Small Craft Advisory 868, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
434 PM AKDT SAT NOV 1 2014

.ANALYSIS AND UPPER LEVELS...BRISTOL BAY UPPER LOW HAS TWO
SIGNIFICANT IMPULSES IN ITS CIRCULATION. ONE SWINGING SOUTHEAST
ACROSS THE EASTERN ALEUTIANS ALASKA PENINSULA IS FOLLOWED BY
COLDER AIR AND SNOW SHOWERS RIDING SOUTHEASTWARD ON NORTHWESTERLY
GALES. WINDS SATURDAY MORNING HAVE BEEN OBSERVED GUSTING 40 TO 50
MPH ACROSS THE ALASKA PENINSULA AND TAKE A MORE WESTERLY DIRECTION
AS THEY SWEEP ACROSS MARINE ZONE 155. MINIMUM GALES EXTEND
WESTWARD TO ADAK TODAY BUT WILL DROP OFF LATER TODAY BUT PERSIST
THROUGH SUNDAY FROM SITKINAK TO CAPE SARICHEF. LEADING EDGE OF
THIS SURGE OF COLD AIR HAS PUSHED TO ABOUT 155W BY 1PM AND IS
PASSING KODIAK ISLAND BY TO THE SOUTH. THE SECOND IMPULSE IS
ACTUALLY A PRETTY FORMIDABLE OCCLUDED FRONT THAT'S PUSHED UP TO
THE NORTH GULF COAST. THIS FEATURE HAS A BAND OF 35 TO 40 KT
GALES. STORM FORCE GUST WERE OBSERVED OVER ZONES 119 AND 120 DUE
TO THE STEEPER GRADIENT OF THE FRONT WRAPPING BACK INTO THE 975 MB
SURFACE LOW WHICH WILL BE AROUND 60 NM SOUTH OF SEWARD AT 00Z (4
PM) SUNDAY. THIS SURFACE LOW APPEARS TO BECOME NEARLY STATIONARY
UNTIL IT TROFS OUT AND KICKS INLAND ACROSS THE KENAI PENINSULA AS
EARLY AS MID AFTERNOON SUNDAY, OR, AS LATE AS SOMETIME SUNDAY
EVENING AS UPPER LEVEL FLOW BACKS TO A MORE SOUTHERLY DIRECTION.
BRISTOL BAY UPPER LOW WILL CONTINUE ITS EASTWARD DRIFT SUNDAY TO A
POSITION VERY CLOSE TO THE SURFACE LOW ABOUT 50 NM SOUTH OF
SITKINAK 4 PM MONDAY.

&&

.MODEL DISCUSSION...OUTPUT PROVIDED BY THE EC IS WHAT THE EASTERN
AND WESTERN DOMAIN FORECASTERS FOLLOWED SATURDAY WHILE THE NAM RAN
SECOND.

&&

.SHORT TERM FORECAST...SEVERAL ADDITIONAL SURGES OF MOISTURE WILL
MOVE TO SOUTHERN ALASKA INTO SUNDAY EVENING. PERIODS OF RAIN FOR
THE NORTH GULF COAST WITH RAIN AND SNOW WESTWARD ACROSS THE
BARRENS TO KAMASHAK BAY AND NORTH ALONG THE EASTERN SLOPES OF THE
WESTERN ALASKA RANGE TONIGHT THROUGH SUNDAY NIGHT BEGIN TO
SIGNIFICANT DIMINISH LATER MONDAY AND TUESDAY BUT WONT END
COMPLETELY ALONG THE COAST TO KODIAK ISLAND. GALE FORCE NORTHERLY
FOR THE EASTERN BERING AND ALEUTIANS MONDAY NIGHT AND TUESDAY
DIMINISH BY WED AS A RIDGE AXIS MOVES EASTWARD.

&&

.LONG TERM FORECAST (WED-SAT)...THE BIGGEST STORY IN THIS TIME
PERIOD WILL MOST CERTAINLY TAKE PLACE CLOSER TO NEXT WEEKEND.
MODELS CONTINUE TO SHOW THE POTENTIAL FOR A DEEP PHASING LOW
DEVELOPING SOMETIME FRIDAY INTO SATURDAY. WE'LL GET TO THAT MORE
SHORTLY. BEFORE THAT THOUGH...THE MIDDLE PART OF THE WEEK WILL
FEATURE A PARENT LOW NEAR THE KAMCHATKA PENINSULA...A WEAKENING
RIDGE OVER THE EASTERN BERING...AND A RESIDUAL AREA OF LOW
PRESSURE IN THE GULF. THE PARENT LOW WILL SEND A SWEEPING OCCLUDED
FRONT ACROSS THE ALEUTIANS WITH MINIMUM GALE FORCE WINDS ON
WEDNESDAY. THE LOW IN THE GULF WILL KEEP UNSETTLED WEATHER
THROUGHOUT THE COASTAL AREAS WITH GUSTY WINDS. WEAK UPPER LEVEL
WAVES WILL SERVE TO PUSH SOME OF THIS UNSETTLED WEATHER INLAND ON
OCCASION AFFECTING PARTS OF THE KENAI PENINSULA AND THE COOK
INLET. BY THURSDAY...MODELS AGREE THAT A TRIPLE POINT LOW WILL
TAKE SHAPE ALONG THIS BOUNDARY JUST SOUTH OF THE EASTERN
ALEUTIANS. THIS WILL SERVE TO ABSORB SOME OF THE ENERGY FROM THE
LOW IN THE GULF AND GIVE A BRIEF REPRIEVE TO AREAS ALONG THE
COAST. THE TRIPLE POINT WILL THEN SWING THROUGH THE GULF ON FRIDAY
BRINING ANOTHER ROUND OF RAIN FOR THE COAST AND SNOW FOR IMMEDIATE
INLAND LOCATIONS.

NOW TO THE AFORE MENTIONED PHASING LOW POSSIBLY IMPACTING AREAS
FROM THE CENTRAL ALEUTIANS TO THE ALASKA PENINSULA NEXT WEEKEND.
MODELS STARTED HINTING AT THIS YESTERDAY AND THEY ARE STARTING TO
SHOW A LITTLE MORE PROMISE. IT WOULD BE THE EXTRA-TROPICAL
REMNANTS OF NOW TYPHOON NURI. THERE ARE STILL MAJOR DISCREPANCIES
THE STRENGTH OF THIS FEATURE. THE ECMWF HAS BEEN HOVERING AROUND
960MB FOR A CENTRAL SURFACE PRESSURE WHILE ONE OF THE GFS ENSEMBLE
MEMBERS CAME IN RIDICULOUSLY LOW AT 924MB. WHILE THE FORECAST
CERTAINLY DID NOT BITE OFF COMPLETELY ON THAT DEPTH...WE DID TREND
IN A STRONGER DIRECTION. MANY MANY THINGS COULD CHANGE WITH THIS
FEATURE AS IT DRAWS CLOSER IN TIME...ESPECIALLY BECAUSE IT IS
TROPICAL REMNANTS WHICH MODELS NOTORIOUSLY HANDLE POORLY. EITHER
WAY...WE WILL BE KEEPING AN EYE ON ITS DEVELOPMENT.

AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER WEATHER ADVISORY 121
MARINE...GALE WARNING 150 155 165 170 172 174 175 181 185 352
FIRE WEATHER...NONE

DP/MSO NOV 14