Gale Warning 18, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
600 AM AKST THU JAN 22 2015

.SHORT TERM...SATELLITE IMAGERY THIS MORNING IS SHOWING THE NEXT
IN A SERIES OF FRONTS MOVING NORTH AND EAST OVER THE EASTERN GULF
AND PANHANDLE. ASSOCIATED PARENT LOW IS WELL TO THE WEST. A WAVE
IS LOCATED SOUTH ON THE FRONTAL BOUNDARY AND IS FORECAST TO
DEVELOP INTO A CLOSED SURFACE LOW LATER TODAY UNDER VERY GOOD
UPPER LEVEL JET SUPPORT. MARINE WINDS IN ADVANCE OF THIS FEATURE
WILL INCREASE TO 30 KT OVER THE COASTAL MARINE ZONES. ALSO HAVE A
GALE WARNING IN PLACE FOR CLARENCE STRAIT, WITH UP TO 40 KTS
EXPECTED FURTHER SOUTH IN THE DIXON ENTRANCE AND HECATE STRAIT.
THE LOW WILL WEAKEN RAPIDLY AS IT MOVES ASHORE THIS EVENING AND
PULLS AWAY FROM THE ASSOCIATED JET SUPPORT. FARTHER NORTH, THE
FORECAST STARTS OUT VERY WINDY FOR THE FAR NORTHERN INNER CHANNELS
AS WELL AS LYNN CANAL. SURFACE RIDGING FROM THE SOUTH COMBINED
WITH A REFORMED LOW OVER THE YUKON IS PRODUCING 50 TO 55 MPH GUSTS
IN SKAGWAY THIS MORNING. OVER LYNN CANAL, SUSTAINED WINDS
OVERNIGHT WERE ONLY 45 KTS, BUT FREQUENT GUSTS TO 70 KTS OR HIGHER
PROMPTED A STORM WARNING. WINDS THERE HAVE SINCE RELAXED A BIT,
BUT A GALE WARNING REMAINS IN PLACE FOR THE MORNING. WINDS OVER
THE CANAL AND NORTHERN INNER CHANNEL PUBLIC ZONES EXPECTED TO
DIMINISH DRAMATICALLY THIS AFTERNOON, BUT STRONG WIND GUSTS ARE
EXPECTED TO RETURN TO SKAGWAY LATER TONIGHT.

SOUTHEAST ALASKA HAS SEEN SOME RECORD PRECIPITATION AS WELL AS
SOME RECORD WARMTH OVER THE PAST 48 HOURS. MOST LOCATIONS WILL SEE
A BREAK IN THE EXCESSIVE RAIN TODAY AND THE FLOOD ADVISORY WAS
ALLOWED TO EXPIRE OVERNIGHT. THE OUTER COAST NORTH OF CAPE SPENCE
AND THE YAKUTAT AREA ARE, HOWEVER, FORECAST TO SEE MORE HEAVY
PRECIPITATION TODAY. ELSEWHERE, A BREAK IN HEAVY PRECIP DOES NOT
MEAN A BREAK FROM THE RAIN AND ALL PANHANDLE LOCATIONS ARE
FORECAST TO SEE MORE RAIN TODAY. SNOW LEVELS CONTINUE TO BE
SUFFICIENTLY HIGH THAT ONLY WHITE PASS IS EXPECTED TO SEE ANY SNOW
TODAY. WITH HIGHS TODAY RANGING FROM THE UPPER 40S TO LOWER 50S
AND SO MUCH RAIN, ITS HARD TO BELIEVE THIS IS REALLY WINTER.

USED A BLEND OF NAM, ECMWF, AND GEM FOR UPDATES TO PRESSURE AND
WIND. TWEAKS TO POP AND QPF PER THE SAME 3 MODELS. UPDATES TO
TEMPERATURES PER NAM AND BIAS CORRECTED NAM. EVEN SO, INITIAL
FORECAST DAYTIME HIGHS LAGGING BEHIND ACTUAL EARLY MORNING VALUES.
OVERALL FORECAST CONFIDENCE IS ABOVE AVERAGE BUT TRENDING BELOW
AVERAGE FOR DAYTIME HIGH TEMPERATURES.

.LONG TERM...A GALE FORCE LOW DEVELOPING AROUND 43 N 153 W EARLY
THIS MORNING WILL CLIMB NORTHEAST ACROSS THE NORTH PACIFIC TO
ARRIVE IN THE EASTERN GULF BY FRIDAY AFTERNOON AND MOVE ASHORE
AROUND YAKUTAT FRIDAY EVENING. NOT TO BE OUTDONE, ANOTHER GALE
FORCE LOW WILL FOLLOW SATURDAY. TOGETHER WITH THE FRONT PUSHING
THROUGH THE PANHANDLE TODAY, CONSIDER THESE FEATURES LIKE
MAGI...BRINGING GIFTS OF WIND, MILD TEMPERATURES, AND OF COURSE
LOTS OF RAIN TO SOUTHEAST ALASKA WHERE MANY WOULD RATHER REJECT
THESE GIFTS LIKE AN UNGRATEFUL CHILD.

