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000
FXAK68 PAFC 221334
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
534 AM AKDT FRI AUG 22 2014

.ANALYSIS AND UPPER LEVELS...

THE GENERAL CHARACTERISTICS OF THE UPPER AIR PATTERN CONTINUE TO
REMAIN THE SAME FROM PREVIOUS DAYS...WITH A CLOSED UPPER LOW OVER
THE WESTERN BERING SEA...A LARGE EASTERN PACIFIC RIDGE EXTENDING
NORTH INTO THE ALASKA PANHANDLE...AND AN ACTIVE SUBTROPICAL JET
STREAM WRAPPING AROUND THE PERIPHERY OF THE AFOREMENTIONED CLOSED
LOW. WEAK SHORTWAVE DISTURBANCES ARE EJECTING OFF THE SUBTROPICAL
JET AS THEY INTERACT WITH THE EASTERN PACIFIC HIGH...WITH TWO OF
THESE WAVES TRACKING INTO THE GULF OF ALASKA. WITH TIME...THE
WESTERN BERING LOW WILL BEGIN TO PROPAGATE EAST AS IT MERGES WITH
THE SUBTROPICAL JET...WITH AN ASSOCIATED WARM FRONT TRACKING INTO
SOUTHERN ALASKA LATE SATURDAY AND SUNDAY.

&&

.MODEL DISCUSSION...

THE NUMERICAL MODELS ARE IN DECENT AGREEMENT WITH THE LARGE SCALE
PATTERN THROUGH TUESDAY...BUT THEY CONTINUE TO STRUGGLE WITH THE
TIMING AND STRENGTH OF A PACIFIC FRONT MOVING INTO SOUTHERN ALASKA
THIS WEEKEND. THAT SAID...THE GUIDANCE HAS COME INTO MUCH BETTER
AGREEMENT FROM PREVIOUS DAYS...ALTHOUGH THE ECMWF CONTINUES TO BE
THE FASTEST. THE FORECAST WILL CONTINUE TO MAKE USE OF A BLEND OF
THE GFS AND ECMWF TO ACCOUNT FOR TIMING DIFFERENCES.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
A FAST MOVING DISTURBANCE MOVING IN FROM THE GULF OF ALASKA IS
SPREADING MID AND HIGH CLOUDS OVER SOUTHCENTRAL THIS MORNING...AND
WILL PROVIDE JUST ENOUGH LIFT TO ENHANCE SHOWER ACTIVITY THIS
AFTERNOON...ESPECIALLY OVER THE MOUNTAINS. A LIGHT SOUTH TO
SOUTHWEST STEERING FLOW WILL HELP MOVE SOME SHOWERS OFF THE
MOUNTAINS INTO LOWER ELEVATION LOCATIONS. PATCHY FOG NEAR COOK
INLET WILL DIMINISH RAPIDLY AFTER MORNING. BY SATURDAY...SHORTWAVE
RIDGING WILL BUILD IN...WITH CLEARING SKIES AND ONLY ISOLATED
SHOWERS OVER THE MOUNTAINS. A FRONT MOVING INTO THE SOUTHWEST GULF
WILL SPREAD RAIN INTO KODIAK AND THE KENAI COAST SATURDAY
AFTERNOON AND EVENING...THEN SPREAD INLAND LATE SUNDAY INTO
MONDAY.

SOUTHWEST ALASKA...
A WEAK DISTURBANCE ALOFT IS CURRENTLY SPREADING MID AND HIGH
CLOUDS OVER THE REGION TODAY. THERE WILL BE ENOUGH DIURNAL HEATING
TO HELP INITIATE CONVECTIVE SHOWERS IN THE AFTERNOON...BUT THE
CLOUDS WILL HELP LIMIT INSTABILITY ENOUGH TO KEEP COVERAGE
ISOLATED TO SCATTERED...AND MAINLY OVER THE MOUNTAINS. A WEAK
FRONT WILL MOVE INTO THE EASTERN BERING SATURDAY...WITH CLOUDS
OVERSPREADING SOUTHWEST. THE BEST CHANCES FOR RAIN WILL REMAIN
RELEGATED TO COASTAL LOCATIONS NEAR BRISTOL BAY...AND ALONG THE
ALASKA PENINSULA. SOUTHEAST WINDS...ESPECIALLY THROUGH GAPS IN THE
ALASKA AND ALEUTIAN RANGES...WILL INCREASE AS THE FRONT
APPROACHES...AND WILL ALSO HELP DOWNSLOPE SHADOW LOCATIONS IN THE
LEE OF THE ALASKA AND ALEUTIAN RANGES. A MUCH STRONGER FRONT
MOVES INTO SOUTHWEST ON SUNDAY...WITH WIDESPREAD RAIN MOVING INTO
THE AREA.

BERING SEA/ALEUTIANS...

RAIN WILL OVERSPREAD THE CENTRAL ALEUTIANS AND PRIBILOF ISLANDS
TODAY AND TONIGHT AS A LOW MAKES EASTWARD PROGRESSION...FOLLOWED
BY THE EASTERN ALEUTIANS SATURDAY. SHOWERS WILL LINGER ACROSS THE
CENTRAL AND EASTERN BERING THROUGH SUNDAY AS THE LOW MOVES EAST.
WEAK HIGH PRESSURE OVER THE WESTERN BERING WILL LINGER INTO
SATURDAY BEFORE ANOTHER LOW SPREADS RAIN INTO THE AREA SUNDAY AND
MONDAY.

&&

.LONG TERM FORECAST (TUESDAY AUG 26TH - FRI AUG 29)...

ON TUESDAY...THE REMNANTS OF THE BERING LOW WILL BE TRACKING INTO
THE YUKON...LEAVING SHOWERS AND CLOUDS OVER MOST OF SOUTHERN
ALASKA...ESPECIALLY OVER SOUTHCENTRAL. THERE IS QUITE A BIT OF
DISCREPANCY WITH THE TRACK OF A POTENTIAL LOW MOVING FROM THE
BERING INTO SOUTHERN ALASKA LATE WEEK...WITH THE ECMWF AND
CANADIAN GDPS FAVORING A SPLIT FLOW SCENARIO WITH THE LOW
REMAINING DISPLACED FROM THE NORTHERN STREAM JET...WHILE THE GFS
FAVORS A PHASED AND STRONG LOW. WITH THAT SAID...ALL THE GLOBAL
NUMERICAL GUIDANCE IS IN GOOD AGREEMENT WITH THE DEVELOPMENT OF A
LARGE VORTEX OVER NORTHERN ALASKA AND THE BEAUFORT SEA...KEEPING
SOUTHERN ALASKA UNDER THE THREAT OF INCREASED PRECIPITATION
CHANCES AS WEAK WAVES ALOFT ROTATE OVER THE REGION. IN OTHER
WORDS...NO SIGNIFICANT WARM OR DRY PERIODS ARE EXPECTED THROUGH
THE EXTENDED.

&&

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

$$

AHSENMACHER AUG 14




000
FXAK68 PAFC 221334
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
534 AM AKDT FRI AUG 22 2014

.ANALYSIS AND UPPER LEVELS...

THE GENERAL CHARACTERISTICS OF THE UPPER AIR PATTERN CONTINUE TO
REMAIN THE SAME FROM PREVIOUS DAYS...WITH A CLOSED UPPER LOW OVER
THE WESTERN BERING SEA...A LARGE EASTERN PACIFIC RIDGE EXTENDING
NORTH INTO THE ALASKA PANHANDLE...AND AN ACTIVE SUBTROPICAL JET
STREAM WRAPPING AROUND THE PERIPHERY OF THE AFOREMENTIONED CLOSED
LOW. WEAK SHORTWAVE DISTURBANCES ARE EJECTING OFF THE SUBTROPICAL
JET AS THEY INTERACT WITH THE EASTERN PACIFIC HIGH...WITH TWO OF
THESE WAVES TRACKING INTO THE GULF OF ALASKA. WITH TIME...THE
WESTERN BERING LOW WILL BEGIN TO PROPAGATE EAST AS IT MERGES WITH
THE SUBTROPICAL JET...WITH AN ASSOCIATED WARM FRONT TRACKING INTO
SOUTHERN ALASKA LATE SATURDAY AND SUNDAY.

&&

.MODEL DISCUSSION...

THE NUMERICAL MODELS ARE IN DECENT AGREEMENT WITH THE LARGE SCALE
PATTERN THROUGH TUESDAY...BUT THEY CONTINUE TO STRUGGLE WITH THE
TIMING AND STRENGTH OF A PACIFIC FRONT MOVING INTO SOUTHERN ALASKA
THIS WEEKEND. THAT SAID...THE GUIDANCE HAS COME INTO MUCH BETTER
AGREEMENT FROM PREVIOUS DAYS...ALTHOUGH THE ECMWF CONTINUES TO BE
THE FASTEST. THE FORECAST WILL CONTINUE TO MAKE USE OF A BLEND OF
THE GFS AND ECMWF TO ACCOUNT FOR TIMING DIFFERENCES.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
A FAST MOVING DISTURBANCE MOVING IN FROM THE GULF OF ALASKA IS
SPREADING MID AND HIGH CLOUDS OVER SOUTHCENTRAL THIS MORNING...AND
WILL PROVIDE JUST ENOUGH LIFT TO ENHANCE SHOWER ACTIVITY THIS
AFTERNOON...ESPECIALLY OVER THE MOUNTAINS. A LIGHT SOUTH TO
SOUTHWEST STEERING FLOW WILL HELP MOVE SOME SHOWERS OFF THE
MOUNTAINS INTO LOWER ELEVATION LOCATIONS. PATCHY FOG NEAR COOK
INLET WILL DIMINISH RAPIDLY AFTER MORNING. BY SATURDAY...SHORTWAVE
RIDGING WILL BUILD IN...WITH CLEARING SKIES AND ONLY ISOLATED
SHOWERS OVER THE MOUNTAINS. A FRONT MOVING INTO THE SOUTHWEST GULF
WILL SPREAD RAIN INTO KODIAK AND THE KENAI COAST SATURDAY
AFTERNOON AND EVENING...THEN SPREAD INLAND LATE SUNDAY INTO
MONDAY.

SOUTHWEST ALASKA...
A WEAK DISTURBANCE ALOFT IS CURRENTLY SPREADING MID AND HIGH
CLOUDS OVER THE REGION TODAY. THERE WILL BE ENOUGH DIURNAL HEATING
TO HELP INITIATE CONVECTIVE SHOWERS IN THE AFTERNOON...BUT THE
CLOUDS WILL HELP LIMIT INSTABILITY ENOUGH TO KEEP COVERAGE
ISOLATED TO SCATTERED...AND MAINLY OVER THE MOUNTAINS. A WEAK
FRONT WILL MOVE INTO THE EASTERN BERING SATURDAY...WITH CLOUDS
OVERSPREADING SOUTHWEST. THE BEST CHANCES FOR RAIN WILL REMAIN
RELEGATED TO COASTAL LOCATIONS NEAR BRISTOL BAY...AND ALONG THE
ALASKA PENINSULA. SOUTHEAST WINDS...ESPECIALLY THROUGH GAPS IN THE
ALASKA AND ALEUTIAN RANGES...WILL INCREASE AS THE FRONT
APPROACHES...AND WILL ALSO HELP DOWNSLOPE SHADOW LOCATIONS IN THE
LEE OF THE ALASKA AND ALEUTIAN RANGES. A MUCH STRONGER FRONT
MOVES INTO SOUTHWEST ON SUNDAY...WITH WIDESPREAD RAIN MOVING INTO
THE AREA.

BERING SEA/ALEUTIANS...

RAIN WILL OVERSPREAD THE CENTRAL ALEUTIANS AND PRIBILOF ISLANDS
TODAY AND TONIGHT AS A LOW MAKES EASTWARD PROGRESSION...FOLLOWED
BY THE EASTERN ALEUTIANS SATURDAY. SHOWERS WILL LINGER ACROSS THE
CENTRAL AND EASTERN BERING THROUGH SUNDAY AS THE LOW MOVES EAST.
WEAK HIGH PRESSURE OVER THE WESTERN BERING WILL LINGER INTO
SATURDAY BEFORE ANOTHER LOW SPREADS RAIN INTO THE AREA SUNDAY AND
MONDAY.

