Gale Warning 93, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
605 AM AKST MON FEB 10 2014

.SHORT TERM...WINDY AND COLD FOR THE CENTRAL AND NORTHERN
PANHANDLE WITH SNOW DEVELOPING OVER THE SOUTHERN PANHANDLE. HIGH
PRESSURE WILL BUILD OVER THE YUKON AS IT SHIFTS SOUTH THIS MORNING
THEN WEAKEN TONIGHT AS THE HIGH CENTER TRACKS INTO NORTHER BRITISH
COLUMBIA. AN ELONGATED LOW WITH TWIN 992 MB CENTER IS LOCATED JUST
SOUTH OF THE AK GULF. THE FIRST CENTER IS JUST OF THE COAST OF
HAIDA GWAII AND WILL CROSS OVER DIXON ENTRANCE INTO SOUTHERN BC
THROUGH THE DAY. THE ASSOCIATED WEATHER FRONT CAN BE SEEN ON
SATELLITE IMAGERY JUST HITTING THE SOUTHERN PANHANDLE COAST.
PRECIP WILL DEVELOP THROUGH THE MORNING THEN DIMINISH MONDAY
EVENING. SOME MODEL SPREAD REGARDING THE NORTHERLY EXTENT OF THE
PRECIP AND EXACT POSITION OF QPF VALUES. ECMWF.UKMET MOVE PRECIP
AS FAR NORTH AS FREDERICK SOUND WHILE THE GFS/NAM KEEP POP SOUTH
OF SUMNER STRAIT. LEANED MORE TOWARD THE GFS/NAM BUT DID BLEND
SOME ECMWF. AS THE SYSTEM IS FAST MOVING AND 6 HOUR QPF VALUES ARE
ONLY IN THE 0.15 TO 0.25 RANGE THINK SNOW FALL AMOUNTS FOR AKZ27
WILL BE IN THE 1 TO 3 INCH RANGE WHILE AKZ28 SNOW TOTALS WILL BE
IN THE 2 TO 5 INCH RANGE THROUGH THE EVENING. AKZ29 AND HYDER WILL
GET A BIT MORE SNOW WITH AMOUNTS UPWARDS OF 7 INCHES NEAR THE
CANADIAN BORDER AS THE FRONT WILL REMAIN OVER THE AREA LONGER.

 ANOTHER 500 MB TROUGH MOVES DOWN FORM THE YUKON BRINGING MORE
COLD AIR TO THE REGION. SOUTHERN AREA HIGH TEMPS WILL BE IN THE
UPPER 20S TO LOW 30S DUE TO THE ADVANCING FRONT BUT NORTHERN
LOCATIONS WILL BE IN THE TEENS TO LOW 20S. OVERNIGHT LOWS WILL BE
IN THE IN THE SINGLE DIGITS WITH THE ARCTIC AIR MOVING IN AND
RADIATIONAL COOLING DUE TO CLEAR SKIES. HIGHER ELEVATION WILL BE
WELL BELOW ZERO.

 THE MAIN WEATHER ISSUE CONTINUES TO BE THE HIGH WINDS WITH THE
STRONG PRESSURE GRADIENT BETWEEN THE YUKON HIGH AND HAIDA GWAII
LOW. TAKU WIND EVENT FOR DOWNTOWN JUNEAU IS SHAPING UP WITH
COMPONENTS OF CROSS BARRIER FLOW, CRITICAL LEVEL AND INVERSION
DEVELOPING THROUGH THE MORNING. EXPECTING GUSTS IN THE 60 TO 70
MPH RANGE AS FLOW REVERSAL AT 600 MB REFLECT THE CROSS BARRIER
FLOW TO THE SURFACE. OUTFLOW WINDS ALONG THE CENTRAL INNER
CHANNELS ALREADY REPORTING GUSTS UPWARDS OF 50 MPH AND ARE ONLY
EXPECTED TO INCREASE. STORM FORCE WINDS FOR NORTHER LYNN CANAL
WILL LAST INTO THE EVENING WHEN THE GRADIENT WILL BEGIN TO
DIMINISH AS THE HIGH SHIFT INTO BC AND THE LOW MOVES EXITS TO THE
EAST. HIGH SEAS IN THE 10 TO 14 FOOT RANGE EXTENDING DOWN LYNN
CANAL INTO NORTHERN CHATHAM STRAIT DUE TO THE LONG FETCH OF
NORTHERLY WINDS.

