Small Craft Advisory 147, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
444 PM AKST TUE FEB 11 2014

.SHORT TERM...A LOW PRESSURE SYSTEM NEAR DIXON ENTRANCE WILL
TRACK OVER THE FAR SOUTHERN PANHANDLE TONIGHT. THIS SYSTEM IS
CURRENTLY CAUSING MODERATE SNOW IN KLAWOCK AND LIGHT SNOW OVER
SOUTHERN BARANOF ISLAND TO WRANGELL AND EAST. ADVISORIES FOR SNOW
ARE IN EFFECT FOR WRANGELL, KLAWOCK AND HYDER ZONES. A WINTER
STORM WARNING REMAINS IN EFFECT FOR THE KETCHIKAN ZONE. THERE MAY
BE SOME RAIN MIXED IN OVER THE FAR SOUTHERN LAND AREAS THIS
EVENING AS TEMPERATURES IN HYDABURG, ANNETTE AND METLAKATLA HAVE
ALL RISEN TO AROUND 32F. THOSE AREAS WILL SEE LESS ACCUMULATION
AS A RESULT. HAVE EXTENDED THE ADVISORY FOR THE HYDER ZONE
BECAUSE THE LOW WILL DEPARTS TO THE EAST THEY WILL SEE SNOW
LASTING LONGER THAN THE OTHER AREAS. SEE THE WARNING/ADVISORY
STATEMENTS FOR MORE DETAILS ON AMOUNTS/TIMING.

 NORTH OF THE LOW AN UPPER LEVEL WAVE IS MOVING NORTHWARD AND IS
CAUSING SOME FLURRIES TO FALL OUT OF A MID LEVEL DECK...CURRENTLY
OVER JUNEAU AND ANGOON. DO NOT EXPECT ANY ACCUMULATION WITH
THIS...IN FACT THE CLOUDS WILL LIKELY BREAK UP MORE THIS EVENING
AND BECOME PARTLY CLOUDY TONIGHT.

 THE LOW TO THE SOUTH IS KEEPING THE STRONG PRESSURE GRADIENT IN
TACT WITH THE YUKON HIGH...ALTHOUGH NOT NEARLY AS STRONG AS ON
MONDAY. NORTHERN LYNN CANAL CONTINUES TO HAVE GALE FORCE WINDS
AND THUS SKAGWAY AND HAINES HAVE STRONG WIND GUSTS OF ABOUT
45 MPH IN THE FORECAST FOR TONIGHT. OTHER GAP OUTFLOW WIND
LOCATIONS WILL BE THE STRONGEST THIS EVENING DUE TO THE LOW
PASSING BY. LATE TONIGHT AND WEDNESDAY MORNING EXPECT WINDS TO
GRADUALLY EASE AS THE LOW WEAKENS AND MOVES AWAY. SEVERAL
LOCATIONS WILL BECOME LIGHT AND VARIABLE AND THE SOUTHERN HALF OF
THE REGION WILL EVENING SHIFT TO THE SOUTHEAST IN THE AFTERNOON.
THIS IS DUE TO A NEW LOW DEVELOPING IN THE NORTHERN GULF. THIS
NEW SYSTEM WILL CAUSE SELY WINDS TO INCREASE THROUGH THE
AFTERNOON FOR THE OUTSIDE WATERS AND COASTAL AREAS. PRECIP ASSOC
WITH THIS SYSTEM WILL START TO MOVE INTO OUR AREA...BUT ONLY HAVE
A CHANCE ALONG THE COAST...NAMELY IN YAKUTAT IN THE AFTERNOON.

 USED THE 12Z ECMWF/GEM/NAM FOR PRESSURE AND NUDGED WIND SPEEDS
OUTSIDE WITH THE NAME. BEYOND THAT MAKE ADJUSTMENTS FOR LOCAL
EFFECTS AND OUTFLOW AREAS. KEPT SNOWFALL TOTALS LARGELY IN TACT.
FORECAST CONFIDENCE IS AVERAGE.

 &&

.LONG TERM...MAIN EVENT IN THE EXTENDED RANGE FORECAST PERIOD IS A
POTENTIALLY VERY HEAVY SNOW EVENT FOR YAKUTAT FROM WEDNESDAY
EVENING THROUGH THURSDAY MORNING. A LOW THAT WILL FORM OVER THE
NORTHERN GULF EARLY ON WEDNESDAY WILL ROTATE A SURFACE TROUGH
SOUTH AND TAP INTO A MOISTURE STREAM BEING CARRIED NORTH BY
ANOTHER LOW FURTHER SOUTH. THE DEVELOPING FRONT WILL TRAIN OVER
THE YAKUTAT AREA AND ACCOUNT FOR THE VERY HIGH SNOW TOTALS.

