Small Craft Advisory 141, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
545 AM AKST TUE FEB 9 2016

.SHORT TERM...A TIGHTLY WOUND GALE FORCE LOW CHURNED NORTH THROUGH
THE EASTERN GULF YESTERDAY EVENING AND HOPPED INLAND TO THE
CANADIAN YUKON OVERNIGHT. WINDS RESPONDED IN AN EXCITING WAY
THROUGH THE NORTHERN INNER CHANNELS. CAPE SPENCER EXPERIENCED
HURRICANE FORCE GUSTS (75 KT) OUT OF THE WEST LATE YESTERDAY
EVENING. NORTHERN LYNN CANAL REPORTED GALE FORCE SOUTHERLIES A
FEW HOURS LATER. FINALLY...SKAGWAY'S LIGHT NORTHERLIES FLIPPED TO
SOUTHERLY AND BEGAN GUSTING TO 50 MPH AN HOUR OR TWO AFTER THAT.
SURFACE HIGH PRESSURE HAS NOSED INTO THE CENTRAL PANHANDLE
OVERNIGHT BUT WILL BE PUSHED NORTHWARD THIS MORNING IN RESPONSE TO
A GALE FORCE FRONT REACHING THE CENTRAL AND EASTERN GULF THIS
AFTERNOON AND CONTINUING TO PULL NORTHWEST TONIGHT.

WINDS ARE ALREADY SHIFTING TO NORTH OVER THE SOUTHERN PANHANDLE.
WE EXPECT WINDS ACROSS THE NORTHERN PANHANDLE TO RE-SWITCH TO
NORTH AFTER THE BIG SOUTHERLY CHANGEOVER OVERNIGHT A FEW HOURS
FROM NOW THIS MORNING. GRADIENTS WILL TIGHTEN THIS AFTERNOON AND
LIKELY MAXIMIZE THIS EVENING BEFORE GRADIENTS BECOME ORIENTED MORE
PARALLEL TO NORTH-SOUTH CHANNELS LATE TONIGHT. THUS THE STRONGEST
NORTHERLIES/EASTERLIES WILL LIKELY PEAK THIS EVENING BEFORE SLOWLY
DIMINISHING. WINDS ACROSS THE SOUTH WILL BECOME MORE
SOUTHEASTERLY AND STRENGTHEN TONIGHT AS THE FRONT BRUSHES
SOUTHEAST'S OUTER ISLANDS. AT THIS POINT WE HAVE KEPT ALL OF OUR
CUSTOMARY TRIGGER POINTS: DOWNTOWN JUNEAU...WESTERN PRINCE OF
WALES ISLAND...THE SOUTHERN INNER CHANNELS...BARANOF ISLAND ALL
UNDER 40 MPH GUSTS. WINDS AT 925 MB DO REACH 45 KT TO BE
SURE...BUT THE WARMTH ARRIVING WITH THIS WAVE WILL HAVE A TENDENCY
TO KEEP THESE WINDS ALOFT.

