Gale Warning 630, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKDT SUN SEP 13 2009

.ANALYSIS AND UPPER LEVELS...
UPPER LEVELS...THE UPPER CUTOFF LOW, WHICH DEVELOPED NEAR SAINT PAUL
SATURDAY, HAD TURNED SOUTHEAST AND MOVED INTO THE NORTH PACIFIC JUST
SOUTH OF THE ALASKA PENINSULA. IT CONTINUES TO BE VERTICALLY STACKED
OVER THE SURFACE LOW. THE UPPER RIDGE OVER THE CENTRAL BERING SEA
CONTINUES TO MOVE EAST.

AT THE SURFACE...THERE IS A LARGE COMPLEX LOW SOUTH OF THE ALASKA
PENINSULA AND KODIAK ISLAND WITH A TROUGH EXTENDING NORTH INTO
SOUTHWEST ALASKA. A RIDGE OF HIGH PRESSURE CONTINUES TO DEVELOPED
ALONG THE CENTRAL GULF COAST. THE SURFACE RIDGE OVER THE BERING SEA
CONTINUES TO SHADOW THE UPPER RIDGE. A MODERATE LOW PRESSURE SYSTEM
NEAR THE KAMCHATKA PENINSULA CONTINUES TO MOVE NORTHEAST TOWARD THE
WESTERN BERING SEA.

.MODEL DISCUSSION...
THE MODELS ARE IN THE GOOD AGREEMENT OVER THE BERING SEA THROUGH
TUESDAY NIGHT AND CONFIDENCE IS GOOD THERE. THE MODELS ARE HAVING
PROBLEMS WITH THE HANDLING OF THE LOW SOUTH OF THE GULF OF ALASKA
FROM TUESDAY AFTERNOON ONWARD. NAM AND EC WANT TO KEEP THE MAIN LOW
CENTER SOUTH OF THE GULF WHILE THE GFS MOVES IT INTO THE GULF TUESDAY
NIGHT. AT THIS TIME IT APPEARS THAT THE GFS SOLUTION IS THE OUTLIER
OF THE GROUP.

.SHORT TERM FORECAST...
UPPER LEVEL...THE UPPER LOW SOUTH OF THE ALASKA PENINSULA WILL BECOME
NEARLY STATIONARY OVER THE NORTHEAST PACIFIC MONDAY NIGHT. AN UPPER
RIDGE OVER WESTERN CANADA WILL BUILD INTO THE CENTRAL INTERIOR MONDAY
AND TUESDAY. THE RIDGE OVER THE BERING WILL FLATTEN AS A LOW DEVELOPS
OVER THE KAMCHATKA PENINSULA TONIGHT AND MOVES INTO THE CENTRAL
BERING TUESDAY.

SOUTHCENTRAL AND THE GULF...RAIN SHOWERS OVER THE INTERIOR SECTIONS
WILL DIMINISH TONIGHT AND EARLY MONDAY AND CLOUDS WILL CLEAR LATE
MONDAY AND TUESDAY AS HIGH PRESSURE BUILDS INTO THE CENTRAL INTERIOR.

A SHORT WAVE WILL MOVE THROUGH THE KENAI PENINSULA MONDAY AND WILL
KEEP AREAS OF RAIN ALONG THE GULF COAST THROUGH MONDAY AFTERNOON.

SOUTHWEST ALASKA...SCATTERED SHOWERS WILL DIMINISH OVER THE INTERIOR
SECTION TONIGHT. THE SHORT WAVE OVER THE GULF WILL MOVE THROUGH
BRISTOL BAY AND PRODUCE AREAS OF RAIN MONDAY NIGHT. GUST WINDS ALONG
THE KUSKOKWIM DELTA COAST AND ACROSS THE ALASKA PENINSULA WILL
DIMINISH TONIGHT.

BERING SEA...GUSTY NORTH WINDS OVER THE EASTERN BERING AND THE
EASTERN ALEUTIANS WILL DIMINISH FROM THE WEST TONIGHT AND MONDAY. A
LARGE STORM SOUTHEAST OF THE KAMCHATKA PENINSULA WILL MOVE INTO THE
SOUTHWESTERN BERING MONDAY EVENING THEN TURN EAST AND MOVE INTO THE
SOUTH CENTRAL BERING TUESDAY. THE ASSOCIATED FRONT WILL MOVE INTO THE
WESTERN ALEUTIANS TONIGHT THEN SWING THROUGH THE REST OF THE
ALEUTIANS THROUGH TUESDAY. A LARGE AREA OF GALE FORCE WINDS WILL FORM
AROUND THE LOW THROUGH TUESDAY.

.LONG TERM FORECAST...
THE UPPER LOW OVER THE NORTHEAST PACIFIC TUESDAY WILL MOVE INTO THE
WESTERN GULF WEDNESDAY NIGHT THEN MOVE INTO BRISTOL BAY FRIDAY. THE
UPPER RIDGE OVER THE CENTRAL INTERIOR WILL BE PUSHED INTO NORTHERN
ALASKA BY THE LOW. THIS WILL BRING MORE CLOUDS AND SHOWERS BACK OVER
SOUTHERN ALASKA DURING THE LATTER PART OF THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 170, 172, 175, 176
FIRE WEATHER...NONE.

NM SEP 09