WITH NO SIGNIFICANT WARM AIR ADVECTION, THERE WILL BE LITTLE IF
ANY CHANGE TO NEAR SURFACE TEMPERATURES AND THEY ARE CURRENTLY
MORE THAN COLD ENOUGH TO SUPPORT A SNOW EVENT. LOCATION OF THE
HIGHEST QPF VALUES WILL MAKE OR BREAK THIS FORECAST SUCH THAT IF
THE FRONT DOES TRAIN OVER THE COAST BUT SLIGHTLY EAST OR WEST OF
YAKUTAT, IT WILL BUST BIG TIME.

AFTER THIS EVENT, THERE IS MORE SNOW IN THE EXTENDED RANGE
FORECAST FROM THURSDAY MORNING THROUGH THE WEEKEND WITH ADVISORY
AMOUNTS IN MANY LOCATIONS AND POSSIBLY WINTER STORM AMOUNTS FOR
THE HAINES AND KLONDIKE HIGHWAYS FRIDAY EVENING THROUGH SATURDAY
MORNING. MUCH OF THE PRECIPITATION HEADED FOR SOUTHEAST ALASKA IS
COMING AT US FROM DIRECTIONS NORMALLY ASSOCIATED WITH RAIN
INSTEAD OF SNOW. BUT IT WILL TAKE A WHILE AND SOME STRONG WARM AIR
ADVECTION TO CLEAR OUT THE VERY COLD NEAR SURFACE AIRMASS
CURRENTLY BLANKETING THE PANHANDLE. WITH AS COLD AS IT IS RIGHT
NOW, PRECIPITATION APPROACHING FROM JUST ABOUT ANY DIRECTION WILL
RESULT IN SNOW TO START WITH.

NO CHANGES MADE TO PRESSURE OR WINDS. EFFORTS TODAY FOCUSED VERY
HEAVILY ON TEMPERATURES, DEW POINTS, POP, QPF, AND SNOW. USED A
BLEND OF ECMWF, GEM, GFS, AND NAM AT VARIOUS TIMES FOR POP AND
QPF. TEMPERATURES AND SNOW LEVELS ADJUSTED USING ENSEMBLE GFS.
FORECAST CONFIDENCE IS ABOVE AVERAGE FOR SIGNIFICANT SNOWFALL
DURING THE EXTENDED RANGE FORECAST PERIOD BUT ONLY AVERAGE ON THE
DETAILS OF THE WEDNESDAY NIGHT SNOW EVENT FOR YAKUTAT DUE TO
TRAINING PERPENDICULAR TOT HE COAST.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WINTER WEATHER ADVISORY UNTIL 5 AM AKST WEDNESDAY FOR AKZ026-027.
         WINTER STORM WARNING UNTIL 5 AM AKST WEDNESDAY FOR AKZ028.
         STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ029.
         WINTER WEATHER ADVISORY UNTIL 9 AM AKST WEDNESDAY FOR AKZ029.
         STRONG WIND UNTIL 3 AM AKST WEDNESDAY FOR AKZ019.
         STRONG WIND THROUGH LATE TONIGHT FOR AKZ018.
         WIND CHILL ADVISORY UNTIL NOON AKST WEDNESDAY FOR AKZ018.
         WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     MORNING FOR AKZ017.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ011-051.
         HEAVY FREEZING SPRAY WARNING FOR PKZ013.
         HEAVY FREEZING SPRAY WARNING FOR PKZ012-031.
         GALE WARNING FOR PKZ012-013-022-031-033-035.
         SMALL CRAFT ADVISORY FOR PKZ011-021-032-034-036-041>043-051>053.

&&

FERRIN/FRITSCH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
1004 PM AKST TUE FEB 11 2014

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

0900 PM     NON-TSTM WND GST DOUGLAS                 58.27N 134.39W
02/10/2014  M60.00 MPH                          AK   MESONET

            PEAK GUSTS TO 60 MPH AT SOUTH DOUGLAS BOAT HARBOR
            OBSERVED MON MORNING THROUGH MON NIGHT.

0900 PM     NON-TSTM WND DMG DOUGLAS                 58.27N 134.39W
02/10/2014                                      AK   PUBLIC

            A PLAYHOUSE NEAR GASTINEAU ELEMENTARY WAS LOFTED BY THE
            WIND AND SENT THROUGH THE WINDOW OF A NEARBY HOUSE.

&&

EAL