Small Craft Advisory 24, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
452 AM AKST FRI JAN 9 2015

.ANALYSIS AND UPPER LEVELS...

THE HIGHLY AMPLIFIED PATTERN CONTINUES THIS MORNING ACROSS ALASKA
AS A DEEP NEGATIVE TILT RIDGE AXIS EXTENDING FROM THE SOUTHWEST US
TO THE NORTHEAST SLOPE OF ALASKA DRIVES A PLUME OF MOISTURE ACROSS
SOUTHERN ALASKA. WATER VAPOR SATELLITE IMAGERY DEPICTS THREE
REMNANT UPPER LOWS ASSOCIATED WITH THE LARGER SCALE BERING/NOPAC
TROUGH...ONE WEST OF NUNIVAK ISLAND...ONE OVER WESTERN KODIAK
ISLAND...AND ONE SOUTHWEST OF HAIDA GWAII. THE SPLITTING OF THIS
TROUGH WILL EFFECTIVELY CUT OFF THE NORTH PACIFIC MOISTURE PLUME
INTO ALASKA...AND WILL LEAVE THE MAINLAND REGION UNDER INCREASING
WEAK HIGH PRESSURE RIDGING ALOFT...AND A DIMINISHING SURFACE
PRESSURE GRADIENT. SNOW AND FREEZING RAIN SHOWERS ACROSS SOUTHWEST
ALASKA...AS WELL AS RAIN SHOWERS ACROSS THE GULF COAST...WILL
PERSIST INTO TONIGHT BEFORE DIMINISHING AND BECOMING ISOLATED TO
SCATTERED. A SINGLE MID LEVEL LOW WILL ROTATE AROUND THE GULF AND
RETROGRADE WEST SATURDAY AND SUNDAY...WITH INCREASING SHOWERS
ALONG THE GULF COAST AND INTO THE COPPER BASIN. THE BERING SEA AND
ALEUTIANS WILL SEE INCREASING STORMINESS THIS WEEKEND AND EARLY
NEXT WEEK AS A SERIES OF NOPAC LOWS ROTATE NORTHWARD INTO THE
AREA.

THE BRIEF REPRIEVE IN ACTIVE WEATHER ACROSS SOUTHERN ALASKA WILL
LAST THROUGH THE WEEKEND BEFORE A POWERFUL JET STREAM ACROSS THE
NORTH PACIFIC CARVES OUT ANOTHER DEEP ALEUTIAN LOW EARLY NEXT
WEEK. THIS WILL SET THE STAGE FOR A PACIFIC "FIREHOSE" PATTERN TO
UNLEASH A SERIES OF STRONG LOW PRESSURE SYSTEMS INTO THE ALASKA
PENINSULA AND GULF OF ALASKA...KEEPING THE THREAT FOR PERIODS OF
RAIN...CLOUDS...AND WELL ABOVE AVERAGE TEMPERATURES ACROSS ALASKA
DEEP INTO NEXT WEEK. IN OTHER WORDS...THE NEVER ENDING WARM
ANOMALIES WILL CONTINUE WITH NO MAJOR COLD OUTBREAKS OR
SIGNIFICANT SNOW THREATS EXPECTED IN THE NEAR FUTURE. THE RECORD
BREAKING WARMTH OF THIS WINTER LOOKS TO PERSIST FOR THE
FORESEEABLE FUTURE AS HIGH LATITUDE BLOCKING OVER EASTERN SIBERIA
AND THE CHUKCHI SEA DOMINATES THE REGIONAL PATTERN.

&&

.MODEL DISCUSSION...

