Gale Warning 14, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
355 PM AKST MON JAN 20 2014

.SHORT TERM...A DEVELOPING LOW MOVING NORTHWARD INTO THE SOUTH
CENTRAL GULF OF ALASKA CAN BE SEEN ON SATELLITE IMAGERY THIS
AFTERNOON. THIS SYSTEM WILL BRING WITH IT A WARM FRONT THAT WILL
LIFT NORTH OVER THE PANHANDLE TONIGHT. RAIN IS CURRENTLY FALLING
OVER THE SOUTHERN PANHANDLE...MODERATE AT TIMES. THE RAIN WILL
MOVE NORTH INTO THE JUNEAU/ICY STRAIT AREA TOWARD MIDNIGHT THEN
OVER THE NORTHERN AREAS OVERNIGHT. THE SOUTHERN PANHANDLE WILL
SEE RAIN DIMINISHING LATE TONIGHT INTO TUESDAY MORNING...THEN THE
CENTRAL AREAS DIMINISHING IN THE LATE AFTERNOON. EXPECT AREAS OF
FOG TO DIMINISH AS WINDS INCREASE THIS EVENING AND RAIN MOVES
IN...THEN FOG WILL RE-DEVELOPING AS THE RAIN MOVES OUT TOMORROW
AND WINDS EASE AGAIN.

 THE WARM FRONT WILL CAUSE TEMPERATURES TO REMAIN FAIRLY STEADY
TONIGHT OR EVEN RISE SLIGHTLY...THEN DO THE SAME DURING THE DAY
TUESDAY. THE ONLY PLACES THAT COULD SEE SOME SNOW TONIGHT ARE THE
BORDER AREAS INCLUDING HYDER. THE NORTHERN BORDERS WILL BE
DEPENDENT ON HOW MUCH RADIATIONAL COOLING IS ALLOWED THIS EVENING
BEFORE THE FRONTAL PRECIP MOVES IN OVERNIGHT. GENERALLY EXPECT
LESS THAN 1 INCH BEFORE CHANGING TO RAIN.

 E-SE WINDS WILL INCREASE TO GALE FORCE OVER THE OUTSIDE WATERS
WITH THE FRONT. STRONGEST WINDS LOOK TO BE OUT OF CROSS SOUND
WHERE GUSTS TO 50 KT ARE POSSIBLE. FOR THE INSIDE WATERS...THE
LOW/FRONTAL TROUGH TO THE SOUTH IS CAUSING NORTHERLY WINDS THIS
AFTERNOON. THESE WILL INCREASE TO SMALL CRAFT LEVEL AS THE FRONT
APPROACHES TONIGHT IN LYNN CANAL AND GLACIER BAY. THE CENTRAL
INSIDE WATERS WILL FLIP TO THE SOUTH AS THE FRONT MOVES OVER
LATER IN THE EVENING WITH 20-25KT WINDS. SOME STRONGER GUSTS ARE
POSSIBLE OUT OF INTERIOR PASSES TO THE EAST...BUT HAVE LEFT THAT
OUT OF THE TEXT SINCE THERE IS NOT ANY COLD AIR TO DRAIN OUT.
TUESDAY INSIDE WATER WINDS WILL DIMINISH THROUGH THE AFTERNOON
WITH LYNN CANAL AND GLACIER BAY REMAINING NORTHERLY...BUT MAY
BECOME VARIABLE IN THE LATE AFTERNOON. LAND AREAS WILL LIKELY SEE
SOME GUSTY WINDS WITH THE FRONT TONIGHT. THE TYPICAL WINDY
COASTAL AREAS WILL SEE GUSTS TO 35 MPH.

 FOR CHANGES TODAY BLENDED IN THE 12Z NAM WITH THE INHERITED
FORECAST WHICH USED MAINLY THE 00Z ECMWF. USED THE LOCAL WRF
MODEL FOR INSIDE WATERS DIRECTIONS THEN ADJUSTED FOR LOCAL
EFFECTS. FORECAST CONFIDENCE IS AVERAGE.

