Dense Fog Advisory 21, NWS Juneau, AK

370 
WWAK77 PAJK 191730
NPWAJK

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
930 AM AKDT WED SEP 19 2012

AKZ024-025-027-191830-
/X.CAN.PAJK.FG.Y.0021.000000T0000Z-120919T1800Z/
EASTERN BARANOF ISLAND AND SOUTHERN ADMIRALTY ISLAND-
JUNEAU BOROUGH AND NORTHERN ADMIRALTY ISLAND-
DIXON ENTRANCE TO CAPE DECISION COASTAL AREA-
INCLUDING THE CITIES OF...ANGOON...JUNEAU...CRAIG...KLAWOCK
930 AM AKDT WED SEP 19 2012

...DENSE FOG ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN JUNEAU HAS CANCELLED THE DENSE
FOG ADVISORY. 

FOG HAS DIMINISHED ACROSS THE AREA AND VISIBILITIES HAVE IMPROVED.
PATCHY FOG WILL REMAIN FOR A FEW MORE HOURS THIS MORNING.

$$

AKZ026-191830-
/X.CON.PAJK.FG.Y.0021.000000T0000Z-120919T1800Z/
INNER CHANNELS FROM KUPREANOF ISLAND TO ETOLIN ISLAND-
INCLUDING THE CITIES OF...PETERSBURG...WRANGELL...KAKE
930 AM AKDT WED SEP 19 2012

...DENSE FOG ADVISORY REMAINS IN EFFECT UNTIL 10 AM AKDT THIS
MORNING...

AREAS OF DENSE FOG WILL LOWER VISIBILITIES TO LESS THAN ONE
QUARTER MILE AT TIMES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN ADVISORY MEANS THAT DENSE FOG IS ALREADY OCCURRING OR
IMMINENT.

ALL TRAVEL SHOULD BE DONE WITH EXTREME CAUTION.

THIS STATEMENT WILL BE UPDATED BY 1000 AM AKDT WED OR SOONER IF
CONDITIONS WARRANT.

&&

$$

967 
WWAK77 PAJK 191803
NPWAJK

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE JUNEAU AK
1003 AM AKDT WED SEP 19 2012


AKZ026-191915-
/X.EXP.PAJK.FG.Y.0021.000000T0000Z-120919T1800Z/
INNER CHANNELS FROM KUPREANOF ISLAND TO ETOLIN ISLAND-
INCLUDING THE CITIES OF...PETERSBURG...WRANGELL...KAKE
1003 AM AKDT WED SEP 19 2012

...DENSE FOG ADVISORY HAS EXPIRED...

DENSE FOG HAS DIMINISHED ACROSS THE AREA AND VISIBILITY HAS
IMPROVED. LINGERING AREAS OF FOG MAINLY NEAR WRANGELL WILL
CONTINUE TO DISSIPATE THROUGH THE NEXT FEW HOURS.

$$

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
404 PM AKDT TUE SEP 18 2012

.SHORT TERM...A RIDGE OF HIGH PRESSURE HAS BUILT OVER THE
EASTERN GULF TODAY. THIS HAS ALLOWED FOR GENERALLY LIGHT WINDS
AND MOSTLY CLEAR SKIES OVER THE THE SOUTHERN HALF OF THE
PANHANDLE TODAY. A FRONTAL SYSTEM OVER THE WESTERN GULF IS
SPREADING RAIN INTO THE YAKUTAT AREA. RAIN WILL CONTINUE THROUGH
THIS EVENING IN YAKUTAT...WITH CLOUDS AND A FEW SPRINKLES
POSSIBLE OVER THE FAR NORTHERN INNER CHANNELS COMING OVER THE
RIDGE AXIS. HOWEVER THE RIDGE WILL KEEP SHOWERS TO A MINIMUM OVER
THE REST OF THE PANHANDLE. LIGHT WINDS ARE EXPECTED
OVERNIGHT...WITH EXCEPTION OF NORTHERN LYNN CANAL WHERE SMALL
CRAFT LEVEL SOUTHERLY WINDS WILL CONTINUE INTO THE EVENING.

 OVERNIGHT BREAKS IN THE CLOUD COVER...ESPECIALLY OVER THE
SOUTH...WILL RESULT IN RADIATION FOG TO DEVELOP AGAIN. AS WITH
THIS MORNING THE FOG WILL BE THE GREATEST OVER AND NEAR THE
MARINE AREAS.

