Prognostic Meteorological Discussion
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FXHW01 KWNH 151147
PMDHI

HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
747 AM EDT TUE APR 15 2014

VALID 00Z WED APR 16 2014 - 00Z WED APR 23 2014

OF THE 15/00Z ECENS/GEFS/CMC MEANS AND THEIR DETERMINISTIC
RUNS...THE ECENS AND THE ECMWF PROVIDED THE BEST
CONSISTENCY...WITH THE CANADIAN AND ITS MEAN A CLEAR SECOND CHOICE
THROUGH DAY 7 FOR MUCH OF THE NORTHERN PACIFIC OCEAN AND
SUBTROPICS.

THE 15/00Z GEFS/GFS SOLUTION ALOFT (500MB LEVEL) WAS CERTAINLY
VIABLE UNTIL 20/12Z ALONG THE DATELINE AND EAST OF 140W LONGITUDE.
HOWEVER...AFTER 20/12Z...THIS PIECE OF GUIDANCE BECOMES A VERY
FAST OUTLIER--BREAKING OFF A CUTOFF LOW IN THE SOUTHERN GULF OF
ALASKA AND TAKING IT INTO THE MAINLAND WEST COAST A GOOD DAY
EARLIER THAN THE CANADIAN/ECMWF DETERMINISTIC/ENSEMBLE MEAN
SOLUTIONS. THE GFS/GEFS IS AN EVEN FASTER SOLUTION INVOF ALEUTIANS
BETWEEN DAY 6-7...AND THE 15/06Z GFS/GEFS WAS EVEN FASTER!

RECOMMEND USING A BLEND OF THE 15/00Z ECENS MEAN AND ITS
DETERMINISTIC SOLUTION. ANTICIPATE SOME DECREASE IN THE TRADE
WINDS DURING THE FRI/SAT TIME FRAME AS A DEEPENING MID-LATITUDE
CYCLONE TAKES SHAPE IN THE GULF OF ALASKA AND DAMPENS THE
SUBTROPICAL RIDGE FOR 24-26 HOURS. AFTER 20/00Z...THE SURFACE HIGH
OVER THE `SUBTROPICAL-LATITUDE` PACIFIC APPEARS TO RE-ESTABLISH
ITSELF NORTH OF THE ISLANDS FOR DAYS 5-7. BUT THE CENTRAL PRESSURE
OF THE `NEW` SURFACE HIGH LOOKS TO BE A GOOD 3-5 MILLIBARS WEAKER
THAN THE CURRENT 1034 MB+ CELL INVOF 38.5N 144W.

VOJTESAK

$$





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