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000
FXHW01 KWNH 201209
PMDHI

HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
808 AM EDT MON MAY 20 2013

VALID 00Z TUE MAY 21 2013 - 00Z TUE MAY 28 2013

LATEST GUIDANCE AGREES FAIRLY WELL WITH THE LARGE SCALE EVOLUTION
THROUGH THE PERIOD WITH SOME TYPICAL DIFFS AT SMALLER SCALES.  THE
CLOSED LOW ALOFT INITIALLY TO THE N OF THE STATE WILL WEAKEN AND
LIFT AWAY OVER THE COMING DAYS WHILE STRONG NRN PAC SFC HIGH
PRESSURE SHOULD BUILD SWD OVER THE ERN PAC.  AS A RESULT EXPECT
THE SFC FRONT/TROUGH HELPING TO FOCUS PERIODS OF LOCALLY ENHANCED
RNFL EARLY IN THE PERIOD TO WEAKEN AND MOVE WWD... LEAVING A MORE
TYPICAL TRADE REGIME WITH MAINLY WINDWARD FOCUSED SHWRS.  TRADES
SHOULD GRADUALLY STRENGTHEN DURING THE LATTER HALF OF THE FCST AS
THE ERN PAC SFC HIGH STRETCHES A RIDGE WWD ALONG 30N LATITUDE.
THERE REMAINS SOME SPREAD WITH ONE OR MORE PIECES OF MID LVL
ENERGY THAT MAY TRACK OVER/NEAR THE ISLANDS AS A RIDGE ALOFT
BUILDS TO THE W AND EVENTUALLY N OF THE AREA.  CONFIDENCE IN
SPECIFICS OF SUCH DETAILS IS LOW BUT ONE ITEM OF NOTE IS THAT THE
00Z ECMWF/CMC HAVE TRENDED WEAKER/NEWD WITH THEIR MAIN CORE OF
ENERGY VERSUS THEIR RUNS FROM 24 HRS AGO.  THIS WEAKNESS ALOFT MAY
INFLUENCE SHWR ACTIVITY BUT IS NOT EXPECTED TO IMPACT THE SFC
PATTERN.

RAUSCH

$$