Gale Warning 197, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
231 PM AKDT THU JUN 25 2009

.SHORT TERM...SATELLITE IMAGERY REVEALING A LOW SPINNING IN
NORTHERN BC AND A RIDGE IN THE EASTERN GULF OF ALASKA. RIDGE
CONTINUES TO SLOWLY MOVE EAST INTO BC AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE WESTERN GULF. OVC TO BKN SKIES IN THE
NORTHERN ZONES AND BKN SKIES IN THE SOUTHERN HALF OF THE
PANHANDLE. LIGHT RAIN CONTINUES IN HYDER AS WEAKENING LOW
CONTINUES TO SPIN IN BC. BKN MARINE LAYER EVIDENT IN OUTSIDE
WATERS WHILE A MORE SOLID MARINE LAYER PREVAILS OVER OFF SHORE
ZONE. ISOLATED SHOWERS ONGOING ON OUTER COAST FROM PAYA TO PASI.

WINDS IN THE OFF SHORE AND OUTSIDE ZONES ALL BELOW SCA ATTM. SCA
FOR INTERIOR WATERS FOR ALL BUT SUMNER STRAIT AND CLARENCE STRAIT
THIS EVENING AS GRADIENT INCREASES BETWEEN BC LOW AND EASTERN GULF
HIGH PRESSURE RIDGE.

STRONG LOW PRESSURE APPROACHES TOMORROW AFTERNOON SCA CONDITIONS
DEVELOP IN ZONE 41. GALE FORCE WINDS DEVELOP TOMORROW EVENING FOR
ZONES 310...41...42...36...35 AND 33. POPS INCREASE FROM CHANCE TO
LIKELY TONIGHT THROUGH TOMORROW FOR ENTIRE PANHANDLE EXCEPT FOR
PAYA WHERE CHANCE POPS PREVAIL. LIKELY POPS BECOME CATEGORICAL BY
TOMORROW AFTERNOON IN ZONES 27...28 AND 29. 6HR QPF RATES BETWEEN
ONE THIRD AND ONE HALF INCH FOR ZONES 27...28 AND 29 BEGINNING
TOMORROW EVENING.

PREFERRED 12Z GFS GUIDANCE TODAY AS IT INITIALIZED WELL AND HAD
BETTER AGREEMENT WITH BOTH THE ECMWF AND UKMET AS FAR AS
POSITION...TRACK AND STRENGTH OF STRONG LOW TO TRACK INTO THE
PANHANDLE. 12Z NAM 12 PRESENTED A SLOWER AND DEEPER SOLUTION THAT
MAY NOT BE UNREALISTIC BUT WAS CERTAINLY AN OUTLIER SOLUTION
COMPARED TO OTHER MODELS TODAY. AS THE STRONG LOW IS FORECAST TO
DEVELOP RIGHT ALONG THE NAM12 BORDER...PREFERRED GLOBAL MODELS
SOLUTION.

.LONG TERM...AN UNUSUALLY STRONG LOW FOR THIS EARLY IN THE SUMMER
IS STILL TO MOVE NE TO THE EASTERN GULF FRI NIGHT AND ONSHORE THE
PANHANDLE SAT. THE CHANGES BEING MADE FROM FORECAST SHIFT TO
FORECAST SHIFT HAVE BECOME SMALLER AS THE MODELS CONSENSUS HAS
IMPROVED. THE HEAVIEST RAINFALL WILL OCCUR S OF FREDERICK SOUND
ON SATURDAY.

THE LOW SHOULD DEEPEN TO ABT 988 MB 300 NM SW OF PASI ABT 06Z
SAT. AT THAT TIME THE SFC FNT SHOULD BE 400 NM S OF A PASI-PAKT
LINE AND SHOULD REACH PASI-PAKT ABT 18Z SAT.  NOTE THE MARINE
FCSTS DEPICT GALE FORCE WINDS BGNG FRI TO OUR OUTSIDE WATERS
S OF CAPE FAIRWEATHER, AND GALES FOR CLARENCE STRAIT SAT.

THE MODEL CONSENSUS USED IS BETWEEN THE UKMET AND THE GFS. THE
NAM HAS THE LOW WITH A TRACK FARTHER TO THE S BUT IS NOT USED AS
ITS SOLUTION MAY STILL HAVE NESTING PROBLEMS WITH THE EARLY
CYCLONE EVOLUTION NEAR THE MODELS SOUTHERN BOUNDARY.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING FOR PKZ033-035-036-041>043.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-022-031-032-034-051-052.

&&

CCC/JBT