Gale Warning 194, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
356 PM AKST TUE MAR 8 2011

.SHORT TERM...SATELLITE IMAGES THIS MORNING ARE SHOWING A WEAK
FRONT MOVING THROUGH THE SOUTHERN PANHANDLE AT THE MOMENT. THE
FEATURE IS SPREADING SNOW OVER MOST OF THE SOUTHERN AND CENTRAL
PANHANDLE WITH ONLY THE EXTREME SOUTHERN PANHANDLE BEING WARM
ENOUGH TO CHANGE IT OVER TO RAIN. SNOW AMOUNTS HAVE BEEN LIGHT
PARTICULARLY SOUTH OF SUMNER STRAIT WHERE AIR TEMPS ARE JUST A
BIT TOO WARM FOR THE SNOW TO STICK. ELSEWHERE, THE NORTHERN
PANHANDLE IS STILL ENJOYING MOSTLY CLEAR TO PARTLY CLOUDY SKIES
DUE TO SOME OUTFLOW STILL OCCURRING.

 FOR TONIGHT INTO TOMORROW, THE FRONT WILL STALL OUT OVER THE
CENTRAL PANHANDLE TONIGHT AND SHEAR APART BY TOMORROW. PETERSBURG
AND WRANGELL MAY RECEIVE ONE TO TWO INCHES OF SNOW BEFORE IT
DISSIPATES AWAY. THE CONTINUING OUTFLOW SHOULD KEEP AREAS NORTH
OF FREDRICK SOUND RELATIVELY DRY.

 WINDS WILL BE ANOTHER MATTER. THE PRESSURE GRADIENT ALONG THE
PANHANDLE WILL BE INCREASING TOMORROW AS THE HIGH IN CANADA GAINS
STRENGTH AND AN APPROACHING LOW FROM THE SOUTH COME INTO PLAY.
DECIDED TO HOIST WIND ADVISORIES FOR YAKUTAT (INTERIOR PASSES
EAST OF YAKUTAT), SKAGWAY, HAINES (MAINLY ALONG LYNN CANAL), AND
JUNEAU (DOWNTOWN AND DOUGLAS) STARTING TOMORROW. FOR JUNEAU, THE
WIND WILL MAINLY BE FROM YET ANOTHER WEAKER MOUNTAIN WAVE EVENT
AS CROSS BARRIER FLOW INCREASES. THE CRITICAL LEVEL IS A BIT TOO
LOW (AROUND 750 MB) FOR THEIR TO BE OPTIMUM CONDITIONS BUT SHOULD
STILL EXPECT GUSTS TO 50 MPH.

 MODELS WERE IN GOOD AGREEMENT THROUGH THE SHORT TERM PERIOD.
DECIDED TO USE THE NAM WITH A BIT OF THE EC DUE TO THE DETAIL
THAT WAS AVAILABLE IN THE MODELS AS WELL AS HOW WELL THEY
INITIALIZED. FORECAST CONFIDENCE IS ABOVE AVERAGE.

.LONG TERM...NO BIG CHANGES IN THE FORECAST AS THE MODELS
CONTINUE TO BE IN GOOD AGREEMENT THROUGH EARLY NEXT WEEK. THE
OVERALL SYNOPTIC WEATHER PATTERN WILL REMAIN ABOUT THE SAME WITH
THE UPPER HIGH OVER THE NORTHERN BERING WITH MEAN TROF IN THE
GULF. THERE WILL BE A SERIES OF UPPER LEVEL ENERGY THAT WILL
DEVELOP LOW PRESSURE SYSTEMS LATE IN THE WEEK INTO THE WEEKEND
THAT WILL INCREASE THE CHANGE OF PRECIP OF THE MAJORITY OF THE
PANHANDLE WITH THE EXCEPTION OF THE FAR NORTHERN INNER CHANNELS.
P-TYPE WILL BE THE BIGGEST FORECAST CHALLENGE OVER THE WEEKEND
INTO EARLY NEXT WEEK. BUT FIRST THE INNER CHANNELS WILL HAVE TO
GO THROUGH ANOTHER BOUT OF STRONG WINDS FROM THE NORTH AND OUT OF
INTERIOR PASSES.

AT THE START OF THE LONG TERM PERIOD THE SURFACE HIGH OVER THE
YUKON WILL STRENGTHEN AND SEND THE ARCTIC FRONT OVER THE NORTHERN
HALF OF THE PANHANDLE. ALSO A LOW PRESSURE SYSTEM WILL BE LIFTING
OVER THE QUEEN CHARLOTTES AND IN DOING SO IT WILL CONTINUE TO
INCREASE THE PRESSURE GRADIENT. THIS WILL INCREASE THE NORTHERN LY
WINDS TO MAX GALES OVER LYNN CANAL WITH MIN GALES OVER THE REST OF
THE NORTHERN HALF OF THE INNER CHANNELS. ALSO STRONG GUSTS TO 60 KT FROM
INTERIOR PASSES AND OUT OF CROSS SOUND WILL DEVELOP AND PERSIST.
ALONG WITH THE STRONG WINDS OVER THE MARINE WATERS GUSTS TO 50 MPH
OVER ZONE 17,18,19,25 WILL CONTINUE FROM THE SHORT TERM AND PERSIST
THROUGH LATE THURSDAY NIGHT AS THE GRADIENT WEAKENS SOME. BUT
THERE IS A GOOD CHANCE THAT THESE WIND ADVY LEVEL GUSTS WILL
CONTINUE INTO FRIDAY. OTHER LAND BASE AREAS WILL SEE LOCALLY WINDY
CONDITIONS. NORTHERN LYNN WILL INCREASE TO STORM FORCE WINDS
THROUGH THURSDAY BUT RELAX TO GALES BY FRIDAY.

THE LOW WILL SEND A WEATHER FRONT OVER THE FAR SOUTHERN AREAS AND
SPREAD LIGHT MIX PRECIP THROUGH THE WED NIGHT. THIS LOW WILL
REMAIN OVER DIXON ENTRANCE THROUGH THURSDAY AND KEEP A CHANCE OF
PRECIP OF THE SOUTHERN THIRD.

ANOTHER LOW WILL LIFT OUT OF THE NORTH PACIFIC ROTATING AROUND THE
UPPER LOW OVER THE GULF AND DRIFT INTO THE EASTERN GULF AS IT
WEAKENS TO A TROF. THE MID-LEVEL FLOW WILL BACK AROUND TO THE
SOUTHEAST THROUGH THE WEEKEND AND INCREASE THE THREAT OF PRECIP
OVER THE NORTHERN HALF WITH LIKELY POPS OVER THE SOUTHERN HALF.
THIS TREND OF LOW PRESSURE SYSTEMS MOVING OUT OF THE NORTH PACIFIC
WILL CONTINUE INTO NEXT WEEK AND CONTINUE TO KEEP A CHANCE OF
PRECIP OVER THE PANHANDLE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM 9 AM WEDNESDAY TO 5 AM AKST FRIDAY FOR AKZ025.
         WIND ADVISORY FROM NOON WEDNESDAY TO 5 AM AKST FRIDAY FOR AKZ019.
         WIND ADVISORY UNTIL 5 AM AKST FRIDAY FOR AKZ018.
         WIND ADVISORY FROM 3 AM WEDNESDAY TO 5 AM AKST FRIDAY FOR AKZ017.
MARINE...GALE WARNING FOR PKZ011-012-051.
         SMALL CRAFT ADVISORY FOR PKZ013-021-022-031>033-036-043-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041-042.

&&

EAL/ABJ