Small Craft Advisory 781, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
522 AM AKDT WED OCT 8 2014

CORRECTED TYPO

.ANALYSIS AND UPPER LEVELS...
CLEAR SKIES AND BRISK NORTHERLY WINDS CONTINUE TO PREVAIL ACROSS
MUCH OF THE SOUTHERN HALF OF THE MAINLAND THIS MORNING BENEATH
NORTHWESTERLY FLOW ALOFT ON THE WESTERN PERIPHERY OF A LONGWAVE
TROUGH CENTERED OVER THE ALCAN BORDER. AN EMBEDDED LOW OVER THE
CENTRAL INTERIOR IS DROPPING SOUTHWARD TOWARDS SOUTHCENTRAL AK BUT
IS GENERALLY ONLY YIELDING A FEW HIGH CLOUDS. FARTHER WEST...THE
DOMINANT FEATURE IS A 950 MB LOW ASSOCIATED WITH THE REMNANTS OF
TYPHOON PHANFONE THAT IS CURRENTLY LOCATED APPROXIMATELY 370 MILES
SOUTH OF THE CENTRAL ALEUTIANS. GALE FORCE EASTERLY WINDS ARE
IMPACTING A WIDE SWATH OF THE BERING SEA BETWEEN THIS FEATURE TO
THE SOUTH AND HIGH PRESSURE OVER THE NORTHERN BERING AND EASTERN
RUSSIA...WITH STORM FORCE WINDS AND RAIN BEING FELT ALONG A
PERSISTENT FRONT THAT EXTENDS NORTHWESTWARD FROM THE EASTERN
ALEUTIANS INTO THE WESTERN BERING.

&&

.MODEL DISCUSSION...
MODELS REMAIN IN GOOD SYNOPTIC AGREEMENT THROUGH THE END OF THE
WEEK WITH MINOR DIFFERENCES ARISING AS THE LOW TRACKS INTO THE
GULF ON FRIDAY. THE EC REMAINS SLIGHTLY FARTHER EAST THAN THE
GFS/NAM/GEM...BUT THE DIFFERENCE IS FAIRLY NEGLIGIBLE AT THIS
POINT AS ALL MODELS HAVE COME INTO BETTER AGREEMENT IN THE PAST 24
HOURS. GUIDANCE HAS ALSO CONTINUED TO IMPROVE REGARDING THE TIMING
OF THE FRONT INTO THE GULF...WITH THE FRONT ARRIVING OVER THE
SOUTHERN GULF TONIGHT AND THEN BEGINNING TO IMPACT THE GULF COAST
DURING THE DAY ON THURSDAY. UTILIZED A COMBINATION OF NAM AND
REGIONAL GEM EARLY ON FOR GREATER DETAIL AND THEN A COMBINATION OF
THE GFS AND EC THROUGH FRIDAY NIGHT.

&&

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...
THE UPPER LOW DROPPING OUT OF THE INTERIOR MAY BRING A FEW HIGH
CLOUDS TO THE AREA LATER TODAY...BUT FOR THE MOST PART
SOUTHCENTRAL AK WILL REMAIN CLEAR INTO TONIGHT BEFORE THE STRONG
FRONT BEGINS TO IMPACT THE AREA ON THURSDAY. THE EXCEPTION WILL BE
OVER THE COPPER RIVER BASIN AND EASTERN PRINCE WILLIAM SOUND WHERE
A STRATUS DECK WILL CONTINUE TO LINGER AND A FEW SHOWERS WILL BE
POSSIBLE TODAY. RAIN WILL OVERSPREAD KODIAK ISLAND LATE TONIGHT
AS THE FRONT ENTERS THE SOUTHERN GULF AND THEN MOVE TO THE GULF
COAST BY THURSDAY AFTERNOON ACCOMPANIED BY GALE FORCE WINDS...ALONG
WITH SOME STORM FORCE WINDS FROM THE BARREN ISLANDS THROUGH SHELIKOF
STRAIT. SOME SNOW MAY MIX IN AT THE ONSET OF PRECIPITATION BEFORE
THE WARMER AIR MOVES IN AND ALLOWS FOR A TRANSITION TO ALL RAIN
FOR MOST LOCATIONS OVERNIGHT THURSDAY INTO THE DAY ON FRIDAY. RAIN
WILL CONTINUE INTO THE WEEKEND AS THE LOW ITSELF MOVES INLAND ON
SATURDAY.

