Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
306 AM EDT Fri Sep 10 2021

Valid 00Z Sat Sep 11 2021 - 00Z Sat Sep 18 2021

Near to below normal mid-level heights are favored over the region
for about the next week, downstream of a strong upper high near
the Dateline. An upper low east of the islands will continue to
meander near 30N/145W through Saturday before it interacts with
the southern part of a trough that will push into the western
CONUS. It will likely head back west toward Hawaii next week, with
most models indicating it should drift north of the islands.
Through most of the next week, modest trades will support
generally light to perhaps moderate windward and mauka showers as
precipitable water values waver near 1.25 inches. Depending on how
close the upper low comes, this could bring some enhanced
precipitation to the islands, but most models keep the heaviest
QPF signal to the northeast of the region. There remains some
variability with this feature though, so a model consensus
continues to seem the most reasonable for the next seven days.

Santorelli