Small Craft Advisory 702, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
203 PM AKDT SAT SEP 13 2014

.ANALYSIS AND UPPER LEVELS...
SATELLITE ANALYSIS CONTINUES TO SHOW A VERY VISUALLY IMPRESSIVE
LOW THAT IS WOUND UP ALONG THE EASTERN ALEUTIANS THIS AFTERNOON.
ACCOMPANIED WITH THIS LOW ARE SOME INTERESTING FEATURES. FIRST IS
THE REMNANTS OF AN OCCLUDED FRONT STRETCH FROM WEST OF GAMBELL...
NORTH THROUGH NORTON SOUND. THE OCCLUDED FRONT HAS DISSIPATED TO
JUST A WEAK SURFACE REFLECTION ACROSS THE LAND... WHILE THE
REMAINING PORTION OF THE FRONT CONTINUES TO SWEEP EAST ACROSS THE
GULF THIS MORNING AND HAS A VAST STRETCH OF WARMTH AND MOISTURE TO
ACCOMPANY. TUCKED BEHIND THIS FRONT IS A DRY SLOT THAT CLEARED OUT
AREAS ALONG THE KENAI PENINSULA AND MAY WORK INTO THE ANCHORAGE
AREA INTO THIS AFTERNOON...ALLOWING A FEW POKES OF SUNSHINE. WEST
OF THIS LOW ARE WHERE STRONG WINDS REMAIN. THE HIGH WIND WARNING
FOR THE ALEUTIANS WAS ALLOWED TO EXPIRE AS PEAK GUSTS ACROSS THE
AREA DROP WELL BELOW 75 MPH THIS AFTERNOON...THIS DUE TO THE
WEAKENING OF THE SURFACE LOW AND THE MOVEMENT AWAY FROM THE
ALEUTIANS.

&&

.MODEL DISCUSSION...

MODELS ARE IN GOOD AGREEMENT THIS AFTERNOON WITH THE CONTINUED
EVOLUTION OF THE STACKED LOW THAT IS WORKING ACROSS THE EASTERN
BERING / ALEUTIAN CHAIN. ALL MODELS HAVE SIMILARITIES WITH THIS
UPPER LEVEL LOW MOVING EAST AND EVENTUALLY RETROGRADING TO THE
NORTHWEST AND NEAR GAMBELL/SAVOONGA INTO EARLY NEXT WEEK. THE
BIGGEST DIFFERENCE IS WITH THE GFS...AS IT ATTEMPTS TO LIFT THE
LOW NORTH AND ACROSS CAPE NEWENHAM...WHILE ALL OF THE OTHER MAJOR
MODELS /NAM,ECMWF,CANADIAN/ CONTINUE TO MOVE THE ACROSS DILLINGHAM
AND EVENTUALLY NORTHWEST. FOR THOSE REASONS...THE GFS WAS NOT
UTILIZED. ALL OF THE MODELS HAVE A DECENT HANDLE ON MERGING A WEAK
SURFACE LOW THAT WILL DROP SOUTH FROM THE BERING STRAIT AND
ANOTHER LOW THAT WILL MOVE IN FROM THE WESTERN ALEUTIANS...BY THE
BEGINNING OF THE NEXT WORK WEEK. THIS LOW WILL EVENTUALLY WEAKEN
ALONG THE EASTERN ALEUTIANS AS ANOTHER AND STRONGER LOW MOVES IN
FROM THE PACIFIC AND TAKES AIM FOR THE GULF. THE OVERALL TREND IS
THERE...BUT ALL MODELS OFFER VARYING DEGREES OF STRENGTH AND
TIMING OPTIONS. THE EXTENDED FORECAST STUCK CLOSER TO GEFS AND EC
ENSEMBLE MEANS TO KEEP SOME CONSISTENCY AND AGREEMENT IN PLACE FOR
THE LONG RANGE FORECAST.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...THE BULK OF PRECIPITATION WILL CONTINUE TO
MOVE EAST WITH THE FRONT THROUGH THE AFTERNOON AND INTO THE
EVENING HOURS. THE PRESSURE GRADIENT WILL ALSO CONTINUE TO WEAKEN
ALLOWING WINDS ACROSS MUCH OF THE AREA TO DIMINISH. THERE MAY BE
LINGERING GUSTS OF 15 OR SO MPH ALONG THE HILLSIDE THIS
EVENING...WITH NOTHING HIGHER ANTICIPATED. OVERALL SKY CONDITIONS
WILL REMAIN PRETTY CLOUDY THROUGH THE WEEKEND WITH DAYTIME HIGHS
LINGERING IN THE UPPER 50S AND OVERNIGHT LOWS IN THE UPPER 40S.
CLIMATOLOGICAL SPEAKING...THAT IS CLOSE TO ON PAR FOR THE MIDDLE
OF SEPTEMBER...WHERE HIGHS SHOULD BE AROUND 57 AND OVERNIGHT LOWS
SHOULD BE AROUND 43 DEGREES. HYDROGRAPH READINGS AT THE
RESURRECTION RIVER BRIDGE PEAKED THIS MORNING JUST UNDER 18 FEET
FOR A BRIEF PERIOD...BUT WITH RAIN SHIFTING EAST NOW...LEVELS HAVE
DROPPED TO ACTION STAGE AND ARE EXPECTED TO CONTINUE TO DROP. THE
ADVISORY IS CURRENT OUT THROUGH 5 PM TODAY...AND WILL LIKELY BE
ALLOWED TO BE DROPPED WITH NO INCREASE EXPECTED AS OF NOW.

SOUTHWEST ALASKA...SUNSHINE WITH WARMER TEMPERATURES AND GUSTY
WINDS WILL SEE THE DAY CLOSE OUT. AS THE STACKED LOW ACROSS THE
EASTERN ALEUTIAN CHAINS MOVES CLOSER...CHANCES FOR RAIN WILL
INCREASE INTO THE LATE OVERNIGHT HOURS AND INTO THE AFTERNOON
HOURS SUNDAY. DAYTIME HIGHS AND LOWS WONT WAVE MUCH BEYOND WHAT
HAS BEEN HAPPENING /UPPER 50S AND UPPER 40S/ ALREADY. THE GUSTY
WINDS WILL BEGIN TO DIMINISH LATE INTO THE DAY TOMORROW AND
GRADUALLY TURN ONSHORE AND FROM THE SOUTHWEST AS THE SURFACE LOW
MOVES INLAND AND TOWARDS DILLINGHAM.

BERING SEA/ALEUTIANS...
STRONG STORM FORCE WINDS OUT OF THE NORTHWEST WILL ABATE OVERNIGHT
AS THE LOW IN THE EASTERN BERING WEAKENS AND SLIDES INTO WESTERN
ALASKA. TYPICAL STRATUS/FOG WILL BE PRESENT ALONG A WEAK RIDGE IN
THE WESTERN ALEUTIANS AS IT SLOWLY SLIDES TO THE EAST AND SOUTH.
CHANCES FOR RAIN WILL INCREASE AGAIN TOMORROW NIGHT AS A WEAK LOW
WILL DEVELOP SOUTH OF SHEMYA AND MOVE EAST ACROSS THE ALEUTIAN
CHAIN.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 119 155 160 170 171 172 173 174 175 176 180
FIRE WEATHER...NONE.

SSS - SEP 14