Brisk Wind Advisory 35, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
459 AM AKDT TUE APR 14 2015

.ANALYSIS AND UPPER LEVELS...THE DOMINANT FEATURE ACROSS MOST OF
ALASKA THIS MORNING IS A VERTICALLY STACKED LOW THAT IS CURRENTLY
SPINNING JUST SOUTH OF DUTCH HARBOR. THE LOW REACHED ITS MAXIMUM
INTENSITY IN THE LOW 970 MB RANGE EARLY THIS MORNING AND IS NOW
WEAKENING. ONE WEAK UPPER LEVEL TROUGH IS PRESSING RIGHT UP
AGAINST THE NORTHERN GULF COAST AND HELPING TO TRIGGER SOME LIGHT
SNOW SHOWERS NEAR KACHEMAK BAY AND ACROSS COASTAL SITES. THESE
WILL BE SHORT LIVED AS A RATHER STRONG BUT SMALL SHORTWAVE RIDGE
MOVES INTO THE AREA AHEAD OF THE LOW. FOR THE SOUTHWEST...LIGHT
OVERRUNNING CONTINUES TO PRODUCE SOME LIGHT SNOWFALL OVER THE
KUSKOKWIM DELTA COAST. BUT OTHERWISE MOST PLACES ARE STARTING TO
SEE FLOW SHIFT TO THE NORTHEAST AND INCREASE IN ADVANCE OF THE
APPROACHING LOW. THIS WILL HELP THE LOW LEVELS TO FINALLY DRY OUT
UNDER OFFSHORE FLOW EVEN AS MID AND HIGH CLOUDS OVERSPREAD THE
AREA THROUGH THE DAY.

&&

.MODEL DISCUSSION...MODELS REMAIN IN GOOD SYNOPTIC
AGREEMENT IN THE SHORT TERM..ESPECIALLY IN HOW THEY HANDLE THE
NEXT LOW MOVING SOUTH OF THE WESTERN ALEUTIANS WEDNESDAY. THE
CANADIAN REGIONAL WAS UTILIZED FOR TUESDAY AND WEDNESDAY OUT WEST
WITH A TRANSITION TO THE ECMWF LATER ON. FOR SOUTH CENTRAL
ALASKA...THE NAM CONTINUES TO BE THE OUTLIER AS IT STRUGGLES WITH
THE TIMING OF THE VARIOUS FRONTS. SO THE ECMWF WAS UTILIZED FOR
THE SUBTLE CHANGES MADE IN THE SHORT TERM. FROM WEDNESDAY
ONWARD...MODELS CONTINUE TO STRUGGLE WITH THE DETAILS. THE UPPER
LEVELS ARE QUITE DIFFERENT IN HANDLING A NEGATIVELY TILTING TROUGH
COMING IN FROM THE SOUTHWEST AND THE EXACT LOCATION OF THE SURFACE LOW
CENTER REMAINS IN QUESTION. THIS LEADS TO LOW CONFIDENCE IN HOW
MUCH...IF ANY...PRECIPITATION MAKES IT INTO THE COOK INLET.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND
2)...THE WORST CONDITIONS WILL MOVE FROM KODIAK ISLAND THIS
AFTERNOON TO THE GULF COAST BY TONIGHT. KODIAK WILL SEE NORTHEAST
WINDS RAMP UP RATHER QUICKLY AS THE LOW MOVES JUST SOUTH OF THE
ISLAND. THIS WILL MAKE FOR SOME REDUCED VISIBILITY IN THE MORNING
WITH SNOW AND BLOWING SNOW. BUT CONDITIONS WILL IMPROVE BY THE
AFTERNOON AS WARMER AIR HELPS TO TRANSITION THE SNOW TO A RAIN
SNOW MIX AND EVENTUALLY ALL RAIN. THE PRECIPITATION WILL START
IN EARNEST OVER THE EASTERN KENAI PENINSULA THIS MORNING AND WORK
ITS WAY TO THE PRINCE WILLIAM SOUND THIS EVENING. PRECIPITATION
COULD START AS A RAIN SNOW MIX ALONG THE COAST BUT SHOULD QUICKLY
TRANSITION TO ALL RAIN WITH WARMER AIR MOVING IN. THE HEAVIEST
PRECIPITATION WILL BE LIMITED TO AREAS OF THE WESTERN PRINCE
WILLIAM SOUND AND RIGHT ALONG THE COAST AS STRONG OFFSHORE FLOW
WILL LIMIT ANY INLAND PUSH IT SHOULD TRY TO MAKE. THE SAME
OFFSHORE GRADIENT WILL ALLOW NORTHEAST FLOW TO PICK UP OUT OF THE
MATANUSKA VALLEY LATER TODAY AND CONTINUE INTO WEDNESDAY. THE
CROSS BARRIER COMPONENT OF THE FLOW WILL START TO RELAX SOME ON
WEDNESDAY AS THE LOW NEARS THE GULF COAST. THIS WILL BRING AN
INCREASED CHANCE FOR SOME PRECIPITATION TO INLAND AREAS INCLUDING
THE ANCHORAGE BOWL. WITH APRIL AFTERNOON HIGHS STILL EXPECTED TO
CLIMB INTO THE 40S...MOST LOCATIONS WILL SEE ONLY RAIN. AND THE
SYSTEM CONTINUES TO WEAKEN AS IT MOVES NORTHWARD...SO ANY QPF
AMOUNTS WILL BE QUITE LIMITED.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
SOUTHWEST ALASKA WILL STAY UNDER THE INFLUENCE OF A VERTICALLY
STACKED 974 MB LOW CURRENTLY SOUTH OF COLD BAY. THIS LOW IS
FORECAST TO MOVE INTO THE NORTHERN GULF OF ALASKA AND CONTINUE TO
WEAKEN OVER THE NEXT 48 HOURS KEEPING THE REGION IN BROAD CYCLONIC
FLOW. AS THE FLOW TURNS NORTHERLY TONIGHT...COLD AIR ADVECTION
WILL BRING COOLER TEMPERATURES MAINLY TO THE KUSKOKWIM DELTA.
THIS...COMBINED WITH A SHORTWAVE RIDGE EXPECTED TO MOVE INTO THE
CENTRAL BERING TONIGHT...WILL PRODUCE SLIGHTLY STRONGER WINDS
ALONG THE NORTHWESTERN PORTION OF THE KUSKOKWIM DELTA AND NUNIVAK
ISLAND THIS AFTERNOON THROUGH TOMORROW MORNING.