 MAIN MODEL DIFFERENCES WERE THE PORTION AND TIMING OF THE POP
FORM THE WEATHER FRONT OVER THE SOUTHERN PANHANDLE. OTHERWISE THEY
WERE IN GOOD AGREEMENT FOR THE SYNOPTIC PRESSURE PATTERN. CHANGES
WERE MINOR AS KEPT WITH A NAM/ECMWF BLEND. FORECAST CONFIDENCE IS
ABOVE AVERAGE.

 &&

 .LONG TERM...MODELS IN GENERALLY FAIR AGREEMENT THROUGH THE EARLY
PART OF THE WEEK. THE SURFACE LOW MOVES FROM THE SOUTHWEST GULF
ACROSS TO THE DIXON ENTRANCE REGION BY TUESDAY NIGHT AND THEN
ONSHORE. THIS WILL LIKELY BE LEAVING A LOW IN THE PRINCE WILLIAM
SOUND POCKET REGION. THE FLOW PATTERN LOOKS TO KEEP THE ROTATING
PATTERN OF SHORT WAVE GOING TO THE WEEKEND. PULLING A WAVE FROM
SOUTH OF THE GULF TO THE SOUTHERN PANHANDLE AND THEN DRIVING A NEW
ONE SOUTH OF THE GULF FROM THE EASTERN ALEUTIANS.

 THE LOW IS NEARLY VERTICALLY STACKED IT LOOKS LIKE THERE WILL BE
SUBSTANTIAL COLD AIR BEING PULLED SOUTH OVER THE INTERIOR AND INTO
THE WESTERN PORTION OF THE GULF OF ALASKA. THE TIGHT NORTH
GRADIENT AND OUTFLOW WINDS ARE EXPECTED TO CONTINUE THROUGH
TUESDAY NIGHT AND IMPROVING WEDNESDAY.

 FORECAST CONFIDENCE IS AVERAGE OR SLIGHTLY BETTER EARLY...HOWEVER
LATER PERIODS MORE ISSUES ARE CLUSTERING IN. USED GFS AND ECMWF AS
A BLEND FOR MOST OF THE FORECAST ITEMS EARLY. I WENT A HEAD WITH
WITH BETTER AGREEMENT THAN THE PREVIOUS DAY SHIFT I THINK MADE A
CHANGE TO THE EXTENDED A PUTTING MORE OF THE EC/GFS OPERATIONAL
BLEND INTO THE EXTENDED. AM THINKING THAT THE NEW WPC SOLUTION
TODAY WILL BE SIMILAR.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WARNING UNTIL 9 PM AKST THIS EVENING FOR AKZ025.
         STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ022.
         WINTER WEATHER ADVISORY UNTIL 9 PM AKST THIS EVENING FOR AKZ028.
         STRONG WIND THROUGH LATE TONIGHT FOR AKZ018-019.
         WIND CHILL ADVISORY UNTIL NOON AKST TUESDAY FOR AKZ018.
         STRONG WIND THROUGH THIS EVENING FOR AKZ017.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ021.
         HEAVY FREEZING SPRAY WARNING FOR PKZ053.
         HEAVY FREEZING SPRAY WARNING FOR PKZ011>013-031.
         STORM WARNING FOR PKZ012.
         GALE WARNING FOR PKZ011-013-021-022-031-032-034-035-043-051.
         SMALL CRAFT ADVISORY FOR PKZ033-036-041-042-052-053.

&&

PRB/BEZENEK