 &&

 .LONG TERM...A VERY STRONG UPPER LEVEL LONG WAVE RIDGE REMAINS
SITUATED OVER THE WEST COAST OF NORTH AMERICA WHERE IT HAS BEEN
FOR MANY DAYS NOW. TO THE WEST, A NEGATIVELY TILTED UPPER LEVEL
TROUGH IS LOCATED OVER THE ALEUTIANS. THE INTERACTION OF THESE TWO
FEATURES HAS LARGELY BEEN RESPONSIBLE FOR THE ANOMALOUSLY WARM AND
WET WEATHER IN SOUTHEAST ALASKA. MODELS ARE NOW INDICATING A
POSSIBLE PATTERN CHANGE BEGINNING NEXT SUNDAY AS RIDGE BREAKS
DOWN AND TROUGH BECOMES PROGRESSIVE. IF THIS HAPPENS, SOUTHEAST
ALASKA WILL FINALLY SEE AN END TO DEEP AND MOIST SOUTHWEST ONSHORE
FLOW. BOTH GFS AND ECMWF ARE DEPICTING THIS AND BOTH ACCOMPLISH
IT BY RETROGRADING A SMALL CUT OFF LOW WEST OVER THE DESERT
SOUTHWEST AND UNDERCUTTING THE RIDGE. GFS MAINTAINS THIS NEW
PATTERN, BUT ECMWF BUILDS IN THE WEST COAST RIDGE AGAIN BY MID
WEEK, BUT THAT IS BEYOND THE EXTENDED RANGE FORECAST AT THIS TIME.

BEFORE WE GET TO A PATTERN CHANGE, PORTIONS OF SOUTHEAST ALASKA
WILL HAVE TO ENDURE AT LEAST ONE MORE ROUND OF HEAVY PRECIPITATION.
SPECIFICALLY, FROM YAKUTAT DOWN THE COAST TO THE CAPE SPENCER
AREA, AND THEN EAST ALONG THE ICY STRAIT CORRIDOR TO NEAR JUNEAU.
36 HOUR RAINFALL TOTALS BETWEEN WEDNESDAY AFTERNOON AND FRIDAY
MORNING CURRENTLY RANGING FROM AROUND 1.5 INCHES IN HAINES, TO
MORE THAN 6.5 INCHES IN YAKUTAT. SNOW LEVELS REMAINING
SUFFICIENTLY HIGH ENOUGH THAT THIS WILL BE ENTIRELY A RAIN EVENT.
SO WHILE MONUMENTAL SNOW ACCUMULATIONS SEEM OUT OF THE QUESTION,
THIS AMOUNT OF RAINFALL MAY HAVE HYDROLOGICAL IMPLICATIONS.
RAIN...HEAVY AT TIMES WILL LIKELY CONTINUE IN THE YAKUTAT AREA
THROUGH FRIDAY EVENING, BUT DID NOT HAVE ENOUGH CONFIDENCE IN
MODELS THAT FAR INTO THE FUTURE TO MAKE POP GRIDS CATEGORICAL.

GFS LONG RANGE SURFACE RUN TO RUN CONSISTENCY PRETTY GOOD OUT TO
SATURDAY AFTERNOON. SIMILAR FOR ECMWF. 12Z GFS, 12Z GEM, AND 00Z ECMWF
REMAIN VERY CLOSE TO EACH OTHER AT THE SURFACE THROUGH FRIDAY
AFTERNOON BUT DIVERGE ENOUGH THEREAFTER THAT A BLEND OF THE THREE
AFTERWARDS BECOME UNUSABLE. BLENDED NAM, GEM, AND ECMWF THROUGH
THURSDAY AFTERNOON, THEN ECMWF AND GEM THROUGH SATURDAY AFTERNOON.
FINISHED WITH AN ECMWF/WPC BLEND. POP FROM GEM, ECMWF, AND GFS.
QPF PRIMARILY FROM ECMWF. TEMPS ADJUSTED PER ENSEMBLE AND
OPERATIONAL GFS. FORECAST CONFIDENCE IN HEAVY RAIN LATER THIS WEEK
IS ABOVE AVERAGE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ022-043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-031-033>036-041-042-053.

&&

FERRIN/FRITSCH