Small Craft Advisory 672, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
411 PM AKDT SUN OCT 30 2011

.SHORT TERM...RESIDUAL TROUGH FROM A FILLING LOW OVER THE
NORTHERN PANHANDLE WILL MOVE ACROSS THE PANHANDLE. SHOWERS WITH
THE THROUGH ARE LOCALLY HEAVY. SATELLITE IMAGERY SHOWERS ACROSS
THE EASTERN GULF HEADED TOWARDS THE PANHANDLE. STRONG GALE FORCE
WINDS OVER THE GULF WILL CONTINUE INTO THOUGH TONIGHT AND
DIMINISH THROUGH EARLY MONDAY. SURFACE RIDGING OVER THE EASTERN
GULF AND PANHANDLE AHEAD OF THE NEXT SYSTEM HEADED INTO THE
WESTERN GULF OF ALASKA....PARENT LOW OF THE FRONT WEST OF SAINT
PAUL ISLAND...A NEW WEAKER LOW WILL DEVELOP EAST OF KODIAK ISLAND
AND MOVE NORTHEAST TOWARDS PRINCE WILLIAM SOUND WITH THE FRONTAL
BAND EXTENDING WELL TO THE SOUTHWEST. AHEAD OF THE FRONT
DEPENDING ON THE MODEL SOLUTIONS 35 TO 50 KTS OF WINDS OVER THE
GULF. THIS FRONTAL BAND HAD A MID TROPIC MOISTURE SOURCE MODERATE
TO HEAVY RAIN WILL BE SPREADING BACK INTO THE NORTHERN GULF
MONDAY AFTERNOON.

 SUNDAY NIGHT LOOKS LIKE THERE MAY BE SOME COLD ENOUGH AIR
SPILLING OUT OF THE INTERIOR THAT A THERE COULD BE SOME LIGHT
SNOW MIXED IN OVER THE NORTHEAST GULF COAST AND PERHAPS FAR
NORTHERN LYNN CANAL AREA OVER THE INLAND VALLEYS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...THE EXTENDED FORECAST
STARTS OFF WITH A RIDGE OF HIGH PRESSURE OVER THE PANHANDLE AND A
LOW MOVING INTO THE GULF. THE RIDGE WILL CAUSE STRONG SOUTHERLY
WINDS THROUGH N-S ORIENTED CHANNELS...BECOMING WINDY IN SKAGWAY
AND GALES THROUGH LYNN CANAL. THE APPROACHING LOW PRESSURE SYSTEM
WILL CAUSE WIDESPREAD RAIN ACROSS THE REGION DUE TO THE ASSOCIATED
WARM FRONT WEDNESDAY NIGHT. RAIN WILL BECOME HEAVY AT TIMES STARTING
IN YAKUTAT MONDAY NIGHT AND INCREASING OVER THE REMAINING PANHANDLE
TUESDAY WITH THE COLD FRONT. EXPECT WINDY CONDITIONS AREAWIDE
TUESDAY WITH THE COLD FRONT AS A LOW LEVEL JET IS ORIENTED ALONG
IT AND GUSTY WINDS WILL MIX DOWN WITH THE RAIN.

AFTER THE FRONT PASSES TUESDAY NIGHT THE LOW WILL MOVE SOUTH FROM
OFF THE YAKUTAT AREA...THIS WILL CAUSE WINDS TO DECREASE THEN
SHIFT OUT OF THE NORTH ONCE THE LOW PASSES SOUTH. RAIN WILL BECOME
MORE SCATTERED AND TURN TO SHOWERS BY WEDNESDAY MORNING. AS THE
LOW MOVES TO THE SOUTH A HIGH WILL BUILD TO THE NORTH CAUSING A
COLD NORTH WIND OUT OF CANADA. A MID LEVEL OFFSHORE FLOW WILL
DEVELOP AS THE LOW PASSES CREATING A DRYING AFFECT...THIS WILL
DIMINISH ANY REMAINING SHOWERS BY WEDNESDAY EVENING WITH
DECREASING CLOUDS TO THE NORTH. TEMPERATURES WILL BECOME MUCH
COLDER OVERNIGHT WEDNESDAY THROUGH FRIDAY MORNING WITH THE COLD
AIR ADVECTION AND MOSTLY CLEAR SKIES.

ON FRIDAY THE NEXT SYSTEM WILL BE APPROACHING WITH RAIN REACHING
THE COASTAL AREAS FRIDAY MORNING. DUE TO MORNING TEMPERATURES IN
THE UPPER 20S TO LOW 30S SOME AREAS WILL SEE RAIN MIXED WITH SNOW.

MODELS HAVE BEEN STRUGGLING WITH THE PLACEMENT OF THE LOW
PRESSURE FOR MONDAY NIGHT AND TUESDAY AND TIMING OF WHEN IT MOVES
TO THE SOUTH TUESDAY NIGHT THROUGH WEDNESDAY. USED A BLEND OF
MODELS DURING THIS TIME-FRAME WITH AN EMPHASIS ON THE SREF AND 06Z
GFS AND MANUALLY TWEAKED THE LOW PLACEMENT TO GET A SMOOTH
TRANSITION SOUTHWARD. THE ULTIMATE LOCATION OF THE LOW CENTER WILL
DETERMINE TIMING OF WINDS SHIFTING FROM SOUTH TO NORTH. AS A RESULT
FORECAST CONFIDENCE FOR THIS TIME-FRAME IS BELOW AVERAGE.
HOWEVER...CONFIDENCE IS AVERAGE TO ABOVE AVERAGE FOR THE STRONG
WINDS AND HEAVY RAIN EXPECTED FOR MONDAY NIGHT AND TUESDAY. MODELS
COME BACK INTO AGREEMENT FROM WEDNESDAY ONWARD AND USED A BLEND OF
THE ECMWF AND GFS FOR PRESSURE AND MAINLY THE GFS FOR OTHER
FIELDS. MODELS ARE ALSO IN GOOD AGREEMENT FOR THE COLD AIR
OUTBREAK WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND COULD EVEN
BE COLDER THAN IN THIS PACKAGE...WILL MONITOR AND DECREASE AS IT
GETS CLOSER.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ012-022-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-031>036.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.

&&

BEZENEK/HANNON