Small Craft Advisory 616, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
144 PM AKDT THU AUG 14 2014

.ANALYSIS AND UPPER LEVELS...
A BROAD AREA OF LOW PRESSURE OVER THE ALASKA PENINSULA IS BRINGING
RAIN TO AREAS ALL OVER THE SOUTHERN PORTION OF MAINLAND ALASKA DUE
TO THE SOUTHERLY FLOW OFF THE NORTH PACIFIC. FURTHER TO THE WEST
ANOTHER LOW IS MOVING EAST ACROSS THE CENTRAL ALEUTIANS BRINGING
RAIN TO THOSE AREAS AS IT CONTINUES TO TRACK ALONG THE CHAIN.

&&

.MODEL DISCUSSION...
FOR THE MOST PART THE MODELS ARE IN GOOD AGREEMENT IN THE SHORT
AND MID TERMS. THERE ARE SOME MINOR DISCREPANCIES WITH THE BROAD
AREA OF LOW PRESSURE OVER THE ALASKA PENINSULA AND WITH A WAVE
MOVING NORTH THROUGH THE EASTERN GULF TONIGHT...BUT NOTHING
OVERLY INCONSISTENT. ALTHOUGH THE 00Z NAM WAS STRUGGLING TO TRACK THE
LOW ACROSS THE ALEUTIANS BUT THE 12Z NAM HAS MOVED IN LINE WITH
THE OTHER MODELS. THE 00Z NAM HAD KEPT THE LOW SOUTH OF THE ALASKA
PENINSULA SATURDAY WHILE THE OTHER MODELS PUSHED IT INTO BRISTOL
BAY.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
MULTIPLE LOWS MOVING THROUGH THE BERING AND WESTERN PART OF THE
STATE WILL KEEP MOIST SOUTHERLY FLOW OVER THE SOUTHCENTRAL THROUGH
THE WEEKEND. AS THE VARIOUS TROUGHS MOVE THROUGH THE AREA RAIN
WILL BE STRONGER BUT THERE WILL BE GAPS OF INTERMITTENT LIGHT
RAIN IN BETWEEN. THE BIGGEST UNCERTAINTY FOR THE SOUTHCENTRAL IS
WITH AN AREA OF DRIER AIR PUSHING IN BEHIND THE FRONT THAT IS
MOVING THROUGH THE AREA TODAY. IF THE DRIER AIR CAN MAKE IT
FURTHER INLAND TO AREAS AROUND THE TALKEETNA MOUNTAINS BEFORE
FILLING BACK IN...THEN THERE WILL BE AN OPPORTUNITY FOR
THUNDERSTORMS IN THE TALKEETNA MOUNTAINS LATER THIS AFTERNOON AND
EVENING.

ADDITIONALLY...THE HIGHER AMOUNTS OF RAIN SEEN OVER THE KENAI
PENINSULA OVER THE LAST COUPLE OF DAYS HAVE RISEN THE WATER
LEVELS OF THE KENAI AND KASILOF RIVERS. THIS HAS LED TO WATER
LEVELS AT PLACES ALONG THESE RIVERS TO BE NEAR FLOOD STAGE.

SOUTHWEST ALASKA...
THE SOUTHWEST WILL SEE WET CONDITIONS THROUGH THE WEEKEND DUE TO
THE MULTIPLE LOWS MOVING THROUGH THE BERING. IN THE MORNINGS THE
RAIN WILL BE LIGHTER AND MORE INTERMITTENT...HOWEVER WITH THE
UNSTABLE CONDITIONS AND HEATING IN THE AFTERNOON AND EVENING HOURS
THUNDERSTORMS WILL DEVELOP TODAY AND FRIDAY. THESE WILL BE MOST
LIKELY OVER INLAND LOCATIONS.

BERING SEA/ALEUTIANS...
THE MAIN LOW OVER THE CENTRAL ALEUTIANS IS BRINGING RAIN TO THE
AREA AND WILL BE OVER THE EASTERN ALEUTIANS BY FRIDAY AFTERNOON.
FROM THERE IT WILL TRACK INTO BRISTOL BAY BY SATURDAY AFTERNOON
BRINGING RAIN TO THE AREAS AROUND IT AS IT PASSES. BEHIND THE LOW
MUCH OF THE RAIN WILL CLEAR UP BUT THERE WILL BE LINGERING
ISOLATED SHOWERS.

&&

.LONG TERM FORECAST...
A RAINY WEEKEND WILL GIVE WAY TO IMPROVING CONDITIONS BY EARLY NEXT
WEEK AS THE LAST IN A SERIES OF LOW PRESSURE SYSTEMS AFFECTING
MAINLAND ALASKA WEAKENS AND DEPARTS TO THE NORTHEAST. THIS WILL
BE REPLACED BY A RELATIVELY WEAK FLOW PATTERN ALOFT...WITH A
LONGWAVE TROUGH REMAINING OVER THE BERING AND AN UPPER RIDGE
BEGINNING TO BUILD OVER THE EASTERN GULF AND ALCAN BORDER REGION
BY THE MIDDLE OF THE WEEK. THIS WILL YIELD GENERALLY PLEASANT
CONDITIONS CHARACTERIZED BY DIURNAL SHOWER ACTIVITY ACROSS THE
SOUTHERN MAINLAND...WITH SHOWERS ALSO POSSIBLE ACROSS MUCH OF THE
BERING BENEATH THE UPPER TROUGH.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FLOOD ADVISORY...121.
MARINE...GALE WARNING...119 130 131 175 176.
FIRE WEATHER...NONE.

&&

AUG 14