WINDS WITH FRIDAY'S LOW WILL BE STRONGEST ON THE BACK SIDE WITH 40
KT FROM THE SOUTHWEST BLOWING ACROSS OUR SOUTHERN GULF WATERS BY
FRIDAY AFTERNOON. ONCE THE LOW MAKES LANDFALL, LEE SIDE TROUGHING
WILL INCREASE THE PRESSURE GRADIENT ACROSS THE NORTH-SOUTH INSIDE
PASSAGES, AND THUS MORE SOUTHERLY GALES ARE EXPECTED THROUGH LYNN
CANAL AND STEPHENS PASSAGE BY FRIDAY NIGHT. ACCOMPANYING STRONG
WINDS ARE QUITE POSSIBLE FOR SKAGWAY AND JUNEAU WITH THIS SET-UP
AS WELL. RAINFALL AMOUNTS ARE NOT EXPECTED TO BE AS GREAT AS WHAT
WE HAVE EXPERIENCED AS OF LATE; THE MAIN JET WILL REMAIN SOUTH OF
THE PANHANDLE DIRECTING THE BULK OF THE MOISTURE INTO THE BC
COAST. SNOW LEVELS MAY BEGIN TO LOWER AROUND WHITE PASS BY FRIDAY
AFTERNOON AS SOME COOLER AIR FROM THE SOUTHWEST FILTERS IN, BUT IT
IS WILL LIKELY BE MIXED WITH RAIN EVEN HERE.

SATURDAY'S LOW WILL TAKE A MORE SOUTHERLY TRACK. HENCE WINDS AND
RAINFALL WILL BE GREATEST IN THE SOUTHERN PANHANDLE. GALE FORCE
WINDS WILL SPREAD ONCE AGAIN IN ZONE 41 AND CLARENCE STRAIT BY
SATURDAY AFTERNOON. BETWEEN SYSTEMS WINDS ACROSS THE SOUTH WILL FLIP
FROM SOUTH ON FRIDAY NIGHT TO NORTH THROUGH THE DAY ON SATURDAY.
THIS LOW WEAKENS AS IT CROSSES THE SOUTH CENTRAL PANHANDLE
SATURDAY NIGHT. RAIN WILL SPREAD NORTHWARD ONCE AGAIN, AT LEAST AS
FAR NORTH AS JUNEAU BEFORE DIMINISHING THROUGH SUNDAY AS ONSHORE
FLOW WRINGS OUT THE MOISTURE. A POSSIBLE BRIEF BREAK IN THE RAIN
ESPECIALLY SATURDAY MORNING FOR THE NORTHERN PANHANDLE, BUT WOULD
NOT COUNT ON MUCH OF ONE.

WE ARE STILL LOOKING AT A COOL DOWN BEGINNING IN YAKUTAT SUNDAY
AND SPREADING EASTWARD SUNDAY NIGHT INTO MONDAY. ATMOSPHERIC
THICKNESSES WILL LOWER ENOUGH TO SUPPORT A CHANGEOVER TO SNOW FOR
MUCH OF THE NORTHERN PANHANDLE. THERE IS STILL SOME MODEL
DISAGREEMENT ON HOW MUCH PRECIPITATION WILL ACTUALLY FALL. LATEST
RUNS OF BOTH GFS AND ECMWF HAVE DRIED THINGS OUT AS THE COOLER AIR
FILTERS IN, BUT GIVEN A WESTWARD MOVING DISTURBANCE PUSHING ACROSS
THE ALASKA RANGE INTO THE GULF LATE IN THE WEEKEND, THIS LOOKS TO
SPIN UP SOMETHING IN THE NORTHERN GULF, SO FOR NOW KEEPING THE
CHANCES OF PRECIPITATION IN.

LOOKING FARTHER INTO NEXT WEEK, SOUTHEAST ALASKA WILL BE
POSITIONED BETWEEN COOLER AND SLIGHTLY DRIER ZONAL FLOW TO THE
NORTH AND MOIST, WARMER SOUTHERLY FLOW TO THE SOUTH. THIS SHOULD
SPELL MORE WET CONDITIONS FOR US WITH RAIN/SNOW LINE PRECARIOUSLY
CLOSE. MODELS SEEM TO BE POINTING IN A COOLER DIRECTION, BUT
RECENT HISTORY PULLS IN FAVOR OF WARM AIR. TIME WILL TELL.

USED ECMWF FOR UPDATES THROUGH SATURDAY EVENING BEFORE
TRANSITIONING TO WPC SATURDAY EVENING THROUGH SUNDAY NIGHT.
FEW CHANGES MADE MONDAY BEYOND. FORECAST CONFIDENCE AVERAGE FOR
FAST MOVING LOWS AND GIVEN MODEL DISPARITY. FALLS NEXT WEEK.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 6 AM AKST EARLY THIS MORNING FOR AKZ019.
         STRONG WIND UNTIL 3 PM AKST THIS AFTERNOON FOR AKZ018.
         STRONG WIND LATE TONIGHT FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-013-031-036.
         SMALL CRAFT ADVISORY FOR PKZ011-022-032>035-041>043-051-052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.

&&

FRITSCH/JWA

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JUNEAU AK
341 PM AKST THU JAN 22 2015

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

0400 PM     NON-TSTM WND DMG 15 NNW KETCHIKAN        55.54N 131.79W
01/21/2015                                      AK   PUBLIC

            3 TREES DOWNED DUE TO HIGH WIND GUSTS.

&&

RCL