027.
         STRONG WIND UNTIL 7 PM AKDT THIS EVENING FOR AKZ028.
MARINE...GALE WARNING FOR PKZ036. SMALL CRAFT ADVISORY FOR
PKZ012-013-041-042. SMALL CRAFT ADVISORY DUE TO SEAS FOR
PKZ043-051-052.

&&

$$

AHN/WESLEY

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










000
FXAK67 PAJK 302339
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
323 PM AKDT MON MAR 30 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE SHOWS A 991 MB LOW NEAR
DIXON ENTRANCE MOVING NORTH TOWARD THE SOUTHERN PANHANDLE WITH
STRONG WINDS WRAPPING AROUND THE LOW AND MODERATE RAINFALL ACROSS
THE SOUTHERN ZONES. CLOUDS OUT-SKIRTING FROM THE LOW CENTRAL SPREAD
NORTH. OFFSHORE FLOW CONTINUES OVER THE NORTHERN PANHANDLE WITH A
PLENTY OF SUNSHINE...BUT CLOUDS SLOWLY INCREASE FROM THE SOUTH.
TEMPERATURES SOAR UP TO THE MID 40S. SCATTERED TO NUMEROUS RAIN
SHOWERS WILL CONTINUE ACROSS THE PANHANDLE THROUGH TUESDAY.

MODELS REMAIN IN FAIR AGREEMENT FOR THE LOW OVER THE SOUTHERN
PANHANDLE THIS AFTERNOON WEAKENS AND MOVES NORTHWESTWARD TO THE
NORTHERN GULF TONIGHT...THEN CONSOLIDATES WITH A LOW IN THE
CENTRAL GULF THROUGH TUESDAY AFTERNOON. REFRESHED THE INHERITED
FORECAST WITH THE GFS AND NAM FOR THEIR GOOD CONSENSUS. SOLID SMALL
CRAFT LEVEL WINDS ACROSS THE SOUTHERN OUTER WATERS AND SOUTHERN
INNER CHANNELS THIS EVENING WILL DIMINISH...BUT ROUGH SEAS DUE TO
LONG PERIOD OF SOUTHWEST SWELLS WILL REMAIN OVER THE OUTSIDE
WATERS THROUGH TUESDAY. NOT MUCH DIURNAL TEMPERATURE FLUCTUATION
IS EXPECTED AND OVERNIGHT LOWS WILL BE MOSTLY IN THE MID TO UPPER
30S WITH TUESDAY HIGHS BACK TO MID 40S.

AS THE LOW MOVES NORTH...STRONG WINDS OVER THE SOUTHERN PANHANDLE
WILL DECREASE BEHIND THE LOW...BUT BRIEFLY INCREASE ACROSS THE
SOUTH CENTRAL PANHANDLE THIS EVENING. A WEAK RIDGE OF HIGH
PRESSURE WILL BUILD OVER BRITISH COLUMBIA COAST TUESDAY AND
BETWEEN THE RIDGE AND THE LOW IN THE CENTRAL GULF WILL PRODUCE
WARM MOIST SUBTROPICAL AIR FEEDING INTO DIXON ENTRANCE EAST.

