412
FXHW01 KWNH 140754
PMDHI
HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
354 AM EDT THU MAY 14 2026
VALID 00Z FRI 15 MAY 2026 - 00Z FRI 22 MAY 2026
THE SYNOPTIC PATTERN FOR THE UPCOMING PERIOD WILL BE DEFINED BY
THE TRANSITION FROM A STANDARD TRADE WIND REGIME TO A MORE
UNSETTLED MID-LEVEL ENVIRONMENT, THEN FOLLOWED BY A STRONG SURFACE
HIGH BUILDING BACK IN NORTH OF THE STATE. EARLY IN THE PERIOD, A
SHORTWAVE DROPS SOUTHWARD, EAST OF A PROMINENT UPPER-LEVEL HIGH,
THEN EVOLVE INTO A CLOSED UPPER-LEVEL LOW NORTH OF THE STATE
BEFORE CONTINUING ITS SOUTHWARD TRACK OVER THE STATE FRIDAY-FRIDAY
NIGHT. THIS SYNOPTIC EVOLUTION MAY PROVIDE THE NECESSARY UPPER-
LEVEL SUPPORT TO POTENTIALLY WEAKEN THE TRADE WIND INVERSION AND
LEAD TO AN INCREASE IN ORGANIZED SHOWER ACTIVITY ACROSS THE STATE,
ESPECIALLY AS TROPICAL MOISTURE IS TAPPED AND PWAT VALUES INCREASE
TO 1.6-1.8 INCHES BY LATE SATURDAY. THIS MID-LEVEL LOW IS
EXPECTED TO WEAKEN/OPEN OVER THE ISLANDS BY SUNDAY BEFORE
GRADUALLY SHIFTING EASTWARD EARLY NEXT WEEK. AT THE SURFACE, A
STRONG HIGH PRESSURE SYSTEM CENTERED NORTH OF THE ISLANDS WILL
DRIFT EAST; HOWEVER, THE RESULTING PRESSURE GRADIENT IS EXPECTED
TO MAINTAIN A MOSTLY STEADY LOW-LEVEL EASTERLY TRADE WIND FLOW
ACROSS THE ISLAND CHAIN THROUGH THE FORECAST PERIOD. WHILE THE
UPPER LOW WILL ENHANCE PRECIPITATION POTENTIAL, THE PERSISTENT
SURFACE RIDGING SHOULD KEEP THE OVERALL WIND REGIME RELATIVELY
STABLE.
HURLEY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page