PRECIPITATION IS LIMITED THIS MORNING TO LIGHT SNOW ALONG THE
KUSKOKWIM COAST AND ISOLATED SHOWERS ALONG THE ALEUTIAN RANGE AND
THE ALASKA PENINSULA. PRECIPITATION SHOULD BEGIN TO TAPER OFF
TODAY ALONG THE KUSKOKWIM COAST WITH SCATTERED AREAS OF MIXED RAIN
AND SNOW ALONG THE ALASKA PENINSULA AND THE KILBUCK MOUNTAINS.
PRECIPITATION SHOULD TAPER OFF TONIGHT WITH THE NORTHERLY FLOW
BRINGING A COLDER AND DRIER AIRMASS INTO THE REGION.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE 974 MB LOW THAT IS CURRENTLY SOUTH OF COLD BAY WILL CONTINUE
TO MOVE EASTWARD THIS MORNING AND INTO THE NORTHERN GULF OF ALASKA.
WITH THE LOW LOCATED SOUTH OF THE ALEUTIAN CHAIN...THE AREA WILL
REMAIN IN NORTHEAST TO NORTHERLY FLOW THROUGH WEDNESDAY MORNING
WHEN A SHORTWAVE RIDGE WILL MOVE INTO THE CENTRAL ALEUTIANS.
ANOTHER STRONG LOW IS FORECAST TO MOVE SOUTH OF THE ALEUTIANS NEAR
SHEMYA BY WEDNESDAY AFTERNOON.

