Small Craft Advisory 919, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
526 AM AKST TUE NOV 18 2014

.ANALYSIS AND UPPER LEVELS...
THE AMPLIFIED NEGATIVE TILTED RIDGE REMAINS ALONG SOUTHEAST
ALASKA AREA EXTENDING NORTHWEST TOWARDS BARROW. A SECONDARY RIDGE
EXTEND THROUGH SOUTHCENTRAL ALASKA INTO THE KUSKOKWIM VALLEY WHICH
WILL KEEP THE TURNAGAIN ARM WINDS GUSTY. THIS WILL HELP KEEP THE
PRESSURE GRADIENT STRONG...WHILE COINCIDING WITH THE UPPER LEVEL
TROUGH TRACKING INTO THE WESTERN GULF LATER THIS MORNING. THE
NORTHERN GULF BARRIER JET IS FORMING WITH A SHIP OBSERVATION
REPORTING GUSTS TO 50 KNOT ALONG THE SOUTHERN EASTERN KENAI
PENINSULA THIS MORNING. AT THE SURFACE THERE IS A GALE FORCE LOW
JUST ENTERING THE SOUTHWESTERN GULF. WHILE THE SATELLITE IMAGERY
HAS WIDESPREAD MOISTURE STREAMING INTO THE GULF AND INTO
SOUTHWEST ALASKA REGION. THERE IS A SOUTH TO NORTH 100 KNOT
MERIDIONAL JET THROUGH THE CENTRAL GULF. THE CENTRAL ALEUTIANS
HAS AN UPPER LEVEL VERTICALLY STACKED LOW WITH A GALE FORCE LOW AT
THE SURFACE POSITIONED JUST WEST OF UNALASKA THIS MORNING.
SEVERAL SHORTWAVES CONTINUE TO PUSH THROUGH SOUTHWEST ALASKA AND
THE EASTERN BERING SEA THIS MORNING. THE RADAR IS SHOWING
WIDESPREAD RAIN THROUGH THE BRISTOL BAY AREA AND THE KUSKOKWIM
DELTA MOVING FROM THE SOUTH TO THE NORTH.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE LOW ENTERING INTO THE
SOUTHWESTERN GULF THIS MORNING BEFORE TRACKING  INTO THE SHELIKOF
STRAIT BY THIS AFTERNOON. THIS WILL BRING STEADY RAIN FOR KODIAK
NORTHWARD WITH GALE/STORM FORCE WINDS THROUGH THE BARREN ISLANDS
AND ALONG THE NORTHERN GULF COAST. THE MODELS CONTINUE TO BE IN
GOOD AGREEMENT WITH THE NORTH PACIFIC LOW TRACKING JUST WEST OF
UNALASKA THIS MORNING. THIS WILL BRING WIDESPREAD RAIN WITH GUSTY
GALE FORCE WINDS THROUGH WEDNESDAY AS THE LOW BECOMES STATIONARY.
THE PREFERRED MODEL OF CHOICE WAS THE NAM/GEM-REG. THE FORECAST
CONFIDENCE REMAINS ABOVE AVERAGE THROUGH WEDNESDAY.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A STRONG LOW OVER THE GULF WILL MOVE NORTHWEST TODAY...CROSSING
KODIAK IN THE EARLY AFTERNOON. STORM FORCE WINDS WILL CUT A
SWATHE ACROSS THE NORTHERN GULF FROM CAPE SUCKLING TO AFOGNAK
ISLAND...AS WELL AS IN THE SOUTHERN COOK INLET AND KAMISHAK BAY.
DURING THE EVENING THE LOW WILL CROSS THE ALEUTIAN RANGE. AS THIS
HAPPENS THE SURFACE GRADIENT WILL REVERSE ACROSS SOUTH CENTRAL
ALASKA AND WINDS WILL BECOME MORE SOUTHERLY. THE ASSOCIATED UPPER
TROUGH WILL PUSH INTO SOUTHERN ALASKA FROM THE SOUTH AND BRING
COOLER AIR ALOFT. HOWEVER...SURFACE TEMPERATURES WILL STAY FAIRLY
WARM TONIGHT WITH THE SOUTHERLY WINDS.

THE UPPER TROUGH ANCHORED OVER THE SOUTHERN BERING AND ALEUTIANS
WILL KEEP SOUTHERLY FLOW ALOFT OVER SOUTH CENTRAL ALASKA ON
WEDNESDAY. SOME BRIEF RIDGING IS EXPECTED WEDNESDAY NIGHT AHEAD OF
ANOTHER STRONG LOW SPINNING UP OVER THE SOUTHWEST GULF.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 THROUGH 3)...

