Small Craft Advisory 415, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
600 AM ADT SAT MAY 10 2008

.ANALYSIS AND UPPER LEVELS...
BENIGN WEATHER ACROSS OUR DOMAIN EARLY THIS MORNING WHILE WE
TRANSITION OUR FOCUS FROM TWO VERTICALLY STACKED WEAKENING LOWS TO A
RAPIDLY DEVELOPING NORTH PACIFIC LOW TODAY. THE FIRST LOW IS A 1000
MB LOW JUST NORTHWEST OF THE PRIBILOFS AND THE SECOND IS A MATURE 990
MB LOW IN THE SOUTHERN GULF. A DEFORMATION ZONE EXISTS FROM THE GULF
LOW NORTHWEST TO BRISTOL BAY AND THE LOWER KUSKOKWIM VALLEY WHERE
RAIN CONTINUES TO FALL. THE DEVELOPING SYSTEM WELL SOUTH OF THE
CENTRAL ALEUTIANS IS ESTIMATED TO BE 998 MB BUT WILL RAPIDLY DEEPEN
TO 972 MB BY THIS TIME TOMORROW.

.MODEL DISCUSSION...
CONFIDENCE IS GROWING AS ALL MAJOR MODELS HAVE SIMILAR SOLUTIONS
THROUGH THE MEDIUM RANGE. GFS HAS ESPECIALLY BEEN CONSISTENT THE LAST
3 RUNS REGARDING THE DEVELOPING LOW AND ITS TRACK TO THE ALASKA
PENINSULA EARLY NEXT WEEK. HAVE MADE ONLY LITTLE CHANGES TO THE
CURRENT FORECAST.

.SHORT TERM FORECAST...
SOUTH AND EAST OF THE ALASKA RANGE...
SKIES ARE CLEARING OUT THIS MORNING ACROSS SOUTHCENTRAL ALASKA IN
RESPONSE TO THE DISSIPATING LOW PRESSURE IN THE GULF AND THE UPPER
LEVEL RIDGE BUILDING OVER THE EASTERN INTERIOR. THE LOAN SPOT WITH
INCLEMENT WEATHER IS ACROSS KODIAK ISLAND...ALTHOUGH RAIN SHOULD BE
LETTING UP TODAY AND FINALLY GIVE KODIAK CITY A BREAK. TORRENTIAL
RAIN HAS FALLEN OVER THE PAST WEEK IN KODIAK CITY WHERE THEY HAVE
TALLIED OVER 8 INCHES OF PRECIPITATION THIS MONTH. ONSHORE FLOW WILL
LIKELY KEEP CEILINGS LOW WITH PERIODS OF LIGHT RAIN BEFORE THE NEXT
FRONT APPROACHES SUNDAY AFTERNOON...BRINGING ANOTHER ROUND OF HEAVY
RAIN TO THE AREA.

THE REST OF SOUTHCENTRAL WILL STAY DRY AND PLEASANT THROUGH SUNDAY
EVENING. RAIN WILL BEGIN TO FALL AGAIN OVER THE COASTAL AREAS LATE
SUNDAY WHILE THE INTERIOR WINDS WILL INCREASE IN RESPONSE TO THE
RAPIDLY DEEPENING LOW TO THE SOUTHWEST AND THE APPROACHING FRONTAL
BOUNDARY. TURNAGAIN ARM AND HIGHER ELEVATIONS AROUND THE ANCHORAGE
BOWL WILL SEE AT LEAST 45 MPH WINDS SUNDAY EVENING THROUGH MONDAY.
OTHER AREAS LIKE THE COPPER RIVER BASIN, THE MATANUSKA VALLEY, AND
WEST ANCHORAGE WILL SEE WINDS 15 TO 30 MPH.

THE COMBINATION OF THE WINDS AND LOW RH VALUES WILL RESULT IN FIRE
WEATHER CONCERNS FOR 111 AND 141. A FIRE WEATHER WATCH WILL BE ISSUED
FOR 111 THIS MORNING AND POSSIBLY 141 LATER TODAY.

CLOUDS AND ISOLATED SHOWERS WILL RETURN SUNDAY NIGHT AND MONDAY TO
THE INTERIOR. THE MAJORITY OF THE RAIN WITH THIS SYSTEM WILL FALL
ALONG THE COAST.

WEST OF THE ALASKA RANGE...
DEFORMATION ZONE STILL THE FOCUS FOR LIGHT RAIN FROM BRISTOL BAY TO
THE LOWER KUSKOKWIM. SHOWER COVERAGE WILL DIMINISH OVER THE NEXT 24
HOURS. FOCUS WILL SHIFT FURTHER WEST WITH THE DEVELOPING LOW SOUTH OF
THE ALEUTIANS. RAIN WILL SPREAD NORTH AND EAST ALONG THE OCCLUDED
FRONT...AFFECTING THE SOUTHWEST COAST SOMETIME LATE SUNDAY AND
SPREADING AS FAR INLAND AS WESTERN 151 MONDAY. AT THIS POINT...NO
STORM WARNINGS ASSOCIATED WITH THIS LOW BUT STRONG GALES WILL BE
WIDESPREAD. THE POTENTIAL IS CERTAINLY THERE FOR STORM FORCE GUSTS SO
WILL MONITOR THE EVOLUTION OF THE LOW THE NEXT 12 HOURS TO SEE IF
THAT INCREASE WILL BE NECESSARY.

COOL TEMPERATURES CONTINUE WEST OF 170W WHICH WILL CONTINUE AS THE
MEAN ANCHOR UPPER LEVEL LOW POSITION REMAINS UNCHANGED. COLD
NORTHERLY FLOW TO THE WEST OF 170W HELPING KEEP THE ICE EDGE FROM
RETREATING TOO FAST AND SNOW SHOWERS STILL IN THE FORECAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130 132 138 140 150 155 160 165 170 172 180 .
FIRE WEATHER...FIRE WEATHER WATCH 111.

AB MAY 08