422
FXHW01 KWNH 090833
PMDHI
HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
433 AM EDT SUN AUG 9 2026
VALID 00Z MON 10 AUG 2026 - 00Z MON 17 AUG 2026
..HEAVY RAIN/INCREASING WIND THREAT FROM FRIDAY ONWARD
THE GENERAL FLOW PATTERN FEATURES AN UPPER LEVEL TROUGH
RETROGRADING AWAY THROUGH THE PAPAHANAUMOKUAKEA MARINE NATIONAL
MONUMENT MID-WEEK AND A WARM CORE RIDGE STRENGTHENING/BROADENING
TO THE NORTHEAST OF HAWAI'I. TRADE WINDS CONTINUE THROUGH AT
LEAST THURSDAY.
AN EASTERLY WAVE/LOW-LEVEL SWIRL TO THE SOUTH-SOUTHEAST OF THE BIG
ISLAND INCREASES MOISTURE THROUGH SUNDAY/POSSIBLY INTO MONDAY
WHICH INCREASES HEAVY RAIN POTENTIAL PRIMARILY ON THE ISLAND OF
HAWAI'I. MAUKA SHOWERS ARE EXPECTED THEREAFTER THROUGH AT LEAST
THURSDAY.
A DEVELOPING/STRENGTHENING TROPICAL CYCLONE IS FORECAST TO MOVE
NEAR HAWAI'I AS EARLY AS FRIDAY OR SATURDAY, BRINGING AN
ASSOCIATED HEAVY RAIN THREAT. UNLIKE THE GUIDANCE FROM 24 HOURS
AGO, IT'S NO LONGER CLEAR WHICH SIDE OF THE ARCHIPELAGO IT WOULD
TRACK (SOUTH, VERY CLOSE, OR NORTH) LEAVING THE WIND DIRECTION
FORECAST UNCLEAR. WINDS COULD VERY WELL INCREASE ACROSS SOME OF
THE MAIN ISLANDS WITH THIS SYSTEM LATE IN THE WEEK/NEXT WEEKEND.
SEE NATIONAL HURRICANE CENTER TROPICAL WEATHER OUTLOOKS FOR MORE
ON THIS IMPENDING SYSTEM.
ROTH
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