Gale Warning 386, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
409 PM AKDT SUN MAY 8 2016

.ANALYSIS AND UPPER LEVELS...
THE START OF THE WEEK IS SETTING UP INTO A CLOUDY AND WET PATTERN
ACROSS THE SOUTHERN MAINLAND AS AN UPPER LOW CENTERED OVER THE
ALASKA PENINSULA AND EASTERN BERING SLOWLY LIFTS NORTH. THE UPPER
RIDGE ACROSS THE GULF AND SOUTHCENTRAL ON SATURDAY IS NOW
AMPLIFYING AHEAD OF THIS SYSTEM AND HELPING TO STREAM ABUNDANT
MOISTURE INTO THE GULF AND ACROSS SOUTHCENTRAL. LIGHT RAIN IS
DEVELOPING NORTH OF THE LOW WITH WIDESPREAD ACTIVITY ACROSS THE
SOUTHWEST TO THE SUSITNA VALLEY AND GULF AREAS. SHORTWAVES MOVING
FROM THE SYSTEM BROUGHT SHOWERS INTO THE NORTHERN KENAI AND
ANCHORAGE BOWL BY LATE MORNING...WITH THE SATURATED AIRMASS
SPREADING QUICKLY EASTWARD THROUGH EARLY AFTERNOON.

TO THE WEST...ANOTHER LOW PRESSURE SYSTEM IS DEVELOPING JUST
SOUTH OF THE KAMCHATKA PENINSULA. AN ASSOCIATED FRONT IS MOVING
INTO THE WESTERN AND CENTRAL ALEUTIANS THIS AFTERNOON WITH SMALL
CRAFT WINDS GENERALLY FROM THE SOUTH.

&&

.MODEL DISCUSSION...
MODELS ARE IN VERY GOOD AGREEMENT WITH THE SYNOPTIC PATTERN
THROUGH EARLY TUESDAY MORNING. THE GENERAL OVERVIEW FOR THE
BEGINNING OF THE WEEK STARTS WITH THE LOW CENTER OVER THE ALASKA
PENINSULA LIFTING NORTH AS THE RIDGE ACROSS THE EASTERN
PACIFIC/GULF BUILDS TOWARD THE CENTRAL MAINLAND. AT THE SAME
TIME...THE LOW NEAR THE KAMCHATKA PENINSULA MOVES TO THE WESTERN
BERING. FORECAST CONFIDENCE REMAINS HIGH FOR THE AFTERNOON PACKAGE
WITH ONLY MINOR ADJUSTMENTS NEEDED FOR TIMING AND COVERAGE OF
PRECIPITATION.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A WEAK FRONTAL TROUGH WILL CONTINUE TO PUSH THROUGH THE NORTHERN
GULF AND SOUTHCENTRAL ALASKA TONIGHT...KEEPING WET AND CLOUDY
CONDITIONS WIDESPREAD OVER THE AREA THROUGH MONDAY AFTERNOON. A
BRIEF PERIOD OF POST FRONTAL SHOWERS IS LIKELY TO FOLLOW IN THE
WAKE OF THIS SYSTEM THROUGH MONDAY NIGHT. HIGH PRESSURE WILL THEN
BUILD BACK OVER MUCH OF SOUTHCENTRAL LATE MONDAY NIGHT...BRINGING
MORE STABLE CONDITIONS AND PATCHY FOG TO THE AREA THROUGH TUESDAY
AFTERNOON. ANOTHER WAVE OF PRECIPITATION WILL BEGIN TO PUSH INTO
THE WESTERN GULF AND KODIAK ISLAND BY TUESDAY AFTERNOON.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
RAIN AND SHOWERS WILL CONTINUE THROUGH THE OVERNIGHT HOURS AND
INTO EARLY MONDAY AS A SHORTWAVE CONTINUES TO PUSH NORTHEASTWARD
THROUGH THE REGION. RAINFALL WILL TAPER OFF SOMEWHAT ON MONDAY AS
THE SHORTWAVE EXITS THE REGION AND A WEAK AREA OF HIGH PRESSURE
MOVES QUICKLY ACROSS THE AREA. THE NEXT FRONT WILL BE CROSSING THE
BERING SEA MONDAY...REACHING THE KUSKOKWIM DELTA BY MIDDAY MONDAY
AND THE REST OF SOUTHWEST MAINLAND BY MONDAY EVENING. THE FRONT
WILL THEN SLOW ITS EASTWARD MOVEMENT AND STEADY RAIN WILL CONTINUE
INTO TUESDAY.

COASTAL FOG WILL REMAIN AS ONSHORE FLOW WILL CONTINUE THROUGH THE
OVERNIGHT AND INTO MONDAY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THERE IS LITTLE CHANGE IN FORECAST THINKING WITH THIS PACKAGE
WITH MODELS IN GOOD AGREEMENT WITH THE SYNOPTIC PATTERN THROUGH
TUESDAY. THE LOW NOW APPROACHING THE WESTERN ALEUTIANS WILL
CONTINUE INTO THE WESTERN BERING AND SLOWLY WEAKEN AS IT DRIFT
INTO THE CENTRAL BERING SEA THROUGH TUESDAY. THE ASSOCIATED FRONT
WILL PROGRESS EASTWARD THROUGH THE REGION WITH WINDS NEAR GALE
FORCE ALONG MOST OF THE FRONT. AS THE FRONT GOES THROUGH THE
EASTERN ALEUTIANS AND THE ALASKA PENINSULA TOMORROW...WINDS WILL
INCREASE TO MINIMAL GALES WITH THE STRONGEST WINDS THOUGH
CHANNELED TERRAIN AND PASSES.

AS THE RIDGE BUILDS TO THE EAST BY TUESDAY...EXPECT DEEP
SOUTHERLY FLOW OVER THE EASTERN ALEUTIANS AND THE ALASKA
PENINSULA...BRINGING A BAND OF MOISTURE INTO THE REGION FROM ABOUT
35-40N. THIS WILL KEEP RAINFALL IN THE FORECAST FOR THE EASTERN
PORTIONS OF THE FORECAST AREA WITH THE HIGHEST TOTALS ALONG THE
PACIFIC SIDE OF THE EASTERN ALEUTIANS AND ALASKA PENINSULA.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THE BLOCKING PATTERN OVER THE STATE WILL CONTINUE INTO THURSDAY
KEEPING MOSTLY WARM SOUTHERLY FLOW OVER THE AREA THAT WILL RESULT
IN RAIN FOR AREAS WEST OF THE COPPER RIVER BASIN. LATER ON
THURSDAY A CONSOLIDATED HIGH WILL FORM OVER THE EASTERN PART OF
THE STATE AND ELONGATE TO THE WEST. THIS WILL CLEAR OUT SKIES AND
RESULT IN WARM AND SUNNY AFTERNOONS THROUGH SATURDAY. THE MODELS
ARE IN GOOD AGREEMENT WITH THIS SOLUTION RESULTING IN ABOVE
AVERAGE CONFIDENCE.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING 165 170 172 180.

&&

SYNOPSIS AND MODEL DISCUSSION...KH
SOUTHCENTRAL ALASKA...TP
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...LIW/RF
LONG TERM...DK