.LONG TERM...EXTENDED GRIDS A BIT DIFFICULT OBTAIN CONFIDENCE IN
INITIALLY DUE TO LACK OF EC DATA FROM LAST NIGHT...BUT FORTUITOUSLY
THAT RUN WAS AN OUTLIER PER HPC COORD. NEW RUN CAME MORE INLINE
WITH GEM AND GFS RUNS SO DESPITE THE SLOW START REASONABLE
CONFIDENCE FOR DAYS 4 ONWARD WAS ATTAINED. WEAK LOW OVER THE
EASTERN GULF ON TUES NIGHT WEAKENS FURTHER AND MOVES SLOWLY
INLAND...LIKELY WILL CONTINUE TO PRODUCE SCATTERED SHOWERS OVER THE
PANHANDLE INTO WED AFTERNOON. IN THE MEANTIME THE MORE SIGNIFICANT
LOW PRESSURE TAKES OVER THE EASTERN GULF FROM THE WEST BY WED
MORNING AND GENERATES SCA-LEVEL WINDS OFFSHORE AND OVER ALL INNER
CHANNELS EXCEPT FOR LYNN CANAL AND GLACIER BAY BY WED
AFTERNOON/EVENING... AND INTO THURS FOR SOME CHANNELS AND OFFSHORE
ZONES. UTILIZED NAM/EC COMBO FOR THIS PORTION OF THE FORECAST AS
AGREEMENT WAS STRONG...WIND FIELD NEEDED TWEAKING OVER A FEW
SOUTHERN/CENTRAL CHANNELS AS WELL AS OFFSHORE CONTINUING A BIT OF
AN UPWARD TREND. ALSO A SIGNIFICANT BARRIER JET IS PROGGED OVER THE
NORTHWEST PORTION AND GIVEN THE LONGEVITY OF THE LOW SEE NO REASON
NOT TO BELIEVE THIS. THE LOW STALLS OVER THE GULF ON GUIDANCE AND
EVENTUALLY WEAKENS ON THE MODELS BUT WILL LEAD TO WIDESPREAD
INSTABILITY- DOMINATED AREAS OF RAIN SHOWERS POTENTIALLY THROUGH
THE END OF THE WEEK.

AFTER THIS LOW MOVES OFF TO THE SOUTHEAST THERE IS WEAK UPPER
RIDGING ON THE MODELS OVER THE GULF BUT THE PANHANDLE REMAINS IN
ENOUGH NORTHWESTERLY FLOW ALOFT...MOIST ON THE GEM, EC AND GFS
GUIDANCE UPDATES...THAT PRECIP ALONG WITH COOLER CONDITIONS ARE ON
TAP FOR THIS WEEKEND. EVEN COOL ENOUGH FOR A CHANCE OF MIXED PRECIP
AT SEA LEVEL OVER THE NORTHERN FRINGE AND THE STRONGER EC IS
POINTING TOWARDS EVEN JUNEAU FOR THE LATE WEEKEND. BRIEF PERIOD OF
STRATIFORM PRECIP IS POSSIBLE FOR LATE SUNDAY OVER AT LEAST THE
NORTHERN PANHANDLE AND THIS WILL NEED TO BE MONITORED ON UPCOMING
MODEL UPDATES FOR THE POTENTIAL OF SOME SNOW. AFTER THIS
PERIOD..MODEL GUIDANCE VARIES TO SOME DEGREE BUT APPEARS THAT
THERE IS A BETTER-THAN-EVEN CHANCE THAT TROUGHING WILL AMPLIFY
SOMEWHERE NEAR THE ALEUTIANS AND FRONTS WILL CONTINUE TO ENTER THE
GULF IN THE MON-WED PERIOD. WITH THE GENERAL AGREEMENT IN THE 3
MAJOR MODELS WENT WITH WPC GUIDANCE FOR THIS PERIOD...ALTHOUGH DO
NOT LIKE THE WAY THE POP FIELDS ARE SMEARED ACROSS THE PANHANDLE.
CANNOT REASONABLY RULE OUT ANY PERIOD FOR PRECIP CHANCES SO NO
CHOICE BUT TO GO WITH THE ENSEMBLE AT THIS POINT. THIS SCENARIO
WOULD BE A WARM MOIST ONE FOR ALL OF THE PANHANDLE UNLIKE WHAT IS
LIKELY ON TAP FOR THE WEEKEND. OVERALL...FOR THE WEEKEND AND NEXT
WEEK...POSITION/STRENGTH OF THE GULF FRONTS WILL DEPEND ON THE
STRENGTH OF THE LATE-WEEKEND UPPER TROUGH OVER THE NORTHERN
PANHANDLE AND THE SAME FOR THE DEEP TROUGHING WELL TO THE WEST
EARLY NEXT WEEK. JUST TOO EARLY TO TELL AT THIS POINT. MODEL
CONFIDENCE A BIT ABOVE AVERAGE FOR THE EXTENDED AFTER THE GAPS IN
EC AND WPC GUIDANCE WERE FILLED.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 7 PM AKDT THIS EVENING FOR AKZ027.
         STRONG WIND UNTIL 7 PM AKDT THIS EVENING FOR AKZ028.
MARINE...GALE WARNING FOR PKZ036. SMALL CRAFT ADVISORY FOR
PKZ012-013-041-042. SMALL CRAFT ADVISORY DUE TO SEAS FOR
PKZ043-051-052.

