Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
342 AM EDT Fri Mar 21 2025

Valid 00Z Sat 22 Mar 2025 - 00Z Sat 29 Mar 2025

Guidance shows moderate to brisk trades with windward shower 
focus late this week and then a steady weakening of trades during 
the weekend as a cold front approaches from the northwest. Expect 
near to below normal values of moisture to support mostly light 
activity, with a transition toward more sea breeze focus by Sunday
as the winds trend lighter. The front should drop into or near 
the main islands by early next week. Then shortwave energy and 
frontal waves should produce an area of heavy rainfall to the 
northwest of the islands around Tuesday. Consensus of most other 
dynamical and machine learning guidance suggests this axis of 
enhanced rain should align somewhat farther northwest than 
forecast by the 00Z GFS. Guidance 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.

Rausch