ALL THE NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH THE GENERAL
PATTERN DEEP INTO THE WEEKEND...AND ARE IN VERY GOOD AGREEMENT
DEEP INTO NEXT WEEK IN TERMS OF THE OVERALL LARGE SCALE SYNOPTIC
PATTERN. THEY ARE...HOWEVER...STRUGGLING WITH A COMPLEX NORTH
PACIFIC LOW PRESSURE PATTERN AS AN INCREASINGLY STRONG NORTH
PACIFIC JET MAKES EASTWARD PROGRESS. NUMEROUS LOWS ARE EXPECTED TO
EVENTUALLY ROTATE NORTH INTO THE SOUTHERN BERING THROUGH THE DAY 7
PERIOD...AND LARGE TRACK DISCREPANCIES BEGIN TO EMERGE AS EARLY AS
SATURDAY NIGHT OVER THE BERING. AS A RESULT...A GENERAL BLENDED
APPROACH WAS FAVORED OVER THE BERING TO ACCOUNT FOR THESE
CHALLENGES. OVER SOUTHERN ALASKA...NO MODEL WAS FAVORED AS THEY
ARE ALL DEPICTING SIMILAR SCENARIOS. CONFIDENCE IS HIGH OVER
SOUTHERN ALASKA...AND MODERATE OVER THE BERING SEA.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (FRIDAY AND SATURDAY)...
THE LOW IN THE SOUTHWEST GULF AND ITS ASSOCIATED FRONT OVER SOUTH
CENTRAL ALASKA WILL WEAKEN THROUGH TONIGHT. THE AIR MASS IS STILL
FAIRLY WARM AND MOST PRECIPITATION IS FALLING AS LIQUID OR
FREEZING...WITH THE EXCEPTION OF THE COPPER RIVER BASIN WHERE SOME
SNOW IS POSSIBLE. INLAND AREAS WILL BE DRY SATURDAY AND SATURDAY
NIGHT WITH A WEAK RIDGE OVER THE AREA. THE WEAK RIDGE WILL LEAD TO
FAIRLY STAGNANT AIR...WHICH INTRODUCES THE POSSIBILITY OF FOG
AROUND THE COOK INLET TONIGHT THROUGH SATURDAY NIGHT.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (FRIDAY AND SATURDAY)...
12Z SOUNDINGS FROM KING SALMON AND BETHEL DEPICT TEMPERATURES IN
THE 40S JUST OFF OF THE SURFACE AHEAD OF A FRONT SLOWLY MOVING ITS
WAY INLAND OVER THE SOUTHWEST MAINLAND. ONE SIGNIFICANT PROBLEM IS
THAT THE AIR AT THE SURFACE IS AT OR BELOW FREEZING IN THE
KUSKOKWIM DELTA AND THROUGH THE KUSKOKWIM RIVER ZONES.
THEREFORE...A FREEZING RAIN ADVISORY WAS ISSUED OVERNIGHT FOR THE
KUSKOKWIM DELTA ZONE OVERNIGHT...AND WILL BE EXTENDED THROUGH 9 AM
WITH THE MORNING FORECAST PACKAGE. LIKEWISE...A NEW FREEZING
ADVISORY IS BEING ISSUED THROUGH 4 PM THIS AFTERNOON FOR THE
KUSKOKWIM VALLEY ZONE. TEMPERATURES AT THE SURFACE ARE WELL ABOVE
FREEZING THROUGHOUT BRISTOL BAY WITH NO THREAT FOR ICING
ACCUMULATIONS.

COLD AIR ALOFT WILL CONTINUE TO ERODE THE WARM LAYER FROM
ABOVE...EVENTUALLY TURNING THE FREEZING RAIN AND RAIN TO SNOW
BEFORE ENDING FROM SOUTHWEST TO NORTHEAST ACROSS THE AREA TODAY.

PATCHY FOG MAY DEVELOP TONIGHT ESPECIALLY IN SHELTERED AREAS WHERE
WARMER BERING SEA AIR WILL SETTLE OVER THE FROZEN GROUND...MAINLY
IN THE KUSKOKWIM VALLEY AND BRISTOL BAY ZONES.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (FRIDAY AND SATURDAY)...
QUIET CONDITIONS BY BERING SEA STANDARDS WILL CONTINUE OVER THE
REGION THROUGH SATURDAY. BY SATURDAY NIGHT...THERE ARE SIGNIFICANT
MODEL DISCREPANCIES YIELDING LOW CONFIDENCE IN ANY ONE MODEL
SOLUTION...BUT ALL AGREE WITH PUSHING A LOW AND ASSOCIATED FRONT
NORTH TOWARD THE ALEUTIAN CHAIN. THE MAIN IMPACTS FOR SATURDAY
NIGHT WILL BE INCREASING WINDS ALONG THE ISLAND
CHAIN...PARTICULARLY THROUGH CHANNELED AREAS NEAR DUTCH
HARBOR...WITH A POSSIBLE BARRIER JET FORMING ALONG THE PACIFIC
SIDE OF THE ALASKA PENINSULA.

