Small Craft Advisory 795, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT FRI OCT 11 2013

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL LOW OVER THE BERING SEA AND ALEUTIANS WITH
A DEVELOPING SURFACE LOW NEAR DUTCH HARBOR. FRONTAL PRECIPITATION
WITH THIS LOW IS CURRENTLY PUSHING INTO SOUTHWEST ALASKA. THERE IS
A BROAD RIDGE OVER EASTERN ALASKA. A WEATHER SYSTEM MOVING INTO THIS
RIDGE IS CURRENTLY DISSIPATING OVER SOUTH CENTRAL ALASKA. THERE IS
AN UPPER LEVEL LOW CENTERED JUST NORTH OF JAPAN THAT IS MOVING
RAPIDLY TO THE EAST.

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH 84 HOURS.
NATURALLY THERE ARE SOME DIFFERENCES IN DETAILS...BUT OVER-ALL THE
FORECAST CONFIDENCE IS HIGHER THAN NORMAL.

.SHORT TERM FORECAST...
THE DUTCH HARBOR LOW WILL PUSH NORTH INTO THE BERING SEA THIS
EVENING AND THEN SLOW DOWN...STALLING BETWEEN THE PRIBILOFS AND CAPE
NEWENHAM BY SATURDAY AFTERNOON. WINDS WILL BE FAIRLY STRONG WITH
THIS LOW...WITH SOME STORM FORCE WINDS NEAR THE ALASKA PENINSULA AND
IN THE EASTERN BERING SEA TONIGHT AND SATURDAY. THE FRONTAL
PRECIPITATION AND WINDS WILL PUSH INTO SOUTH CENTRAL ALASKA TONIGHT.
MOST OF THE WINDS/PRECIPITATION WILL BE ALONG THE COASTAL AREAS AND
THROUGH TURNAGAIN ARM...WITH ANCHORAGE SOMEWHAT IN A RAIN SHADOW
WITH THE UPPER LEVEL FLOW SWITCHING FROM SOUTHWEST TO SOUTH.

THE EASTERN BERING LOW WILL DRIFT EAST AND WEAKEN BEGINNING SATURDAY
EVENING AND PUSH INTO THE NORTHERN GULF SUNDAY EVENING. AHEAD OF
THIS LOW A SYSTEM WILL DEVELOP ALONG THE LEADING FRONT OVER THE
SOUTHERN GULF OF ALASKA AND RAPIDLY MOVE NORTH. THIS WILL BRING
STRONG WINDS TO THE NORTHERN GULF SATURDAY NIGHT WITH A DECENT
BARRIER JET...THAT HAS SOME UPPER LEVEL SUPPORT THAT WILL HELP TO
PUSH IT THROUGH TURNAGAIN ARM. AS THE MAIN LOW MOVES INTO THE GULF
LATER SUNDAY THE FLOW ALOFT WILL BECOME SOUTHWEST AGAIN AND OPEN UP
THE INLAND AREAS TO MORE RAIN/SHOWERS.

THE JAPAN SYSTEM WILL RAPIDLY MOVE EAST AND BEGINNING TO AFFECT THE
WESTERN ALEUTIANS/WESTERN BERING SEA ON SATURDAY NIGHT. THE FRONTAL
WINDS/PRECIPITATION WILL PUSH ACROSS THE BERING SEA AND ALEUTIANS
THROUGH SUNDAY NIGHT AND REACH SOUTHWEST ALASKA ON MONDAY. MEANWHILE
SHOWERY CONDITIONS WILL CONTINUE OVER SOUTH CENTRAL ALASKA WITH THE
PASSAGE OF THE REMNANTS OF THE PREVIOUS SYSTEM.

.LONG TERM FORECAST...
THE GENERAL PATTERN WILL CONSIST OF THE MEAN LOW POSITION OVER THE
BERING SEA AND THE MEAN RIDGE POSITION JUST TO THE EAST OF ALASKA.
THIS WILL USHER IN A PATTERN THAT FAVORS WARM...WET...AND POSSIBLY
WINDY CONDITIONS FOR SOUTHERN ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING 155 179 180 185.
         GALE WARNING 119 120 125 130 131 132 138 139 141 150 160
                     165 170 171 172 173 174 175 176 177 178 181.
FIRE WEATHER...NONE.

LUDWIG OCT 13

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1215 PM AKDT FRI OCT 11 2013

AKZ101-111-121-125-131-135-141-145-152-155-161-121300-

...ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH NEXT WEEK...

AN UNUSUAL WEATHER PATTERN FOR ALASKA IS VERY LIKELY TO CONTINUE
THROUGH MID-OCTOBER...WITH A STORM TRACK ACROSS THE SOUTHERN BERING
SEA AND THEN INTO WESTERN ALASKA POTENTIALLY TAPPING INTO DEEP
TROPICAL MOISTURE. THIS PATTERN IS EXPECTED TO PERSIST INTO NEXT
WEEKEND.

WHILE THE EXACT TRACKS OF INDIVIDUAL STORMS WILL ONLY BE FORECAST
SEVERAL DAYS IN ADVANCE...THE BASIC PATTERN WILL RESULT IN LOCAL
HEAVY PRECIPITATION OVER THE COURSE OF THE WEEK...ALONG WITH
SIGNIFICANTLY ABOVE NORMAL TEMPERATURES FOR NEARLY ALL OF ALASKA.
THIS IS IN SHARP CONTRAST TO OCTOBER 2012...WHICH WAS UNUSUALLY COLD
OVER THE EASTERN TWO-THIRDS OF THE STATE.

PRECIPITATION IS VERY LIKELY TO BE WELL ABOVE NORMAL ALONG COASTAL
AREAS AND ON THE WINDWARD MOUNTAIN SLOPES. WITH THE MILD
TEMPERATURES...SNOW ELEVATION LEVELS WILL BE UNUSUALLY HIGH FOR THIS
LATE IN THE AUTUMN AND KEEP LOW ELEVATION SNOW AT BAY POSSIBLY
THROUGH AT LEAST NEXT WEEK. IN ADDITION...THE RESULTANT PATTERN MAY
LEAD TO COASTAL EROSION PROBLEMS ALONG THE WEST COAST OF ALASKA AND
KEEP RIVERS SWOLLEN ACROSS SOUTH CENTRAL ALASKA.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
100 PM AKDT FRI OCT 11 2013

AKZ161-181-120300-
100 PM AKDT FRI OCT 11 2013

...MINOR ASHFALL POSSIBLE FOR AREAS BETWEEN PORT MOLLER AND PILOT
POINT...

REPORTS INDICATED THAT VENIAMINOF VOLCANO WAS ERUPTING. ASHFALL IS
EXPECTED TO MOVE TOWARDS THE NORTH. TRACE AMOUNTS OF ASHFALL ARE
POSSIBLE FROM PORT MOLLER TO PILOT POINT.

PEOPLE IN AREAS OF VERY LIGHT ASH FALL WITH HEALTH OR RESPIRATORY
PROBLEMS SHOULD CONTACT THEIR HEALTH PROVIDER TO SEEK ADVICE.

THE NEXT STATEMENT WILL BE ISSUED AS NECESSARY.