Small Craft Advisory 134, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
612 AM AKST THU FEB 10 2011

.SHORT TERM...A LOW ABOUT 600 NM SOUTH OF KODIAK ISLAND IS
MOVING TO NORTHEAST TO THE CENTRAL GULF OF ALASKA AND DEEPENING
TO THE MID 980 MB RANGE. THE ASSOCIATED FRONTAL BAND APPROACHES
THE PANHANDLE. A WARM FRONT MOVES ACROSS THE PANHANDLE ON
THURSDAY MORNING AND THE COLD FRONT APPROACHES THE PANHANDLE
THURSDAY EVENING. GALE FORCE WINDS APPROACH THE COASTAL WATERS
AHEAD OF THE COLD FRONT FOR THURSDAY NIGHT. THESE WINDS I THINK
WILL BE ENOUGH TO BRING GUSTS TO 40 MPH FOR EXPOSED AREAS FOR
BARANOF ISLANDS.

WARM TEMPERATURES AHEAD OF THE COLD FRONT ENOUGH TO MAKE ALL
PRECIPITATION RAIN. SHOULD EXPECT A FAIR AMOUNT OF RAIN FROM THE
FRONT WITH RAIN FALL ACCUMULATIONS AROUND A HALF TO AN INCH OF
WATER.

MODEL AGREEMENT WAS FAIRLY GOOD THROUGH THURSDAY NIGHT WHICH IS
THE SHORT TERM TIME FRAME. USED A GFS/NAM BLEND AS THIS SEEMED TO
BE A GOOD ESTIMATE OF WHAT WILL BE HAPPENING OVER NIGHT FOR THE
PRESSURE PATTERN.

.LONG TERM...ONLY MINOR CHANGES HAVE BEEN MADE TO THE FORECASTS
FOR FRIDAY ONWARD.  OUR AREA OF RESPONSIBILITY WILL HAVE A N TO S
SEQUENCE OF RAIN CHANGING TO SNOW FOLLOWED BY A COLDER AND DRY
CONDITIONS. CONFIDENCE IN THE OVERALL TREND IS AVERAGE.

THE LOW DISCUSSED IN THE SHORT RANGE SECTION ABOVE WILL BE ABOUT
982 MB 100 NM S OF PAMD AT 12Z. THE ASSOCIATED FRONT WILL BE AN
OCCLUSION MOVING ONSHORE AT ABOUT THAT TIME AND BEGINNING TO
WEAKEN. A SECOND LOW AND FRONT WILL FOLLOW IN A SIMILAR CONFIGURATION
ABT 12Z SAT. THE SYSTEMS DISCUSSED IN THIS PARAGRAPH WILL PROVIDE
THE ONSHORE FLOW THAT WILL FIRST PRODUCE RAIN, AND THEN TURN TO
SNOW DUE TO THE ARCTIC OUTBREAK FROM THE N.

THE ARCTIC AMS WILL DVLP SEWD ACRS YUKON TRRTY AND REACH NW B.C.
BY THE END OF THE WEEKEND. GALE FORCE N WINDS IN LYNN CANAL SHOULD
DEVELOP BY MON MORNING. AN ARCTIC OUTBREAK WILL BE ENHANCED BY A
500H LONG- WAVE RIDGE ALOFT WHICH AT 00Z TUE WILL EXTEND FM THE
NPAC TO OVER PADK AND N OVER THE BERING. THE ASSOCIATED COOLING
TREND AND TRANSITION FROM RAIN TO SNOW WILL JUST EXTEND TO THE SRN
PNHDL TUESDAY AS THE PRECIPITATION ENDS IN A N TO S SEQUENCE ALONG
THE PNHDL.

THE LARGE SCALE PATTERN FAVORS CYCLOGENESIS AND FRONTOGENESIS
BECOMING STRONGER FOR THE CENTRAL AND ERN GLFALSK FROM NOW THROUGH
12Z SAT. LONGWAVE 500H TROUGH XTDG S FM PACD WILL DRIFT E AND XTD
S FM PAWD 00Z SAT, WHILE DIGGING S.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM 6 PM THIS EVENING TO 3 AM AKST FRIDAY FOR
     AKZ023.
MARINE...GALE WARNING FOR PKZ041>043.
         SMALL CRAFT ADVISORY FOR PKZ011-021-022-033>036-051-052.

&&

BEZENEK/JBT