Prognostic Meteorological Discussion
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000
FXHW01 KWNH 011208
PMDHI

HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
807 AM EDT SAT OCT 01 2016

VALID 00Z SUN OCT 02 2016 - 00Z SUN OCT 09 2016

VERY GRADUAL WEAKENING OF SURFACE HIGH PRESSURE TO THE NORTHEAST
OF THE STATE SHOULD PROMOTE A SIMILAR TREND FOR TRADE FLOW OVER
THE COMING DAYS.  DEPENDING ON THE STRENGTH OF MID-LEVEL TROUGHING
JUST NORTH/NORTHWEST OF THE REGION, AROUND MID-LATE WEEK A SURFACE
TROUGH MIGHT DEVELOP NEARBY AND LEAD TO FURTHER WEAKENING OF THE
TRADES OR A MORE SOUTHEASTWARD ORIENTATION.  COMPARED TO OTHER
CURRENT GUIDANCE THE 00Z/06Z GFS RUNS ARE STRONGEST ALOFT AND
LIKEWISE MOST PRONOUNCED WITH SURFACE TROUGHING.  WITH SOME
DIFFERENCES IN DETAILS GUIDANCE GENERALLY SUGGESTS THAT TRADES
SHOULD BECOME EASTERLY ONCE AGAIN NEXT WEEKEND AS HIGH PRESSURE
BECOMES ELONGATED ALONG OR JUST NORTH OF 30N LATITUDE.

THERE IS STILL REASONABLE AGREEMENT THAT MOISTURE AND AREAS OF
ENHANCED RAINFALL WILL BE INCREASING THIS WEEKEND AND PERSIST INTO
AT LEAST WEDNESDAY-THURSDAY.  SOME OF THIS MOISTURE WILL BE
ASSOCIATED WITH THE REMNANTS OF ULIKA.  SOME SPREAD EXISTS IN
EXACTLY HOW FAR NORTHWESTWARD THE HIGHEST PRECIPITABLE WATER
VALUES REACH BUT GFS/ECMWF RUNS AGREE THAT THE BIG ISLAND SHOULD
SEE A PERIOD WITH PWATS REACHING OR EXCEEDING 2 INCHES.  THE
WEAKNESS ALOFT WILL LIKELY PLAY A PART IN ENHANCING
MOISTURE/RAINFALL.  A DRYING TREND SHOULD BEGIN BY FRIDAY-SATURDAY
THOUGH WITH A FAIR AMOUNT OF UNCERTAINTY OVER EXACT TIMING AND
EXTENT.

RAUSCH

$$




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