Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
346 AM EDT Thu Aug 29 2024

Valid 00Z Fri Aug 30 2024 - 00Z Fri Sep 06 2024

...Continuing to monitor potential effects of weakening Tropical
Storm Gilma late this week...

Moderate to brisk trades and windward/mountain shower focus should
extend into Thursday.  Over the past day or so, track guidance for
what is left of T.S. Gilma has been fairly steady, with the 03 UTC
Central Pacific Hurricane Center advisory showing Gilma tracking
just north of the main islands Thursday night through Friday as it
weakens from a tropical depression to a remnant low. Gilma's
remaining moisture should bring a period of enhanced rainfall late
in the week while a brief disruption of the trades would allow for
some sea breeze influence on rainfall.  Continue to monitor CPHC
forecasts as rainfall will be very sensitive to the exact path of
the surface low (lighter with a more northward track, heavier if
farther south).  Behind Gilma, T.S. Hector should dissipate within
the next couple days but associated moisture will likely cross the
islands around Sunday.  However, a strengthening ridge aloft
should temper what increase in rainfall occurs.

Guidance is consistent and agreeable in showing a drier period for
next week as precipitable water values settle to below
climatological levels by Tuesday-Thursday, even with some
differences in upper level flow showing up by mid-late week. 
Surface high pressure to the northeast should establish moderate
to brisk trades and windward shower focus by early next week,
followed by a weakening trend Wednesday-Thursday as the surface
high lifts away and a front reaches a position to the northwest of
the state.

Rausch