Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
326 AM EDT Thu Jul 25 2024

Valid 00Z Fri Jul 26 2024 - 00Z Fri Aug 02 2024

Guidance continues to show high pressure along 40N latitude
tracking from east to west during the period, supporting a trade
pattern with primarily windward/mountain focus for showers.
Somewhat brisk and gusty winds may continue into Saturday,
followed by a steady decline in wind speeds as the high continues
to the west and upper troughing approaches from the northeast by
midweek. After an area of enhanced moisture departs on Thursday,
guidance agrees that most of the main islands should remain in an
axis of below-climatology precipitable water values for several
days. Upper ridging through the first part of next week should
also help to keep rainfall totals on the light side. By
Tuesday-Thursday there is some spread for details of the upper
trough pushing in from the northeast, with the 00Z ECMWF a bit on
the amplified extreme and the 00Z GFS on the flat side (keeping a
ridge over the islands longer than other guidance). The ensemble
means and the 18Z GFS offer a reasonable intermediate solution for
this aspect of the forecast.

Rausch