Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
423 AM EDT Sun Sep 6 2026

Valid 00Z Mon 07 Sep 2026 - 00Z Mon 14 Sep 2026


An active tropical pattern across the central to eastern Pacific 
between Lowell passing to the south and then west of the Islands 
and Karina passing to the northeast of the Islands, will keep 
trades disrupted across the Islands into at least the mid part of 
the upcoming week. See the latest NHC advisories for official 
tropical watches and warnings on both Lowell and Karina. The track
of Lowell should result in a northward transport of anomalous PW 
values, 2 to 4 standard deviations above the mean, across all of 
the state beginning Sunday night and continuing into Wednesday 
afternoon. This will support potential for heavy rains across all 
of the Islands. Rainfall totals of 4 to 8 inches with maximum 
amounts of 12+ inches possible for Kauai, 2 to 6 inches with
maximum totals of 10 inches for the Big Island, 2 to 4 inches 
with maximum amounts of 8"+ possible for Maui, and rainfall 
totals of 2 to 4 inches across the remainder of the Islands. This
rainfall may produce flash flooding and mudslides, especially in 
areas of steep terrain. A more normal trade pattern should re- 
establish across the Island Thursday and Friday. However, broad 
low pressure to the south of the Islands may again disrupt the 
trades heading into next weekend.

Oravec