&&

$$

AHN/WESLEY

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











000
FXAK67 PAJK 302339
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
323 PM AKDT MON MAR 30 2015

.SHORT TERM...AFTERNOON SATELLITE IMAGE SHOWS A 991 MB LOW NEAR
DIXON ENTRANCE MOVING NORTH TOWARD THE SOUTHERN PANHANDLE WITH
STRONG WINDS WRAPPING AROUND THE LOW AND MODERATE RAINFALL ACROSS
THE SOUTHERN ZONES. CLOUDS OUT-SKIRTING FROM THE LOW CENTRAL SPREAD
NORTH. OFFSHORE FLOW CONTINUES OVER THE NORTHERN PANHANDLE WITH A
PLENTY OF SUNSHINE...BUT CLOUDS SLOWLY INCREASE FROM THE SOUTH.
TEMPERATURES SOAR UP TO THE MID 40S. SCATTERED TO NUMEROUS RAIN
SHOWERS WILL CONTINUE ACROSS THE PANHANDLE THROUGH TUESDAY.

MODELS REMAIN IN FAIR AGREEMENT FOR THE LOW OVER THE SOUTHERN
PANHANDLE THIS AFTERNOON WEAKENS AND MOVES NORTHWESTWARD TO THE
NORTHERN GULF TONIGHT...THEN CONSOLIDATES WITH A LOW IN THE
CENTRAL GULF THROUGH TUESDAY AFTERNOON. REFRESHED THE INHERITED
FORECAST WITH THE GFS AND NAM FOR THEIR GOOD CONSENSUS. SOLID SMALL
CRAFT LEVEL WINDS ACROSS THE SOUTHERN OUTER WATERS AND SOUTHERN
INNER CHANNELS THIS EVENING WILL DIMINISH...BUT ROUGH SEAS DUE TO
LONG PERIOD OF SOUTHWEST SWELLS WILL REMAIN OVER THE OUTSIDE
WATERS THROUGH TUESDAY. NOT MUCH DIURNAL TEMPERATURE FLUCTUATION
IS EXPECTED AND OVERNIGHT LOWS WILL BE MOSTLY IN THE MID TO UPPER
30S WITH TUESDAY HIGHS BACK TO MID 40S.

AS THE LOW MOVES NORTH...STRONG WINDS OVER THE SOUTHERN PANHANDLE
WILL DECREASE BEHIND THE LOW...BUT BRIEFLY INCREASE ACROSS THE
SOUTH CENTRAL PANHANDLE THIS EVENING. A WEAK RIDGE OF HIGH
PRESSURE WILL BUILD OVER BRITISH COLUMBIA COAST TUESDAY AND
BETWEEN THE RIDGE AND THE LOW IN THE CENTRAL GULF WILL PRODUCE
WARM MOIST SUBTROPICAL AIR FEEDING INTO DIXON ENTRANCE EAST.

.LONG TERM...EXTENDED GRIDS A BIT DIFFICULT OBTAIN CONFIDENCE IN
INITIALLY DUE TO LACK OF EC DATA FROM LAST NIGHT...BUT FORTUITOUSLY
THAT RUN WAS AN OUTLIER PER HPC COORD. NEW RUN CAME MORE INLINE
WITH GEM AND GFS RUNS SO DESPITE THE SLOW START REASONABLE
CONFIDENCE FOR DAYS 4 ONWARD WAS ATTAINED. WEAK LOW OVER THE
EASTERN GULF ON TUES NIGHT WEAKENS FURTHER AND MOVES SLOWLY
INLAND...LIKELY WILL CONTINUE TO PRODUCE SCATTERED SHOWERS OVER THE
PANHANDLE INTO WED AFTERNOON. IN THE MEANTIME THE MORE SIGNIFICANT
LOW PRESSURE TAKES OVER THE EASTERN GULF FROM THE WEST BY WED
MORNING AND GENERATES SCA-LEVEL WINDS OFFSHORE AND OVER ALL INNER
CHANNELS EXCEPT FOR LYNN CANAL AND GLACIER BAY BY WED
AFTERNOON/EVENING... AND INTO THURS FOR SOME CHANNELS AND OFFSHORE
ZONES. UTILIZED NAM/EC COMBO FOR THIS PORTION OF THE FORECAST AS
AGREEMENT WAS STRONG...WIND FIELD NEEDED TWEAKING OVER A FEW
SOUTHERN/CENTRAL CHANNELS AS WELL AS OFFSHORE CONTINUING A BIT OF
AN UPWARD TREND. ALSO A SIGNIFICANT BARRIER JET IS PROGGED OVER THE
NORTHWEST PORTION AND GIVEN THE LONGEVITY OF THE LOW SEE NO REASON
NOT TO BELIEVE THIS. THE LOW STALLS OVER THE GULF ON GUIDANCE AND
EVENTUALLY WEAKENS ON THE MODELS BUT WILL LEAD TO WIDESPREAD
INSTABILITY- DOMINATED AREAS OF RAIN SHOWERS POTENTIALLY THROUGH
THE END OF THE WEEK.

