Prognostic Meteorological Discussion
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000
FXHW01 KWNH 301154
PMDHI

HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
753 AM EDT TUE SEP 30 2014

VALID 00Z WED OCT 01 2014 - 00Z WED OCT 08 2014

THE 30/00 UTC GFS/GEFS AND ECMWF/ECENS WERE VERY MUCH IN MASS
FIELD AGREEMENT HEADING INTO THE WEEKEND. BOTH MIGRATE A LOW
PRESSURE AREA NEAR 45N 170W NORTHEASTWARD INTO THE NORTH CENTRAL
GULF OF ALASKA AND ROTATE A SURFACE TROUGH SOUTH-SOUTHEASTWARD
INTO THE SUBTROPICS ALONG 30N 160W. THIS SURFACE
TROUGH---MIGRATING GRADUALLY EASTWARD ALONG 150W INTO EARLY NEXT
WEEK AND DISPLACING THE SUBTROPICAL RIDGE. BEYOND DAY 6 (MONDAY),
A BROAD CYCLONIC FLOW AND DEEP SURFACE CYCLONE SETS UP IN THE
SOUTHERN BERING SEA AND CENTRAL ALEUTIANS. THIS FEATURE WILL
CONTINUE DISPLACING THE SUBTROPICAL RIDGE EASTWARD---AND CLOSER TO
THE CALIFORNIA AND BAJA CALIFORNIA COASTLINES.

APPEARS THAT TRADES REMAIN SLIGHT AND A PERSISTENCE FORECAST MAY
BE IN ORDER. EARLY IN THE FORECAST PERIOD, THE SENSIBLE WEATHER
FORECAST WILL BE TIED TO A MID-LEVEL CIRCULATION INVOF 23.5N
154W---DRIFTING VERY SLOWLY NORTHWESTWARD TO THE IMMEDIATE NORTH
OF HAWAI`I. THIS CIRCULATION CREATES A WEST-TO EAST BAND OF
MID-LEVEL SHEAR AND ISOLATED DEEP CONVECTIVE RAIN BANDS FOR THE
WESTERN HALF OF THE STATE. THIS QUASI-STATIONARY MID-LEVEL FEATURE
WILL CREATE LOCALLY HEAVY RAINFALL FOR KAUAI AND OAHU--AND
MAINTAIN A SULTRY...MORE HUMID WEATHER PATTERN OVER THE ENTIRE
REGION.

VOJTESAK

$$





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