Gale Warning 523, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM AKDT MON AUG 3 2009

.ANALYSIS AND UPPER LEVELS...
ALOFT...RIDGE REMAINS IN PLACE OVER THE EASTERN HALF OF THE ALASKA
MAINLAND WITH A DEEP TROUGH CENTERED OVER THE BERING SEA AND CENTRAL
ALEUTIANS. AN UPPER LOW SITTING IN THE BASE OF THE TROUGH IS
CURRENTLY OVER THE CENTRAL ALEUTIANS. VARIOUS SHORTWAVES ARE ROTATING
AROUND THE PERIPHERY OF THE UPPER LOW.

AT THE SURFACE...HIGH PRESSURE OVER THE GULF OF ALASKA IS
WEAKENING...WHILE A LOW NEAR DUTCH HARBOR MOVES NORTHWARD INTO THE
BERING. A FRONT ASSOCIATED WITH THIS LOW IS MOVING INTO THE WESTERN
GULF. ANOTHER LOW EVIDENT ON SATELLITE IMAGERY IS CURRENTLY SOUTHEAST
OF SHEMYA. THIS LOW WILL WEAKEN WHILE MERGING WITH THE LOW NEAR
DUTCH HARBOR.

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT THROUGH THE MIDDLE OF THE WEEK.
DIFFERENCES BEGIN TO ARISE CONCERNING THE EVOLUTION OF THE LOW MOVING
INTO THE BERING...AS WELL AS THE BREAKDOWN OF THE RIDGE OVER
SOUTHCENTRAL. GENERALLY EXPECTING FLOW TO BECOME PROGRESSIVE OVER THE
AREA AS WE HEAD INTO THE WEEKEND...WITH THE RIDGE SLIPPING EASTWARD
INTO CANADA WHILE LOW PRESSURE MEANDERS IN THE BERING. THE AFTERNOON
PACKAGE WAS CONSTRUCTED USING THE GFS/NAM SOLUTIONS.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
AS THE AFOREMENTIONED FRONT MOVES INTO SOUTHCENTRAL TONIGHT AND
TOMORROW RAIN WILL BEGIN OVERSPREADING THE REGION. GUSTY GAP WINDS
WILL ALSO BE POSSIBLE...WITH GALE FORCE WINDS POSSIBLE AROUND THE
BARREN ISLANDS. HEAVIEST RAIN WILL IMPACT KODIAK ISLAND
TONIGHT...SPREADING INTO THE SOUTHERN KENAI PENINSULA TOMORROW.
LIGHTER RAIN WILL SPREAD ACROSS THE REST OF SOUTHCENTRAL LATE TUESDAY
INTO WEDNESDAY. SHOWERS WILL PERSIST ACROSS THE AREA THROUGH
THURSDAY. THE POSSIBILITY OF RED FLAG CONDITIONS WILL HAVE TO BE
MONITORED ALONG THE COPPER RIVER BASIN TOMORROW AND PERHAPS WEDNESDAY
AS MOISTURE WILL REMAIN LOW AND WINDS WILL INCREASE TOMORROW.

.SOUTHWEST...
CONTINUED COOL AND WET THROUGH MIDWEEK AS SOUTHERLY FLOW REMAINS OVER
THE REGION. BULK OF RAIN WILL FALL ALONG COASTAL LOCATIONS...AS THE
LOW MOVING NORTHWARD INTO THE BERING PUSHES A FRONT INTO SOUTHWEST.
ADDITIONALLY...WINDS WILL REMAIN GUSTY ALONG THE COAST THROUGH
TOMORROW.

.BERING SEA AND ALEUTIANS...
UNSETTLED WEATHER CONTINUES AS VARIOUS LOWS IMPACT THE ISLANDS. RAIN
ASSOCIATED WITH THE LOW SOUTHEAST OF SHEMYA WILL BE CLEARING OUT OF
THE CENTRAL ALEUTIANS TONIGHT. RAIN ASSOCIATED WITH THE LOW NEAR
DUTCH HARBOR WILL BE WIDESPREAD ACROSS THE EASTERN ISLANDS TONIGHT
AND TOMORROW. AS THE LOW MOVES INTO THE BERING...BULK OF PRECIP WILL
BE FELT IN THE PRIBILOFS. THE LOW WILL CONTINUE MEANDERING AROUND THE
BERING THROUGH MIDWEEK...KEEPING SHOWERS AROUND THE CENTRAL AND
EASTERN ISLANDS. THE WESTERN ISLANDS SHOULD REMAIN RELATIVELY DRY AS
BULK OF MOISTURE REMAINS TO THE EAST.

.LONG TERM FORECAST...
AS FLOW BECOMES INCREASINGLY PROGRESSIVE ACROSS THE AREA THROUGH THE
END OF THE WEEK...EXPECT A RETURN TO MORE UNSETTLED AND COOLER
WEATHER ACROSS THE SOUTHERN MAINLAND. TIMING OF INDIVIDUAL TROUGH AND
SHORT WAVE PASSAGES IS UNCERTAIN THIS FAR OUT...SO CONFIDENCE IS LOW
REGARDING INDIVIDUAL DETAILS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130 132 138 160.
FIRE WEATHER...FIRE WEATHER WATCH 141.

NRH AUG 09