SOUTHWEST ALASKA...
NORTHERLY FLOW WILL CONTINUE TO YIELD MAINLY CLEAR SKIES OVER THE
NEXT FEW DAYS AS THE MAIN IMPACTS FROM THE SYSTEM ENTERING THE GULF
REMAIN SOUTH OF THE SOUTHWEST MAINLAND. THE LONE EXCEPTION WILL BE
COASTAL PORTIONS OF BRISTOL BAY...WHERE SOME RAIN AND SNOW WILL BE
POSSIBLE THURSDAY AFTERNOON AS THE FRONT PROGRESSES NORTHWARD
TOWARDS THE GULF COAST. OTHERWISE...THE BIGGEST IMPACT FROM THIS
SYSTEM WILL BE GUSTY NORTHERLY WINDS WHICH WILL BEGIN TO INCREASE
THIS AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO THE
LOW MOVING FARTHER NORTH.

BERING SEA/ALEUTIANS...
MORE OF THE SAME IS IN STORE FOR THE BERING AS EASTERLY GALES
CONTINUE OVER MUCH OF THE REGION THROUGH THURSDAY BETWEEN THE
POWERFUL LOW TO THE SOUTH AND HIGH PRESSURE TO THE NORTH...WITH AN
EMBEDDED AREA OF STORM FORCE WINDS PERSISTING INTO TONIGHT ALONG
THE FRONT BETWEEN THE EASTERN ALEUTIANS AND PRIBILOF ISLANDS. THE
FRONT WILL THEN BE OVERTAKEN BY THE LOW AS IT CONTINUES TO TRACK
NORTHEASTWARD TONIGHT...WITH RAIN CONTINUING THROUGH FRIDAY FROM
DUTCH HARBOR TO THE AKPEN ON THE NORTHERN PERIPHERY OF THE SYSTEM.
FARTHER WEST...RAIN AND WINDS WILL BEGIN TO DIMINISH BY THURSDAY
AS THE LOW PUSHES OFF TO THE EAST.

&&

.LONG TERM FORECAST (SAT-TUE)...
THE "LEFTOVER" TROUGH IN THE GULF OF AK TO START THE PERIOD WILL
BE REINFORCED BY ENERGY DROPPING INTO THE AREA FROM THE NORTH.
MODELS ARE ALREADY IN RELATIVELY GOOD AGREEMENT ON THIS NORTHERN
TIER ENERGY SLIDING DOWN THE EAST FLANK OF THE RIDGE OVER THE
BERING TOWARDS BRISTOL BAY EARLY SAT. THE BIGGEST DIFFERENCE IS
HOW THEY HANDLE THE TRACK OF THE LOW AS IT MOVES S OF 60N. THE
GFS/GEM GLOBAL DRIVE IT FURTHER SOUTH INTO THE TROUGH OVER THE
GULF. THE EC ON THE OTHER HAND HOLDS IT OVER BRISTOL BAY BEFORE
TRACKING IT NE RIGHT THROUGH SOUTH CENTRAL. THE MOST SIGNIFICANT
PIECE OF THIS IS THAT THE EC WOULD BRING A ROBUST ROUND OF COLD
AIR ADVECTION INTO THE AREA THROUGH THE END OF THE WEEKEND. 850 MB
TEMPERATURES BY MONDAY MORNING ON THE GFS ARE PROGGED TO BE AROUND
-2C OVER ANCHORAGE WHILE THE EC PAINTS NEARLY -10C. WITH LINGERING
MOISTURE FROM THE TROUGH IN THE GULF...THE EC SOLUTION WOULD BRING
WIDESPREAD SNOW TO SOUTH CENTRAL BY EARLY NEXT WEEK. IF THE
GFS/GEM SOLUTION WERE TO PAN OUT...LOWER ELEVATIONS WOULD LIKELY
JUST SEE SOME MORE LIGHT RAIN WITH MIXED PRECIPITATION HIGHER UP.
MEANWHILE OVER THE BERING AND ALEUTIANS...THINGS SHOULD BE
TRENDING DOWNWARD IN TERMS OF PRECIPITATION CHANCES AND WINDS. A
RIDGE WILL BUILD EARLY IN THE WEEK AND SHOULD KEEP MOST OF THE
ACTIVE WEATHER SOUTH AND NORTH OF THE AREA.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE
MARINE...STORM WARNING 130 131 138 170 173
 		 GALE WARNING 119 120 132 136 137 139 150 155 160 165 171
					  172 174 175 176 177 178 179 180 181 185
FIRE WEATHER...NONE

&&

CB/MSO OCT 14