


Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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604 FXHW01 KWNH 250747 PMDHI Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 347 AM EDT Fri Apr 25 2025 Valid 00Z Sat 26 Apr 2025 - 00Z Sat 03 May 2025 Flow around the southwest periphery of eastern Pacific high pressure, plus a nearby surface trough to the west, should promote southeasterly winds on average Friday into the early weekend with primarily windward shower focus. The surface trough and its enhanced moisture should then move into the main islands while an upper trough to the north of the state closes off a low that may track just northeast of the state around Tuesday before continuing eastward. As for the path of the upper low, machine learning (ML) models generally suggest a compromise between the 12Z ECens mean/00Z CMC-CMCens mean (closest to the main islands) and farther northeast 00Z GFS. The combined evolution at the surface and aloft should lead to sea/land breeze influence and potential for locally heavy rainfall early next week. Departure of the upper feature and high pressure crossing the mid-latitude Pacific will promote a return of trades and windward shower focus by mid-late week. Rausch