Small Craft Advisory 885, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
510 PM AKST FRI NOV 7 2014

.ANALYSIS AND UPPER LEVELS...
SOUTHWEST BERING UPPER LOW AT 500 MB WILL BECOME THE DEEPEST IN
THE HEMISPHERE FRIDAY NIGHT (479) DUE TO THE BIG PRESSURE FALLS AT
THE SURFACE. UPPER TROF KODIAK ISLAND LIFTS NORTHWARD SATURDAY
WHILE THE ASSOCIATED SURFACE LOW WEAKENS AND SLIDES NORTHWARD JUST
EAST OF THE ISLAND TONIGHT. THAT LOW WILL MAKE LANDFALL ON THE
KENAI PENINSULA COAST WEST OF RESURRECTION BAY MIDDAY OR EARLY
AFTERNOON SATURDAY. BY SUNDAY MORNING A SOUTHERLY JET WILL HAVE
SET UP ALONG 155W BETWEEN THE DEEP SOUTHCENTRAL BERING UPPER LOW
AND A BUILDING RIDGE ALONG 140W. THIS PATTERN IS KNOWN FOR ITS
PERSISTENCE AND PROBABLY WILL LINGER FOR AT LEAST 4 OR 5 DAYS
KEEPING TEMPERATURES ABOVE NORMAL AND SNOWFALL BELOW.

&&

.MODEL DISCUSSION...ALL FOUR FORECASTERS DECIDED TO USE THE EC HIGH
RESOLUTION MODEL DUE TO BETTER CONSISTENCY, INTENSITY AND TRACK.
THROUGH 72 HOURS THE DIFFERENCES BETWEEN THE BETWEEN THE TWO ARE
NOT TOO GREAT AND EVEN NONEXISTENT IN AREAS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
LAST NIGHTS FRONT DID NOT DISAPPOINT. STORM FORCE WINDS WERE
OBSERVED ACROSS MUCH OF THE NORTHERN GULF OF ALASKA ALL THE WAY
DOWN THROUGH THE BARREN ISLANDS. EVEN THE PRINCE WILLIAM SOUND HAD
A GUST TO 47KT. THE UPPER LEVEL THAT HELPED TO PUSH THAT FRONT
ACROSS THE AREA CONTINUES TO SPIN SOUTH OF KODIAK ISLAND. IT WILL
CONTINUE TO LIFT WEAK WAVES FROM THE SOUTH GULF TO THE COAST
TONIGHT AND EARLY SATURDAY. THESE WAVES WILL CAUSE THE GUSTY
NORTHEAST TO SOUTHEAST WINDS AND HEAVIER PRECIP TO EBB AND FLOW.

