783
FXHW01 KWNH 100845
PMDHI

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
445 AM EDT Fri Apr 10 2026

Valid 00Z Sat 11 Apr 2026 - 00Z Sat 18 Apr 2026

...Periods of Heavy Rainfall Expected Across the Islands this
Weekend into next week...

The closed upper low well to the northwest of the Islands,
initially near 36N 166W, will remain nearly stationary through
late Monday, and then only begin to push slowly eastward Tuesday
and Wednesday. Model consensus continues to show mid to upper level
southwesterly flow aloft remaining established across the islands,
to the southeast of this nearly stationary closed low. This will
allow and axis of much above average PW values, 2 to 4+ standard
deviations above the mean, to build back to the west across the
Island chain early in the forecast period and remain in place
across the state through this weekend and into much of next week.

Shortwaves in this persistent southwest mid to upper level flow
will continue to enhance large scale uvvs in the anomalous PW
axis, supporting rounds of heavy rainfall and an elevated risk of
life threatening flash flooding and mudslides/debris flows this
weekend and for much of the upcoming week.

Periods of heavy rainfall are likely in this anomalous PW axis,
with model consensus for the greatest chance of heavy rains
through late Monday. After this, models are not as emphatic about
widespread heavy rains. However, with the anomalous PW axis
remaining across the Islands Tuesday, through Friday, locally
heavy rains will be possible each day.

Oravec