


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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388 FXHW01 KWNH 040613 PMDHI Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 213 AM EDT Fri Apr 4 2025 Valid 00Z Sat 5 Apr 2025 - 00Z Sat 12 Apr 2025 A trailing frontal boundary extending southward from a large occluded low pressure system well to the north of Hawaii is expected to reside over the northwestern Islands for Friday into Saturday, and then gradually wash out going into Sunday. Surface high pressure then rebuilds northwest of the state near 30-35 degrees north, with mainly ENE trade wind flow expected. This likely remains the case into the middle to end of next week, with good overall model agreement across the Hawaii domain. In terms of rainfall prospects, most of the mainly light to moderate showers with the stationary front through this weekend should be mainly north and west of Honolulu, and typical trade wind showers extending southeast to the Big Island. The ensemble means suggest an upper trough could develop near 150 degrees west by midweek, and this may result in a slightly greater coverage of showers during this time. Hamrick $$