Area Forecast Discussion
Issued by NWS Anchorage, AK

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FXAK68 PAFC 271301
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
501 AM AKDT WED AUG 27 2014

.ANALYSIS AND UPPER LEVELS...
A COMPLEX PATTERN IS TAKING SHAPE OVER THE BERING SEA THIS
MORNING...A FAR CRY FROM THE CONSISTENT NATURE OF THE LONG-WAVE
PATTERN FOR THE PAST WEEK. THE TWO MAIN FEATURES DRIVING THE LARGE
SCALE PATTERN ARE A CLOSED OFF KAMCHATKA UPPER LEVEL LOW AND
ANOTHER UPPER LOW IN OPEN WAVE FORM DROPPING INTO THE BERING SEA.
WHILE THESE FEATURES ARE NOT PHASING/MERGING THEY DO REPRESENT A
CONFLUENCE OF THE NORTHERN STREAM JET AND THE SOUTHERN STREAM
JET ENERGY. CURRENTLY THERE ARE A FEW LOW AMPLITUDE SHORTWAVE
TROUGHS IN THE FLOW ONE OF WHICH IS PHASING WITH THE NORTHERN
STREAM TROUGH AND DEVELOPING A COMPACT BUT STRONG CIRCULATION JUST
NORTH OF THE PRIBILOF ISLANDS. TOWARD THE SOUTHCENTRAL...A LOW
AMPLITUDE DIRTY RIDGE SITS OVER THE MAINLAND WITH SEVERAL WEAK
SHORTWAVES COMING THROUGH THE MOSTLY ZONAL FLOW. SHOWERS AND AREAS
OF RAIN FROM THE FIRST WAVE ARE MOVING NORTHWARD FROM THE NORTHERN
KENAI PENINSULA THROUGH THE SUSITNA VALLEY.

&&

.MODEL DISCUSSION...
GUIDANCE CONTINUES TO STRUGGLE WITH THE SMALL SCALE FEATURES OVER
THE BERING SEA. THE FURTHER NORTHWEST AND STRONGER TREND HAS
CONTINUED FOR GUIDANCE CONCERNING THE COMPACT BERING SYSTEM.
HOWEVER GUIDANCE IS IN REASONABLE AGREEMENT AND THE RECENT
STRUGGLES ARE NOT INDICATIVE OF HOW MODELS ARE HANDLING THE LARGE
SCALE DRIVERS OF THE PATTERN. THE GENERAL CONSENSUS IS THE BERING
SEA SYSTEM WILL SWING INTO THE GULF OF ALASKA AND BECOME A COMPLEX
LOW AT THE SURFACE...STACKED IN THE UPPER LEVELS.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...SHOWERS AND AREAS OF LIGHT RAIN WILL BE ON
THE INCREASE FROM THE NORTHERN KENAI UP INTO THE SUSITNA VALLEY
EARLY THIS MORNING. THE MAJORITY OF THE ACTIVITY WILL BE IN THE
SUSITNA VALLEY WHERE THE BEST FORCING AND MOISTURE LIE BUT SOME
SHOWERS FURTHER SOUTH CAN`T BE COUNTED OUT. THE FLOW ALOFT VEERS
TO THE SOUTH AND SOUTHEAST PRETTY QUICKLY TODAY AS THE BERING SEA
SYSTEM SLIDES INTO THE GULF. THE NORTH GULF COAST WILL BEAR THE
BRUNT OF THE INCOMING SYSTEM AS THE FRONT ROTATES UP LATE THIS
EVENING. TURNAGAIN ARM WINDS ARE ALREADY ON THE INCREASE WHICH
SHOULD CONTINUE THROUGH THE AFTERNOON AND EVENING. WINDWARD SIDES
OF THE ALASKA RANGE WILL SEE STEADY LIGHT RAIN BUT THE MAJORITY OF
AREAS WILL ONLY SEE THE OCCASIONAL LIGHT RAIN OR SHOWER. ONCE THE
GULF SYSTEM EXITS TO THE EAST ANOTHER TROUGH DROPS IN FROM THE
NORTHWEST KEEPING IN THE CHANCE FOR LIGHT RAIN IN THE NORTHERN
COOK INLET REGION.

SOUTHWEST ALASKA...A BATCH OF SHOWERS WILL APPROACH THE MAINLAND
THIS MORNING AHEAD OF FRONT THAT WILL JUST CLIP THE COAST...MAINLY
OVER BRISTOL BAY. A TROUGH FROM THE NORTHWEST WILL KEEP LIGHT RAIN
IN THE FORECAST...ESPECIALLY ALONG THE WINDWARD SIDES OF THE
KUSKOKWIM MOUNTAINS AND THE ALASKA RANGE WITH COOLER TEMPERATURES
ACROSS THE MAINLAND.

BERING SEA/ALEUTIANS...A FRONTAL SYSTEM WILL SLIDE ACROSS THE
EASTERN ALEUTIANS AND ALASKA PENINSULA TODAY. GUSTY NORTHWESTERLY
WINDS WILL FOLLOW THE SYSTEM AS IT EXITS. ANOTHER FRONT WILL
AFFECT THE WESTERN ALEUTAINS TODAY AND WEAKEN AS IT SLIDES EAST
OVER THE WEEK.


&&

.LONG TERM FORECAST...
AN UPPER LEVEL WEAK RIDGE WILL CONTINUE TO BUILD OVER THE
NORTHERN GULF OF ALASKA COASTLINE RESULTING IN THE TURNAGAIN ARM
WINDS PICKING UP THROUGH THIS UPCOMING WEEKEND. A LOW PRESSURE
SYSTEM WILL BE MOVING THROUGH THE BRISTOL BAY REGION HEADING INTO
THE WEEKEND. THE FRONTAL BOUNDARY ASSOCIATED WITH THIS SYSTEM
WILL BE POSITIONED NEAR KODIAK ISLAND RESULTING IN SOUTHWESTERLY
FLOW AIDING IN BRINGING MOISTURE UP THROUGH THE COOK INLET INTO
THE SOUTHEAST MAINLAND. BY MONDAY AFTERNOON THE LOW WILL BE
LOCATED NEAR SEWARD WITH MOISTURE BEING PUSHED FARTHER INLAND INTO
THE SOUTHEAST MAINLAND. THE MATANUSKA VALLEY AND COOK INLET
EXTENDING FARTHER SOUTHWARD WILL BE ON THE BACKSIDE OF THE LOW
PRESSURE SYSTEM RESULTING IN NORTHERLY WINDS BY MONDAY GOING INTO
TUESDAY. A LOW PRESSURE SYSTEM WILL BE POSITIONED OVER THE
EASTERN BERING SEA SATURDAY MORNING WITH THE FRONTAL BOUNDARY
MOVING INLAND OVER THE SOUTHWEST ALASKA COASTLINE. THIS SYSTEM
WILL TRACK THROUGH THE BRISTOL BAY AREA BRINGING MORE CLOUDS AND
RAIN TO THE SOUTHWEST ALASKA REGION THROUGH THE WEEKEND. BY MONDAY
THE MAJORITY OF THE BERING SEA AND SOUTHWEST ALASKA WILL HAVE AN
UPPER LEVEL RIDGE MOVING INTO THE AREA. THIS WILL RESULT IN
NORTHWESTERLY FLOW AND DRIER CONDITIONS HEADING INTO THE EARLY
PART OF NEXT WEEK.



&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 155.
FIRE WEATHER...NONE.
&&

$$
MTL
AUG 14



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