Prognostic Meteorological Discussion
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FXHW01 KWNH 271220
PMDHI

HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
818 AM EDT THU AUG 27 2015

VALID 00Z FRI AUG 28 2015 - 00Z FRI SEP 04 2015

THE 27/00Z HAWAI`I RAOBS DEPICT A LIGHT AND VARIABLE WIND PROFILE
TO 500MB, HIGH CAPE VALUES, -5 TO -6 LIS, AND ABOVE NORMAL PW
VALUES. THIS TROPICAL MOISTURE INFLUENCE AND NO TRADEWIND
INVERSION SHOULD CONTINUE TO BE A PERSISTENCE FORECAST FOR THE
NEXT TWO DAYS---BEFORE SOMETHING `RESEMBLING` MORE OF AN
EAST-NORTHEASTERLY TRADEWIND (AND INVERSION) RETURNS OVER THE
WEEKEND. THE NORMAL TRADE WIND CIRCULATION DOES NOT LAST FOR
LONG---BUT LONG ENOUGH TO GIVE THE FORECAST AREA `DESERVED` BREAK
FOR WHAT HAS BEEN AN UNUSUAL STRETCH OF EXTREMELY WET AUGUST
WEATHER. JUST A QUICK LOOK AT THE PRIMARY AIRPORT AND CLIMATE
STATIONS PRECIPITATION AMOUNTS SO FAR---(FOR THE MOST PART)
DISPLAY WELL ABOVE NORMAL AUGUST TOTALS.

THEN NEXT WEEK, THE UNUSUAL FLOW PATTERN RETURNS---WITH THE
TROPICAL SYSTEMS IN THE SOUTHEAST PACIFIC -`IGNACIO` AND `JIMENA`-
PROVIDING ANOTHER NORTHWESTWARD BURST OF MOISTURE AND INSTABILITY
FOR THE FORECAST AREA. FOR THE LATEST SHORT-TERM INFORMATION
CONCERNING THE TRACK AND INTENSITY FORECASTS FOR THESE 2
SYSTEMS---PLEASE REFER TO THE NATIONAL HURRICANE CENTER (NHC).

RECENT 27/00Z ECENS/GEFS ENSEMBLE GUIDANCE SUGGESTS THE
COMBINATION OF REMNANTS FROM `ATSANI` AND `LOKE` EVENTUALLY ERODE
THE `BLOCKY` FLOW INVOF THE DATELINE AND 40N---BUT THE DEVELOPMENT
OF ANOTHER SERIES OF QUASI-STATIONARY TUTT CELLS AND CUTOFF LOWS
ALONG 30N ARE NOT OUT OF THE QUESTION. GIVEN THE NEXT TWO
TROPICALS BECOME ENTRAINED IN THE `VERY UNSEASONAL` MID-LEVEL FLOW
REGIME ACROSS THE SUBTROPICAL PACIFIC---FELT A GEFS/ECENS BLEND
AFTER DAY 4 MIGHT BE THE WAY TO GO WITH THE MEDIUM RANGE PORTION
OF THIS FORECAST PACKAGE.

VOJTESAK



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