AFTER THIS LOW MOVES OFF TO THE SOUTHEAST THERE IS WEAK UPPER
RIDGING ON THE MODELS OVER THE GULF BUT THE PANHANDLE REMAINS IN
ENOUGH NORTHWESTERLY FLOW ALOFT...MOIST ON THE GEM, EC AND GFS
GUIDANCE UPDATES...THAT PRECIP ALONG WITH COOLER CONDITIONS ARE ON
TAP FOR THIS WEEKEND. EVEN COOL ENOUGH FOR A CHANCE OF MIXED PRECIP
AT SEA LEVEL OVER THE NORTHERN FRINGE AND THE STRONGER EC IS
POINTING TOWARDS EVEN JUNEAU FOR THE LATE WEEKEND. BRIEF PERIOD OF
STRATIFORM PRECIP IS POSSIBLE FOR LATE SUNDAY OVER AT LEAST THE
NORTHERN PANHANDLE AND THIS WILL NEED TO BE MONITORED ON UPCOMING
MODEL UPDATES FOR THE POTENTIAL OF SOME SNOW. AFTER THIS
PERIOD..MODEL GUIDANCE VARIES TO SOME DEGREE BUT APPEARS THAT
THERE IS A BETTER-THAN-EVEN CHANCE THAT TROUGHING WILL AMPLIFY
SOMEWHERE NEAR THE ALEUTIANS AND FRONTS WILL CONTINUE TO ENTER THE
GULF IN THE MON-WED PERIOD. WITH THE GENERAL AGREEMENT IN THE 3
MAJOR MODELS WENT WITH WPC GUIDANCE FOR THIS PERIOD...ALTHOUGH DO
NOT LIKE THE WAY THE POP FIELDS ARE SMEARED ACROSS THE PANHANDLE.
CANNOT REASONABLY RULE OUT ANY PERIOD FOR PRECIP CHANCES SO NO
CHOICE BUT TO GO WITH THE ENSEMBLE AT THIS POINT. THIS SCENARIO
WOULD BE A WARM MOIST ONE FOR ALL OF THE PANHANDLE UNLIKE WHAT IS
LIKELY ON TAP FOR THE WEEKEND. OVERALL...FOR THE WEEKEND AND NEXT
WEEK...POSITION/STRENGTH OF THE GULF FRONTS WILL DEPEND ON THE
STRENGTH OF THE LATE-WEEKEND UPPER TROUGH OVER THE NORTHERN
PANHANDLE AND THE SAME FOR THE DEEP TROUGHING WELL TO THE WEST
EARLY NEXT WEEK. JUST TOO EARLY TO TELL AT THIS POINT. MODEL
CONFIDENCE A BIT ABOVE AVERAGE FOR THE EXTENDED AFTER THE GAPS IN
EC AND WPC GUIDANCE WERE FILLED.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 7 PM AKDT THIS EVENING FOR AKZ027.
         STRONG WIND UNTIL 7 PM AKDT THIS EVENING FOR AKZ028.
MARINE...GALE WARNING FOR PKZ036. SMALL CRAFT ADVISORY FOR
PKZ012-013-041-042. SMALL CRAFT ADVISORY DUE TO SEAS FOR
PKZ043-051-052.