&&

.LONG TERM FORECAST (TUESDAY AUG 26TH - FRI AUG 29)...

ON TUESDAY...THE REMNANTS OF THE BERING LOW WILL BE TRACKING INTO
THE YUKON...LEAVING SHOWERS AND CLOUDS OVER MOST OF SOUTHERN
ALASKA...ESPECIALLY OVER SOUTHCENTRAL. THERE IS QUITE A BIT OF
DISCREPANCY WITH THE TRACK OF A POTENTIAL LOW MOVING FROM THE
BERING INTO SOUTHERN ALASKA LATE WEEK...WITH THE ECMWF AND
CANADIAN GDPS FAVORING A SPLIT FLOW SCENARIO WITH THE LOW
REMAINING DISPLACED FROM THE NORTHERN STREAM JET...WHILE THE GFS
FAVORS A PHASED AND STRONG LOW. WITH THAT SAID...ALL THE GLOBAL
NUMERICAL GUIDANCE IS IN GOOD AGREEMENT WITH THE DEVELOPMENT OF A
LARGE VORTEX OVER NORTHERN ALASKA AND THE BEAUFORT SEA...KEEPING
SOUTHERN ALASKA UNDER THE THREAT OF INCREASED PRECIPITATION
CHANCES AS WEAK WAVES ALOFT ROTATE OVER THE REGION. IN OTHER
WORDS...NO SIGNIFICANT WARM OR DRY PERIODS ARE EXPECTED THROUGH
THE EXTENDED.

&&

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

$$

AHSENMACHER AUG 14





000
FXAK68 PAFC 212146
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
146 PM AKDT THU AUG 21 2014

.ANALYSIS AND UPPER LEVELS...UPPER LOW WESTERN ALEUTIANS. MAIN JET
SOUTH OF THE AREA AS IT RIDES OVER THE NORTHEAST PACIFIC RIDGE.
OTHERWISE A LIGHT SOUTHWESTERLY DELIQUESCENCE FLOW IS SEEN ACROSS
ALL OF THE SOUTHERN MAINLAND.


&&

.MODEL DISCUSSION...AT THIS POINT PREFERRING THE GFS OVER THE NAM
SINCE IT HAS A GOOD HANDLE ON THE SYSTEM AT 39N 171E, BUT MAY GO
WITH A COMPROMISE SUNDAY AFTERNOON AND EVENING. THE WEAK
DISTURBANCE NOW PASSING SOUTH OF KODIAK INTO THE GULF STAYS SOUTH
WITH NEARLY ALL OF THE PRECIPITATION REMAINING OFFSHORE. A VERY
WEAK UPPER LOW DOES SLIP INTO SOUTHERN PRINCE WILLIAM SOUND BY
MIDDAY FRIDAY. MODELS TAKE THE WESTERN ALEUTIAN UPPER LOW AND
MOVE IT TO BRISTOL BAY LATE SUNDAY AND THEN TRACK IT EASTWARD
ACROSS SOUTHERN ALASKA MONDAY. NAM IS SLOWEST DOING THIS. THERE
ARE THE USUAL DIFFERENCES WITH THE TRIPLE POINT LOW AND WAVES
FORMING ALONG THE FRONT. GFS AND EC SPREAD RAIN WITH THE OCCLUDED FRONT
WELL INTO SOUTHERN ALASKA WHILE THE NAM KEEPS IT MOSTLY SOUTH OF
THE NORTH GULF COAST.


&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
COOK INLET FOG WILL BE LESS EXTENSIVE
TONIGHT AND FRIDAY MORNING DUE TO AN INCREASE OF MIDLEVEL
MOISTURE AND INCREASING OUTFLOW THROUGH TURNAGAIN ARM. WEAK
DIFFLUENT UPPER FLOW SUPPORTS SCATTERED MOUNTAIN SHOWERS AND
ISOLATED THUNDERSTORMS THURSDAY EVENING. WEAK UPPER RIDGING AHEAD
OF THE ALEUTIAN STORM WILL SUPPRESS THIS FRIDAY EVENING WITH ONLY
ISOLATED SHOWERS POSSIBLE.

SOUTHWEST ALASKA...VARIABLE CLOUDS WITH SCATTERED OR ISOLATED
SHOWERS THIS AFTERNOON AND EVENING SHOULD BE MORE ISOLATED FRIDAY
AND SATURDAY AS HIGHER PRESSURE BUILDS IN. RAIN SHOULD REACH THE
COAST SATURDAY NIGHT AND SPREAD INLAND TOWARD MORNING WHICH WILL
MAKE FOR A CLOUDY WET DAY ON SUNDAY. NO SIGNIFICANT WINDS
EXPECTED BUT MAY INCREASE TO 20 TO 30 KTS SATURDAY NIGHT AHEAD OF
THE FRONT.

BERING SEA/ALEUTIANS...CLOUDY WITH PERIODS OF RAIN OR SHOWERS
THROUGH THE WEEKEND. DRY IN THE WEST AS HIGHER PRESSURE MOVES IN
FOLLOWED BY RAIN SATURDAY NIGHT AND SUNDAY AS THE NEXT FRONT MOVES
IN. NO GALES EXPECTED.


&&


.LONG TERM FORECAST...
AN UPPER LEVEL LOW WILL CONTINUE TO TRACK ACROSS THE ALASKA
PENINSULA INTO THE SOUTHEAST MAINLAND BY THE EARLY PART OF NEXT
WEEK. THIS WILL BRING SHOWERY CONDITIONS WITH SMALL CRAFT WINDS
INTO THE GULF OF ALASKA. THE BERING SEA WILL HAVE AN UPPER LEVEL
LONG WAVE TROUGH NEAR THE KAMCHATKA PENINSULA DROPPING DOWN INTO
THE WESTERN BERING SEA AND WESTERN ALEUTIANS BY MONDAY. THIS
FEATURE WILL HAVE A SURFACE LOW AT THE BASE OF THE TROUGH NEAR THE
WESTERN ALEUTIANS AND WILL SLOWLY MOVE EASTWARD ACROSS THE
ALEUTIANS FROM WEDNESDAY INTO NEXT WEEKEND. THIS WILL PRODUCE
SHOWERY CONDITIONS WITH MARINE LAYER STRATUS AND FOG.


&&

PLD

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

DB PERCY AUG 14

$$




000
FXAK68 PAFC 212146
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
146 PM AKDT THU AUG 21 2014

.ANALYSIS AND UPPER LEVELS...UPPER LOW WESTERN ALEUTIANS. MAIN JET
SOUTH OF THE AREA AS IT RIDES OVER THE NORTHEAST PACIFIC RIDGE.
OTHERWISE A LIGHT SOUTHWESTERLY DELIQUESCENCE FLOW IS SEEN ACROSS
ALL OF THE SOUTHERN MAINLAND.


&&

.MODEL DISCUSSION...AT THIS POINT PREFERRING THE GFS OVER THE NAM
SINCE IT HAS A GOOD HANDLE ON THE SYSTEM AT 39N 171E, BUT MAY GO
WITH A COMPROMISE SUNDAY AFTERNOON AND EVENING. THE WEAK
DISTURBANCE NOW PASSING SOUTH OF KODIAK INTO THE GULF STAYS SOUTH
WITH NEARLY ALL OF THE PRECIPITATION REMAINING OFFSHORE. A VERY
WEAK UPPER LOW DOES SLIP INTO SOUTHERN PRINCE WILLIAM SOUND BY
MIDDAY FRIDAY. MODELS TAKE THE WESTERN ALEUTIAN UPPER LOW AND
MOVE IT TO BRISTOL BAY LATE SUNDAY AND THEN TRACK IT EASTWARD
ACROSS SOUTHERN ALASKA MONDAY. NAM IS SLOWEST DOING THIS. THERE
ARE THE USUAL DIFFERENCES WITH THE TRIPLE POINT LOW AND WAVES
FORMING ALONG THE FRONT. GFS AND EC SPREAD RAIN WITH THE OCCLUDED FRONT
WELL INTO SOUTHERN ALASKA WHILE THE NAM KEEPS IT MOSTLY SOUTH OF
THE NORTH GULF COAST.


&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
COOK INLET FOG WILL BE LESS EXTENSIVE
TONIGHT AND FRIDAY MORNING DUE TO AN INCREASE OF MIDLEVEL
MOISTURE AND INCREASING OUTFLOW THROUGH TURNAGAIN ARM. WEAK
DIFFLUENT UPPER FLOW SUPPORTS SCATTERED MOUNTAIN SHOWERS AND
ISOLATED THUNDERSTORMS THURSDAY EVENING. WEAK UPPER RIDGING AHEAD
OF THE ALEUTIAN STORM WILL SUPPRESS THIS FRIDAY EVENING WITH ONLY
ISOLATED SHOWERS POSSIBLE.

SOUTHWEST ALASKA...VARIABLE CLOUDS WITH SCATTERED OR ISOLATED
SHOWERS THIS AFTERNOON AND EVENING SHOULD BE MORE ISOLATED FRIDAY
AND SATURDAY AS HIGHER PRESSURE BUILDS IN. RAIN SHOULD REACH THE
COAST SATURDAY NIGHT AND SPREAD INLAND TOWARD MORNING WHICH WILL
MAKE FOR A CLOUDY WET DAY ON SUNDAY. NO SIGNIFICANT WINDS
EXPECTED BUT MAY INCREASE TO 20 TO 30 KTS SATURDAY NIGHT AHEAD OF
THE FRONT.

BERING SEA/ALEUTIANS...CLOUDY WITH PERIODS OF RAIN OR SHOWERS
THROUGH THE WEEKEND. DRY IN THE WEST AS HIGHER PRESSURE MOVES IN
FOLLOWED BY RAIN SATURDAY NIGHT AND SUNDAY AS THE NEXT FRONT MOVES
IN. NO GALES EXPECTED.


&&


.LONG TERM FORECAST...
AN UPPER LEVEL LOW WILL CONTINUE TO TRACK ACROSS THE ALASKA
PENINSULA INTO THE SOUTHEAST MAINLAND BY THE EARLY PART OF NEXT
WEEK. THIS WILL BRING SHOWERY CONDITIONS WITH SMALL CRAFT WINDS
INTO THE GULF OF ALASKA. THE BERING SEA WILL HAVE AN UPPER LEVEL
LONG WAVE TROUGH NEAR THE KAMCHATKA PENINSULA DROPPING DOWN INTO
THE WESTERN BERING SEA AND WESTERN ALEUTIANS BY MONDAY. THIS
FEATURE WILL HAVE A SURFACE LOW AT THE BASE OF THE TROUGH NEAR THE
WESTERN ALEUTIANS AND WILL SLOWLY MOVE EASTWARD ACROSS THE
ALEUTIANS FROM WEDNESDAY INTO NEXT WEEKEND. THIS WILL PRODUCE
SHOWERY CONDITIONS WITH MARINE LAYER STRATUS AND FOG.


&&

PLD

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

DB PERCY AUG 14

$$





000
FXAK68 PAFC 211329
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
529 AM AKDT THU AUG 21 2014

.ANALYSIS AND UPPER LEVELS...

NO DRAMATIC CHANGE IN THE LARGE SCALE UPPER AIR PATTERN FROM
YESTERDAY...WITH A CLOSED LOW OVER THE WESTERN BERING...AND AN
EASTERN PACIFIC RIDGE CENTERED OVER 40N. AN ACTIVE SUBTROPICAL JET
STREAM IS WRAPPING AROUND THE AFOREMENTIONED UPPER TROUGH...WITH
THE FIRST OF MANY SHORTWAVE DISTURBANCES TRACKING INTO THE
SOUTHWEST GULF OF ALASKA. ACROSS THE MAINLAND...SHORTWAVE RIDGING
IS TRANSITING THE NORTHERN GULF OF ALASKA...WITH WEAK UPPER LEVEL
MIGRATORY WAVES TRACKING THROUGH SOUTHWEST ALASKA. THIS WEAK FLOW
PATTERN/PRESSURE GRADIENT PATTERN ACROSS THE MAINLAND IS PROMOTING
AREAS OF FOG AND STRATUS...ESPECIALLY ACROSS PORTIONS OF THE
NORTHERN GULF AND COOK INLET. WITH TIME...THE PATTERN WILL BEGIN
TO TRANSITION TO A MORE ACTIVE ONE AS THE WESTERN BERING TROUGH
MOVES EAST...WITH THE SUBTROPICAL JET STREAM TRACKING INTO
SOUTHERN ALASKA LATE THIS WEEKEND.

