Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
348 AM EDT Wed Mar 26 2025

Valid 00Z Thu 27 Mar 2025 - 00Z Thu 03 Apr 2025

Guidance shows good continuity from now into the weekend, 
indicating multiple days of east/southeasterly trades. Still 
expect background flow to be sufficient to support some windward 
focus for showers over some areas while at other times/locations 
it may be weak enough to allow for sea breeze influence. Rainfall 
should be lightest late this week into the early weekend time 
frame as an upper ridge builds into and settles over the area.

Models and ensembles begin to diverge around Sunday-Monday with 
more pronounced spread developing over the central-eastern Pacific
heading into midweek. There is a general theme for winds to turn 
more southerly as a system develops well to the northwest, but the
GFS/GEFS keep the system more distant and thus are weaker with 
winds over the state. Toward midweek these differences lead to 
most guidance (even the GEFS) bringing enhanced frontal moisture 
closer to or even into the western islands. On the other hand, 
latest machine learning (ML) models that produce QPF maintain 
continuity from yesterday in keeping the enhanced rainfall 
somewhat farther west than the ECMWF and ensemble means, at least 
to the extent of the 00Z CMC if not the 00Z GFS. The 00Z ML models
do not add any confidence to the upper level forecast, as their 
solutions over the central-eastern Pacific vary about as much as 
the dynamical guidance. This dramatic spread recommends a 
conservative intermediate approach for the state's forecast 
specifics during the early-middle part of next week.

Rausch