Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
820 AM EDT Wed Jul 12 2017

Valid 00Z Thu Jul 13 2017 - 00Z Thu Jul 20 2017

Models are in good agreement on a large mid/upper-level ridge
remaining anchored well north and northwest of Hawai'i through the
weekend, with some retrogression occurring by the beginning to
middle of next week. Two areas of negative height anomalies will
initially be centered both west and east of the Islands, with a
broad trough expanding across Hawai'i by Friday and persisting
into next week as the upper ridge shifts westward. At the surface,
high pressure anchored well north of the Islands will keep
easterly trades in place across Hawaii into next week. Easterlies
will be 5-10 kt initially, but should strengthen to 10-20 kt by
the weekend as the pressure gradient tightens slightly. This
pattern will keep typical isolated to scattered showers and
thunderstorms in the picture, particularly across the eastern
Islands. Drier air is expected to gradually work its way into the
region over the next several days, which should somewhat decrease
shower coverage as well.

Ryan