Gale Warning 365, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
346 PM AKST WED NOV 4 2015

.SHORT TERM...AN UPPER RIDGE IS BUILDING INTO THE EASTERN GULF THIS
EVENING AS AN UPPER SHORT WAVE KICKS OUT INTO BRITISH COLUMBIA.
THIS HAS SET UP BRIEF LOW LEVEL WESTERLIES ALONG THE OUTER COAST. A
WEAK SURFACE HIGH IS OVER THE YUKON BUT WILL RAPIDLY SHIFT EASTWARD
AS A STRONG FRONT COMES INTO THE EASTERN GULF THURSDAY.
RADAR SHOWS LINGERING SHOWERS ESPECIALLY FOR THE SOUTH PARTS.
CONFIDENT ABOUT FOG TONIGHT BUT IFFY ON THE INTENSITY. HOW MUCH
CLEARING? WILL ANY WIND KICK IN TO MIX? MENTIONED AREAS. RAIN
APPROACHES WITH THE FRONT TOMORROW AFTERNOON.

.LONG TERM...THE STRONG WELL WRAPPED UP LOW CURRENTLY OVER THE
ALEUTIANS WILL CONTINUE ITS EASTERLY TRACK MOVING OVER KODIAK BY
FRIDAY MORNING WHILE WEAKENING TO 980 MB. THE ASSOCIATED FRONT
WILL CROSS OVER THE EASTERN GULF THEN THE PANHANDLE THROUGH
THURSDAY NIGHT BRINGING IN HEAVY RAIN AND STRONG WINDS. THE LOW
CONTINUES TO MOVE EAST AND WEAKEN, LINGERING OVER THE NORTHERN
GULF THROUGH SATURDAY BEFORE DROPPING TO THE SOUTH. A HIGH
PRESSURE RIDGE BUILDS OVER THE AK GULF AND MOVES OVER THE
PANHANDLE SUNDAY INTO MONDAY, BUT ANY DRY WEATHER FROM THIS RIDGE
WILL BE SHORT LIVED AS WAVES ASSOCIATED WITH A LOW DROPPING INTO
THE BERING SEA THE START OF NEXT WEEK MOVE INTO THE AK GULF. IF
THE CURRENT OPERATIONAL MODELS FOR NEXT WEEK ARE CORRECT THEN
THIS SYSTEM WILL BRING IN COLD AIR AND HAVE POTENTIAL FOR SNOW.

 MAX GALE FORCE WINDS OVER THE EASTERN GULF WILL QUICKLY DIMINISH
BY EARLY MORNING WITH THE PASSING OF THE FRONT. WINDS OVER THE
INNER CHANNELS WILL PICK UP TO SMALL CRAFT OF MAX SMALL CRAFT THEN
DROP WITH THE PASSING FRONT. AS THE LOW MOVES INTO THE N GULF
RIDGING OVER THE PANHANDLE WILL CREATE A TIGHTENING SOUTHERLY
GRADIENT WITH SMALL CRAFT WINDS OVER N AND S LYNN CANAL. BEFORE
THE LOW WEAKEN SMALL CRAFT WINDS WILL REMAIN OVER THE GULF BUT
GREATER IMPACT WITH BE THE HIGH SEAS, 18 TO 24 FEET, FROM THE
SWELL AROUND THE LOW.

HEAVY RAIN INCREASES THROUGH THE NIGHT WITH 6 HOUR QPF AMOUNTS OF
OVER HALF AN INCH EXPECTED THROUGH FRIDAY MORNING FROM THE FRONT.
MOST AREAS WITH SEE PRECIP AS RAIN WITH SNOW LEVELS STEADY AROUND
2000 FT. THE EXCEPTION BEING AT HIGHER ELEVATIONS SUCH AS WHITE
PASS WHERE SNOW FALL AMOUNTS OF 2 TO 5 INCHES ARE POSSIBLE. RAIN
WILL LAST THROUGH SATURDAY BECOMING MORE SHOWERY IN NATURE WITH
COLDER AIR BEHIND THE LOW. POTENTIAL DRY PERIOD SUNDAY INTO SUNDAY
NIGHT THEN BACK TO HIGHER POPS AS THE NEXT WAVES MOVE IN FROM THE
WEST.

MODELS IN FAIR AGREEMENT AT UPPER LEVELS THROUGH THE WEEKEND. SOME
MINOR DIFFERENCES WITH THE POSITION OF THE SURFACE LOW IN THE N
GULF FRIDAY AND SATURDAY BUT NOT ENOUGH TO MAKE MAJOR CHANGES TO
THE FORECAST. MAIN DIFFERENCE SIS THE TIMING OF MOVING THE LOW TO
THE SOUTH, WITH NAM THE FASTEST AND ECMWF THE SLOWEST. USED MORE
GFS20 TO UPDATE INHERITED GRIDS. MODELS SPREAD INCREASES WITH NEXT
LARGE LOW MOVING INTO THE BERING, SO USED THE ENSEMBLE BLEND
CREATED BY WPC FOR DAY 5 TO DAY 8. FORECAST CONFIDENCE IS ABOVE
AVERAGE THEN DROPS BY THE START OF NEXT WEEK.

&&

.AVIATION...WENT IFR FOR SOME OF THE TAFS IN FOG TONIGHT AND SHOWED
MVFR IN LOTS OF TAFS. MORNING BREAKOUT TIME WILL BE A DIFFICULT
CALL DUE TO TRAPPED MOISTURE VERSUS WHEN THE WIND WILL KICK IN FOR
THE APPROACHING FRONT.

&&

.MARINE...WESTERLIES ARE ALMOST OVER. A FEW NORTH WINDS WITH THE
HIGH IN THE YUKON THIS EVENING. THERE IS PLENTY OF SWELL THIS
EVENING. NEXT UP IS WHOLE GALES AHEAD OF THIS MONDO FRONT WHICH
WILL PUSH UP SOME NASTY SHORT PERIOD WIND WAVES. SMALL CRAFTS FOR
MANY OF THE INSIDE WATERS & USE AFTERNOON AS TIMING.

&&

.HYDROLOGY...COORDINATED QPF WITH RFC. NOT ENUF IN THE FRONT TO SET
OFF THE STREAMS AND RIVERS. THEY WILL BE IN OPERATIONS FOR TWO MORE
DAYS THEN WINTER HOURS.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ042-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-012-021-022-031>036-041-053.

&&

JC/PRB

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