Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
346 AM EDT Sun Sep 21 2025

Valid 00Z Mon 22 Sep 2025 - 00Z Mon 29 Sep 2025

Surface high pressure and upper ridging over/north of Hawaii will
maintain easterly trade winds into the early part of the week. 
Weak troughing over the state may bring a period of rain and 
thunderstorm chances Sunday and Monday. After this, there is good 
agreement in the guidance that a cutoff low will advance 
southwestward towards Hawaii mid to late next week which may 
increase moisture and rainfall chances across the island chain 
again with winds light and variable. Another trough to the north 
will push this low away with a possible cold front swinging 
through at least the northern islands next weekend. 

Santorelli