MOISTURE ASSOCIATED WITH THE LOW SOUTHEAST OF KODIAK ISLAND WILL
CONTINUE TO OVERSPREAD SOUTHWEST ALASKA DURING THE DAY. WHILE THE
BRISTOL BAY AREA WILL SEE PERIODS OF RAIN...IT IS APPEARING MORE
AND MORE LIKELY THAT THE KUSKOKWIM DELTA AND LOWER KUSKOKWIM
VALLEY WILL HAVE A SHOT AT FREEZING RAIN DURING THE DAY TODAY.
WHILE TEMPERATURES ACROSS THE DELTA WARMED INTO THE MID TO UPPER
30S OVERNIGHT...STRONG NORTHEASTERLY WINDS WILL USHER IN COOLER
SURFACE TEMPERATURE FROM BETHEL NORTHWARD. THIS WILL LEAD TO A
TRANSITION FROM RAIN IN TO THE MORNING TO LIGHT FREEZING RAIN IN
THE AFTERNOON. THIS FREEZING RAIN IS EXPECTED TO CONTINUE INTO THE
LATE EVENING BEFORE TEMPERATURES ALOFT BEGIN TO COOL AND AND
FAVOR A TRANSITION TO SNOW. ICE ACCUMULATION AROUND ONE TENTH OF
AN INCH COULD BE SEEN...WITH THE GREATEST AMOUNTS NORTH OF BETHEL.
FREEZING RAIN IS ALSO EXPECTED IN THE LOW LYING AREAS OF THE
KUSKOKWIM DELTA WHERE TEMPERATURES ARE EXPECTED TO REMAIN BELOW
FREEZING THROUGHOUT THE DAY TODAY. PRECIPITATION WILL MOVE INTO
THE VALLEY BY MID AFTERNOON AND CONTINUE THROUGH THE LATE
EVENING...WITH AROUND ONE TENTH OF AN INCH OF ICE ACCUMULATION
POSSIBLE.

CONDITIONS WILL BEGIN TO IMPROVE ACROSS SOUTHWEST ALASKA BY
TUESDAY MORNING AND CONTINUE THROUGH THURSDAY MORNING WITH
SLIGHTLY CLEARING SKIES IS SIGNIFICANTLY REDUCED PRECIPITATIONS
CHANCES. HOWEVER...ATTENTION THEN TURNS TO A RAPIDLY DEVELOPING
LOW FROM THE NORTH PACIFIC THAT IS FORECASTED TO TRACK SOUTH OF
THE ALASKA PENINSULA WHERE IT EVENTUALLY STALLS OUT. THIS WILL
BRING ANOTHER PERIOD OF RAIN AND WINDS TO SOUTHWEST ALASKA.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 THROUGH 3)...

THE AREA OF LOW PRESSURE OVER THE EASTERN ALEUTIANS WILL SLOWLY
DRIFT TO THE WEST/NORTHWEST THROUGH THE MIDDLE OF THE WEEK. THIS
WILL KEEP DECENT CHANCES FOR RAIN AND RAIN SHOWERS ACROSS THE
BERING SEA AND ALEUTIAN ISLANDS DURING THIS TIME FRAME. A RAPIDLY
DEVELOPING LOW FROM THE NORTH PACIFIC WILL PUSH SOUTH OF THE
ALEUTIAN ISLANDS AND PHASE WITH THE LOW IN THE WESTERN BERING SEA.
THE DEVELOPING IS THEN EXPECTED TO STALL OVER THE ALASKA
PENINSULA...WHICH WILL CONTINUE TO KEEP RAIN AND PERIODS OF GALE
FORCE WINDS IN THE FORECAST.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...

BEGINNING THURSDAY...A POTENTIAL STORM FORCE NORTH PACIFIC LOW
WILL BE TRACKING SOMEWHERE FROM SOUTH OF THE SHUMAGIN ISLANDS TO
SOUTH OF THE ALASKA PENINSULA. THIS SYSTEM WILL SPREAD RAIN ALONG
MOST OF THE NORTH GULF COAST AND INTO KODIAK ISLAND...ALTHOUGH THE
HEAVIEST PRECIP WILL BE FROM THE KENAI COAST TO KODIAK. THIS
SYSTEM WILL EVENTUALLY BECOME AN ANCHOR FOR ANOTHER PERSISTENT
LOW...THIS TIME CENTERED OVER THE EASTERN ALEUTIANS. THE
ASSOCIATED WARM FRONT WILL MOVE INTO THE GULF OF ALASKA...WITH
RAIN AND RAIN SHOWERS IMPACTING COASTAL LOCATIONS INTO NEXT WEEK.
INLAND LOCATIONS WILL REMAIN GENERALLY ON THE DRY SIDE AS MOST
PRECIPITATION WILL FALL ACROSS THE COASTAL MOUNTAINS...WITH
LIGHTER SHOWERY PRECIP OVER THE INLAND MOUNTAINS. TEMPERATURES AS
A WHOLE WILL CONTINUE TO REMAIN WELL ABOVE AVERAGE ACROSS MOST OF
SOUTHCENTRAL THROUGH THE EXTENDED FORECAST PERIOD ALTHOUGH THEY
WILL GRADUALLY TREND DOWN EARLY NEXT WEEK. IN OTHER WORDS...NO
DRAMATIC SHIFT IN THE SENSIBLE WEATHER PATTERN FOR MOST OF
SOUTHCENTRAL ALASKA...ALTHOUGH SOUTHWEST ALASKA WILL TREND DRIER
THROUGH EARLY WEEK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FREEZING RAIN ADVISORY 152 155.
MARINE...GALE 125 132 136 137 138 140 141 172 174 176-179 185.
         STORM 119 120 130 131 139.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...LUDWIG
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CLAY
LONG TERM...AHSENMACHER