Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 827 AM EDT Tue Aug 01 2017 Valid 00Z Wed Aug 02 2017 - 00Z Wed Aug 09 2017 The synoptic pattern over the central Pacific will be rather blocked in nature as a closed low spins across the mid-latitudes. This system is eventually forecast to lift northward while well above average mid-level heights build along the International Dateline. Across the latitudes closer to Hawai`i, a closed low is expected to spin off toward the west while general ridging extends over the subtropical eastern Pacific. At the surface, persistent ridging to the north will maintain a steady period of trade winds to the region. During the first few days of the period, models show slightly stronger trades toward the Big Island as speeds reach the 20 knot range. By the weekend, an uptick in the local wind fields is noted as much of the island chain can expect an increase to around 20 to 25 knots before weakening a bit into next week. Regarding threats for precipitation, the usual windward showers is expected to rule with the better tropospheric moisture generally south of the islands. Rubin-Oster