Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
821 AM EDT Fri Apr 05 2019

Valid 00Z Sat Apr 06 2019 - 00Z Sat Apr 13 2019

Upper ridging to the south and southwest of the area near 180 will
bridge to the east-northeast and form another upper ridge center
closer to Baja California this weekend (near 130W). As ridging
builds along 180, troughing will deepen near and just east of the
island chain starting midweek. The vast majority of ensemble
members forecast an upper low over or east of the area by next
Thursday, but the 00Z/06Z GFS runs were farthest west over the
islands. The 00Z ECMWF/Canadian and 06Z FV3-GFS were nearer to
150W, closer to the ensemble consensus, which is the preference.

At the surface, a cold front will approach the area from the
northwest this weekend and likely stall over Kauai with
precipitable water values between 1.00-1.30 inches. Otherwise,
oscillating near to below average PW values will help keep the
rainfall amounts light overall. Trades will remain light until
next week. By next Wed/Thu, PW values over an inch state-wide and
lower heights will support more scattered showers over the area,
but a connection to the deep tropics is not forecast, and the
multi-inch rainfall forecast by the GFS was discounted.

Fracasso