&&

.MODEL DISCUSSION...

THE NUMERICAL GUIDANCE IS IN GOOD AGREEMENT WITH THE GENERAL
SYNOPTIC PATTERN HEADING INTO NEXT WEEK...BUT IS IN POOR
AGREEMENT WITH THE TIMING AND STRENGTH OF A SUBTROPICAL WARM FRONT
EXPECTED TO IMPACT SOUTHERN ALASKA THIS WEEKEND. ALL THE NUMERICAL
GUIDANCE IS STRUGGLING MIGHTILY WITH THE PHASING OF A WEAK LOW
NEAR KAMCHATKA WITH THE LARGER SCALE TROUGH...AND THE EVENTUAL
DEVELOPMENT OF THE SURFACE LOW AS IT TRACKS INTO THE EASTERN
BERING SEA. THE ECMWF IS THE MOST AGGRESSIVE AND FAST...WHILE THE
GFS AND NAM ARE SLOWER. FOR NOW...THE FORECAST WILL TAKE A MIDDLE
GROUND APPROACH WITH A BLEND TO THE GFS AND ECMWF TO ACCOUNT FOR
THE UNCERTAINTY.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
WEAK FLOW ALOFT WILL CONTINUE TO SUPPORT DIURNAL AFTERNOON AND
EVENING MOUNTAIN SHOWERS...WITH A WEAK SOUTHWESTERLY COMPONENT
ALOFT HELPING TO PUSH SOME OF THOSE SHOWERS INLAND...ESPECIALLY
NEAR THE TALKEETNA AND WRANGELL MOUNTAINS. MARINE FOG AND LOW
STRATUS CONTINUES TO LINGER ACROSS PORTIONS OF COOK INLET...AND IT
HAS MADE FURTHER PROGRESS INTO THE SOUTHERN SUSITNA VALLEY AND THE
ANCHORAGE BOWL. MOST FOG WILL DIMINISH WITH DAYTIME HEATING...BUT
THE POSSIBILITY EXISTS FOR A RETURN TO FOG OVERNIGHT...ESPECIALLY
ACROSS THE NORTHERN KENAI ALONG THE INLET. ON FRIDAY...A
DISTURBANCE WILL SPREAD CLOUDS AND MORE WIDESPREAD SHOWERS INTO
MUCH OF SOUTHCENTRAL BEFORE RETURNING TO LARGELY PLEASANT LATE
SUMMER CONDITIONS SATURDAY.

SOUTHWEST ALASKA...
WEAK DISTURBANCES ALOFT MOVING IN FROM THE SOUTH WILL CONTINUE TO
SUPPORT EXTENSIVE CLOUDS AND ISOLATED TO SCATTERED RAIN SHOWERS
ACROSS PORTIONS OF THE KUSKOKWIM DELTA AND BRISTOL BAY REGION.
AFTERNOON AND EARLY EVENING CONVECTIVE SHOWERS WILL CONTINUE TO
DEVELOP ALONG THE ALASKA AND ALEUTIAN RANGE TODAY AND AGAIN FRIDAY
BEFORE A WARM FRONT MOVES IN LATE SATURDAY INTO SUNDAY...SPREADING
RAIN ACROSS ALL OF SOUTHWEST ALASKA.

BERING SEA/ALEUTIANS...
THE WESTERN BERING LOW WILL BEGIN TO TRACK EAST FRIDAY...WITH
SHOWERS MOVING ACROSS THE WESTERN AND CENTRAL ALEUTIANS. ON
SATURDAY...A MORE STOUT WARM FRONT WILL MOVE INTO THE EASTERN
BERING AND ALEUTIANS...WITH WIDESPREAD RAIN IMPACTING THOSE
LOCATIONS.

&&

.LONG TERM FORECAST (MONDAY AUG 25 - THU AUG 28)...

AN ACTIVE WAVE PATTERN WILL BE UNDERWAY MONDAY AS THE REMNANTS OF
THE BERING TROUGH WILL BE TRANSITING ACROSS SOUTHERN ALASKA...WITH
CLOUDS AND RAIN SHOWERS LINGERING INTO TUESDAY. A BRIEF BREAK MAY
DEVELOP LATE TUESDAY INTO WEDNESDAY BEFORE ANOTHER BERING
LOW...PHASING WITH A LARGE COLD UPPER VORTEX OVER NORTHERN
ALASKA...MOVES INTO SOUTHERN ALASKA...WITH MORE RAIN AND CLOUDS.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121
         DENSE FOG ADVISORY 101 121.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

AHSENMACHER AUG 14





000
FXAK68 PAFC 211329
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
529 AM AKDT THU AUG 21 2014

.ANALYSIS AND UPPER LEVELS...

NO DRAMATIC CHANGE IN THE LARGE SCALE UPPER AIR PATTERN FROM
YESTERDAY...WITH A CLOSED LOW OVER THE WESTERN BERING...AND AN
EASTERN PACIFIC RIDGE CENTERED OVER 40N. AN ACTIVE SUBTROPICAL JET
STREAM IS WRAPPING AROUND THE AFOREMENTIONED UPPER TROUGH...WITH
THE FIRST OF MANY SHORTWAVE DISTURBANCES TRACKING INTO THE
SOUTHWEST GULF OF ALASKA. ACROSS THE MAINLAND...SHORTWAVE RIDGING
IS TRANSITING THE NORTHERN GULF OF ALASKA...WITH WEAK UPPER LEVEL
MIGRATORY WAVES TRACKING THROUGH SOUTHWEST ALASKA. THIS WEAK FLOW
PATTERN/PRESSURE GRADIENT PATTERN ACROSS THE MAINLAND IS PROMOTING
AREAS OF FOG AND STRATUS...ESPECIALLY ACROSS PORTIONS OF THE
NORTHERN GULF AND COOK INLET. WITH TIME...THE PATTERN WILL BEGIN
TO TRANSITION TO A MORE ACTIVE ONE AS THE WESTERN BERING TROUGH
MOVES EAST...WITH THE SUBTROPICAL JET STREAM TRACKING INTO
SOUTHERN ALASKA LATE THIS WEEKEND.

&&

.MODEL DISCUSSION...

THE NUMERICAL GUIDANCE IS IN GOOD AGREEMENT WITH THE GENERAL
SYNOPTIC PATTERN HEADING INTO NEXT WEEK...BUT IS IN POOR
AGREEMENT WITH THE TIMING AND STRENGTH OF A SUBTROPICAL WARM FRONT
EXPECTED TO IMPACT SOUTHERN ALASKA THIS WEEKEND. ALL THE NUMERICAL
GUIDANCE IS STRUGGLING MIGHTILY WITH THE PHASING OF A WEAK LOW
NEAR KAMCHATKA WITH THE LARGER SCALE TROUGH...AND THE EVENTUAL
DEVELOPMENT OF THE SURFACE LOW AS IT TRACKS INTO THE EASTERN
BERING SEA. THE ECMWF IS THE MOST AGGRESSIVE AND FAST...WHILE THE
GFS AND NAM ARE SLOWER. FOR NOW...THE FORECAST WILL TAKE A MIDDLE
GROUND APPROACH WITH A BLEND TO THE GFS AND ECMWF TO ACCOUNT FOR
THE UNCERTAINTY.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
WEAK FLOW ALOFT WILL CONTINUE TO SUPPORT DIURNAL AFTERNOON AND
EVENING MOUNTAIN SHOWERS...WITH A WEAK SOUTHWESTERLY COMPONENT
ALOFT HELPING TO PUSH SOME OF THOSE SHOWERS INLAND...ESPECIALLY
NEAR THE TALKEETNA AND WRANGELL MOUNTAINS. MARINE FOG AND LOW
STRATUS CONTINUES TO LINGER ACROSS PORTIONS OF COOK INLET...AND IT
HAS MADE FURTHER PROGRESS INTO THE SOUTHERN SUSITNA VALLEY AND THE
ANCHORAGE BOWL. MOST FOG WILL DIMINISH WITH DAYTIME HEATING...BUT
THE POSSIBILITY EXISTS FOR A RETURN TO FOG OVERNIGHT...ESPECIALLY
ACROSS THE NORTHERN KENAI ALONG THE INLET. ON FRIDAY...A
DISTURBANCE WILL SPREAD CLOUDS AND MORE WIDESPREAD SHOWERS INTO
MUCH OF SOUTHCENTRAL BEFORE RETURNING TO LARGELY PLEASANT LATE
SUMMER CONDITIONS SATURDAY.

SOUTHWEST ALASKA...
WEAK DISTURBANCES ALOFT MOVING IN FROM THE SOUTH WILL CONTINUE TO
SUPPORT EXTENSIVE CLOUDS AND ISOLATED TO SCATTERED RAIN SHOWERS
ACROSS PORTIONS OF THE KUSKOKWIM DELTA AND BRISTOL BAY REGION.
AFTERNOON AND EARLY EVENING CONVECTIVE SHOWERS WILL CONTINUE TO
DEVELOP ALONG THE ALASKA AND ALEUTIAN RANGE TODAY AND AGAIN FRIDAY
BEFORE A WARM FRONT MOVES IN LATE SATURDAY INTO SUNDAY...SPREADING
RAIN ACROSS ALL OF SOUTHWEST ALASKA.

BERING SEA/ALEUTIANS...
THE WESTERN BERING LOW WILL BEGIN TO TRACK EAST FRIDAY...WITH
SHOWERS MOVING ACROSS THE WESTERN AND CENTRAL ALEUTIANS. ON
SATURDAY...A MORE STOUT WARM FRONT WILL MOVE INTO THE EASTERN
BERING AND ALEUTIANS...WITH WIDESPREAD RAIN IMPACTING THOSE
LOCATIONS.

&&

.LONG TERM FORECAST (MONDAY AUG 25 - THU AUG 28)...

AN ACTIVE WAVE PATTERN WILL BE UNDERWAY MONDAY AS THE REMNANTS OF
THE BERING TROUGH WILL BE TRANSITING ACROSS SOUTHERN ALASKA...WITH
CLOUDS AND RAIN SHOWERS LINGERING INTO TUESDAY. A BRIEF BREAK MAY
DEVELOP LATE TUESDAY INTO WEDNESDAY BEFORE ANOTHER BERING
LOW...PHASING WITH A LARGE COLD UPPER VORTEX OVER NORTHERN
ALASKA...MOVES INTO SOUTHERN ALASKA...WITH MORE RAIN AND CLOUDS.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121
         DENSE FOG ADVISORY 101 121.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

AHSENMACHER AUG 14




000
FXAK68 PAFC 202147
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
147 PM AKDT WED AUG 20 2014

.ANALYSIS AND UPPER LEVELS...
AN UPPER-LVL LOW IS CENTERED NEAR SHEMYA AND IS NEARLY STATIONARY.
AN ASSOCIATED OCCLUDED FRONT IS STALLING AND WEAKENING ACROSS THE
CENTRAL ALEUTIAN CHAIN THOUGH SOME LIGHT RAINS STILL FALL OUT THAT
WAY. ALSO OF NOTE IS A WAVE OF LOW PRESSURE NEAR 42N 155E DIPPING
SE AROUND THE AFOREMENTIONED UPPER-LVL LOW. UPPER-LVL RIDGING
SUPPORTS SURFACE HIGH PRESSURE IN THE FAR EASTERN BERING SEA WHICH
NOSES INTO THE SW MAINLAND. DOWNSTREAM OF THAT RIDGE...A SHORTWAVE
TROUGH IS LIFTING NORTHEAST THROUGH THE SUSITNA VALLEY AND NW
REACHES OF THE COPPER RIVER BASIN WITH A FEW PASSING SHOWERS.
MARINE FOG/STRATUS LOOMS OVER COOK INLET AND BRUSHES KODIAK ISLAND
IN WEAK LOW LVL FLOW.

