Small Craft Advisory 530, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
515 AM AKDT SUN JUL 29 2012

.ANALYSIS AND UPPER LEVELS...AN UNSEASONABLY STRONG 100 KT JET
CURRENTLY CURVES ACROSS THE BERING SEA TOWARDS THE KUSKOKWIM DELTA.
THIS JET IS HELPING TO STRENGTHEN A LOW PRESSURE SYSTEM LOCATED NORTH
OF THE DELTA THAT HAS BEEN SUPPORTING SHOWERS ACROSS THE REGION THIS
MORNING. THIS JET IS ALSO HELPING TO QUICKLY TRANSPORT A MUCH WEAKER
LOW IN THE WESTERN BERING EASTWARD THIS MORNING. MEANWHILE A FRONT
ASSOCIATED WITH THE KUSKOKWIM DELTA LOW IS BRINGING RAIN TO MUCH OF
THE BRISTOL BAY AREA.

.MODEL DISCUSSION...
MODELS ARE IN GENERALLY GOOD AGREEMENT IN THE SHORT TERM. MODELS
DIVERGE SLIGHTLY TOWARDS THE END OF THE SHORT TERM...WITH THE NAM
FAVORING A MORE SOUTHERLY PATH FOR A LOW MOVING INTO THE SOUTHERN
GULF THIS TUESDAY. THEREFORE THE GFS WAS FAVORED. IN THE LONG
TERM...MODELS ARE IN ABOVE AVERAGE AGREEMENT AT FIRST...BUT QUICKLY
DIVERGE BY THE END OF NEXT WEEK SO HPC GUIDANCE WAS FAVORED.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...A FRONT IS APPROACHING KODIAK ISLAND THIS
MORNING...AND ALREADY SUPPORTING SHOWERS ACROSS THE AREA. A RIDGE IN
PLACE ALONG THE NORTH GULF COAST HAS BEEN SUPPORTING GUSTS ACROSS
LOCAL GAPS EVEN EARLY THIS MORNING. THE PRESSURE GRADIENT ACROSS
THESE LOCAL GAPS IS EXPECTED TO ONLY WEAKEN SLIGHTLY TODAY AS THE
RIDGE GRADUALLY WEAKENS AND PROGRESSES EASTWARD. CROSS BARRIER FLOW
SHOULD RESULT IN DOWNSLOPING ACROSS THE WESTERN KENAI PENINSULA AND
ANCHORAGE BOWL TODAY...LIMITING PRECIPITATION. HOWEVER...SHOWERS ARE
EXPECTED TO IMPACT MUCH OF SOUTHCENTRAL BY THIS EVENING AS
DOWNSLOPING SUBSIDES.

SOUTHWEST ALASKA...A LOW PRESSURE SYSTEM IS IMPACTING MUCH OF THE
SOUTHWEST MAINLAND THIS MORNING...WITH THE LOW CENTER LOCATED JUST
NORTH OF THE KUSKOKWIM DELTA...AND THE FRONT STRETCHING ACROSS THE
BRISTOL BAY REGION TOWARDS KODIAK ISLAND. AS A RESULT...MUCH OF THE
SOUTHWEST MAINLAND IS EXPERIENCING A SOGGY MORNING. A SECOND LOW WILL
APPROACH THE ALASKA PENINSULA BY THIS AFTERNOON AND SUPPORT
WIDESPREAD RAIN ACROSS MUCH OF THE REGION INTO EARLY MONDAY MORNING.
HOWEVER...A RIDGE WILL BUILD IN BY MONDAY AFTERNOON AND HELP TO BRING
BRIEF DRY CONDITIONS.

BERING SEA/ALEUTIANS...AN ACTIVE WEATHER PATTERN WILL ENSURE
UNSETTLED WEATHER ACROSS MUCH OF THE BERING IN THE SHORT TERM. A LOW
IN THE WESTERN BERING WILL QUICKLY SKIRT ALONG THE ALEUTIAN ISLANDS
TODAY AND REACH BRISTOL BAY BY THIS AFTERNOON. WHILE THE LOW ITSELF
IS RELATIVELY WEAK...ITS ASSOCIATED LOW LEVEL JET WILL SUPPORT GUSTY
WINDS ACROSS THE ALEUTIANS TODAY.

.LONG TERM FORECAST...MODELS INDICATE AN ACTIVE PATTERN OVER THE NEXT
WEEK. THE JET STREAM WILL BE UNDULATING ALONG THE NORTH PACIFIC.  THE
JET WILL RAPIDLY DEVELOP AND TRANSPORT SYSTEMS EASTWARD ACROSS THE
BERING AND INTO THE GULF OF ALASKA. HOWEVER...HIGH PRESSURE MAY BUILD
IN BY THE END OF NEXT WEEK AND BRING DRIER WEATHER.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...
FIRE WEATHER...NONE

ELN JUL 12