&&

$$

AHN/WESLEY

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











000
FXAK69 PAFG 302226
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
226 PM AKDT MON MAR 30 2015

.DISCUSSION...
ALOFT...5150 METER LOW JUST NORTHWEST OF KOTZEBUE WILL DRIFT
NORTHWEST TO WRANGELL ISLAND 1 AM WED. UPPER TROUGH MOVING SOUTH
OVER THE CANADIAN ARCTIC WILL APPROACH THE ARCTIC COAST WED AM AND
THEN A WEAK LOW AT THE END OF THE TROUGH 200 MILES NORTH OF
PRUDHOE BAY WHICH WILL THEN DRIFT NORTH. VORTICITY CENTER MOVING
NORTH TO NUNIVAK ISLAND 10 PM MON MOVING NORTH TO THE BERING
STRAIT 4 AM WED. WEAK RIDGING OVER EASTERN INTERIOR PERSISTING
THROUGH THU THOUGH A SHORT WAVE TROUGH WILL MOVE NORTH OVER THE
AREA THU. A LOW OVER THE WESTERN ALEUTIANS WILL TRACK EAST TO THE
GULF OF ALASKA WED THROUGH THU AND CREATE A BROAD TROUGH OVER
MAINLAND ALASKA WHICH WILL CAUSE SLOW MID LEVEL COOLING
THROUGHOUT THE FORECAST AREA TUE THROUGH THU.

SURFACE...1035 MB HIGH 500 MILES NORTH OF PRUDHOE BAY BUILDING TO
1046 MB AND DRIFTING TO 80N LAT 180W LON THROUGH 10 AM THU. 1002
MB LOW NEAR KIVALINA DRIFTING NORTHWEST AND WEAKENING 101014 MB
WED AM NEAR WRANGELL ISLAND. WEAK LOW PRESSURE OVER THE GULF OF
ALASKA DISSIPATING WITH A LOW OVER THE WESTERN ALEUTIANS MOVING TO
THE GULF OF ALASKA WED EVENING AT 1000 MB.

MODELS...AGREE OK THROUGH THU ON THE MAIN FEATURES MENTIONED
ABOVE. IN THE EXTENDED PERIOD THE GFS/CANADIAN ARE IN MUCH BETTER
AGREEMENT THAN THE ECMWF...THE LATTER WHICH IS DEVELOPING A STRONG
LOW MOVING INTO THE SOUTHERN CHUKCHI SEA ON FRI...QUITE A
DEPARTURE FROM THE USUAL PATTERN DURING THIS SEASON. HAVE AGREED
WITH WPC TO AVOID THIS ECMWF SOLUTION.

NORTH SLOPE...WINDS INCREASING SOME OVERNIGHT AND APPEARS THEY
WILL NOT DIMINISH MUCH UNTIL LATE TUESDAY AT THE EARLIEST...LIKE
WHEN THE TROUGH ALOFT NEARING THE ARCTIC OCEAN STALLS THEN
WEAKENS INTO A SMALL LOW. UPGRADED EASTERN BEAUFORT SEA COAST TO
BLIZZARD AND EXTENDED CENTRAL BEAUFORT SEA COAST ADVISORY THROUGH
TUE...AND ADDED THE NORTHERN ARCTIC COAST.

WESTERN ALASKA...SOME LIGHT SNOW INNER COASTAL AREAS TONIGHT INTO
TUE EVENING AS UPPER LOW SLOWLY MOVES OUT OF THE AREA AND WEAK
VORTICITY CENTER MOVES NORTH OVER OUTER NORTON SOUND. ACCUMULATIONS
SHOULD BE AN INCH OR LESS. THEREAFTER EXPECT SOME SPOTTY SNOW
SHOWERS LINGERING OVER NORTHERN INTERIOR AREAS.