WINDS WILL REMAIN GALE FORCE THIS MORNING ALONG THE EASTERN
ALEUTIANS AND THE ALASKA PENINSULA BEFORE DECREASING THIS
AFTERNOON/TONIGHT AS THE LOW SOUTH OF COLD BAY CONTINUES TO MOVE
INTO THE NORTHERN GULF. WINDS WILL REMAIN BRISK OVER THE EASTERN
HALF OF THE BERING TODAY AND...COMBINED WITH THE COLD NORTHERLY
FLOW...WILL PRODUCE HEAVY FREEZING SPRAY THROUGH WED IN THE
NORTHEASTERN PORTIONS OF THE BERING SEA AND THE PRIBILOF ISLANDS.
THE NORTHERLY FLOW WILL ALSO PRODUCE WIDESPREAD AREAS OF SHOWERS
OVER THE REGION. WINDS WILL BEGIN TO DECREASE AS THE SHORTWAVE
RIDGE MOVES INTO THE REGION LATE TONIGHT. AS THE LOW APPROACHING
SHEMYA MOVES SOUTH OF THE CHAIN WEDNESDAY NIGHT...WINDS AND SEAS
ARE EXPECTED TO INCREASE ON THE PACIFIC SIDE OF THE ALEUTIANS WITH
WINDS APPROACHING GALE FORCE.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
THERE IS GOOD AGREEMENT IN THE MID TERM WITH A WEAKENING LOW IN
THE NORTHERN GULF MOVING NORTHWEST THROUGH COOK INLET AND INTO THE
ALASKA RANGE ON THU. THIS WILL BRING A RAIN AND SNOW MIX TO MUCH
OF SOUTHCENTRAL...WITH THE POTENTIAL FOR MORE SIGNIFICANT SNOWFALL
OVER THE NORTHERN SUSITNA VALLEY THU NIGHT INTO FRI. THE MAJOR
FEATURE MOVING INTO THE WEEKEND IS A LOW TRACKING TO THE SOUTH OF
THE ALEUTIANS FROM THE WEST. THERE IS GOOD AGREEMENT WITH ITS
EASTERLY TRACK BUT WHEN IT STARTS TO MOVE NORTH FRIDAY NIGHT SOME
DISCREPANCIES ARISE.

THE EC AND ITS ENSEMBLE MOVE THE LOW ALONG THE WEST COAST OF THE
STATE WHILE THE GFS...ITS ENSEMBLE AND THE GEM HAVE A MORE
EASTERLY SOLUTION OVER MAINLAND ALASKA. BECAUSE OF GOOD AGREEMENT
WITH STRONG RIDGING BUILDING IN OVER THE EASTERN PART OF THE STATE
THE MORE WESTERLY TRACK OF THE EC WAS PREFERRED. THE DIFFERENCES
IN THE POSITIONING OF THIS LOW AND ITS ASSOCIATED FRONT WILL
IMPACT THE TIMING OF THE FRONTS ARRIVAL TO THE SOUTHCENTRAL LATE
FRIDAY.

THIS ALL MEANS RAIN AND SNOW SHOWERS FOR THE BERING AND
ALEUTIANS...AND SOUTHWEST AK INTO EARLY NEXT WEEK. FOR
SOUTHCENTRAL DURING THE SAME PERIOD...MORE RAIN ALONG THE COAST
WITH RAIN AND SNOW SHOWERS INLAND.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...STORMS 119
         GALES 120 130-132 136-139 150 155 165 170 172 174 180
         HEAVY FREEZING SPRAY 179 180
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...MO
SOUTHCENTRAL ALASKA...MO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...RF
LONG TERM...DK/DS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
130 PM AKDT TUE APR 14 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0129 PM     SNOW             WHITTIER                60.79N 148.65W
04/14/2015  E6.0 INCH                           AK   PUBLIC

            6 TO 7 INCHES OF SNOW ESTIMATED TO HAVE FALLEN BETWEEN
            4AM AND 130PM.

&&

RDUELL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
233 PM AKDT TUE APR 14 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0222 PM     SNOW             30 ESE HOPE             60.73N 148.81W
04/14/2015  E4.0 INCH                           AK   PUBLIC

            4-6 INCHES OF SNOW REPORTED THROUGH TURNAGAIN PASS. 3-4
            INCHES REPORTED TURNAGAIN ARM PORTAGE VALLEY. SLUSH AND
            SNOW ON ROADS WITH SLICK CONDITIONS.

&&

RDUELL