Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
801 AM EDT Mon May 20 2019

Valid 00Z Tue May 21 2019 - 00Z Tue May 28 2019

Upper-level ridging is forecast by all guidance to remain in place
across Hawaii through the week, with some signs of perhaps gradual
slight by the weekend. As a surface high north of the state slides
east over the next couple days, low-level winds should veer
slightly to the east-southeast. An upper-level trough well
northwest of the state is expected to push a cold front several
hundred miles west of the state before it stalls, allowing surface
winds across Hawaii to become light and variable by Mon night-Tue.
By late in the week, another batch of shortwave energy reinforcing
the broader upper trough west of the state should push another
cold front toward Hawaii, although the front is still forecast to
remain west of the state. Light to moderate trades should resume
by later in the week as the second surface front washes out and
surface high pressure attempts to rebuild north of the state. This
pattern should support isolated to scattered windward and interior
showers through the week, with little impact to Hawaii from the
surface cold fronts in terms of precipitation.


Ryan