ON SATURDAY...AS THE MONSTER OVER THE BERING SLOWLY PROGRESSES
EASTWARD...IT WILL DO A FEW THINGS. FIRST...IT WILL GIVE ENOUGH OF
A PUSH TO THE PREVIOUSLY MENTIONED UPPER LEVEL LOW TO DRIFT
THROUGH SOUTH CENTRAL. AS THAT LOW MOVES THROUGH IT SHOULD BRING A
SLIGHTLY ENHANCED CHANCES FOR PRECIPITATION LATE SATURDAY INTO
SUNDAY AS THE DOWNSLOPING WINDS SHUT OFF. IT WILL THEN SEND A
SURGE OF ABOUT 10C DEGREES IN THE MID LEVELS FORWARD UNDERNEATH
THE NORTH AMERICAN RIDGE. THIS WILL SERVE TO DRAMATICALLY BUILD
THIS RIDGE UP NORTH OF THE NORTH SLOPE. THIS WILL PUT SOUTHCENTRAL
UNDER DEEP AND RATHER STRONG SOUTHERLY FLOW TOWARDS EARLY NEXT
WEEK. THE MAIN FRONT ASSOCIATED WITH NURI REMNANTS WILL RIDE THIS
FLOW TOWARD THE COAST LATE SUNDAY. AS FOR NOW...IT LOOKS LIKE
PRECIPITATION WILL BE HEAVIEST FOR COASTAL AREAS ONCE AGAIN WITH
DOWNSLOPING WINDS "PROTECTING" INLAND LOCATIONS. IT WILL CAUSE THE
TYPICAL SPOTS...TURNAGAIN ARM...THOMPSON PASS...KACHEMAK BAY...TO
BLOW. THE MAT-SU VALLEY COULD ALSO SEE AN INCREASE IN NORTHEAST
WINDS LATE SUNDAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
SCATTERED RAIN AND SNOW SHOWERS OVER THE BRISTOL BAY AREA CONTINUE
TO TAPER OFF THIS EVENING...WITH MOST OF THE RAIN ALONG THE
ALASKA PENINSULA AND PRIMARILY SNOW ELSEWHERE. THE REST OF THE
SOUTHWEST WILL REMAIN RELATIVELY DRY...EXCEPT FOR SOME LINGERING
ISOLATED SNOW SHOWERS AROUND THE EASTERN PART OF THE KUSKOKWIM
DELTA AND SCATTERED SNOW SHOWERS EAST OF SLEETMUTE TONIGHT.
MOVING INTO THE WEEKEND PRECIPITATION AROUND BRISTOL BAY WILL
LIGHTEN UP UNTIL A FRONT MOVES IN FROM THE WEST SATURDAY AFTERNOON.
THIS FRONT WILL BRING WARMER AIR THROUGHOUT THE SOUTHWEST WHICH
WILL BRING THE RAIN LINE FURTHER NORTH IN BRISTOL BAY. THE
KUSKOKWIM DELTA AND LOWER KUSKOKWIM VALLEY WILL ALSO SEE SOME SNOW
FROM THIS SYSTEM THAT WILL START TO MIX WITH RAIN AS MORE WARM
AIR PUSHES IN FROM THE SOUTH.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
RAIN AND SNOW SHOWERS OVER THE EASTERN ALEUTIANS HAVE TAPERED OFF
WITH WEAK RIDGING FROM THE WEST QUICKLY PASSING THROUGH THE
EASTERN ALEUTIANS TONIGHT. RAIN AND GUSTY WILL PICK UP AGAIN FROM
WEST TO EAST AFTER MIDNIGHT...AS THE FRONT ASSOCIATED WITH THE
EXTRATROPICAL CYCLONE OUT WEST CONTINUES TOO TRACK EASTWARD.
FURTHER OUT WEST...THE LOW NORTHWEST OF SHEMYA WILL SLOWLY TRACK
TOWARD THE CENTRAL BERING BY LATE SUNDAY MORNING...CONTINUING TO
BRING RAIN AND GUSTY WINDS TO THE WESTERN AND CENTRAL ALEUTIANS
THROUGH SUNDAY. WARNING LEVEL WINDS ARE EXPECTED TO PICKUP AGAIN
TONIGHT OVER THE WESTERN ALEUTIANS AND PERSIST THROUGH TOMORROW
MORNING...THEN SLOWLY DIMINISH AS THE LOW PROGRESSES EASTWARD.

&&

.LONG TERM FORECAST (SUNDAY NIGHT THROUGH THURSDAY NIGHT)...

THE CLOSED UPPER LOW OVER THE CENTRAL BERING WILL REMAIN STATIONARY
SUNDAY NIGHT THROUGH MONDAY AND THEN ELONGATE AS A RIDGE BUILDS OVER
EASTERN ALASKA. AT THE SURFACE...THE FRONT ACROSS THE SOUTHWEST AND
WESTERN GULF WILL CONTINUE TO MOVE NORTHEAST. WITH A GENERAL
SOUTHEAST FLOW NEAR THE SURFACE...THE GULF COASTAL LOCATIONS WILL
SEE THE HIGHEST PRECIPITATION AMOUNTS WITH ISOLATED TO SCATTERED
SHOWERS INLAND. PRECIPITATION TYPE WILL BE A MIX OF RAIN AND SNOW
ACROSS THE SOUTHWEST SUNDAY NIGHT INTO MONDAY. WITH A WARMER AIRMASS
MOVING INTO THE SOUTHERN MAINLAND BEHIND THE FRONT...SOUTHCENTRAL
WILL SEE RAIN AND SNOW MIXES. GULF COASTAL LOCATIONS CONTINUE WITH
RAIN AS ANOTHER SURGE OF WARM AIR MOVES UP THROUGH THE GULF ON
TUESDAY. THE COPPER RIVER VALLEY REMAINS COLD ENOUGH TO STAY SNOW
UNTIL THE NEXT WARM AIR MASS SURGES NORTH ON WEDNESDAY BRINGING A
CHANCE FOR A MIXED RAIN AND SNOW.

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 130 131 132 138 150 155 160 165 170 171 172 173 174
              175 179 180 181 185 414.
         STORMS 176 177 411 412 413. HURRICANE FORCE 178.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...DP
SOUTHCENTRAL ALASKA...MO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...KH