Small Craft Advisory 368, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
250 PM AKDT THU JUN 14 2012

.SHORT TERM...FEATURES PRESENTLY IN THE GULF WILL DISSIPATE OR
BE MOVED OUT OF OUR AOR DUE TO THE APPROACH OF AN STRONG POLAR
FRONT ZONE SYSTEM CURRENTLY WITHIN 600 N S OF OF THE AK PEN AND
PADQ.

 THE UNSEASONABLY STRONG SYSTEM INCLUDES STRONG FRONTAL
BOUNDARIES AND TRIPLE PT THAT ARE OBVIOUS ON THE IR AND VIS WITH
THE TRIPLE PT ABOUT 600 N S OF PADQ. NOTE THE GALE AND SCA
LISTINGS IN MARINE TABLE BELOW. GALE FORCE WINDS ARE UNUSUAL IN
JUNE. PUBLIC ZONE 27 IS BEING GIVEN A WIND HEADLINE FOR FRIDAY
BECAUSE GUSTS AS HIGH AS 35 MPH CAN OCCUR.

 THE TRIPLE PT REGION IS CYCLOGENETIC AND BY 00Z SAT SHOULD
RESULT IN A 990 MB LOW 400 NM S OF PAMD, WITH A STRONG OCFNT XTDG
E TO A NEW TRIPLE PT 200 SSW OF PAKT.

 MORE ABOUT THE FEATURES CURRENTLY IN OUR AOR: A 1012 MB LOW
200 NM S OF PAMD IS QSTNRY AND WILL DISSIPATE BY 12Z. A HIGH
PRESSURE RIDGE EXTENDS NNW ALONG THE PNHDL AND IN AN ARC ALONG
THE N GLF COAST WILL MOVE TO THE NE AND BEGIN TO MOVE E PAST THE
COAST RANGE BY 18Z FRI, AND ALL THE AOR S OF A PAJN- PAYA LN WILL
HAVE A PERIOD OF OUTFLOW DRYG THAT WILL STOP PRECIP UNTIL THE
ONSET OF THE FRONT RELATED PRECIP SATURATES THE COLUMN. VISUALIZE
VIRGA REACHING THE GROUND AS THE ONSET OF ACCUMULATION.

 &&

.LONG TERM...

 A 976 MB OCCLUDED LOW IS CURRENTLY LOCATED IN NORTH CENTRAL
PACIFIC OCEAN...ABOUT 600 MILES SOUTH OF DUTCH HARBOR. SOUTH OF
THE LOW...AN UPPER LEVEL JET IS TRANSPORTING SUBTROPICAL MOISTURE
TO THE SOUTHEASTERN PERIPHERY OF THIS STORM SYSTEM. A FRONTAL
BAND AND A SECONDARY LOW IS DEVELOPING EAST OF THE STATIONARY
OCCLUDED LOW. THESE WEATHER FEATURES WILL BE TRACKING
NORTHEASTWARD...AND WILL BE IMPACTING SOUTHEAST ALASKA FOR THE
BEGINNING OF THE WEEKEND.

 AS THE WEATHER FRONT PUSHES NORTHEASTWARD...RAIN WILL SPREAD
NORTHWARD ON FRIDAY EVENING ACROSS THE PANHANDLE...WITH THE
HIGHEST QPF AMOUNTS IN THE SOUTHERN AREAS. FOR THE OUTSIDE
WATERS...SMALL CRAFT ADVISORY AND GALE FORCE WINDS ARE EXPECTED
TO CONTINUE OVERNIGHT INTO SATURDAY. WITH OVERCAST CLOUD COVER
AND CATEGORICAL POP...PANHANDLE SHOULD CONTINUE TO SEE DAYTIME
TEMPERATURES ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR SATURDAY. AS
THE LOW PRESSURE SYSTEM CONTINUES TO MOVE NORTH AND WEAKEN...WIND
SHOULD DIMINISH ON SUNDAY. PRECIPITATION WILL LINGER IN THE
AREA...AND GRADUAL DRYING IS EXPECTED THROUGH SUNDAY EVENING.

 MODELS ARE HINTING THAT A ZONAL FLOW WILL TAKE PLACE NEXT WEEK
AS A BROAD RIDGE OF HIGH PRESSURE DEVELOPS OVER THE GULF...AND
THIS WILL BRING SEASONABLE TEMPERATURES AND DRIER CONDITIONS TO
THE PANHANDLE FROM MONDAY ONWARDS. THE BIGGEST CHANGE MADE IN THE
EXTENDED RANGE IS THE MAXIMUM TEMPERATURE GRIDS. INCREASED THE
HIGH TEMPERATURES ABOUT 5 DEGREES TO AROUND 60 DEGREES NEXT WEEK.
LATER SHIFTS MAY NEED TO INCREASE THE MAXIMUM TEMPERATURES
FURTHER IF DRIER CONDITIONS ARE EXPECTED TO PREVAIL EARLY NEXT
WEEK.

 FORECAST CONFIDENCE IS AVERAGE. GFS IS INCONSISTENT FROM RUN TO
RUN. EC HAS RUN TO RUN CONSISTENCY...AND ALSO CONSISTENT WITH
OTHER MODELS SUCH AS NAM AND UKMET. HPC ALSO USES EC AND EC
ENSEMBLES FOR THE EXTENDED RANGE. DECIDED TO USE EC FROM FRIDAY
NIGHT INTO SUNDAY NIGHT. THEN TRANSITION TO HPC FROM MONDAY
ONWARDS.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ041>043.
         SMALL CRAFT ADVISORY FOR PKZ012-022-033-035-036-051-052.

&&

JBT/RWT