Gale Warning 519, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 AM AKDT SUN AUG 8 2010

.ANALYSIS AND UPPER LEVELS...
ACTIVE PATTERN IN PLACE OVER THE REGION. A 976 MB GALE FORCE LOW IS
LOCATED IN THE WESTERN BERING SEA EARLY THIS MORNING. THIS LOW HAS
NICE UPPER LEVEL JET SUPPORT WHICH WILL ALLOW IT TO PROGRESS EAST
THROUGH THE BERING SEA. A STRONG OCCLUDED FRONT EXTENDS WELL OUT
AHEAD OF THE LOW AND IS MOVING ONSHORE THE SOUTHWEST MAINLAND
TODAY...AND WILL MOVE INTO THE WESTERN GULF OF ALASKA THIS AFTERNOON
AND TONIGHT. INTERESTINGLY...THE ATMOSPHERE AT MID LEVELS HAS BEEN
UNSTABLE ENOUGH JUST BEHIND THE FRONT TO PRODUCE SOME THUNDERSTORMS
SATURDAY NIGHT OVER THE EASTERN BERING. A WEAKENING UPPER LEVEL LOW
ALONG THE NORTH GULF COAST EARLY THIS MORNING WILL MOVE INTO
SOUTHEAST ALASKA LATER TODAY...ALLOWING ANY LINGERING RAIN TO END
OVER SOUTHCENTRAL BEFORE RETURNING TONIGHT.

.MODEL DISCUSSION...
MODELS ARE IN VERY NICE AGREEMENT THROUGH THE SHORT TERM REGARDING
THE PROGRESSION OF THE OCCLUDED FRONT AND THE PROGRESSION OF THE LOW
ITSELF THROUGH THE BERING. HIGH CONFIDENCE IN GLOOMY WEATHER
CONTINUING AREAWIDE.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
LIGHT RAIN IS COMING TO AN END THIS MORNING AS THE UPPER LEVEL LOW
MOVES EAST INTO SOUTHEAST ALASKA. PATCHY FOG WILL BE PRESENT THIS
MORNING WITH PERHAPS A SUNNY BREAK OR TWO THIS AFTERNOON.
HOWEVER...A FAIRLY STRONG OCCLUDED FRONT WILL MOVE INTO THE WESTERN
GULF THIS AFTERNOON WITH RAIN FOR KODIAK THIS AFTERNOON...SPREADING
NORTHEAST INTO PRETTY MUCH ALL OF SOUTHCENTRAL TONIGHT. WIDESPREAD
SMALL CRAFT WINDS WILL OCCUR FOR THE MARINE AREAS...WITH THE USUAL
STRONGER WINDS OUT OF TURNAGAIN ARM. EXPECTING THE TURNAGAIN ARM
WINDS TO SPREAD INTO MUCH OF ANCHORAGE AS WELL LATE TODAY THROUGH
MONDAY NIGHT. A STRONG UPPER LEVEL SOUTHWESTERLY JET WILL BE PRESENT
OVERHEAD AS WELL...CONTRIBUTING TO TURBULENT FLYING WEATHER.
SOMEWHAT OF A RAIN SHADOW IS EXPECTED TO DEVELOP MONDAY AND MONDAY
NIGHT RIGHT ALONG THE WEST SIDE OF THE CHUGACH AND INTO THE COPPER
RIVER BASIN...THOUGH RAIN WILL CONTINUE ELSEWHERE. ANOTHER SHORTWAVE
IN SOUTHWEST FLOW SHOULD HELP FILL BACK IN THE PRECIP ON TUESDAY.

SOUTHWEST MAINLAND...
RAIN IS DEVELOPING FROM WEST TO EAST THIS MORNING OVER THE SOUTHWEST
MAINLAND AS AN OCCLUDED FRONT MOVES ONSHORE. RAIN WITH THIS FRONT
WILL BE FAIRLY SUBSTANTIAL TODAY BEFORE TAPERING OFF TO SHOWERS
BEHIND THE FRONT TONIGHT AND MONDAY. FAIRLY WIDESPREAD SHOWER
ACTIVITY WILL CONTINUE INTO TUESDAY AS A LOW PRESSURE SYSTEM
APPROACHES THE YUKON DELTA FROM THE WEST. GUSTY WINDS WILL BE
PRESENT OVER THE NEXT COUPLE DAYS FOR THE SOUTHWEST MAINLAND. WITH A
LONG WESTERLY FETCH BEHIND THE FRONT...WILL NEED TO WATCH OUT FOR
MINOR COASTAL FLOODING AROUND MONDAY. EXTRATROPICAL STORM SURGE
GUIDANCE AT THIS TIME ONLY HAS SEAS GETTING LESS THAN ONE FOOT ABOVE
MAX ASTRONOMICAL TIDE WHICH IS NOT MUCH OF A CONCERN...BUT IT IS
WORTH KEEPING AN EYE ON. NO ADVISORIES OR WARNINGS EXPECTED AT THIS
TIME.

BERING/ALEUTIANS/ALASKA PENINSULA...
A STRONG 976 MB LOW IS LOCATED IN THE WEST/SOUTHWEST BERING THIS
MORNING. GALE FORCE WINDS SURROUND THE LOW WITH SOME STORM FORCE
GUSTS ESPECIALLY SOUTH OF THE LOW CENTER. THE OCCLUDED FRONT OUT
AHEAD OF THE LOW IS MOVING ONSHORE THE SOUTHWEST MAINLAND THIS
MORNING WITH SCATTERED SHOWER ACTIVITY IN ITS WAKE. THE LOW WILL
MOVE NORTHEAST ACROSS THE BERING FOR THE NEXT FEW DAYS AND GRADUALLY
WEAKEN...EVENTUALLY NEARLY STALLING OUT JUST OFF THE YUKON DELTA
MONDAY NIGHT THROUGH TUESDAY NIGHT. THE STRONGEST WINDS TODAY WILL
BE IN THE WESTERN AND CENTRAL ALEUTIANS ON THE SOUTH SIDE OF THE
LOW...SPREADING EAST TO THE PRIBILOFS...EASTERN ALEUTIANS...AND
ALASKA PENINSULA TONIGHT AND MONDAY. WINDS WILL GRADUALLY EASE INTO
TUESDAY AS SHOWER ACTIVITY SUBSIDES.

.LONG TERM FORECAST...
AS USUAL THERE IS A HIGH AMOUNT OF UNCERTAINTY IN THE EXTENDED
FORECAST FROM WEDNESDAY AND BEYOND. LATEST MODELS ARE NOT HOLDING
OUT MUCH HOPE FOR ANY SORT OF PATTERN CHANGE THROUGH THE WEEKEND.
MODELS AGREE ON KEEPING A BLOCKING HIGH PRESSURE OVER THE FAR
EAST/SOUTHEAST GULF OF ALASKA AND EXTENDING FURTHER SOUTH. AS LONG
AS THIS FEATURE PERSISTS...UPPER LEVEL SOUTH TO SOUTHWEST FLOW WILL
CONTINUE OVER SOUTHERN ALASKA...WHICH MEANS WET AND COOL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING ZONES 155 165 170 172 175 176 180 185 410 411
          412 413.
FIRE WEATHER...NONE.

FOISY AUG 10