Gale Warning 52, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
229 PM AKST SAT JAN 16 2010

.SHORT TERM...SATELLITE IMAGERY REVEALS A LOW IN THE NORTHERN
GULF APPROACHING THE KENAI PENINSULA. SURFACE AND MARITIME
OBSERVATIONS INDICATING THAT THE FRONT IS COMING ASHORE AT CAPE
SUCKLING AS OF EARLY THIS AFTERNOON. PRESSURE GRADIENT
ORIENTATION MADE IT NECESSARY TO ISSUE A WIND ADVISORY FOR ZONE
17 AS WELL AS STARTING THE ADVISORY FOR ZONE 22 EARLY. OUTFLOW
WINDS IN MOTION AND HAVE SEEN LOCALLY WINDY CONDITIONS THROUGHOUT
THE DAY IN THE JUNEAU AREA. FARTHER SOUTH...STORM FORCE WINDS IN
CLARENCE STRAIT AND ONE 56 KT GUST IN HYDABURG. PRECIP ALMOST
ENTIRELY IN THE FORM OF RAIN. EXCEPTIONS INCLUDE YAKUTAT WHICH
REPORTED A LITTLE MIXED PRECIPITATION EARLIER TODAY. RAIN IN
SKAGWAY BUT SNOW IS INFERRED ON THE KLONDIKE HIGHWAY BASED ON
TEMPS AT SKAGWAY AND CONFIRMED BY SKAGWAY CUSTOMS PERSONNEL.
LIKEWISE ALONG THE HAINES HIGHWAY WITH THE SENSOR AT THE CHILKAT
RIVER BRIDGE REPORTING IN THE LOW 30S ALL DAY AND OVERNIGHT SNOW
TOTALS OF 7.5 INCHES AT HAINES CUSTOMS AS OF THIS MORNING. SNOW
WILL CONTINUE IN THESE LOCATIONS AND WILL LET THE ASSOCIATED
WARNING AND ADVISORY RUN THROUGH MIDNIGHT TONIGHT. ADDITIONAL
SNOW EXPECTED TO FALL ALONG THE HIGHWAYS...BUT ACCUMULATION RATES
EXPECTED TO TAPER OFF BELOW ADVISORY CRITERIA LATE TONIGHT.

 A WAVE ALONG THE FRONTAL BOUNDARY IS CURRENTLY DEVELOPING INTO A
CLOSED LOW SW OF THE QUEEN CHARLOTTES. AS THAT FEATURE DEEPENS
AND TRACKS NORTH...THE PRESSURE GRADIENT ALONG THE SOUTHERN HALF
OF THE PANHANDLE WILL MAINTAIN. AS A RESULT...WIND ADVISORIES FOR
ZONES 23...26...S7...AND 28 WILL CONTINUE THROUGH THE NIGHT.
OTHER WARNINGS AND ADVISORIES EXPIRING BY MIDNIGHT.

 PLENTY OF WIND SHEAR IN TAFS THIS MORNING AND EXPECT TO HAVE
SOME IN THE AFTERNOON ISSUANCE AS WELL...BUT THE HEAVY WEATHER
TREND FOR AVIATION...MARINE...AND PUBLIC FORECASTS IS DEFINITELY
DOWN BY THE END OF THE SHORT TERM FORECAST PERIOD.

&&

.LONG TERM...LONG TERM PERIOD BEGINS WITH 300 MB LONG WAVE TROUGH
DIGGING SOUTHEAST ACROSS THE NORTHERN PACIFIC AND GULF OF ALASKA
WHILE AN UPPER LEVEL RIDGE OVER THE WEST COAST WEAKENS AND MOVES
EAST OVER THE MIDWEST MONDAY THROUGH THURSDAY. AS THE LONGWAVE
TROUGH CONTINUES TO DIG TO THE SOUTHEAST MOST OF THE ENERGY WILL
BE IMPACTING WA OR AND CA. AN UPPER LEVEL RIDGE FORMS OVER THE BERING
SEA AND WESTERN ALASKA FRIDAY AND SATURDAY.

 ON THE SURFACE A 967 MB 200 NM SOUTH OF COLD BAY WEAKENS MONDAY
AND TUESDAY AS A 960 MB LOW PINWHEELS FROM WEST OF WA NORTHWARD TO
JUST WEST OF THE QUEEN CHARLOTTES AND THEN WESTWARD INTO THE
CENTRAL GULF OF ALASKA WEDNESDAY AND THURSDAY. SURFACE HIGH
PRESSURE DEVELOPS IN THE EASTERN INTERIOR OF ALASKA AND MOVES
SLOWLY EAST SOUTHEAST THROUGH THE WEEKEND.

 NET AFFECT ON THE SOUTHEAST PANHANDLE WEATHER WILL BE WEAK
ONSHORE FLOW IN THE UPPER LEVELS AND MODERATE OFF SHORE FLOW IN
THE LOW LEVELS. POPS WILL DIMINISH THROUGH THE WEEK ACROSS THE
PANHANDLE AS HIGH PRESSURE DEVELOPING IN THE INTERIOR AND THE LOWS
SOUTH OF THE PANHANDLE HANDLE BRING OFFSHORE FLOW IN THE LOW
LEVELS. EXPECT LOW LEVEL POPS IN THE SOUTHERN ZONES WITH PROXIMITY
TO LOWS AND BETTER VERTICAL MOTIONS AND MINIMAL POPS IN THE
NORTHERN ZONES. GRADIENT TIGHTENS UP ALONG HE COASTAL MOUNTAINS BY
LATE WEEK BETWEEN THE HIGH IN THE INTERIOR THAT MOVES EAST AND
THEN SOUTHEAST AND THE LOWS MOVING THROUGH THE GULF. GUSTY GAP
FLOWS OUT OF INTERIOR PASSES ALONG WITH COLDER TEMPERATURES IN THE
INNER CHANNELS DEVELOPING FRIDAY THROUGH SUNDAY.

 GLOBAL MODELS ARE IN FAIR AGREEMENT ON A GLOBAL PATTERN
TRANSITION BUT CONTINUE TO DIVERGE ON THE DETAILS TO ACHIEVE THE
PATTERN CHANGE. MADE ONLY MINOR UPDATES TO INHERITED GRIDS WITH
UKMET AND GFS BLEND THROUGH DAY 4 AND A TRANSITION TO ECMWF BLEND
WITH LATEST HPC GUIDANCE FOR THE REST OF THE LONG RANGE. FORECAST
CONFIDENCE IS ABOVE AVERAGE THROUGH DAY 4 AND AVERAGE PAST THAT POINT.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 6 AM AKST SUNDAY FOR AKZ026.
         WIND ADVISORY UNTIL 6 AM AKST SUNDAY FOR AKZ023-027-028.
         WIND ADVISORY UNTIL MIDNIGHT AKST TONIGHT FOR AKZ022.
         WINTER STORM WARNING UNTIL MIDNIGHT AKST TONIGHT FOR AKZ019.
         WINTER WEATHER ADVISORY UNTIL 6 PM AKST THIS EVENING FOR AKZ018.
         WIND ADVISORY UNTIL 6 PM AKST THIS EVENING FOR AKZ017.
MARINE...STORM WARNING FOR PKZ036.
         GALE WARNING FOR PKZ041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-022-031>035.

&&

FRITSCH/CCC