Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
805 AM EDT Mon Sep 02 2019

Valid 00Z Tue Sep 03 2019 - 00Z Tue Sep 10 2019

A typical trade wind pattern is expected across Hawaii through the
next week as models show consensus that an upper-level ridge
should become established north of the state, with a strong
surface high anchored over the north Pacific. This should allow a
couple weak surface troughs/disturbances in the ITCZ to
periodically increase moisture and shower activity for Hawaii. The
first of these should pass Wed-Thu, with a second one potentially
arriving by next Mon. Models show generally good agreement on the
timing of these features, although some differences are evident as
to the northern extent of the moisture with the system early next
week. In that case, the GFS keeps the deeper moisture just south
of the state while the ECMWF spreads 2+ inch PWs across the Big
Island. Weak to moderate trades should gradually strengthen
through the week, reaching 20-25 kt by Thu-Fri. Depending on the
intensity of the wave early next week, further increase in trades
is possible as the pressure gradient tightens somewhat between the
large surface high farther north and the low pressure trough
passing Hawaii.

Ryan