Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
209 AM EST Fri Dec 20 2024

Valid 00Z Sat Dec 21 2024 - 00Z Sat Dec 28 2024

A very active Pacific storm track will be in place north of Hawaii
through the upcoming weekend, with an extremely strong surface low
tracking east between 40-45 degrees north, and its trailing cold
front will likely reach or just pass the northwestern Islands.  A
second front likely follows behind this one in rapid succession. 
Meanwhile, the axis of the subtropical ridge will generally be
centered just north of 20 degrees, placing the state in a region
of weaker pressure gradient and thus lighter and more variable
winds. 

Going into next week, the model guidance agrees well that the
surface high should rebuild north of the state near 30 degrees
north, and thus a more steady easterly trade wind flow should
resume.  This high should then be northeast of the state by
midweek with an expansive low pressure system developing well to
the northwest of the state.  Another col may develop in the
surface ridge as another trailing cold front approaches the state
late in the forecast period, with the ensemble means in reasonably
good agreement on this.  No major rainfall events are currently
expected across the state over the next 7 days.

Hamrick