&&

.MODEL DISCUSSION...
MODELS ARE STRUGGLING WITH SOME OF THE MAIN FEATURES AND RUN TO
RUN CONSISTENCY HAS BEEN VERY POOR OF LATE. THE UPPER RIDGE IN THE
EASTERN BERING IS DEPICTED MOVING EASTWARD TOWARDS THE ALCAN
BORDER THU AFTERNOON AND DAMPENING AS BOTH SHORTWAVE AND JET
STREAM ENERGY WORK UP AGAINST IT`S WESTERN FLANK. MODELS SHOW A
1015 MB PACIFIC LOW CENTERED AROUND 320 NM S OF SITKINAK THU
EVENING WILL MOVE TO AROUND 270 NM SE OF KODIAK CITY AT 1019 MB
FRI AFTERNOON BEFORE DISSIPATING AS IT TRACKS TO THE SOUTHERN AK
PANHANDLE ON SAT. THIS SYSTEM LOOKS TO BE A NON-PLAYER FOR THE
SOUTHERN MAINLAND AND KODIAK ISLAND. THE 1002 MB LOW NEAR SHEMYA
IS SHOWN DRIFTING TO AROUND 170 MI SE OF KISKA FRI AFTERNOON AT
1010 MB. THE SURFACE WAVE NEAR 42N 155E WILL DROP TO AROUND 1000
MI SOUTH OF ADAK THU EVENING...THEN PIVOT NORTHEAST TO AROUND 350
MI S OF UNALASKA EARLY SAT. BUT THERE ARE CONSIDERABLE DIFFERENCES
WITH HOW THE RESIDUAL SHEMYA LOW WILL INTERACT WITH THIS
APPROACHING SYSTEM...AS WELL AS THE SYSTEM`S ORIENTATION AS
STRONGER JET STREAM ENERGY INTERACTS WITH IT ALONG IT`S
SOUTHEASTERN FLANK. NO OPERATIONAL MODEL LIKELY HAS A GOOD HANDLE
ON THINGS...SO HAVE TRIED TO RETAIN THE SPIRIT OF THE INHERITED
FORECAST/GRIDS WHICH LEANED ON THE 20/00Z ECMWF. DESPITE MODEL
PROBLEMS WITH MANY DETAILS...A GENERAL POSITION OF THE PARENT
UPPER-LOW LOOKS TO BE IN THE VICINITY OF NIKOLSKI SAT AFTERNOON.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

ACROSS KODIAK ISLAND...THE MARINE LAYER HAS HUGGED THE COAST MOST
OF THE DAY. LIGHT WIND FLOW AND SOME RIDGING MOVING OVERHEAD KEEPS
THE THREAT OF IT NOSING BACK ASHORE DURING THE OVERNIGHT HOURS
THERE. THE LOW-LVL WIND FLOW DOES TREND MORE SOUTHERLY WITH
TIME...AND THIS MAY SHOVE THE LION`S SHARE OF WHAT IS LEFT IN THE
ADJACENT WATERS NORTHWARD TO COOK INLET AND NORTHERN GULF AREAS.
THUS REFORMATION IS UNLIKELY TO BE AS LONG LASTING TOMORROW AS IT
WAS TODAY SHOULD IT REFORM. ASIDE FROM A GLANCING SHOWER FROM THE
SYSTEM THAT TRACKS THROUGH THE SOUTHERN GULF THU NIGHT...THE
ISLAND LOOKS TO REMAIN LARGELY PRECIPITATION FREE UNTIL THE
WEEKEND.

FORECAST CHALLENGES THROUGH THU SURROUND THE POTENTIAL FOR RE-
DEVELOPMENT AND EXPANSION OF THE MARINE LAYER THROUGH UPPER COOK
INLET. THE BOUNDARY LAYER REMAINS RATHER MOIST AND SATELLITE
IMAGERY WOULD SUGGEST THAT THE BURNOFF/RETREAT OF THE LAYER FROM
COASTAL AREAS HAS BEEN STUBBORNLY SLOW TO NIL. THE LONGER IT WEARS
ON THROUGH THE DAY THE HIGHER THE LIKELIHOOD IT RETURNS IN
EARNEST OVERNIGHT EVEN THOUGH WIND FLOW IS LIGHT. THE UPPER-LVL
RIDGING OVER SW AK MIGRATES THROUGH THE REGION TONIGHT AS WELL AND
THIS ADDED SUBSIDENCE COULD ASSIST IN THE SPREADING/RE-
DEVELOPMENT. AREAS MOST PRONE ARE THE NW KENAI PENINSULA UP
THROUGH THE ANCHORAGE BOWL/KNIK ARM. FOR AREAS WHICH DO NOT SEE
STABLE AIR FROM THE MARINE LAYER...THERE EXISTS POTENTIAL FOR
DIURNAL SHOWERS THIS EVENING...WITH A FEW PASSING THUNDERSTORMS
ALONG THE MOUNTAINS OF THE SUSITNA VALLEY. ONCE THE UPPER-RIDGE
AXIS MOVES EAST OF SOUTHCENTRAL AK DURING THE DAY THU...UPSTREAM
SHORTWAVE ENERGY TRAVERSING THROUGH WILL BE FAIR GAME TO SUPPORT
PASSING SHOWERS OR SPRINKLES...EVEN DURING THE EVENING HOURS. THE
FOCUS HOWEVER SHOULD BE THE HIGHER TERRAIN. ORGANIZED AREAS OF
PRECIPITATION ARE NOT EXPECTED UNTIL POSSIBLY LATER THIS WEEKEND
AND AT LEAST SOME PARTIAL SUNSHINE LOOKS REASONABLE FOR THE
COMING DAYS OVER THE SOUTHERN MAINLAND.

SOUTHWEST ALASKA... UPPER-RIDGING IS SUPPRESSING MUCH OF THE
CONVECTION OVER SW AK THIS EVENING. WITH IT`S PASSAGE
TOMORROW...SHORTWAVE LIFT MAY HELP PROMOTE MORE SHOWERS ON THU.
THE ATMOSPHERE WILL BECOME MARGINALLY UNSTABLE AND BECAUSE THE
ENERGY MOVES THROUGH MORE DURING THE EVENING HOURS THU...ACTIVITY
WOULD HOLD OFF UNTIL THEN. SHOULD A FEW THUNDERSTORMS FORM...THEY
ARE MORE PRONE OVER THE ALEUTIAN/ALASKA RANGES OF BRISTOL BAY.
LIKE SOUTHCENTRAL...FOLLOW-UP SUBTLE DISTURBANCES ON THE UPSTREAM
SIDE OF THE RIDGE KEEP THE THREAT OF SOME SHOWERS AROUND TO CLOSE
OUT THE WEEK.

BERING SEA/ALEUTIANS/AKPEN...
FRONTAL LIFT IS WANING AS THE SHEMYA LOW FILLS...SO PRECIPIATON
OVER THE CENTRAL TO WESTERN CHAIN THROUGH THU SHOULD BE ON THE
LIGHT SIDE. THE APPROACH OF THE N PACIFIC WAVES/ENERGY SHOULD
MANIFEST THEMSELVES INTO AN EXPANDING SHIELD OF RAIN BY FRI TO
ENCOMPASS THE ENTIRE CHAIN AND PERHAPS UP TO THE PRIBILOF ISLANDS
AND AKPEN. CONSIDERABLE FORECAST UNCERTAINTY WITH REGARDS TO
WINDS ACROSS THE MARINE AREAS...PENDING SURFACE LOW(S) TRACK/STRENGTH.

&&

.LONG TERM FORECAST...
GUIDANCE CONTINUES TO STRUGGLE WITH THE BERING SEA TROUGH
TRANSLATING EAST TOWARD THE WEEKEND. THE ONLY CONTINUITY BOTH
TEMPORALLY AND RUN TO RUN/MODEL TO MODEL IS THAT THE TROUGH AND
ASSOCIATED FRONT WILL PUSH ONTO THE MAINLAND LATER THIS WEEKEND
INTO EARLY NEXT WEEK. BEYOND THAT TIMEFRAME CONTINUITY BREAKS DOWN
BUT IT DOES NOT APPEAR THAT THE PATTERN FAVORS LARGE STORM
DEVELOPMENT AFTER THE CURRENT SYSTEM EXITS. THE FRONT WILL BRING
RAIN TO MOST AREAS OF THE MAINLAND ON SUNDAY WHILE THE UPPER
TROUGH PASSAGE WILL KEEP RAIN IN THE FORECAST INTO TUESDAY. FOR
THE LATTER HALF OF NEXT WEEK EXPECT SEASONABLE TEMPERATURES AND
DRIER CONDITIONS.


&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

JAM/MTL




000
FXAK68 PAFC 202147
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
147 PM AKDT WED AUG 20 2014

.ANALYSIS AND UPPER LEVELS...
AN UPPER-LVL LOW IS CENTERED NEAR SHEMYA AND IS NEARLY STATIONARY.
AN ASSOCIATED OCCLUDED FRONT IS STALLING AND WEAKENING ACROSS THE
CENTRAL ALEUTIAN CHAIN THOUGH SOME LIGHT RAINS STILL FALL OUT THAT
WAY. ALSO OF NOTE IS A WAVE OF LOW PRESSURE NEAR 42N 155E DIPPING
SE AROUND THE AFOREMENTIONED UPPER-LVL LOW. UPPER-LVL RIDGING
SUPPORTS SURFACE HIGH PRESSURE IN THE FAR EASTERN BERING SEA WHICH
NOSES INTO THE SW MAINLAND. DOWNSTREAM OF THAT RIDGE...A SHORTWAVE
TROUGH IS LIFTING NORTHEAST THROUGH THE SUSITNA VALLEY AND NW
REACHES OF THE COPPER RIVER BASIN WITH A FEW PASSING SHOWERS.
MARINE FOG/STRATUS LOOMS OVER COOK INLET AND BRUSHES KODIAK ISLAND
IN WEAK LOW LVL FLOW.

&&

.MODEL DISCUSSION...
MODELS ARE STRUGGLING WITH SOME OF THE MAIN FEATURES AND RUN TO
RUN CONSISTENCY HAS BEEN VERY POOR OF LATE. THE UPPER RIDGE IN THE
EASTERN BERING IS DEPICTED MOVING EASTWARD TOWARDS THE ALCAN
BORDER THU AFTERNOON AND DAMPENING AS BOTH SHORTWAVE AND JET
STREAM ENERGY WORK UP AGAINST IT`S WESTERN FLANK. MODELS SHOW A
1015 MB PACIFIC LOW CENTERED AROUND 320 NM S OF SITKINAK THU
EVENING WILL MOVE TO AROUND 270 NM SE OF KODIAK CITY AT 1019 MB
FRI AFTERNOON BEFORE DISSIPATING AS IT TRACKS TO THE SOUTHERN AK
PANHANDLE ON SAT. THIS SYSTEM LOOKS TO BE A NON-PLAYER FOR THE
SOUTHERN MAINLAND AND KODIAK ISLAND. THE 1002 MB LOW NEAR SHEMYA
IS SHOWN DRIFTING TO AROUND 170 MI SE OF KISKA FRI AFTERNOON AT
1010 MB. THE SURFACE WAVE NEAR 42N 155E WILL DROP TO AROUND 1000
MI SOUTH OF ADAK THU EVENING...THEN PIVOT NORTHEAST TO AROUND 350
MI S OF UNALASKA EARLY SAT. BUT THERE ARE CONSIDERABLE DIFFERENCES
WITH HOW THE RESIDUAL SHEMYA LOW WILL INTERACT WITH THIS
APPROACHING SYSTEM...AS WELL AS THE SYSTEM`S ORIENTATION AS
STRONGER JET STREAM ENERGY INTERACTS WITH IT ALONG IT`S
SOUTHEASTERN FLANK. NO OPERATIONAL MODEL LIKELY HAS A GOOD HANDLE
ON THINGS...SO HAVE TRIED TO RETAIN THE SPIRIT OF THE INHERITED
FORECAST/GRIDS WHICH LEANED ON THE 20/00Z ECMWF. DESPITE MODEL
PROBLEMS WITH MANY DETAILS...A GENERAL POSITION OF THE PARENT
UPPER-LOW LOOKS TO BE IN THE VICINITY OF NIKOLSKI SAT AFTERNOON.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

ACROSS KODIAK ISLAND...THE MARINE LAYER HAS HUGGED THE COAST MOST
OF THE DAY. LIGHT WIND FLOW AND SOME RIDGING MOVING OVERHEAD KEEPS
THE THREAT OF IT NOSING BACK ASHORE DURING THE OVERNIGHT HOURS
THERE. THE LOW-LVL WIND FLOW DOES TREND MORE SOUTHERLY WITH
TIME...AND THIS MAY SHOVE THE LION`S SHARE OF WHAT IS LEFT IN THE
ADJACENT WATERS NORTHWARD TO COOK INLET AND NORTHERN GULF AREAS.
THUS REFORMATION IS UNLIKELY TO BE AS LONG LASTING TOMORROW AS IT
WAS TODAY SHOULD IT REFORM. ASIDE FROM A GLANCING SHOWER FROM THE
SYSTEM THAT TRACKS THROUGH THE SOUTHERN GULF THU NIGHT...THE
ISLAND LOOKS TO REMAIN LARGELY PRECIPITATION FREE UNTIL THE
WEEKEND.

