Area Forecast Discussion
Issued by NWS Anchorage, AK

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FXAK68 PAFC 151402
AFDAFC

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
602 AM AKDT MON SEP 15 2014

.ANALYSIS AND UPPER LEVELS...
THE UPPER LEVELS ARE DOMINATED BY THE CLOSED UPPER LEVEL LOW
POSITIONED NEAR KING SALMON THIS MORNING. THIS IS REFLECTED WITH
A 995 MB SURFACE LOW SOUTH OF KING SALMON AND A SECOND WEAK LOW
OVER THE KUSKOKWIM DELTA. THE EASTERN BERING SEA HAS GUSTY
NORTHWESTERLY WINDS THAT ARE SPREADING THROUGH THE EASTERN
ALEUTIANS. AN UPPER LEVEL TROUGH IS LOCATED OVER THE WESTERN
ALEUTAINS RESULTING IN A WAVE FORMING SOUTH OF ADAK THIS MORNING.
AN UPPER LEVEL NEGATIVE TILTED RIDGE IS POSITIONED OVER THE YUKON
TERRITORY EXTENDING TOWARDS BARROW. THE SATELLITE IMAGERY SHOWS A
SWATH OF MOISTURE THROUGH SOUTHCENTRAL MAINLAND AND THE REMNANTSOF
THE OCCLUDED LOW LOCATED NEAR KING SALMON. THE GULF HAS CLEARING
SKIES WITH THE SURFACE FRONT PUSHING THROUGH THE NORTHERN GULF.

&&


.MODEL DISCUSSION...
THE MODEL ARE IN GOOD AGREEMENT FOR THE NEXT SEVERAL DAYS WITH THE
OCCLUDED LOW THAT IS MOVING INTO THE BRISTOL BAY REGION OVER THE
ALASKA PENINSULA THIS MORNING. THE NAM/GFS WERE IN GOOD AGREEMENT
WITH THE EC LAGGING BEHIND WITH TRACKING OF THE NEXT LOW TRACKING
INTO THE WESTERN ALEUTIANS TODAY. THE MODELS KEEP THIS LOW RUNNING
PARALLEL WITH THE ALEUTIAN CHAIN THROUGH WEDNESDAY BEFORE MERGING
WITH A NORTH PACIFIC LOW BY WEDNESDAY AFTERNOON. THE GFS HANDLED
THE QPF BETTER THAN THE OTHER MODELS. THE FORECAST CONFIDENCE IS
HIGH THROUGH SEVERAL DAYS.

&&

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
THE FRONT BOUNDARY IS POSITIONED OVER THE NORTHERN GULF THIS
MORNING AND WILL MOVE INLAND BY THIS AFTERNOON. THIS FRONT WILL
BRING MORE CLOUDS AND RAIN THROUGH TOMORROW. THE FLOOD ADVISORY
FOR RIVERS AND STREAMS IN THE WESTERN SUSITNA VALLEY WILL REMAIN
IN EFFECT UNTIL 1130 AM AKDT TODAY. THE NEXT SHORTWAVE WILL PUSH
THROUGH KODIAK BY LATE TUESDAY EVENING AND TRACK THROUGH PRINCE
WILLIAM SOUND BY WEDNESDAY BEFORE MOVING INLAND. THE UPPER LEVEL
LOW OVER BRISTOL BAY WILL HAVE SHORTWAVES ROTATE AROUND THE LOW.
THESE SHORTWAVES WILL TRACK THROUGH THE WESTERN GULF AND INTO THE
SOUTHCENTRAL ALASKA REGION FOR REST OF THE WEEK BRINGING MORE
WIDESPREAD CLOUDS AND RAIN.

SOUTHWEST ALASKA...
THE OCCLUDED LOW OVER THE ALASKA PENINSULA THIS MORNING WILL
BECOME ELONGATED AND FORM A WEAK SECONDARY LOW OVER BETHEL BEFORE
DISSIPATING BY TUESDAY. THIS WILL CONTINUE TO BRING SHOWERY
PRECIPITATION TO THE REGION WITH WINDS SHIFTING TO THE SOUTH TO
SOUTHWESTERLY ALONG THE SOUTHWEST COASTLINE LATER THIS AFTERNOON.
THE ONSHORE FLOW WILL HELP TRANSPORT THE MARINE LAYER STRATUS AND
PATCHY FOG INLAND FOR THE NEXT SEVERAL DAYS. BY TUESDAY EVENING A
LOW WILL TRACK INTO THE BRISTOL BAY AREA BRINGING GUSTY WINDS
ALONG THE SOUTHWEST COASTLINE AND RAIN TO THE REGION.

BERING SEA/ALEUTIANS...
THE LOW OVER THE BRISTOL BAY AREA WILL CONTINUE TO FILL AND MOVE
INLAND BEFORE DISSIPATING BY EARLY TUESDAY MORNING. THE NEXT LOW
PRESSURE SYSTEM WILL TRACK INTO THE WESTERN ALEUTIANS BY THIS
MORNING. THE LOW WILL TRACK ALONG THE ALEUTIAN CHAIN AND MERGE
WITH A NORTH PACIFIC LOW BY WEDNESDAY. THIS WILL BRING IN GUSTY
NORTHERLY WINDS FOR MAJORITY OF THE BERING SEA COINCIDING WITH A
90 KNOT NORTHERLY MERIDIONAL JET STREAK TRACKING THROUGH THE
CENTRAL BERING SEA. THE NORTHERLY FLOW WILL BRING COOLER
TEMPERATURES GOING INTO NEXT WEEKEND.

&&

.LONG TERM FORECAST...
THE BROAD LONGWAVE TROUGH CENTERED OVER THE EASTERN BERING WILL
BEGIN TO SHIFT EASTWARD DURING THE MIDDLE OF THE WEEK AND THEN
REMAIN OVER THE WESTERN GULF AND SLOWLY WEAKEN THROUGH NEXT
WEEKEND. THIS WILL WILL RESULT IN A GENERALLY CLOUDY AND SHOWERY
PATTERN OVER THE MAINLAND AS VARIOUS DISTURBANCES ROTATE AROUND
THE EASTERN PERIPHERY OF THE TROUGH...WITH STEADIER RAIN LIKELY
ALONG THE NORTHERN GULF COAST IN CLOSER PROXIMITY TO AN ATTENDANT
SURFACE LOW. THE EASTERN BERING WILL ALSO REMAIN SHOWERY AS BRISK
NORTHERLY FLOW BECOMES ESTABLISHED OVER THE REGION WITH THE TROUGH
DEPARTING TO THE EAST AND HIGH PRESSURE BUILDING IN OVER THE
WESTERN ALEUTIANS.


&&


.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...145.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

$$

PLD/CB SEP 14



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