948
FXHW01 KWNH 180750
PMDHI
HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
350 AM EDT SAT APR 18 2026
VALID 00Z SUN 19 APR 2026 - 00Z SUN 26 APR 2026
LATEST MODEL GUIDANCE INDICATES A SHIFTING SYNOPTIC PATTERN AS
HIGH PRESSURE PASSING NORTH OF THE STATE SLIDES EASTWARD, ALLOWING
FOR A BRIEF RETURN TO TYPICAL EASTERLY TRADE WINDS EARLY THIS
WEEKEND. MEANWHILE, SOME FLAT TROUGHING ON THE SOUTHEAST
PERIPHERY OF A MID-UPPER TROUGH WILL TRAVERSE THE ISLAND CHAIN
EARLY IN THE PERIOD. AS THIS OCCURS, LOW PRESSURE WEST OF THE
ISLANDS WILL LIFT N AND THEN NE THROUGH EARLY NEXT WEEK, WITH THIS
LOW AND ASSOCIATED FRONT FAR ENOUGH TO AVOID A WIDESPREAD HEAVY
RAIN EVENT, WHILE CLOSE ENOUGH TO VEER WINDS TO THE SOUTHEAST AND
SOUTH BY SUNDAY AND MONDAY. A BLEND OF THE ECMWF WITH BOTH THE
ECENS AND GFS ENSEMBLE MEANS IS PREFERRED.
AS THE FLOW VEERS MORE SE-S, DEEPER TROPICAL MOISTURE (HIGHER
PWATS) WILL SPREAD NORTHWARD ACROSS THE WESTERN END OF THE ISLAND
CHAIN. INSTABILITY WILL ALSO BE INCREASING AS THE UPPER LEVEL
TROUGH APPROACHES. AS A RESULT, SHOWERS WILL BECOME MORE LIKELY
SUNDAY THROUGH TUESDAY, ESPECIALLY FOR THE WESTERN ISLANDS
(KAUAI/OAHU).
DURING THE MID TO LATTER PART OF NEXT WEEK, A RETURN TO A MORE
TYPICAL TRADE WIND PATTERN IS EXPECTED. HIGH PRESSURE BUILDING
ACROSS THE STATE FROM THE EAST AND EVENTUALLY NORTH DURING THIS
PERIOD WILL DROP PWATS TO SEASONAL NORMS FOR LATE APRIL AS THE
EAST-NORTHEAST TRADES RETURN. DURING THIS TIME EXPECT MORE
STABLE/SEASONABLE WEATHER CONDITIONS ACROSS THE STATE, WITH LIGHT
TRADE SHOWERS ACROSS FAVORED WINDWARD SLOPES.
HURLEY
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