FORECAST CHALLENGES THROUGH THU SURROUND THE POTENTIAL FOR RE-
DEVELOPMENT AND EXPANSION OF THE MARINE LAYER THROUGH UPPER COOK
INLET. THE BOUNDARY LAYER REMAINS RATHER MOIST AND SATELLITE
IMAGERY WOULD SUGGEST THAT THE BURNOFF/RETREAT OF THE LAYER FROM
COASTAL AREAS HAS BEEN STUBBORNLY SLOW TO NIL. THE LONGER IT WEARS
ON THROUGH THE DAY THE HIGHER THE LIKELIHOOD IT RETURNS IN
EARNEST OVERNIGHT EVEN THOUGH WIND FLOW IS LIGHT. THE UPPER-LVL
RIDGING OVER SW AK MIGRATES THROUGH THE REGION TONIGHT AS WELL AND
THIS ADDED SUBSIDENCE COULD ASSIST IN THE SPREADING/RE-
DEVELOPMENT. AREAS MOST PRONE ARE THE NW KENAI PENINSULA UP
THROUGH THE ANCHORAGE BOWL/KNIK ARM. FOR AREAS WHICH DO NOT SEE
STABLE AIR FROM THE MARINE LAYER...THERE EXISTS POTENTIAL FOR
DIURNAL SHOWERS THIS EVENING...WITH A FEW PASSING THUNDERSTORMS
ALONG THE MOUNTAINS OF THE SUSITNA VALLEY. ONCE THE UPPER-RIDGE
AXIS MOVES EAST OF SOUTHCENTRAL AK DURING THE DAY THU...UPSTREAM
SHORTWAVE ENERGY TRAVERSING THROUGH WILL BE FAIR GAME TO SUPPORT
PASSING SHOWERS OR SPRINKLES...EVEN DURING THE EVENING HOURS. THE
FOCUS HOWEVER SHOULD BE THE HIGHER TERRAIN. ORGANIZED AREAS OF
PRECIPITATION ARE NOT EXPECTED UNTIL POSSIBLY LATER THIS WEEKEND
AND AT LEAST SOME PARTIAL SUNSHINE LOOKS REASONABLE FOR THE
COMING DAYS OVER THE SOUTHERN MAINLAND.

SOUTHWEST ALASKA... UPPER-RIDGING IS SUPPRESSING MUCH OF THE
CONVECTION OVER SW AK THIS EVENING. WITH IT`S PASSAGE
TOMORROW...SHORTWAVE LIFT MAY HELP PROMOTE MORE SHOWERS ON THU.
THE ATMOSPHERE WILL BECOME MARGINALLY UNSTABLE AND BECAUSE THE
ENERGY MOVES THROUGH MORE DURING THE EVENING HOURS THU...ACTIVITY
WOULD HOLD OFF UNTIL THEN. SHOULD A FEW THUNDERSTORMS FORM...THEY
ARE MORE PRONE OVER THE ALEUTIAN/ALASKA RANGES OF BRISTOL BAY.
LIKE SOUTHCENTRAL...FOLLOW-UP SUBTLE DISTURBANCES ON THE UPSTREAM
SIDE OF THE RIDGE KEEP THE THREAT OF SOME SHOWERS AROUND TO CLOSE
OUT THE WEEK.

BERING SEA/ALEUTIANS/AKPEN...
FRONTAL LIFT IS WANING AS THE SHEMYA LOW FILLS...SO PRECIPIATON
OVER THE CENTRAL TO WESTERN CHAIN THROUGH THU SHOULD BE ON THE
LIGHT SIDE. THE APPROACH OF THE N PACIFIC WAVES/ENERGY SHOULD
MANIFEST THEMSELVES INTO AN EXPANDING SHIELD OF RAIN BY FRI TO
ENCOMPASS THE ENTIRE CHAIN AND PERHAPS UP TO THE PRIBILOF ISLANDS
AND AKPEN. CONSIDERABLE FORECAST UNCERTAINTY WITH REGARDS TO
WINDS ACROSS THE MARINE AREAS...PENDING SURFACE LOW(S) TRACK/STRENGTH.

&&

.LONG TERM FORECAST...
GUIDANCE CONTINUES TO STRUGGLE WITH THE BERING SEA TROUGH
TRANSLATING EAST TOWARD THE WEEKEND. THE ONLY CONTINUITY BOTH
TEMPORALLY AND RUN TO RUN/MODEL TO MODEL IS THAT THE TROUGH AND
ASSOCIATED FRONT WILL PUSH ONTO THE MAINLAND LATER THIS WEEKEND
INTO EARLY NEXT WEEK. BEYOND THAT TIMEFRAME CONTINUITY BREAKS DOWN
BUT IT DOES NOT APPEAR THAT THE PATTERN FAVORS LARGE STORM
DEVELOPMENT AFTER THE CURRENT SYSTEM EXITS. THE FRONT WILL BRING
RAIN TO MOST AREAS OF THE MAINLAND ON SUNDAY WHILE THE UPPER
TROUGH PASSAGE WILL KEEP RAIN IN THE FORECAST INTO TUESDAY. FOR
THE LATTER HALF OF NEXT WEEK EXPECT SEASONABLE TEMPERATURES AND
DRIER CONDITIONS.


&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

JAM/MTL





000
FXAK68 PAFC 201538 AAA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
738 AM AKDT WED AUG 20 2014

.UPDATE...

SOUTHCENTRAL AK...
LOW CLOUDS AND/OR FOG HAVE HAMPERED THE NW KENAI PENINSULA...NE
PRINCE WILLIAM SOUND AND KODIAK ISLAND THIS MORNING. LOW LVL FLOW
IS WEAK BUT WITH DAYTIME HEATING WOULD EXPECT SOME IMPROVEMENTS
TO THESE CONDITIONS. HIGH TEMPERATURES MAY RESIDUALLY BE A FEW
DEGREES COOLER THE LONGER THE MARINE LAYERS HANG AROUND.

UPDATE...JAM


&&

.PREV DISCUSSION... /ISSUED 526 AM AKDT WED AUG 20 2014/

ANALYSIS AND UPPER LEVELS...

THE LARGE SCALE UPPER AIR PATTERN IS DOMINATED BY AN ACTIVE
SUBTROPICAL JET STREAM EXTENDING FROM JAPAN TO THE WEST COAST OF
WASHINGTON STATE. A NEARLY STATIONARY UPPER LOW CENTERED OVER
THE WESTERN ALEUTIANS IS IMPINGING UPON THE SUBTROPICAL JET
STREAM...WITH A DEPRESSION IN THE UPPER LEVEL HEIGHT FIELD
EXTENDING SOUTH TO 35N. WEAKER AND SLOW MOVING MIGRATORY FEATURES
ARE DOMINATING THE UPPER HEIGHT FIELD ACROSS THE GULF OF ALASKA
AND THE MAINLAND...ALL OF WHICH ARE WELL DISPLACED FROM THE POLAR
AND SUBTROPICAL JET STREAMS. ONE WEAK UPPER LEVEL SHORTWAVE TROUGH
IS TRACKING THROUGH THE Y-K DELTA...WITH ANOTHER TRACKING THROUGH
THE SOUTHERN GULF OF ALASKA. THESE FEATURES WILL WEAKEN AND TRACK
EAST TODAY...WITH SHORTWAVE RIDGING BUILDING INTO SOUTHERN ALASKA
THROUGH THURSDAY MORNING BEFORE A FAST MOVING SHORTWAVE TROUGH
BEGINS TO IMPINGE UPON SOUTHWEST ALASKA. THE BIGGER TRANSITION IN
THE PATTERN DOES NOT ARRIVE UNTIL SUNDAY AS THE WESTERN BERING
TROUGH SHIFTS EAST...AND AN ASSOCIATED WEAK FRONT MOVES INTO
SOUTHERN ALASKA.

MODEL DISCUSSION...

THE NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT WITH THE LARGE
SCALE PATTERN THROUGH LATE WEEK BEFORE THEY BEGIN TO DIVERGE LATE
SATURDAY THROUGH MONDAY WITH THE EASTWARD MOVEMENT OF THE WESTERN
BERING SEA TROUGH...AND THE OVERALL INTERACTION WITH THE
SUBTROPICAL JET STREAM. ONE DISTINCT TREND IN THE GUIDANCE OVER
THE PAST TWO DAYS HAS BEEN SLOWER AND WEAKER WITH THE FRONT MOVING
INTO THE GULF OF ALASKA...AND THE STRENGTH OF THE ASSOCIATED LOW
IN THE BERING. ALL GUIDANCE HAS TRENDED TOWARD A WEAKER SYSTEM AS
A WHOLE...WITH SUBTROPICAL ENERGY SPLITTING AND SHEARING ALONG THE
FRONT AS IT TRACKS INTO THE GULF OF ALASKA. THE NAM AND ECMWF WERE
FAVORED THROUGH THE SHORT TERM...WITH A BLEND OF THE ECMWF AND GFS
THEREAFTER.

SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

A WEAK UPPER LOW WILL TRACK ACROSS THE NORTHERN TIER OF THE REGION THIS
MORNING AND EARLY AFTERNOON...WITH MID AND HIGH CLOUDS SPREADING
OVER THE AREA. SHOWERS WILL GENERALLY BE FOCUSED ALONG THE
MOUNTAINS...BUT A FEW SPRINKLES OR ISOLATED SHOWERS WILL BE
POSSIBLE ACROSS LOWER ELEVATIONS AREAS FROM COOK INLET NORTH TO
THE SUSITNA VALLEY. SHOWERS WILL BECOME FOCUSED OVER THE MOUNTAINS
IN THE AFTERNOON...ALTHOUGH INSTABILITY WILL BE LESS THAN PREVIOUS
DAYS...WITH NO THUNDERSTORMS ANTICIPATED. A GENERAL REPEAT IS
EXPECTED ON THURSDAY...WITH MORE DIURNAL MOUNTAIN SHOWERS AND
ANOTHER GENERALLY WARM DAY ACROSS MOST OF THE REGION. A WEAK
DISTURBANCE WILL TRACK WEST TO EAST ACROSS THE NORTHERN GULF
THURSDAY NIGHT INTO FRIDAY...SPREADING CLOUDS AND THE POSSIBILITY
OF SHOWERS ACROSS SOUTHCENTRAL ALASKA. WINDS WILL GENERALLY BE
LIGHT AND VARIABLE THROUGH FRIDAY WITH THE EXCEPTION OF LOCAL
DIURNALLY DRIVEN SEA BREEZES.

SOUTHWEST ALASKA...

GENERALLY QUIET WEATHER ACROSS THE REGION WILL CONTINUE AS HIGH
PRESSURE RIDGING ALOFT BUILDS IN TODAY. AFTERNOON AND EARLY
EVENING MOUNTAIN SHOWERS WILL DEVELOP WITH DAYTIME
HEATING...FAVORING THE ALASKA RANGE...BUT WEAK INSTABILITY WILL
KEEP THUNDERSTORM THREATS AT BAY. A SUBTLE UPPER DISTURBANCE WILL
TRACK IN THURSDAY WITH MORE SCATTERED SHOWER THREATS...FOCUSED
ALONG THE HIGHER MOUNTAINS. QUIESCENT WEATHER AND SPOTTY SHOWERS
WILL CONTINUE THROUGH SATURDAY...WITH A GENERAL WEAK OFFSHORE FLOW
PATTERN KEEPING LOW STRATUS AND FOG OUT OVER THE BERING.