 THE UPPER LEVEL RIDGE BUILDS MORE OVER THE PANHANDLE ON
WEDNESDAY.  THIS WILL INCREASE THE SUBSIDENCE UNDER THE RIDGE
AXIS...WHICH WOULD  RESULT IN TWO THINGS...DECREASING SHOWER
PROBABILITY EVEN FURTHER WHILE STRENGTHENING THE CAPPING
INVERSION. SIMILAR TO THIS MORNING...THE CAPPING INVERSION WILL
KEEP FOG OR A MARINE LAYER OF LOW CLOUDS AROUND LONGER WEDNESDAY
MORNING WHERE EVER IT DEVELOPS OVERNIGHT.

 THE UPPER LEVEL JET ALONG THE FRONT IN THE WESTERN GULF WILL
CAUSE A BARRIER JET TO DEVELOP OVER THE NORTH CENTRAL OUTSIDE
WATERS. HAVE CONTINUED WITH THE GALE WARNING FOR AREA 52 STARTING
TONIGHT WITH WINDS OF 45 KT POSSIBLE ON WEDNESDAY.

 USED MAINLY THE NAM12 WITH SOME HIRES MODELS FOR UPDATES TODAY.
OVERALL OTHER MODELS WERE IN FAIR AGREEMENT KEEPING FORECASTER
CONFIDENCE AVERAGE. MAIN AREAS OF CONCERN WERE WITH AMOUNT OF
CLOUD COVER AND POTENTIAL FOR A MARINE LAYER/FOG. IF EITHER
DEVELOP THEY WILL LIMIT THE MAX/MIN DIURNAL VARIATION.

.LONG TERM...WEDNESDAY NIGHT BEGINS WITH A WEAK WARM FRONT LIFTING
INTO THE NORTHEAST GULF COAST BRINGING RAIN AND A SURFACE RIDGE
FIRMLY IN PLACE OVER THE PANHANDLE. THE BIG STORY WITH THE RIDGE
WILL BE ITS ASSOCIATED WARM TEMPERATURES AND SOME CLEARING SKIES
PARTICULARLY IN THE SOUTHERN ZONES GIVING A NICE
THURSDAY...FRIDAY...AND EARLY SATURDAY ESPECIALLY FROM PETERSBURG
SOUTHEAST. SUBSIDENCE ALOFT FROM THE UPPER LEVEL RIDGE WILL
COMPRESS THE MARINE LAYER AND ALLOW SOME MARINE FOG TO DEVELOP
OFFSHORE OF BARANOF ISLAND WEDNESDAY NIGHT. ALSO, WITH CLEARING
SKIES AND LONGER NIGHTS RADIATIONAL FOG WILL DEVELOP IN THE INSIDE
CHANNELS DURING THE SAME TIME PERIOD. WINDS WILL BE LIGHT FOR THE
MOST PART AS THEY DIMINISH SIGNIFICANTLY IN LYNN CANAL BUT THEY
WILL INCREASE A BIT OUT OF THE NORTHWEST ON THE EAST SIDE OF THE
RIDGE IN THE INSIDE CHANNELS FROM STEPHENS PASSAGE SOUTHEASTWARD.

TEMPERATURES WILL REMAIN WARM THROUGH FRIDAY NIGHT BUT A NEW FRONT
SCHEDULED TO PASS THE PANHANDLE LATE SATURDAY WILL COOL THINGS BACK
TO AT LEAST SEASONABLE LEVELS.  RAIN WILL ALSO BE A GOOD BET OVER
THE WEEKEND FOR THE WHOLE FORECAST AREA.

LOOKING BEYOND THE WEEKEND...NEW HPC GUIDANCE SUGGESTS A NEW FRONT
WILL HOLD OFFSHORE AND ARRIVE MORE SLOWLY...PERHAPS DRAWING MORE ENERGY
THAN PREVIOUSLY THOUGHT. THUS RAIN CHANCES WILL CONTINUE INTO NEXT WEEK.

MODEL CHOICE...USED MOSTLY NAM FOR WED NIGHT AND THURSDAY AND
BLENDED EC TO USE FOR TRANSITION INTO HPC FOR PRESS INTO THE WEEKEND.
FOR PRECIP FIELDS USED A MIXTURE OF SREF...NAM40...AND EC FOLLOWED
BY HPC FOR EXTENDED RANGE.  CONFIDENCE AVERAGE THROUGH THE WEEKEND.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ052.
         SMALL CRAFT ADVISORY FOR PKZ012-043-051.

&&

HANNON/JWA