Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
342 AM EDT Sat Mar 22 2025

Valid 00Z Sun 23 Mar 2025 - 00Z Sun 30 Mar 2025

Expect trades to trend lighter during the weekend as a front
approaches from the northwest. Windward shower focus will likely
transition to some sea breeze influence where winds become
sufficiently weak. Latest guidance suggests the front and its
associated moisture axis should stay just north of the main
islands early next week before waviness to the west/north lifts
the front northward. Recent GFS trends have yielded better
agreement for how far to the north the axis of heavier rainfall 
should be. Guidance still shows the trades returning by Tuesday 
and continuing in easterly or southeasterly fashion for the rest 
of the week, favoring another period of windward showers. An upper
ridge that builds in from the southeast by late week should help 
to keep rainfall totals in the light to moderate range.

By next Saturday the GFS/GEFS diverge from most other guidance in
showing a more amplified east-central Pacific upper trough,
displacing the upper ridge over the state farther southwestward.
The GFS/GEFS upper pattern leads to a greater southward push of
high pressure from the north (with a leading front) along with 
northeasterly winds. In contrast, most of the latest 00Z machine 
learning (ML) guidance holds onto more upper ridging over and 
northeast of the state like the ECMWF, with the surface pattern 
favoring continued easterly/southeasterly winds. Will favor the 
ECMWF pattern given support from the ML majority.

Rausch