BERING SEA/ALEUTIANS...

A STATIONARY LOW OVER THE WESTERN ALEUTIANS WILL REMAIN IN PLACE
THROUGH THURSDAY BEFORE GRADUALLY SHIFTING EAST INTO THE WEEKEND.
SHOWERS AND RAIN WILL SPREAD INTO THE CENTRAL AND EASTERN
ALEUTIANS BY SATURDAY. WEAK HIGH PRESSURE WILL BUILD IN THE WAKE
OF THE LOW AS IT MOVES EAST SATURDAY AND SUNDAY.

LONG TERM FORECAST (SUNDAY AUG 24 - WED AUG 27)...

BEGINNING THE EXTENDED FORECAST ON SUNDAY...A LARGE AND BROAD LOW
OVER THE EASTERN BERING WILL BE TRACKING INTO SOUTHWEST
ALASKA...WITH A DIFFUSE WARM FRONT MOVING INTO THE GULF. THIS WILL
SPREAD INCREASING CLOUDS AND RAIN INTO SOUTHWEST ALASKA
SUNDAY...AND SOUTHCENTRAL ALASKA LATE SUNDAY INTO MONDAY.
SHOWERS...CLOUDS...AND SLIGHTLY COOLER CONDITIONS WILL PERSIST
INTO TUESDAY WITH A MORE ACTIVE PATTERN PERSISTING INTO MIDWEEK.

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

$$

AHSENMACHER AUG 14





000
FXAK68 PAFC 201538 AAA
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
738 AM AKDT WED AUG 20 2014

.UPDATE...

SOUTHCENTRAL AK...
LOW CLOUDS AND/OR FOG HAVE HAMPERED THE NW KENAI PENINSULA...NE
PRINCE WILLIAM SOUND AND KODIAK ISLAND THIS MORNING. LOW LVL FLOW
IS WEAK BUT WITH DAYTIME HEATING WOULD EXPECT SOME IMPROVEMENTS
TO THESE CONDITIONS. HIGH TEMPERATURES MAY RESIDUALLY BE A FEW
DEGREES COOLER THE LONGER THE MARINE LAYERS HANG AROUND.

UPDATE...JAM


&&

.PREV DISCUSSION... /ISSUED 526 AM AKDT WED AUG 20 2014/

ANALYSIS AND UPPER LEVELS...

THE LARGE SCALE UPPER AIR PATTERN IS DOMINATED BY AN ACTIVE
SUBTROPICAL JET STREAM EXTENDING FROM JAPAN TO THE WEST COAST OF
WASHINGTON STATE. A NEARLY STATIONARY UPPER LOW CENTERED OVER
THE WESTERN ALEUTIANS IS IMPINGING UPON THE SUBTROPICAL JET
STREAM...WITH A DEPRESSION IN THE UPPER LEVEL HEIGHT FIELD
EXTENDING SOUTH TO 35N. WEAKER AND SLOW MOVING MIGRATORY FEATURES
ARE DOMINATING THE UPPER HEIGHT FIELD ACROSS THE GULF OF ALASKA
AND THE MAINLAND...ALL OF WHICH ARE WELL DISPLACED FROM THE POLAR
AND SUBTROPICAL JET STREAMS. ONE WEAK UPPER LEVEL SHORTWAVE TROUGH
IS TRACKING THROUGH THE Y-K DELTA...WITH ANOTHER TRACKING THROUGH
THE SOUTHERN GULF OF ALASKA. THESE FEATURES WILL WEAKEN AND TRACK
EAST TODAY...WITH SHORTWAVE RIDGING BUILDING INTO SOUTHERN ALASKA
THROUGH THURSDAY MORNING BEFORE A FAST MOVING SHORTWAVE TROUGH
BEGINS TO IMPINGE UPON SOUTHWEST ALASKA. THE BIGGER TRANSITION IN
THE PATTERN DOES NOT ARRIVE UNTIL SUNDAY AS THE WESTERN BERING
TROUGH SHIFTS EAST...AND AN ASSOCIATED WEAK FRONT MOVES INTO
SOUTHERN ALASKA.

MODEL DISCUSSION...

THE NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT WITH THE LARGE
SCALE PATTERN THROUGH LATE WEEK BEFORE THEY BEGIN TO DIVERGE LATE
SATURDAY THROUGH MONDAY WITH THE EASTWARD MOVEMENT OF THE WESTERN
BERING SEA TROUGH...AND THE OVERALL INTERACTION WITH THE
SUBTROPICAL JET STREAM. ONE DISTINCT TREND IN THE GUIDANCE OVER
THE PAST TWO DAYS HAS BEEN SLOWER AND WEAKER WITH THE FRONT MOVING
INTO THE GULF OF ALASKA...AND THE STRENGTH OF THE ASSOCIATED LOW
IN THE BERING. ALL GUIDANCE HAS TRENDED TOWARD A WEAKER SYSTEM AS
A WHOLE...WITH SUBTROPICAL ENERGY SPLITTING AND SHEARING ALONG THE
FRONT AS IT TRACKS INTO THE GULF OF ALASKA. THE NAM AND ECMWF WERE
FAVORED THROUGH THE SHORT TERM...WITH A BLEND OF THE ECMWF AND GFS
THEREAFTER.

SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

A WEAK UPPER LOW WILL TRACK ACROSS THE NORTHERN TIER OF THE REGION THIS
MORNING AND EARLY AFTERNOON...WITH MID AND HIGH CLOUDS SPREADING
OVER THE AREA. SHOWERS WILL GENERALLY BE FOCUSED ALONG THE
MOUNTAINS...BUT A FEW SPRINKLES OR ISOLATED SHOWERS WILL BE
POSSIBLE ACROSS LOWER ELEVATIONS AREAS FROM COOK INLET NORTH TO
THE SUSITNA VALLEY. SHOWERS WILL BECOME FOCUSED OVER THE MOUNTAINS
IN THE AFTERNOON...ALTHOUGH INSTABILITY WILL BE LESS THAN PREVIOUS
DAYS...WITH NO THUNDERSTORMS ANTICIPATED. A GENERAL REPEAT IS
EXPECTED ON THURSDAY...WITH MORE DIURNAL MOUNTAIN SHOWERS AND
ANOTHER GENERALLY WARM DAY ACROSS MOST OF THE REGION. A WEAK
DISTURBANCE WILL TRACK WEST TO EAST ACROSS THE NORTHERN GULF
THURSDAY NIGHT INTO FRIDAY...SPREADING CLOUDS AND THE POSSIBILITY
OF SHOWERS ACROSS SOUTHCENTRAL ALASKA. WINDS WILL GENERALLY BE
LIGHT AND VARIABLE THROUGH FRIDAY WITH THE EXCEPTION OF LOCAL
DIURNALLY DRIVEN SEA BREEZES.

SOUTHWEST ALASKA...

GENERALLY QUIET WEATHER ACROSS THE REGION WILL CONTINUE AS HIGH
PRESSURE RIDGING ALOFT BUILDS IN TODAY. AFTERNOON AND EARLY
EVENING MOUNTAIN SHOWERS WILL DEVELOP WITH DAYTIME
HEATING...FAVORING THE ALASKA RANGE...BUT WEAK INSTABILITY WILL
KEEP THUNDERSTORM THREATS AT BAY. A SUBTLE UPPER DISTURBANCE WILL
TRACK IN THURSDAY WITH MORE SCATTERED SHOWER THREATS...FOCUSED
ALONG THE HIGHER MOUNTAINS. QUIESCENT WEATHER AND SPOTTY SHOWERS
WILL CONTINUE THROUGH SATURDAY...WITH A GENERAL WEAK OFFSHORE FLOW
PATTERN KEEPING LOW STRATUS AND FOG OUT OVER THE BERING.

BERING SEA/ALEUTIANS...

A STATIONARY LOW OVER THE WESTERN ALEUTIANS WILL REMAIN IN PLACE
THROUGH THURSDAY BEFORE GRADUALLY SHIFTING EAST INTO THE WEEKEND.
SHOWERS AND RAIN WILL SPREAD INTO THE CENTRAL AND EASTERN
ALEUTIANS BY SATURDAY. WEAK HIGH PRESSURE WILL BUILD IN THE WAKE
OF THE LOW AS IT MOVES EAST SATURDAY AND SUNDAY.

LONG TERM FORECAST (SUNDAY AUG 24 - WED AUG 27)...

BEGINNING THE EXTENDED FORECAST ON SUNDAY...A LARGE AND BROAD LOW
OVER THE EASTERN BERING WILL BE TRACKING INTO SOUTHWEST
ALASKA...WITH A DIFFUSE WARM FRONT MOVING INTO THE GULF. THIS WILL
SPREAD INCREASING CLOUDS AND RAIN INTO SOUTHWEST ALASKA
SUNDAY...AND SOUTHCENTRAL ALASKA LATE SUNDAY INTO MONDAY.
SHOWERS...CLOUDS...AND SLIGHTLY COOLER CONDITIONS WILL PERSIST
INTO TUESDAY WITH A MORE ACTIVE PATTERN PERSISTING INTO MIDWEEK.

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

$$

AHSENMACHER AUG 14




000
FXAK68 PAFC 201326
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
526 AM AKDT WED AUG 20 2014

.ANALYSIS AND UPPER LEVELS...

THE LARGE SCALE UPPER AIR PATTERN IS DOMINATED BY AN ACTIVE
SUBTROPICAL JET STREAM EXTENDING FROM JAPAN TO THE WEST COAST OF
WASHINGTON STATE. A NEARLY STATIONARY UPPER LOW CENTERED OVER
THE WESTERN ALEUTIANS IS IMPINGING UPON THE SUBTROPICAL JET
STREAM...WITH A DEPRESSION IN THE UPPER LEVEL HEIGHT FIELD
EXTENDING SOUTH TO 35N. WEAKER AND SLOW MOVING MIGRATORY FEATURES
ARE DOMINATING THE UPPER HEIGHT FIELD ACROSS THE GULF OF ALASKA
AND THE MAINLAND...ALL OF WHICH ARE WELL DISPLACED FROM THE POLAR
AND SUBTROPICAL JET STREAMS. ONE WEAK UPPER LEVEL SHORTWAVE TROUGH
IS TRACKING THROUGH THE Y-K DELTA...WITH ANOTHER TRACKING THROUGH
THE SOUTHERN GULF OF ALASKA. THESE FEATURES WILL WEAKEN AND TRACK
EAST TODAY...WITH SHORTWAVE RIDGING BUILDING INTO SOUTHERN ALASKA
THROUGH THURSDAY MORNING BEFORE A FAST MOVING SHORTWAVE TROUGH
BEGINS TO IMPINGE UPON SOUTHWEST ALASKA. THE BIGGER TRANSITION IN
THE PATTERN DOES NOT ARRIVE UNTIL SUNDAY AS THE WESTERN BERING
TROUGH SHIFTS EAST...AND AN ASSOCIATED WEAK FRONT MOVES INTO
SOUTHERN ALASKA.

&&

.MODEL DISCUSSION...

