Small Craft Advisory 418, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
522 AM AKDT MON MAY 26 2014

.ANALYSIS AND UPPER LEVELS...
AN UPPER LEVEL RIDGE OF HIGH PRESSURE REMAINS OVER THE SOUTHWEST
ALASKA AND FROM THE MATSU VALLEY SOUTHWARD INTO THE WESTERN GULF
OF ALASKA. AN UPPER LEVEL MINOR SHORTWAVE IS POSITIONED OVER THE
BROOKS RANGE EXTENDING INTO FAIRBANKS WITH THE SATELLITE IMAGERY
SHOWING MID TO HIGH CLOUDS TOWARDS THE TALKEETNA MOUNTAINS AND
ALONG THE ALASKA RANGE MOVING EASTWARD TOWARDS THE WRANGELL
MOUNTAINS. THE BERING SEA HAS AN UPPER LEVEL CLOSED LOW JUST NORTH
ADAK WITH THE TROUGH EXTENDING THROUGH THE EASTERN ALEUTIANS.
THERE IS AN 100 KNOT ZONAL JET STREAK POSITIONED JUST SOUTH OF THE
CENTRAL ALEUTIANS. THE SATELLITE IMAGERY HAS A LARGE SWATH OF
MOISTURE ALONG THE CENTRAL TO EASTERN ALEUTIANS STREAMING ACROSS
INTO THE CENTRAL TO EASTERN BERING SEA.

&&

.MODEL DISCUSSION...
THE MODELS REMAIN IN GOOD AGREEMENT WITH MINOR DISAGREEMENTS WITH
THE PLACEMENT OF THE NORTH PACIFIC LOW TRACKING ACROSS THE WESTERN
ALEUTIANS INTO THE CENTRAL BERING SEA ON TUESDAY. THE FORECAST
CONFIDENCE REMAINS HIGH THROUGH TUESDAY.

&&

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
THE HIGH PRESSURE RIDGE OVER SOUTHCENTRAL WILL CONTINUE TO MOVE
EASTWARD. THE UPSTREAM FRONTAL SYSTEM MOVES INTO SOUTHWEST ALASKA
AND KODIAK ISLAND BY MONDAY EVENING ACCOMPANIED BY SOUTHWESTERLY
WINDS AND RAIN. BY TUESDAY THE HIGH PRESSURE RIDGE WILL BE
POSITIONED ALONG THE NORTHERN GULF COAST WITH INCREASED PRESSURE
GRADIENTS RESULTING IN GUSTY TURNAGAIN ARM WINDS. THE FRONTAL
SYSTEM WILL BRING RAIN INTO THE ANCHORAGE BOWL AND THROUGH THE
MATSU VALLEY BY TUESDAY. THE COPPER RIVER BASIN WILL HAVE RED
FLAG CRITERIA FOR STRONG WIND FOR MONDAY AFTERNOON THROUGH LATE
MONDAY NIGHT DUE TO THE INCREASE IN PRESSURE GRADIENTS AS THE HIGH
PRESSURE BUILDS INTO THE AREA AND COINCIDING WITH THE LOWER
RELATIVE HUMIDITIES. BY WEDNESDAY THERE WILL BE CONTINUED
SOUTHWESTERLY FLOW WITH EMBEDDED SHORTWAVES INCREASING THE
CHANCES FOR MORE SHOWERY PRECIPITATION.

SOUTHWEST ALASKA...
THE HIGH PRESSURE RIDGE WILL MOVE EASTWARD ALLOWING THE FRONTAL
SYSTEM TO MOVE INTO THE REGION BY WITH SOUTHWESTERLY FLOW WITH A
SWATH OF MOISTURE/RAIN MOVING WEST TO EAST FROM THE COASTLINE IN
THE AFTERNOON. BY TUESDAY ANOTHER TROUGH WILL PUSH THROUGH THE
SOUTHWEST ALASKA REGION WITH MORE CLOUDS AND PRECIPITATION.

BERING SEA/ALEUTIANS...
THE LOW PRESSURE IN THE WESTERN BERING SEA WILL CONTINUE TO TRACK
TO THE NORTHWEST OF THE PRIBILOF ISLANDS BY TUESDAY AFTERNOON AND
BECOME ELONGATED TOWARDS SAINT LAWRENCE ISLAND. THE FRONTAL
SYSTEM ASSOCIATED WITH THE LOW PRESSURE WILL MOVE ACROSS THE
CENTRAL/EASTERN ALEUTIANS AND SPILL OVER INTO THE CENTRAL/EASTERN
BERING SEA WITH RAIN/FOG THROUGH LATE MONDAY NIGHT. BY WEDNESDAY
HIGH PRESSURE WILL START TO BUILD INTO THE WESTERN ALEUTIANS AND
WESTERN BERING SEA.

&&

.LONG TERM FORECAST...
THE JET STREAK WILL BECOME MERIDIONAL WITH A STRONG 120 KNOT
SOUTHERLY JET STREAK OVER THE EASTERN ALEUTIANS BY THURSDAY
MORNING. THERE WILL BE LONG WAVE TROUGH POSITIONED NEAR THE
CHUKCHI PENINSULA EXTENDING THROUGH THE EASTERN ALEUTIANS
SOUTHWARD TO 37N. THIS WILL BRING WARMER TEMPERATURES TO
SOUTHWEST/SOUTHCENTRAL ALASKA AS THE HIGH PRESSURE RIDGE OVER THE
NORTHERN GULF STRENGTHENS WITH THE WARM AIR ADVECTION BY MIDWEEK
THROUGH NEXT WEEKEND. THERE WILL BE AN INCREASE IN MOISTURE AND
PRECIPITATION WITH THE TROUGH BECOMING NEGATIVELY TILTED BY FRIDAY
WITH EMBEDDED SHORTWAVES MOVING THROUGH SOUTHWEST/SOUTHCENTRAL
ALASKA.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...RED FLAG WARNING...141

&&

PLD MAY 14