Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
159 AM EDT Sat Sep 11 2021

Valid 00Z Sun Sep 12 2021 - 00Z Sun Sep 19 2021

Near to below normal mid-level heights are favored over the region
for about the next week, downstream of a strong upper high
centered near the Dateline. An upper low east of the islands will
likely head back west and drift north of Hawaii next week. Modest
trades through the period will support generally light to perhaps
moderate windward and mauka showers as precipitable water values
waver near 1.25 inches. Southerly flow west of a ridge axis to the
east of the state may try to direct higher PW air towards the
islands. The GFS is more robust with this moisture while the ECMWF
keeps the best moisture well south. Depending on this, some more
enhanced precipitation may impact Hawaii later next week, but both
the ECMWF and GFS continue to suggest the highest QPF should stay
north or south of the islands.

Santorelli