Small Craft Advisory 988, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
355 AM AST SAT NOV 24 2007

.ANALYSIS AND UPPER LEVELS...
A STRONG JET STREAM SOUTH OF THE ALEUTIANS CONTINUES TO FUEL STRONG
AREAS OF LOW PRESSURE WHICH FORM ON THE NORTH SIDE OF THE JET AND
DRIFT NORTH INTO OUR FORECAST AREA. THIS MORNING...THERE ARE TWO
PRIMARY LOWS OF INTEREST. ONE LOW IS VERTICALLY STACKED...NEARLY
STATIONARY...AND WEAKENING JUST NORTHWEST OF ATTU. ALTHOUGH THIS LOW
IS WEAKENING...IT IS STILL RATHER STRONG THIS MORNING WITH GALE FORCE
WINDS. THE OTHER PRIMARY LOW IS AN INTENSIFYING SURFACE LOW JUST
SOUTH OF DUTCH HARBOR THIS MORNING...MOVING NORTHEAST INTO THE
EASTERN BERING TODAY. THIS LOW ALSO HAS SOME HIGH END GALE FORCE
WINDS. A WEAK RIDGE OF HIGH PRESSURE IS PRESENT THIS MORNING OVER THE
SOUTHWEST MAINLAND WITH AREAS OF FOG. OVER SOUTHCENTRAL...THERE IS A
WEAK TROUGH WHICH IS ALLOWING SOME LIGHT RAIN AND SNOW TO PERSIST
THIS MORNING.

.MODEL DISCUSSION...
MODELS ARE IN MUCH BETTER AGREEMENT THAN THEY HAVE BEEN THROUGH EARLY
NEXT WEEK. IN PARTICULAR...MODELS ARE IN BETTER AGREEMENT ON A VERY
STRONG LOW TO MOVE NORTH TO JUST SOUTH AND EAST OF KODIAK SUNDAY AND
SUNDAY EVENING. THERE ARE SEVERAL OTHER STRONG LOWS TO AFFECT THE
REGION THROUGH EARLY NEXT WEEK...ALL OF WHICH THE MODELS AGREE WELL
ON. PROBABLY ONE OF THE MOST IMPORTANT MODEL ISSUES IS JUST HOW FAR
NORTH THE GULF LOW CAN MAKE IT SUNDAY NIGHT BEFORE IT HITS A WALL AND
CURVES SOUTHEAST...AS MODELS STILL DISAGREE ON THIS. THE FURTHER
NORTH THE LOW MAKES IT...THE FURTHER NORTH THE PRECIPITATION AND WARM
AIR CAN MAKE IT.

.SHORT TERM FORECAST...
SOUTHCENTRAL AND THE GULF...
ONLY WEAK DYNAMICS REMAIN OVER SOUTHCENTRAL THIS MORNING...BUT THERE
IS ENOUGH FOR SOME LIGHT PRECIPITATION TO PERSIST IN WEAK BUT MOIST
SOUTHERLY FLOW. THIS INCLUDES SOME SNOW IN THE ANCHORAGE BOWL.
PRECIPITATION WILL SLOWLY TAPER OFF OVER MOST OF MAINLAND
SOUTHCENTRAL THIS AFTERNOON AND EVENING. HOWEVER...A LOW IN THE
EASTERN BERING THIS AFTERNOON WILL SEND A FRONT EAST INTO THE WESTERN
GULF. THIS WILL BRING A RETURN TO RAIN AND WARM TEMPERATURES FOR
KODIAK THIS AFTERNOON AND...YOU GUESSED IT...THE SOUTHERN/EASTERN
KENAI PENINSULA TONIGHT. THIS FRONT WEAKENS OVER THE NORTHWEST GULF
AS A VERY STRONG LOW MOVES UP TO JUST SOUTH AND EAST OF KODIAK SUNDAY
AND SUNDAY NIGHT. THIS LOW WILL LIKELY BRING STORM FORCE WINDS TO THE
MARINE ZONES...WITH MAYBE SOME LOCALIZED HURRICANE FORCE WINDS AS
WELL. AS FAR AS RAIN GOES...ONCE THE RAIN SETS IN FOR KODIAK THIS
AFTERNOON IT PROBABLY WILL NOT STOP UNTIL MONDAY EVENING. THE
RECENTLY HARD HIT AREAS OF THE SOUTHERN/EASTERN KENAI PENINSULA ARE
IN A SIMILAR QUAGMIRE...WITH PRECIPITATION ALMOST NONSTOP THIS
EVENING THROUGH MONDAY MORNING. AS MENTIONED IN THE MODEL
DISCUSSION...JUST HOW FAR NORTH THE GULF LOW MAKES IT WILL DETERMINE
PRECIP TOTALS. AT THIS POINT...BELIEVE THAT THE LOW WILL STAY FAR
ENOUGH SOUTH TO WHERE SOUTHERN/EASTERN KENAI PRECIP TOTALS WILL NOT
BE TOO EXCESSIVE. TEMPERATURES MAY ALSO BE COLD ENOUGH FOR SNOW AT
TIMES AS WELL...MAINLY INLAND. PRECIPITATION IS EXPECTED TO REMAIN
LIGHT OR NONEXISTENT FOR THE COOK INLET REGION UP INTO THE SUSITNA
VALLEY DUE TO DOWNSLOPE FLOW...AND PRECIPITATION SHOULD BE LIGHT FOR
VALDEZ UNLESS THE LOW MOVES FURTHER NORTH THAN WE THINK. THE LOW WILL
EVENTUALLY MOVE SOUTHEAST INTO THE EASTERN GULF ON MONDAY...WITH
PERHAPS A PERIOD OF QUIET WEATHER SETTING UP FOR THE WORKWEEK.

