Small Craft Advisory 474, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
431 PM AKDT TUE AUG 28 2012

.SHORT TERM...THE CURRENT SATELLITE IMAGERY SHOWS THE PESKY LOW
STILL OVER THE EASTERN GULF WITH RAIN FALLING OVER MOST OF THE
FORECAST AREA. THE LOW WILL SLOWLY DROP TO THE CENTRAL AREAS BY
LATE TONIGHT THEN INTO DIXON ENTRANCE BY THE AFTERNOON. THE
SURFACE HIGH BUILDING OVER THE YUKON THIS AFTERNOON WILL CONTINUE
TO PRODUCE STRONG OUTFLOW WINDS OVER THE NORTHERN GULF THIS
AFTERNOON. THE HIGH WILL DRIFT TO THE EAST ACROSS THE YUKON
THROUGH WEDNESDAY. THIS HIGH IS PRODUCING STRONG OUTFLOW WINDS
OVER THE NORTHERN GULF TO 30 KT ALONG WITH SMALL CRAFT WINDS OVER
NORTHERN LYNN. THESES WINDS WILL SPREAD OVER THE NORTHERN THIRD
THROUGH TONIGHT AS THE HIGH ESTABLISHES ITS SELF AND THE LOW
DROPS SOUTH. SOUTH OF THE LOW THERE IS SE WINDS FROM 15 TO 25 KT
WITH THE STRONGEST WINDS NEAR PKZ 36. AS THE LOW WEAKENS THE
WINDS WILL ALSO DIMINISH AND EVENTUALLY BACK AROUND TO THE NORTH.

AS THE UPPER LEVEL LOW OVER THE NORTHERN GULF DROPS SOUTH THROUGH
TONIGHT THE RAIN THAT IS MODERATE AT TIMES THIS AFTERNOON ALONG
WITH AREAS OF FOG WILL DIMINISH FROM NORTH TO SOUTH. THE UPPER
HIGH TO THE WEST OF THE AREA WILL DRIFT EAST AND WILL INCREASE THE
OFFSHORE FLOW AND ADVECT DRIER AIR. SO THE ALL THE LOW CLOUDS OVER
THE AREA WILL STILL AROUND THROUGH TONIGHT WITH AREAS OF FOG BUT
THROUGH WEDNESDAY THE CLOUDS WILL DECREASE FROM NORTH TO SOUTH AND
THE NORTHERN HALF WILL BE MOSTLY SUNNY BY THE AFTERNOON. THE LOW
WILL LINGER OVER THE FAR SOUTHERN AREAS TO KEEP SOME CLOUDS ALONG
WITH SOME SCATTERED SHOWERS.

THERE IS LOW FORECASTER CONFIDENCE FOR THE NEXT 24HRS AS THE
FORECAST ALL DEPENDS ON THE MOVEMENT OF THE UPPER AND SURFACE LOW
SOUTHWARD. THE MODELS HAVE BEEN STRUGGLING ON THE SPEED OF THE SE
DRIFT.

&&

.LONG TERM...WEDNESDAY NIGHT THE LOW FINALLY EXITS INTO B.C. AS
DRY OFFSHORE FLOW TAKES OVER IN THE NORTHERN ZONES. KEPT
TEMPERATURES COOL WEDNESDAY NIGHT WITH THE EXCEPTION OF THE
SOUTHERN ZONES TO REFLECT THE CLEARING SKIES. AREAS OF FOG COULD
DEVELOP AS A RESULT OF THE RADIATIONAL COOLING...HAVE KEPT MENTION
OF FOG OUT OF THE FORECAST FOR NOW WITH EXCEPTION OF A MARINE
LAYER DEVELOPING OUT OVER THE GULF. THURSDAY AND FRIDAY THE
SURFACE RIDGE BUILDS FURTHER OVER THE PANHANDLE AND CONTINUING
THE POTENTIAL FOR A MARINE LAYER OFFSHORE. THE BUILDING RIDGE WILL
CAUSE WINDS TO SHIFT FROM NORTH TO SOUTH AND INCREASE THROUGH THE
NORTHERN INSIDE WATERS. ON FRIDAY A NEW FRONT MOVES IN FROM THE
WEST TO BRING IN THE NEXT SIGNIFICANT WAVE OF PRECIP JUST IN TIME
FOR THE HOLIDAY WEEKEND. MOST MODELS SUGGESTING HEAVY RAIN AROUND
YAKUTAT FOR SATURDAY. MORE ZONAL ONSHORE FLOW IS EXPECTED OVER A
WEAK RIDGE THEREAFTER...MEANING AT LEAST A CHANCE OF RAIN THROUGH
MONDAY AND TUESDAY WITH MORE NORMAL TEMPERATURES AND MAINLY CLOUDY
SKIES.

DID BRING WINDS HIGHER IN GULF OF ALASKA FRIDAY AS LATEST MODELS
INDICATING STRENGTHENING GRADIENT WITH THE FRONT. OTHERWISE...SOME
TOUCH UPS TO INSIDE CHANNELS DIRECTION FOR LOCAL EFFECTS. CONFIDENCE
HIGHER WEDNESDAY NIGHT THROUGH FRIDAY WITH THE RIDGE BUT MODELS
DIVERGE STARTING FRIDAY WITH THE FIRST FRONT ARRIVAL. USED A BLEND
OF LATEST GFS AND ECMWF FOR MOST CHANGES AND INCORPORATED HPC LATER
ON.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ012.
         SMALL CRAFT ADVISORY FOR PKZ011-022-041>043-051-052.

&&

ABJ/HANNON/JWA