CENTRAL AND EASTERN INTERIOR...TEMPERATURES COOLING A BIT THROUGH
THU. PERHAPS SOME SPOTTY SNOW SHOWERS MAINLY NORTH OF FAIRBANKS
THROUGH THURSDAY THOUGH OTHERWISE DRY.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ230-PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ225.
&&

$$

JL MAR 15




000
FXAK69 PAFG 302226
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
226 PM AKDT MON MAR 30 2015

.DISCUSSION...
ALOFT...5150 METER LOW JUST NORTHWEST OF KOTZEBUE WILL DRIFT
NORTHWEST TO WRANGELL ISLAND 1 AM WED. UPPER TROUGH MOVING SOUTH
OVER THE CANADIAN ARCTIC WILL APPROACH THE ARCTIC COAST WED AM AND
THEN A WEAK LOW AT THE END OF THE TROUGH 200 MILES NORTH OF
PRUDHOE BAY WHICH WILL THEN DRIFT NORTH. VORTICITY CENTER MOVING
NORTH TO NUNIVAK ISLAND 10 PM MON MOVING NORTH TO THE BERING
STRAIT 4 AM WED. WEAK RIDGING OVER EASTERN INTERIOR PERSISTING
THROUGH THU THOUGH A SHORT WAVE TROUGH WILL MOVE NORTH OVER THE
AREA THU. A LOW OVER THE WESTERN ALEUTIANS WILL TRACK EAST TO THE
GULF OF ALASKA WED THROUGH THU AND CREATE A BROAD TROUGH OVER
MAINLAND ALASKA WHICH WILL CAUSE SLOW MID LEVEL COOLING
THROUGHOUT THE FORECAST AREA TUE THROUGH THU.

SURFACE...1035 MB HIGH 500 MILES NORTH OF PRUDHOE BAY BUILDING TO
1046 MB AND DRIFTING TO 80N LAT 180W LON THROUGH 10 AM THU. 1002
MB LOW NEAR KIVALINA DRIFTING NORTHWEST AND WEAKENING 101014 MB
WED AM NEAR WRANGELL ISLAND. WEAK LOW PRESSURE OVER THE GULF OF
ALASKA DISSIPATING WITH A LOW OVER THE WESTERN ALEUTIANS MOVING TO
THE GULF OF ALASKA WED EVENING AT 1000 MB.

MODELS...AGREE OK THROUGH THU ON THE MAIN FEATURES MENTIONED
ABOVE. IN THE EXTENDED PERIOD THE GFS/CANADIAN ARE IN MUCH BETTER
AGREEMENT THAN THE ECMWF...THE LATTER WHICH IS DEVELOPING A STRONG
LOW MOVING INTO THE SOUTHERN CHUKCHI SEA ON FRI...QUITE A
DEPARTURE FROM THE USUAL PATTERN DURING THIS SEASON. HAVE AGREED
WITH WPC TO AVOID THIS ECMWF SOLUTION.

NORTH SLOPE...WINDS INCREASING SOME OVERNIGHT AND APPEARS THEY
WILL NOT DIMINISH MUCH UNTIL LATE TUESDAY AT THE EARLIEST...LIKE
WHEN THE TROUGH ALOFT NEARING THE ARCTIC OCEAN STALLS THEN
WEAKENS INTO A SMALL LOW. UPGRADED EASTERN BEAUFORT SEA COAST TO
BLIZZARD AND EXTENDED CENTRAL BEAUFORT SEA COAST ADVISORY THROUGH
TUE...AND ADDED THE NORTHERN ARCTIC COAST.

WESTERN ALASKA...SOME LIGHT SNOW INNER COASTAL AREAS TONIGHT INTO
TUE EVENING AS UPPER LOW SLOWLY MOVES OUT OF THE AREA AND WEAK
VORTICITY CENTER MOVES NORTH OVER OUTER NORTON SOUND. ACCUMULATIONS
SHOULD BE AN INCH OR LESS. THEREAFTER EXPECT SOME SPOTTY SNOW
SHOWERS LINGERING OVER NORTHERN INTERIOR AREAS.

CENTRAL AND EASTERN INTERIOR...TEMPERATURES COOLING A BIT THROUGH
THU. PERHAPS SOME SPOTTY SNOW SHOWERS MAINLY NORTH OF FAIRBANKS
THROUGH THURSDAY THOUGH OTHERWISE DRY.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ202-AKZ203.

GALE WARNING FOR PKZ230-PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ225.
&&

$$

JL MAR 15



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