SOUTHWEST MAINLAND...
A WEAK RIDGE OF HIGH PRESSURE OVER THE SOUTHWEST MAINLAND TODAY WILL
RAPIDLY GIVE WAY TO A WEATHER FRONT MOVING THROUGH THE AKPEN TODAY
REACHING THE SOUTHWEST COAST THIS EVENING. SOME PRETTY STRONG WINDS
ARE EXPECTED WITH THIS SYSTEM TONIGHT ALONG WITH A RETURN TO MILD
AIR...BUT PRECIPITATION IS EXPECTED TO REMAIN FAIRLY LIGHT DUE TO
DOWNSLOPING SOUTHEAST FLOW. GENERALLY UNSETTLED WEATHER CONTINUES
UNTIL MONDAY...WHEN A RIDGE OF HIGH PRESSURE BUILDS IN.

BERING/ALEUTIANS...
THE STORY FOR THE BERING/ALEUTIANS IS BIG LOW PRESSURE SYSTEMS AND
LOTS OF THEM. THE LOW CROSSING THE WESTERN END OF THE AKPEN TODAY
MOVES NORTH TO AROUND SAINT MATTHEW ISLAND SUNDAY NIGHT AND WEAKENS.
THE LOW JUST NORTHWEST OF ATTU THIS MORNING WILL DRIFT SOUTH AND
DISSIPATE LATE SUNDAY. THE NEXT NEW BIG LOW PRESSURE WILL INTENSIFY
SOUTH OF THE CENTRAL ALEUTIANS SUNDAY AND MOVE NORTH THROUGH THE
CENTRAL ALEUTIANS MONDAY. THROUGH MONDAY...MOST OF THE HEAVIER
PRECIPITATION OVER THE BERING/ALEUTIANS WILL FALL AS RAIN. AN
EXCEPTION IS THE PRIBILOFS...WHICH COULD SEE A FEW INCHES OF SNOW
TODAY AND TONIGHT ON THE WEST SIDE OF THE LOW MOVING INTO THE EASTERN
BERING FROM THE SOUTH.

.LONG TERM FORECAST...
UNSETTLED WEATHER WITH NUMEROUS LOW PRESSURES SYSTEMS WILL PERSIST
OVER THE BERING/ALEUTIANS THROUGH ALL OF NEXT WEEK. THE MAINLAND IS A
LITTLE TOUGHER CALL. AT THIS POINT...IT LOOKS LIKE THE MAINLAND WILL
GET A BREAK IN THE PRECIPITATION FROM ABOUT MONDAY TO WEDNESDAY.
AROUND WEDNESDAY NIGHT OR THURSDAY...THE STORMINESS IN THE
BERING/ALEUTIANS MAY BEGIN TO WORK EAST BACK INTO THE SOUTHWEST
MAINLAND AND WESTERN GULF.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING ZONES 120 130 132 138 150 351 352
         GALE WARNING ZONES 125 140 141 155 160 165 170 171 176 179
         180 414.
         HEAVY FREEZING SPRAY WARNING 180.
FIRE WEATHER...NONE.

FOISY NOV 07