588
FXHW01 KWNH 020754
PMDHI
HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 AM EST MON FEB 2 2026
VALID 00Z TUE 03 FEB 2026 - 00Z TUE 10 FEB 2026
MODEL GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT REGARDING THE
SYNOPTIC SCALE EVOLUTION ACROSS THE CENTRAL PACIFIC THROUGH THE
SHORT TERM (INTO THURSDAY), WITH AGAIN SIGNIFICANT DIVERGENCE IN
THE GUIDANCE APPEARING TOWARD NEXT WEEKEND.
THROUGH WEDNESDAY, THE GLOBAL GUIDANCE ALL DEPICT A PROGRESSIVE,
POSITIVE-TILT SHORTWAVE TROUGH LIFTING NORTHEAST OF THE ISLANDS.
THE SURFACE FRONT MEANWHILE APPROACHES KAUAI AND OAHU MONDAY
AFTERNOON, ACCOMPANIED BY AN UPTICK IN PRE-FRONTAL SOUTHWESTERLY
FLOW. WHILE A BRIEF PERIOD OF MODERATE RAINFALL IS EXPECTED AS THE
FRONT TRAVERSES KAUAI, OAHU, AND MAUI COUNTY LATE MONDAY INTO
TUESDAY MORNING, THE PROGRESSIVE MOVEMENT OF THE UPPER
TROUGH AND ASSOCIATED SURFACE FRONT WILL LIMIT DURATION AND
AMOUNTS, AS WILL THE RELATIVELY STABLE CONDITIONS ALOFT.
MEANWHILE, THE FRONT IS STILL EXPECTED TO DISSIPATE NEAR THE BIG
ISLAND BY LATE TUESDAY. BEHIND THE FRONT, A NOTICEABLE CHANGE IN
AIRMASS IS EXPECTED AS THE FLOW VEERS NORTHWESTERLY AND BRINGS A
COOLER/DRIER AIRMASS TO THE ISLANDS. ESPECIALLY BY TUESDAY AND
TUESDAY NIGHT, WHEN DEWPOINTS DROP INTO THE 50S.
FROM LATE WEEK INTO THE WEEKEND, THE PATTERN ALOFT AMPLIFIES
SIGNIFICANTLY. GLOBAL MODELS AND THEIR RESPECTIVE ENSEMBLES AGREE
ON A DIGGING LONGWAVE TROUGH APPROACHING FROM THE NORTHWEST.
HOWEVER, CONSIDERABLE SPREAD (AND THUS LOWER FORECAST CONFIDENCE)
EXISTS REGARDING THE AMPLITUDE ALONG WITH THE TIMING/LOCATION OF
THE EVENTUAL CLOSED/CUTOFF UPPER LOW. OBVIOUSLY THE LOCATION OF
AMPLIFYING TROUGH AXIS AND ANY CLOSED LOW THROUGH AT LEAST THE MID
LEVELS WILL DICTATE WHERE THE AREA OF MAXIMUM DOWNSTREAM
DIVERGENCE/DIFLUENCE WILL BE, ALONG WITH THE AXIS OF HIGHEST DEEP-
LAYER THETA-E, PW, AND INSTABILITY WITHIN THE WARM CONVEYOR BELT
(WCB) -- ALL OF WHICH WILL FACTOR TO WHERE THE MORE WIDESPREAD
AND HEAVIER PRECIPITATION WILL FALL OVER THE WEEKEND. WHILE THESE
DETAILS WILL LIKELY TAKE A FEW MORE FORECAST CYCLES TO RESOLVE,
CONFIDENCE NEVERTHELESS CONTINUES TO GROW FOR A RATHER UNSETTLED
PATTERN ACROSS THE ISLANDS THIS WEEKEND INTO EARLY NEXT WEEK, AS
POPS INCREASE FRIDAY NIGHT AND PEAK SATURDAY AND SUNDAY.
HURLEY
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