THE WARMTH OF FEBRUARY 8TH WAS RECORD-BREAKING. KLAWOCK AND
JUNEAU BOTH EXPERIENCED RECORD HIGH TEMPERATURES. RECORD-BREAKING
WARMTH GENERALLY CAUSES ISSUES FOR GUIDANCE RESOURCES, AS RECORDS
ARE THERE FOR A REASON, AND GUIDANCE LIKE MANY PEOPLE HAVE
DIFFICULTY COPING WITH NEW SITUATIONS. AT THIS POINT, WE FEEL THAT
GIVEN THE STRONG WARM AIR ADVECTION ASSOCIATED WITH THE SOUTHERLY
PUSH AHEAD OF LAST NIGHT'S SURFACE LOW THAT JUMPED INTO
CANADA...MANY HIGH TEMPERATURES HAVE ALREADY BEEN REACHED ACROSS
THE NORTH. THEREFORE, THERE MAY BE A LITTLE COOLING THROUGH THE
DAY. HOWEVER, MORE WARMING IS DUE TONIGHT, SO LOOK FOR
TEMPERATURES TO BOTTOM OUT IN MANY AREAS THIS EVENING BEFORE
RISING AGAIN FOR THE SOUTHERN AND CENTRAL PANHANDLE. A COUPLE OF
AREAS TO WATCH THAT MAY BUCK THIS FORECAST ARE YAKUTAT AND HAINES
WHERE SNOW LEVELS MAY BE LOWER THAN FORECAST. ALL MODELS TREND SNOW
LEVELS DOWN ACROSS THE NORTH. THIS MAKES SENSE AS NORTHERLIES
WILL DRAW DRYER AIR, IF NOT APPRECIABLY COOLER AIR ACROSS THE
BORDER. AT THIS POINT, WE FEEL THIS WEDGING WILL NOT BE STRONG
ENOUGH TO CHANGE PRECIP TYPE TO SNOW, BUT IT COULD. TONIGHT'S
PUSH OF WARM AIR SEEMS EVEN MORE IMPRESSIVE THAN YESTERDAY'S.
HENCE FOR NOW, WE ARE LEAVING EVERYTHING EXCEPT WHITE PASS RAIN.

USED NAM/ECMWF AS GUIDANCE FOR SMALL CHANGES. OVERALL FORECAST
LOOKS VERY SIMILAR FROM LAST PACKAGE. FORECAST CONFIDENCE GOOD
EXCEPT FOR ISSUES MENTIONED ABOVE.

.LONG TERM...MORE OF THE SAME FOR THE NEARER TIME FRAMES BUT THE
LONGER RANGE SOLUTIONS MAY BE TRYING TO HINT AT A PATTERN SHIFT
FOR NEXT WEEK. THROUGH FRIDAY THE SOUTHERLY FLOW PATTERN ALOFT
WILL CONTINUE TO STREAM MOIST WARMER AIR NORTHWARD TO THE EASTERN
GULF. THE BLOCKING RIDGE ALOFT OVER THE CANADIAN ROCKIES WILL BE
BROKEN DOWN BY THE TROUGH OVER GULF BEING MOVED EASTWARD AND
KICKED INLAND BY SUNDAY. THE UPPER LEVEL LOW THAT HAD BEEN
SUPPORTING THE GENERAL TROUGH WAS WEAKENED BY A STRONG LONG WAVE
FEATURE THAT IS STRENGTHEN AS IT MOVES EAST FROM NORTHERN JAPAN.
THIS LOW WILL REPLACE THE OTHER ONE BY EARLY NEXT WEEK AS THE
SOUTHER PORTION OF THE TROUGH ROTATES TO EAST ACROSS THE CENTRAL
PACIFIC.

THIS MEANS WARM AND WET PATTERN THROUGH THE WEEK WILL CONTINUE.
TROF OR FRONT WILL MOVE NORTH OVER THE EASTERN GULF ABOUT 24 HOURS
APART FROM EACH OTHER BEFORE A STRONGER FRONTAL BAND ASSOCIATED
WITH THE NEW LOW MOVES ACROSS THE GULF TO IMPACT SOUTHEAST ALASKA
OVER THE EARLY WEEKEND.

THE SUCCESSIVE FRONTS AND TROFS THROUGH THE WEEK WILL LIKELY
BRING WINDS UPTO GALE FORCE AS THE MOVE NORTH SO THERE WILL BE
BREEZY CONDITIONS EXPECTED ALONG THE OUTER COASTAL AREAS. THE LOW
CIRCULATIONS WITH THIS FRONTS ARE EXPECTED TO TURN WEST BACK
TOWARDS THE NORTHWEST AND NORTHERN GULF BEFORE THEY GET ABSORBED
BAY INTO THE GENERAL LOW PRESSURE.

CONFIDENCE IS AVERAGE THROUGH THE FORECAST.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ022-043.
     SMALL CRAFT ADVISORY FOR PKZ011-012-021-033-035-036-041-042-051-
     052.
     SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.
&&

JWA/BEZENEK

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU