Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 748 AM EDT Tue Aug 15 2017 Valid 00Z Wed Aug 16 2017 - 00Z Wed Aug 23 2017 A slow moving upper-level weakness will slowly press westward across the state over the next week. Despite some instability aloft, surface high pressure is expected to remain in control and allow light to moderate easterly trades with some windward showers. The operational versions of the gfs and ecmwf indicate precipitable water values to remain below average through a good part of this coming weekend, values at or about 1 inch. By late weekend into early next week, the moisture content will increase and become a bit more elevated across the islands. Operational and ensemble guidance indicate a possible easterly wave and influx of moisture along the ITCZ (Inter Tropical Convergence Zone) to advect in from the east and southeast. This may result in some more organized and persistent shower activity to perhaps reach the eastern portion of the state, this remains in question though. Musher