Prognostic Meteorological Discussion
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000
FXHW01 KWNH 271132
PMDHI

HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
731 AM EDT FRI MAY 27 2016

VALID 00Z SAT MAY 28 2016 - 00Z SAT JUN 04 2016

TODAY`S MODEL AND ENSEMBLE MEAN GUIDANCE OFFERS GOOD AGREEMENT
WITH THE OVERALL PATTERN THROUGH WEDNESDAY JUNE 1.  SOUTHEASTERLY
LOW LEVEL FLOW ON THE EXTREME PERIPHERY OF EASTERN PACIFIC HIGH
PRESSURE WILL LIKELY WEAKEN FRI INTO THE WEEKEND AS AN UPPER
TROUGH PASSING TO THE NORTH OF THE STATE BRINGS A FRONT THROUGH
THE ISLANDS, POSSIBLY AS A SHEAR LINE, BETWEEN SATURDAY NIGHT AND
MONDAY.  TRAILING HIGH PRESSURE SHOULD SUPPORT EASTERLY OR
EAST-NORTHEASTERLY TRADES IN THE LIGHTER HALF OF THE SPECTRUM
MON-WED, WEAKENING SOME BY THU.

ON THURSDAY JUNE 2, THE 06Z GFS WAS MORE
AGGRESSIVE/WESTERLY/SLOWER WITH A SYSTEM TRACKING ALONG THE 40TH
PARALLEL, WHICH PREMATURELY WEAKENS THE SUBTROPICAL RIDGE NORTH OF
HAWAI`I AND BRINGS A FRONT TOWARDS THE PAPAHANAUMOKUAKEA MARINE
NATIONAL MONUMENT.  THE 00Z CANADIAN WAS FASTER WITH THE SYSTEM
AND BROUGHT THE FRONT/SHEAR LINE QUICKER INTO THE ARCHIPELAGO THAN
THE OTHER GUIDANCE.  SINCE THE GFS HAS DECENT SUPPORT ALOFT FROM
THE ENSEMBLE MEANS, PREFER A COMPROMISE OF THE 06Z GFS/00Z ECMWF
THURSDAY INTO NEXT FRIDAY AND MAINTAIN THE SUBTROPICAL RIDGE
LONGER THAN THE GFS SUGGESTS.

EXPECT BEST POTENTIAL FOR SOME PRECIPITATION TO HAVE A SEA BREEZE
FOCUS THIS WEEKEND WHEN GUIDANCE ANTICIPATES THE LIGHTEST TRADES
AND A FRONT/SHEAR LINE PASSING THROUGH THE ISLAND CHAIN.  ABOVE
NORMAL PRECIPITABLE WATER VALUES AT THE START OF THE PERIOD WILL
TREND TOWARD CLIMATOLOGY BY LATE WEEKEND/EARLY NEXT WEEK, THEN
PERHAPS DRIFT A BIT HIGHER AGAIN LATE NEXT WEEK AS THE NEXT
FRONTAL BOUNDARY APPROACHES.

ROTH
$$




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