&&

.LONG TERM FORECAST (SUNDAY THROUGH THURSDAY)...
MUCH OF THE SOUTHERN MAINLAND WILL EXPERIENCE A BRIEF PERIOD OF
QUIET WEATHER THROUGH SUNDAY WITH LIGHT WINDS AND PARTLY CLOUDY
SKIES...BUT TEMPERATURES WILL REMAIN ABOVE NORMAL FOR MOST AREAS.
HOWEVER...BY MONDAY THE FIRST OF A SERIES OF SYSTEMS WILL MOVE
INTO THE GULF...BRINGING MORE UNSETTLED TO THE SOUTHERN MAINLAND
THAT LOOKS TO CONTINUE THROUGH THE MIDDLE OF NEXT WEEK. BROAD
SOUTHERLY FLOW WILL KEEP ABUNDANT SHOWER ACTIVITY FOCUSED ALONG
THE NORTHERN GULF COAST WITH WINDS INCREASING AS VARIOUS
DISTURBANCES ROTATE NORTHWARD INTO THE AREA.

OVER THE BERING SEA REGION...A GALE FORCE LOW WILL APPROACH THE
ALEUTIANS ON SUNDAY...BRINGING RAIN AND GUSTY WINDS THROUGHOUT THE
ALEUTIANS AND PRIBILOF ISLANDS INTO THE BEGINNING OF NEXT WEEK.
SHOWERS WILL THEN REMAIN IN THE FORECAST FOR MUCH OF THE BERING
FOR MOST OF NEXT WEEK...ESPECIALLY ALONG THE ALEUTIANS AS A DEEP
NORTH PACIFIC LOW RETROGRADES WESTWARD ALONG THE CHAIN ACCOMPANIED
BY GUSTY EASTERLY WINDS.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...FREEZING RAIN ADVISORY 131 152 155.
MARINE...GALE 172 173 174 175 176 177 178.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...JA
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CC
LONG TERM...DEK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
945 AM AKST FRI JAN 09 2015

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

0700 AM     FREEZING RAIN    PAXSON                  63.09N 145.61W
01/09/2015  E0.25 INCH                          AK   DEPT OF HIGHWAYS

            THE ALASKA DOT REPORTS FREEZING RAIN ALONG THE RICHARDSON
            HIGHWAY FROM MILEPOST 170 TO MILEPOST 202. THEY ESTIMATE
            BETWEEN ONE EITH AND ONE QUARTER INCH OF ICE ACCUMULATION
            ALONG THIS STRETCH OF HIGHWAY.

&&

SBAINES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
945 AM AKST FRI JAN 09 2015

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

0700 AM     FREEZING RAIN    PAXSON                  63.09N 145.61W
01/09/2015  E0.25 INCH                          AK   DEPT OF HIGHWAYS

            THE ALASKA DOT REPORTS FREEZING RAIN ALONG THE RICHARDSON
            HIGHWAY FROM MILEPOST 170 TO MILEPOST 202. THEY ESTIMATE
            BETWEEN ONE EIGHTH AND ONE QUARTER INCH OF ICE
            ACCUMULATION ALONG THIS STRETCH OF HIGHWAY.

&&

SBAINES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1140 AM AKST FRI JAN 09 2015

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

1103 AM     FREEZING RAIN    VALDEZ                  61.08N 146.30W
01/09/2015  M0.40 INCH                          AK   NWS EMPLOYEE

            WEATHER SERVICE EMPLOYEE MEASURED 0.4 INCHES OF ICE FROM
            18Z YESTERDAY TO 18Z TODAY. PRECIP HAS ENDED FOR NOW.
            MAIN IMPACT WAS VERY ICY STREETS AND THE ROAD CREWS ARE
            WORKING ON THE ROADS.

&&

RDUELL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
218 PM AKST FRI JAN 09 2015

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

0645 AM     FREEZING RAIN    EAGLE RIVER             61.32N 149.57W
01/09/2015  U0.00 INCH                          AK   PUBLIC

            MULTIPLE SOCIAL MEDIA REPORTS OF LIGHT FREEZING RAIN
            BETWEEN EAGLE RIVER AND NORTH ANCHORAGE ON GLENN HIGHWAY
            WITH PATCHES OF BLACK ICE ON ROADS.

0730 AM     FREEZING RAIN    WILLOW                  61.74N 150.06W
01/09/2015  U0.00 INCH                          AK   PUBLIC

            LIGHT FREEZING RAIN REPORTED FROM 7AM UNTIL 8AM.

&&

RDUELL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
233 PM AKST FRI JAN 09 2015

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

0231 PM     FREEZING RAIN    10 SE VALDEZ            60.98N 146.09W
01/09/2015  E0.25 INCH                          AK   DEPT OF HIGHWAYS

            ALASKA DOT REPORTS FREEZING DRIZZLE ALL MORNING
            THROUGHOUT THE VALDEZ AREA AND UP THE RICHARDSON HIGHWAY.
            ESTIMATES ABOUT A QUARTER INCH OF ICE ACCUMULATION ACROSS
            THE REGION.

&&

RDUELL