462
FXHW01 KWNH 180642
PMDHI
HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
242 AM EDT THU JUN 18 2026
VALID 00Z FRI 19 JUN 2026 - 00Z FRI 26 JUN 2026
AN UPPER-LEVEL TROUGH LOCATED TO THE NORTH OF THE ISLANDS AT THE
START OF THE PERIOD AND A SURFACE FRONT POSITIONED WELL TO THE
NORTHWEST WILL COMBINE TO DISRUPT THE TYPICAL TRADE WIND
INVERSION, RESULTING IN LIGHT SURFACE WINDS ACROSS THE REGION
UNTIL EARLY-TO-MID WEEK. THIS PATTERN WILL COEXIST WITH ABOVE-
NORMAL MOISTURE FROM A WEAK WAVE OR INVERTED TROUGH PASSING ACROSS
THE ISLANDS EARLY ON. ALTHOUGH THE INITIAL UPPER TROUGH LIFTS OUT
TO THE NORTH, THE SURFACE BOUNDARY IS EXPECTED TO REMAIN IN PLACE
AND MAY DRIFT CLOSER TO THE ISLANDS AS SHORTWAVE ENERGY MOVING
THROUGH THE WESTERLIES PROVIDES UPPER-LEVEL SUPPORT TO AMPLIFY
ANOTHER TROUGH NORTH OF THE STATE. THIS CONFIGURATION MAY FAVOR A
SHIFT TO A MORE NORTHEASTERLY FLOW OVER THE ISLANDS EARLY NEXT
WEEK. BY LATE IN THE FORECAST PERIOD, A CUT-OFF UPPER LOW MAY SINK
FROM THE NORTH-NORTHEAST AS THE SUBTROPICAL JET ALSO LIFTS NORTH.
THIS MAY LEAD TO ADDITIONAL RAIN CHANCES FOR THE STATE.
SNELL
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