Small Craft Advisory 93, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
454 AM ADT FRI SEP 14 2007

.DISCUSSION...THE SURFACE LOW PRESSURE SYSTEM WHICH CAME IN FROM
THE BERING SEA ON THURSDAY AND IS NOW IN THE SOUTHERN CHUKCHI SEA
CONTINUES TO WEAKEN AS EXPECTED. BRISK SOUTH WINDS ARE STILL
BLOWING OVER THE WEST COAST...BUT THESE WINDS ARE DIMINISHING AND
THE ROUGH MARINE WEATHER IS GRADUALLY SUBSIDING.

THE TIDE OBSERVATIONS FROM NOME SHOW THAT THERE WAS A CREST 4.5
FEET ABOVE MEAN LOW LOW WATER THURSDAY EVENING. TIDE LEVELS ARE
NOW DECLINING. THERE ARE STILL 30 KNOT SOUTHEAST GUSTS AT KIVALINA
AND THE TIDE TABLES INDICATE THAT THE CREST IN WATER LEVELS ALONG
THE CHUKCHI COAST WILL COME LATER TODAY. HENCE THE COASTAL FLOOD
WATCH FOR ZONE 207 BETWEEN CAPE KRUSENSTERN AND CAPE THOMPSON
REMAINS IN EFFECT UNTIL 4 PM THIS AFTERNOON.

A TROUGH ALOFT FROM THE CHUKCHI SEA TO THE SOUTHEAST INTERIOR WILL
GRADUALLY STRENGTHEN OVER THE NEXT 36 HOURS. AN ENERGETIC LOW
PRESSURE SYSTEM IS DUE TO ARRIVE IN THE NORTHEAST GULF OF ALASKA
EARLY SATURDAY. THESE TWO TRENDS WILL BRING SOME PRECIPITATION UP
FROM THE GULF OF ALASKA TO THE SOUTHEAST INTERIOR FOR THE WEEKEND.
COOLING ALOFT OVER THE EASTERN INTERIOR LOOKS LIKE IT WILL BE
STRONG ENOUGH TO BRING THE FIRST SNOWFALL OF THE SEASON TO THE
HIGH COUNTRY OVER THE WEEKEND. WHERE BREAKS HAVE FORMED IN THE
CLOUDS...SOME EARLY FROST HAS OCCURRED IN THE EASTERN INTERIOR.
TODAYS LEADER IS CHALKYITSIK...ON THE YUKON FLATS...WITH 27
DEGREES.

EVEN BEFORE THE PRECIPITATION IN THE INTERIOR THIS WEEKEND...THE
INCREASINGLY MARITIME NATURE OF THE AIR MASS OVER THE INTERIOR IS
BEING REFLECTED BY THE PRESENCE OF SOME RAIN SHOWERS. THESE WILL
GRADUALLY INCREASE OVER THE NEXT 36 HOURS.

IN THE ARCTIC...WINDS ARE SHIFTING FROM SOUTHERLY TO
EASTERLY TODAY. THIS WILL BRING IN COOLER TEMPERATURES AND MORE
LOW CLOUDS AND FOG FROM BARROW EAST TO THE CANADA BORDER STARTING
TODAY. ON THE WEST COAST...THE MOST ACTIVE AREAS OF CLOUDS THINNED
OUT LAST NIGHT AND ONLY A FEW AREAS OF MVFR WEATHER REMAIN.

IN THE MEDIUM RANGE...THE GFS MODEL FORECASTS A VIGOROUS LOW
PRESSURE SYSTEM NOW APPROACHING THE JAPAN SEA TO STRENGTHEN
RAPIDLY SATURDAY NIGHT. THIS SYSTEM ALREADY HAS AN ENERGETIC WARM
SECTOR...THE REMAINS OF TYPHOON NARI ARE PROVIDING SOME FUEL FOR
THIS. FOR MONDAY...MONDAY NIGHT AND TUESDAY THE GFS FORECASTS A
STORM WITH A CENTRAL PRESSURE NEAR 960 MB TO BE IN THE CENTRAL
BERING SEA. THIS IS STILL TOO FAR OUT IN TIME FOR A HIGH
CONFIDENCE FORECAST BUT SOME CRUCIAL PARTS OF THE PATTERN ARE
VISIBLE ON THE GMS SATELLITE IMAGERY AND THE GFS MODEL HAS BEEN
CONSISTENT IN FORECASTING THIS INBOUND ASIAN LOW PRESSURE SYSTEM
TO STRENGTHEN RAPIDLY ONCE IT CLEARS THE JAPAN COASTAL WATERS.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...SUNDAY AND
MONDAY...SOUTHEAST GALE MONDAY PKZ210.

&&

.FIRE WEATHER...
BRISK SOUTH WINDS AND RELATIVE HUMIDITY ABNORMALLY LOW FOR THE
NORTH SLOPE RESULTED IN A FLARE UP OF A TUNDRA FIRE IN ZONE 203 ON
THURSDAY. HUMIDITY THROUGHOUT NORTHERN ALASKA IS COMING UP AS
MARITIME AIR CONTINUES FLOWING INTO THE AREA AND TEMPERATURES
GRADUALLY RETREAT. THE CHINOOK OVER THE BROOKS RANGE HAS
DIMINISHED TO A SOUTH BREEZE. MINIMUM RELATIVE HUMIDITY THIS
AFTERNOON WILL BE 45 PERCENT OR MORE...THE LOWEST LEVELS WILL BE
IN THE SOUTHEAST INTERIOR.

&&

.HYDROLOGY...
RAINFALL OVER THE PAST 24 HOURS WAS CLOSE TO 0.10 INCH OVER MUCH
OF NORTHERN ALASKA...THOUGH THE SOUTHERN SEWARD PENINSULA HAD UP
TO 0.40 INCH OF RAIN. GIVEN RELATIVELY INACTIVE LEVELS ON STREAMS
AND RIVERS AT THE BEGINNING OF THE RECENT RAINS THE RESULT WILL BE
SMALL RISES ON TOP OF BENIGN WATER LEVELS.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
DENSE SMOKE ADVISORY FOR AKZ203.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225.
&&

TF SEP 07