968
FXAK67 PAJK 032000 CCA
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE JUNEAU AK
1159 AM AKDT THU JUL 3 2008
SHORT TERM
NUMEROUS PIREP INDICATED POOR VISIBILITIES AND LOW
CEILINGS EARLY THIS MORNING ALONG THE COASTAL SECTIONS AND
SEVERAL SOUTHERN INNER CHANNELS. BY MID MORNING
HOURS...HOWEVER...MARINE STRATUS WITH FOG LAYER ALONG THE
IMMEDIATE COASTS HAVE MOSTLY LIFTED. MOST INSIDE PASSAGES ARE
REPORTING HIGH CLOUDS FILTERING THE SUNSHINE. JUNEAU AIRPORT
REPORTED ACSL VICINITY SOUTH INDICATING WEAK WAVES ALOFT ACROSS
THE CENTRAL PANHANDLE. THE MORNING SATELLITE LOOP SHOWS A CLUSTER
OF WEAK CONVECTIVE CELLS PROPAGATING NORTHWARD ACROSS THE
SOUTHEAST PANHANDLE FROM THE BRITISH COLUMBIA COASTS. A WEAK
UPPER LEVEL LOW WELL SOUTH OF THE QUEEN CHARLOTTES CONTINUES
PUSHING THIS SHOWER BAND NORTHWARD ALONG THE COAST MOUNTAINS.
THIS POORLY ORGANIZED UPPER LEVEL FEATURE SEEMS TO DISSIPATE BUT
TRACK NORTHWARD AND MAY SLIGHTLY TOUCH SOUTHERN TIP OF THE
PANHANDLE EARLY TONIGHT.
MODELS ARE WELL INITIALIZED AND IN GOOD AGREEMENT FOR TONIGHT AND
INDEPENDENCE DAY WITH A WEAKENING RIDGE OF HIGH PRESSURE ACROSS
SOUTHERN HALF OF PANHANDLE...SLOWLY MOVING EAST AWAY FROM THE
FORECAST AREA EARLY TONIGHT FOLLOWED BY A LEADING EDGE OF AN
INCOMING FRONTAL BOUNDARY ARRIVING NEAR THE COAST. AHEAD OF THE
LEADING EDGE OF THE FRONT...A RAPID INCREASE OF CLOUDINESS IS
EXPECTED ACROSS THE SOUTHEAST ALASKA THIS AFTERNOON AND EVENING
HOURS. THE FRONT WILL CONTINUE TO PUSH NORTHWARD ACROSS THE
EASTERN GULF AND SOUTHEAST ALASKA FOR THE NEXT COUPLE OF DAYS. THE
FRONT WILL BECOME OCCLUDED BY LATE TONIGHT OR EARLY MORNING HOURS
ON THE INDEPENDENCE DAY AND GENERATE CATEGORICAL POPS FOR ENTIRE
SOUTHEAST ALASKA. GRADIENT WINDS SHOULD STAY IN LIGHT
SIDE...EXCEPT IN THE SOUTHERN COASTAL WATERS WHERE PRESSURE
GRADIENT INCREASES DUE TO THE LOW APPROACHING FROM THE WEST ON
INDEPENDENCE DAY. EXPECT UP TO 20 KTS WINDS ACROSS SOUTHERN
OUTSIDE WATERS AND SOUTHERN MOST INNER CHANNELS.
LONG TERM
FOR MOST ZONES SUN NIGHT THROUGH MON NIGHT IS THE
PRIMARY PERIOD OF TIME FOR RAIN LIKELY, AND THIS IS ASSOCIATED
WITH THE CLOSEST APPROACH OF A LARGE SCALE TROUGH TO OUR WEST.
SEE NEXT PARAGRAPH ABOUT THE LARGE SCALE TROUGH ALOFT. FOR THE
REMAINDER OF THE LONG RANGE PKG, BOTH BEFORE AND AFTER THE CLOSEST
APPROACH OF THE TROUGH, POPS ARE GEN NOT ABOVE 40 PERCENT.
LARGE SCALE TROUGH ALF EXTENDS S FM THE ARCTIC OCEAN NEAR POINT
LAY TO OVER SAND POINT AND S TO THE NPAC. THIS TROUGH WILL REMAIN
W OF OUR FCST DOMAIN THROUGH DAY 7. THE FARTHEST EAST SHOULD BE
ABT 12Z MON WHEN IT EXTENDS S FM MIDDLETON ISLAND, BEFORE DRIFTING
SLOWLY W. THIS CYCLE OF MVMNT SEEMS TO BE ASSOCD WITH A PLANETARY
SCALE WAVE PATN OF FIVE TO FOUR.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE.
MARINE...NONE.
SJA/JBT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page