THE NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT WITH THE LARGE
SCALE PATTERN THROUGH LATE WEEK BEFORE THEY BEGIN TO DIVERGE LATE
SATURDAY THROUGH MONDAY WITH THE EASTWARD MOVEMENT OF THE WESTERN
BERING SEA TROUGH...AND THE OVERALL INTERACTION WITH THE
SUBTROPICAL JET STREAM. ONE DISTINCT TREND IN THE GUIDANCE OVER
THE PAST TWO DAYS HAS BEEN SLOWER AND WEAKER WITH THE FRONT MOVING
INTO THE GULF OF ALASKA...AND THE STRENGTH OF THE ASSOCIATED LOW
IN THE BERING. ALL GUIDANCE HAS TRENDED TOWARD A WEAKER SYSTEM AS
A WHOLE...WITH SUBTROPICAL ENERGY SPLITTING AND SHEARING ALONG THE
FRONT AS IT TRACKS INTO THE GULF OF ALASKA. THE NAM AND ECMWF WERE
FAVORED THROUGH THE SHORT TERM...WITH A BLEND OF THE ECMWF AND GFS
THEREAFTER.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

A WEAK UPPER LOW WILL TRACK ACROSS THE NORTHERN TIER OF THE REGION THIS
MORNING AND EARLY AFTERNOON...WITH MID AND HIGH CLOUDS SPREADING
OVER THE AREA. SHOWERS WILL GENERALLY BE FOCUSED ALONG THE
MOUNTAINS...BUT A FEW SPRINKLES OR ISOLATED SHOWERS WILL BE
POSSIBLE ACROSS LOWER ELEVATIONS AREAS FROM COOK INLET NORTH TO
THE SUSITNA VALLEY. SHOWERS WILL BECOME FOCUSED OVER THE MOUNTAINS
IN THE AFTERNOON...ALTHOUGH INSTABILITY WILL BE LESS THAN PREVIOUS
DAYS...WITH NO THUNDERSTORMS ANTICIPATED. A GENERAL REPEAT IS
EXPECTED ON THURSDAY...WITH MORE DIURNAL MOUNTAIN SHOWERS AND
ANOTHER GENERALLY WARM DAY ACROSS MOST OF THE REGION. A WEAK
DISTURBANCE WILL TRACK WEST TO EAST ACROSS THE NORTHERN GULF
THURSDAY NIGHT INTO FRIDAY...SPREADING CLOUDS AND THE POSSIBILITY
OF SHOWERS ACROSS SOUTHCENTRAL ALASKA. WINDS WILL GENERALLY BE
LIGHT AND VARIABLE THROUGH FRIDAY WITH THE EXCEPTION OF LOCAL
DIURNALLY DRIVEN SEA BREEZES.

SOUTHWEST ALASKA...

GENERALLY QUIET WEATHER ACROSS THE REGION WILL CONTINUE AS HIGH
PRESSURE RIDGING ALOFT BUILDS IN TODAY. AFTERNOON AND EARLY
EVENING MOUNTAIN SHOWERS WILL DEVELOP WITH DAYTIME
HEATING...FAVORING THE ALASKA RANGE...BUT WEAK INSTABILITY WILL
KEEP THUNDERSTORM THREATS AT BAY. A SUBTLE UPPER DISTURBANCE WILL
TRACK IN THURSDAY WITH MORE SCATTERED SHOWER THREATS...FOCUSED
ALONG THE HIGHER MOUNTAINS. QUIESCENT WEATHER AND SPOTTY SHOWERS
WILL CONTINUE THROUGH SATURDAY...WITH A GENERAL WEAK OFFSHORE FLOW
PATTERN KEEPING LOW STRATUS AND FOG OUT OVER THE BERING.

BERING SEA/ALEUTIANS...

A STATIONARY LOW OVER THE WESTERN ALEUTIANS WILL REMAIN IN PLACE
THROUGH THURSDAY BEFORE GRADUALLY SHIFTING EAST INTO THE WEEKEND.
SHOWERS AND RAIN WILL SPREAD INTO THE CENTRAL AND EASTERN
ALEUTIANS BY SATURDAY. WEAK HIGH PRESSURE WILL BUILD IN THE WAKE
OF THE LOW AS IT MOVES EAST SATURDAY AND SUNDAY.

&&

.LONG TERM FORECAST (SUNDAY AUG 24 - WED AUG 27)...

BEGINNING THE EXTENDED FORECAST ON SUNDAY...A LARGE AND BROAD LOW
OVER THE EASTERN BERING WILL BE TRACKING INTO SOUTHWEST
ALASKA...WITH A DIFFUSE WARM FRONT MOVING INTO THE GULF. THIS WILL
SPREAD INCREASING CLOUDS AND RAIN INTO SOUTHWEST ALASKA
SUNDAY...AND SOUTHCENTRAL ALASKA LATE SUNDAY INTO MONDAY.
SHOWERS...CLOUDS...AND SLIGHTLY COOLER CONDITIONS WILL PERSIST
INTO TUESDAY WITH A MORE ACTIVE PATTERN PERSISTING INTO MIDWEEK.

&&

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

&&

$$

AHSENMACHER AUG 14





000
FXAK68 PAFC 201326
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
526 AM AKDT WED AUG 20 2014

.ANALYSIS AND UPPER LEVELS...

THE LARGE SCALE UPPER AIR PATTERN IS DOMINATED BY AN ACTIVE
SUBTROPICAL JET STREAM EXTENDING FROM JAPAN TO THE WEST COAST OF
WASHINGTON STATE. A NEARLY STATIONARY UPPER LOW CENTERED OVER
THE WESTERN ALEUTIANS IS IMPINGING UPON THE SUBTROPICAL JET
STREAM...WITH A DEPRESSION IN THE UPPER LEVEL HEIGHT FIELD
EXTENDING SOUTH TO 35N. WEAKER AND SLOW MOVING MIGRATORY FEATURES
ARE DOMINATING THE UPPER HEIGHT FIELD ACROSS THE GULF OF ALASKA
AND THE MAINLAND...ALL OF WHICH ARE WELL DISPLACED FROM THE POLAR
AND SUBTROPICAL JET STREAMS. ONE WEAK UPPER LEVEL SHORTWAVE TROUGH
IS TRACKING THROUGH THE Y-K DELTA...WITH ANOTHER TRACKING THROUGH
THE SOUTHERN GULF OF ALASKA. THESE FEATURES WILL WEAKEN AND TRACK
EAST TODAY...WITH SHORTWAVE RIDGING BUILDING INTO SOUTHERN ALASKA
THROUGH THURSDAY MORNING BEFORE A FAST MOVING SHORTWAVE TROUGH
BEGINS TO IMPINGE UPON SOUTHWEST ALASKA. THE BIGGER TRANSITION IN
THE PATTERN DOES NOT ARRIVE UNTIL SUNDAY AS THE WESTERN BERING
TROUGH SHIFTS EAST...AND AN ASSOCIATED WEAK FRONT MOVES INTO
SOUTHERN ALASKA.

&&

.MODEL DISCUSSION...

THE NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT WITH THE LARGE
SCALE PATTERN THROUGH LATE WEEK BEFORE THEY BEGIN TO DIVERGE LATE
SATURDAY THROUGH MONDAY WITH THE EASTWARD MOVEMENT OF THE WESTERN
BERING SEA TROUGH...AND THE OVERALL INTERACTION WITH THE
SUBTROPICAL JET STREAM. ONE DISTINCT TREND IN THE GUIDANCE OVER
THE PAST TWO DAYS HAS BEEN SLOWER AND WEAKER WITH THE FRONT MOVING
INTO THE GULF OF ALASKA...AND THE STRENGTH OF THE ASSOCIATED LOW
IN THE BERING. ALL GUIDANCE HAS TRENDED TOWARD A WEAKER SYSTEM AS
A WHOLE...WITH SUBTROPICAL ENERGY SPLITTING AND SHEARING ALONG THE
FRONT AS IT TRACKS INTO THE GULF OF ALASKA. THE NAM AND ECMWF WERE
FAVORED THROUGH THE SHORT TERM...WITH A BLEND OF THE ECMWF AND GFS
THEREAFTER.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...

A WEAK UPPER LOW WILL TRACK ACROSS THE NORTHERN TIER OF THE REGION THIS
MORNING AND EARLY AFTERNOON...WITH MID AND HIGH CLOUDS SPREADING
OVER THE AREA. SHOWERS WILL GENERALLY BE FOCUSED ALONG THE
MOUNTAINS...BUT A FEW SPRINKLES OR ISOLATED SHOWERS WILL BE
POSSIBLE ACROSS LOWER ELEVATIONS AREAS FROM COOK INLET NORTH TO
THE SUSITNA VALLEY. SHOWERS WILL BECOME FOCUSED OVER THE MOUNTAINS
IN THE AFTERNOON...ALTHOUGH INSTABILITY WILL BE LESS THAN PREVIOUS
DAYS...WITH NO THUNDERSTORMS ANTICIPATED. A GENERAL REPEAT IS
EXPECTED ON THURSDAY...WITH MORE DIURNAL MOUNTAIN SHOWERS AND
ANOTHER GENERALLY WARM DAY ACROSS MOST OF THE REGION. A WEAK
DISTURBANCE WILL TRACK WEST TO EAST ACROSS THE NORTHERN GULF
THURSDAY NIGHT INTO FRIDAY...SPREADING CLOUDS AND THE POSSIBILITY
OF SHOWERS ACROSS SOUTHCENTRAL ALASKA. WINDS WILL GENERALLY BE
LIGHT AND VARIABLE THROUGH FRIDAY WITH THE EXCEPTION OF LOCAL
DIURNALLY DRIVEN SEA BREEZES.

SOUTHWEST ALASKA...

GENERALLY QUIET WEATHER ACROSS THE REGION WILL CONTINUE AS HIGH
PRESSURE RIDGING ALOFT BUILDS IN TODAY. AFTERNOON AND EARLY
EVENING MOUNTAIN SHOWERS WILL DEVELOP WITH DAYTIME
HEATING...FAVORING THE ALASKA RANGE...BUT WEAK INSTABILITY WILL
KEEP THUNDERSTORM THREATS AT BAY. A SUBTLE UPPER DISTURBANCE WILL
TRACK IN THURSDAY WITH MORE SCATTERED SHOWER THREATS...FOCUSED
ALONG THE HIGHER MOUNTAINS. QUIESCENT WEATHER AND SPOTTY SHOWERS
WILL CONTINUE THROUGH SATURDAY...WITH A GENERAL WEAK OFFSHORE FLOW
PATTERN KEEPING LOW STRATUS AND FOG OUT OVER THE BERING.

BERING SEA/ALEUTIANS...

A STATIONARY LOW OVER THE WESTERN ALEUTIANS WILL REMAIN IN PLACE
THROUGH THURSDAY BEFORE GRADUALLY SHIFTING EAST INTO THE WEEKEND.
SHOWERS AND RAIN WILL SPREAD INTO THE CENTRAL AND EASTERN
ALEUTIANS BY SATURDAY. WEAK HIGH PRESSURE WILL BUILD IN THE WAKE
OF THE LOW AS IT MOVES EAST SATURDAY AND SUNDAY.

&&

.LONG TERM FORECAST (SUNDAY AUG 24 - WED AUG 27)...

BEGINNING THE EXTENDED FORECAST ON SUNDAY...A LARGE AND BROAD LOW
OVER THE EASTERN BERING WILL BE TRACKING INTO SOUTHWEST
ALASKA...WITH A DIFFUSE WARM FRONT MOVING INTO THE GULF. THIS WILL
SPREAD INCREASING CLOUDS AND RAIN INTO SOUTHWEST ALASKA
SUNDAY...AND SOUTHCENTRAL ALASKA LATE SUNDAY INTO MONDAY.
SHOWERS...CLOUDS...AND SLIGHTLY COOLER CONDITIONS WILL PERSIST
INTO TUESDAY WITH A MORE ACTIVE PATTERN PERSISTING INTO MIDWEEK.

&&

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

&&

$$

AHSENMACHER AUG 14




000
FXAK68 PAFC 192156
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
156 PM AKDT TUE AUG 19 2014

.ANALYSIS AND UPPER LEVELS...
A BAGGY LONG-WAVE TROUGH SITS OVER THE WESTERN BERING/ALEUTIANS
WHILE THE JET STREAM DIVES SOUTH FROM EASTERN ASIA AROUND THE BASE
OF THE TROUGH AND POLEWARD OF AN UPPER LEVEL RIDGE OVER THE
EASTERN PACIFIC. ACTIVE WEATHER IN THE SHORT TERM WILL CENTER
AROUND THIS LONG-WAVE TRANSLATING EASTWARD AND ANY EMBEDDED
DISTURBANCES WITHIN THE JET THAT PROPAGATE TOWARD THE SOUTHERN
MAINLAND. A VIGOROUS LOW AMPLITUDE SHORTWAVE TROUGH IS MOVING INTO
THE GULF BUT LOOKS TO BE LOSING ANY JET SUPPORT...SHOULD ONLY
INCREASE CLOUD COVERAGE. SKIES HAVE CLEARED THIS MORNING OVER
COOK INLET UNDER SHORTWAVE RIDGING ALOFT WHICH SHOULD MAKE FOR A
NICE AFTERNOON AND EVENING. THERE ARE NO MAJOR SURFACE FEATURES
TO SPEAK OF WITH MOSTLY SLACK FLOW IN THE LOW LEVELS.

