465
FXHW01 KWNH 230805
PMDHI
HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
305 AM EST TUE DEC 23 2025
VALID 00Z WED 24 DEC 2025 - 00Z WED 31 DEC 2025
AN UPPER-LEVEL RIDGE IS FORECAST TO REMAIN THE DOMINANT FEATURE
OVER THE STATE THROUGH THE FIRST HALF OF THE PERIOD, BEFORE
GRADUALLY SHIFTING EASTWARD TOWARD THE WEEKEND. AT THE SURFACE,
HIGH PRESSURE TO THE NORTH OF THE ISLANDS WILL SUPPORT EASTERLY
TRADE WINDS EARLY IN THE PERIOD. DURING THE LATTER HALF OF THE
WEEK, THE SURFACE HIGH IS EXPECTED TO SHIFT FARTHER EAST,
ALLOWING THE PRESSURE GRADIENT TO RELAX AND LOW-LEVEL WINDS TO
VEER TOWARD THE SOUTHEAST. AS WINDS SLACKEN FURTHER INTO THE
WEEKEND, A TRANSITION TOWARD A MORE LOCALIZED LAND AND SEA BREEZE
CIRCULATION MAY BECOME MORE FAVORED.
ATMOSPHERIC MOISTURE CONTENT IS EXPECTED TO DECREASE AS DRIER AIR
FILTERS INTO THE ISLANDS MIDWEEK, WITH SOME GLOBAL GUIDANCE
SUGGESTING NEGATIVE PRECIPITABLE WATER (PW) ANOMALIES MAY DEVELOP
NEAR THE EASTERN END OF THE STATE DURING THE LATTER HALF OF THE
WEEK. HOWEVER, THE BENIGN PATTERN MAY TRANSITION EARLY NEXT WEEK
AS AN UPPER-LEVEL TROUGH/LOW MOVE ACROSS THE CENTRAL PACIFIC
NORTH OF THE STATE. THIS FEATURE IS EXPECTED TO DRIVE A COLD FRONT
SLOWLY EASTWARD TOWARD THE ISLANDS. WHILE MODEL UNCERTAINTY
PERSISTS REGARDING THE FORWARD SPEED OF THE BOUNDARY, THERE IS
POTENTIAL FOR THE FRONT TO PROGRESS FAR ENOUGH TO SUPPORT MORE
ORGANIZED SHOWERS, ESPECIALLY OVER THE WESTERN ISLANDS BY THE END
OF THE PERIOD.
PEREIRA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page