&&

.MODEL DISCUSSION...
GUIDANCE IS IN PRETTY GOOD SYNOPTIC AGREEMENT FOR THE NEXT COUPLE
DAYS BUT VARIABILITY IS INTRODUCED TOWARD THE WEEKEND CONCERNING
ANOTHER LOW AMPLITUDE SHORTWAVE TROUGH MOVING INTO THE GULF.
MODELS HAVE BEEN FLIP-FLOPPING ON STRENGTH AND POSITION OF THIS
FEATURE. MODEL RUNS FROM YESTERDAY HAD THE ENERGY SLIDING EASTWARD
INTO THE CENTRAL AND SOUTHERN GULF OF ALASKA AWAY FROM THE PARENT
TROUGH OVER THE BERING SEA. THIS MORNING GUIDANCE IS HINTING AT A
MORE PARTIALLY PHASED SOLUTION WITH THE LEADING WAVE STAYING
CONNECTED TO THE PARENT TROUGH...ENDING UP WITH A LEGIT FRONTAL
PUSH TOWARD THE NORTHERN GULF. THE MIDDLE GROUND SOLUTION
INCORPORATES THE 12Z ECMWF WHICH MODERATED FROM THE 00Z
SOLUTION...COMBINED WITH THE 06Z RUN OF THE GFS.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...THE MAIN THREAT FOR PRECIPITATION THIS
AFTERNOON AND EVENING WILL BE DIURNAL SHOWERS...MAINLY OVER HIGHER
TERRAIN. CLEARING FROM EARLY THIS MORNING SHOULD ALLOW FOR AMPLE
SURFACE HEATING THIS AFTERNOON AND EVENING. LINGERING COLD AIR
ALOFT SHOULD PROMOTE SHOWERS BEGINNING MID TO LATE
AFTERNOON...MAINLY ALONG THE MOUNTAINS. WEAK WIND FLOW THROUGH THE
COLUMN WILL KEEP THIS SHOWERY ACTIVITY ANCHORED TO THE HIGHER
TERRAIN. THE SAME PATTERN CONTINUES TOMORROW AND THURSDAY EXCEPT
A WEAK TROUGH WILL PASS THROUGH NEAR PEAK HEATING TOMORROW WHICH
MAY HELP ANY CONVECTIVE ACTIVITY ALONG. THE FLOW WILL REMAIN WEAK
BUT A LITTLE MORE ORGANIZED FROM THE SOUTHWEST SO ANY DIURNAL
SHOWERS SHOULD PROPAGATE NORTHEASTWARD. TEMPERATURES THE NEXT
COUPLE DAYS WILL REMAIN SEASONABLE TO SLIGHTLY ABOVE NORMAL FOR
EARLY FALL. SOME AMOUNT OF UNSETTLED WEATHER APPROACHES ON FRIDAY
BUT CONFIDENCE IS LOWER DUE TO ISSUES COVERED IN THE MODEL
DISCUSSION.

SOUTHWEST ALASKA...LIGHT SHOWERY PRECIPITATION WILL CONTINUE THIS
EVENING AND DECREASE IN COVERAGE TOMORROW AS RIDGING BUILDS IN AT
ALL LEVELS. AREAS ALONG THE ALASKA RANGE COULD STILL SEE RAIN
SHOWERS AS A WEAK DISTURBANCE PASSES OVERHEAD. FOG AND LOW STRATUS
CHANCES INCREASE ALONG THE KUSKOKWIM DELTA OVERNIGHT TONIGHT
BEFORE OFFSHORE DRIER FLOW MOVES IN ON THURSDAY.

BERING SEA/ALEUTIANS...A LOW PRESSURE SYSTEM WILL SLOWLY MAKE ITS
WAY EASTWARD FOR THE NEXT COUPLE DAYS WHILE WEAKENING...KEEPING
RAIN IN THE FORECAST FOR THE WESTERN AND CENTRAL ALEUTIANS. WINDS
WILL REMAIN LIGHT IN THE EASTERN BERING SEA WITH PATCHY FOG AND
LOW STRATUS.


&&

.LONG TERM FORECAST...
WHILE UNCERTAINTY IS ABUNDANT NEAR THE BEGINNING OF THE WEEKEND
FOR THE EXTENDED FORECAST THERE IS SOME CONTINUITY BETWEEN MODEL
GUIDANCE TO GRASP AT. THE VARIABILITY LATE WEEK IS FROM SMALL
SCALE FEATURES WHILE THE FOCUS CHANGES TO THE LARGE SCALE PATTERN
FOR ACTIVE WEATHER EARLY NEXT WEEK. THE LOW PRESSURE SYSTEM MOVING
EASTWARD ACROSS THE BERING SEA WILL DEEPEN AND MOVE NORTHEASTWARD
TOWARD THE MAINLAND. THERE ARE SOME TIMING DIFFERENCES BUT THE
MAINLAND SHOULD SEE A FRONTAL PASSAGE EARLY NEXT WEEK FOLLOWED BY
THE LOW PRESSURE SYSTEM ITSELF. EXPECT AN INCREASE OF CLOUDS AND
MOISTURE AS WELL AS TEMPERATURES DIPPING BACK TOWARD SEASONAL
NORMALS OR SLIGHTLY BELOW.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY 121.
MARINE...NONE.
FIRE WEATHER...NONE.
&&



$$

MTL

AUG 14




000
FXAK68 PAFC 192156
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
156 PM AKDT TUE AUG 19 2014

.ANALYSIS AND UPPER LEVELS...
A BAGGY LONG-WAVE TROUGH SITS OVER THE WESTERN BERING/ALEUTIANS
WHILE THE JET STREAM DIVES SOUTH FROM EASTERN ASIA AROUND THE BASE
OF THE TROUGH AND POLEWARD OF AN UPPER LEVEL RIDGE OVER THE
EASTERN PACIFIC. ACTIVE WEATHER IN THE SHORT TERM WILL CENTER
AROUND THIS LONG-WAVE TRANSLATING EASTWARD AND ANY EMBEDDED
DISTURBANCES WITHIN THE JET THAT PROPAGATE TOWARD THE SOUTHERN
MAINLAND. A VIGOROUS LOW AMPLITUDE SHORTWAVE TROUGH IS MOVING INTO
THE GULF BUT LOOKS TO BE LOSING ANY JET SUPPORT...SHOULD ONLY
INCREASE CLOUD COVERAGE. SKIES HAVE CLEARED THIS MORNING OVER
COOK INLET UNDER SHORTWAVE RIDGING ALOFT WHICH SHOULD MAKE FOR A
NICE AFTERNOON AND EVENING. THERE ARE NO MAJOR SURFACE FEATURES
TO SPEAK OF WITH MOSTLY SLACK FLOW IN THE LOW LEVELS.

&&

.MODEL DISCUSSION...
GUIDANCE IS IN PRETTY GOOD SYNOPTIC AGREEMENT FOR THE NEXT COUPLE
DAYS BUT VARIABILITY IS INTRODUCED TOWARD THE WEEKEND CONCERNING
ANOTHER LOW AMPLITUDE SHORTWAVE TROUGH MOVING INTO THE GULF.
MODELS HAVE BEEN FLIP-FLOPPING ON STRENGTH AND POSITION OF THIS
FEATURE. MODEL RUNS FROM YESTERDAY HAD THE ENERGY SLIDING EASTWARD
INTO THE CENTRAL AND SOUTHERN GULF OF ALASKA AWAY FROM THE PARENT
TROUGH OVER THE BERING SEA. THIS MORNING GUIDANCE IS HINTING AT A
MORE PARTIALLY PHASED SOLUTION WITH THE LEADING WAVE STAYING
CONNECTED TO THE PARENT TROUGH...ENDING UP WITH A LEGIT FRONTAL
PUSH TOWARD THE NORTHERN GULF. THE MIDDLE GROUND SOLUTION
INCORPORATES THE 12Z ECMWF WHICH MODERATED FROM THE 00Z
SOLUTION...COMBINED WITH THE 06Z RUN OF THE GFS.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...THE MAIN THREAT FOR PRECIPITATION THIS
AFTERNOON AND EVENING WILL BE DIURNAL SHOWERS...MAINLY OVER HIGHER
TERRAIN. CLEARING FROM EARLY THIS MORNING SHOULD ALLOW FOR AMPLE
SURFACE HEATING THIS AFTERNOON AND EVENING. LINGERING COLD AIR
ALOFT SHOULD PROMOTE SHOWERS BEGINNING MID TO LATE
AFTERNOON...MAINLY ALONG THE MOUNTAINS. WEAK WIND FLOW THROUGH THE
COLUMN WILL KEEP THIS SHOWERY ACTIVITY ANCHORED TO THE HIGHER
TERRAIN. THE SAME PATTERN CONTINUES TOMORROW AND THURSDAY EXCEPT
A WEAK TROUGH WILL PASS THROUGH NEAR PEAK HEATING TOMORROW WHICH
MAY HELP ANY CONVECTIVE ACTIVITY ALONG. THE FLOW WILL REMAIN WEAK
BUT A LITTLE MORE ORGANIZED FROM THE SOUTHWEST SO ANY DIURNAL
SHOWERS SHOULD PROPAGATE NORTHEASTWARD. TEMPERATURES THE NEXT
COUPLE DAYS WILL REMAIN SEASONABLE TO SLIGHTLY ABOVE NORMAL FOR
EARLY FALL. SOME AMOUNT OF UNSETTLED WEATHER APPROACHES ON FRIDAY
BUT CONFIDENCE IS LOWER DUE TO ISSUES COVERED IN THE MODEL
DISCUSSION.

SOUTHWEST ALASKA...LIGHT SHOWERY PRECIPITATION WILL CONTINUE THIS
EVENING AND DECREASE IN COVERAGE TOMORROW AS RIDGING BUILDS IN AT
ALL LEVELS. AREAS ALONG THE ALASKA RANGE COULD STILL SEE RAIN
SHOWERS AS A WEAK DISTURBANCE PASSES OVERHEAD. FOG AND LOW STRATUS
CHANCES INCREASE ALONG THE KUSKOKWIM DELTA OVERNIGHT TONIGHT
BEFORE OFFSHORE DRIER FLOW MOVES IN ON THURSDAY.

BERING SEA/ALEUTIANS...A LOW PRESSURE SYSTEM WILL SLOWLY MAKE ITS
WAY EASTWARD FOR THE NEXT COUPLE DAYS WHILE WEAKENING...KEEPING
RAIN IN THE FORECAST FOR THE WESTERN AND CENTRAL ALEUTIANS. WINDS
WILL REMAIN LIGHT IN THE EASTERN BERING SEA WITH PATCHY FOG AND
LOW STRATUS.


&&

.LONG TERM FORECAST...
WHILE UNCERTAINTY IS ABUNDANT NEAR THE BEGINNING OF THE WEEKEND
FOR THE EXTENDED FORECAST THERE IS SOME CONTINUITY BETWEEN MODEL
GUIDANCE TO GRASP AT. THE VARIABILITY LATE WEEK IS FROM SMALL
SCALE FEATURES WHILE THE FOCUS CHANGES TO THE LARGE SCALE PATTERN
FOR ACTIVE WEATHER EARLY NEXT WEEK. THE LOW PRESSURE SYSTEM MOVING
EASTWARD ACROSS THE BERING SEA WILL DEEPEN AND MOVE NORTHEASTWARD
TOWARD THE MAINLAND. THERE ARE SOME TIMING DIFFERENCES BUT THE
MAINLAND SHOULD SEE A FRONTAL PASSAGE EARLY NEXT WEEK FOLLOWED BY
THE LOW PRESSURE SYSTEM ITSELF. EXPECT AN INCREASE OF CLOUDS AND
MOISTURE AS WELL AS TEMPERATURES DIPPING BACK TOWARD SEASONAL
NORMALS OR SLIGHTLY BELOW.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY 121.
MARINE...NONE.
FIRE WEATHER...NONE.
&&



$$

MTL

AUG 14





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