Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 316 AM EST Tue Nov 19 2019 Valid 00Z Wed Nov 20 2019 - 00Z Wed Nov 27 2019 An upper-level low is forecast to continue drifting slowly across the Hawaiian Islands through the next couple days as it weakens. The low will enhance instability, which along with PWs in the 1.5-1.8 inch range, will support scattered to numerous showers and thunderstorms, some of which could produce heavy rainfall. Surface high pressure is forecast by all guidance to build north of the state by the middle of this week, which should bring a period of windy conditions as trades increase into the 20-30 kt range (with the potential for higher gusts). Drier air should eventually advect across Hawaii by the weekend as upper-level ridging becomes better established several hundred miles north of Hawaii. Prior to that, however, the combination of lingering moisture and strong trades will make for continued wet conditions, especially at favored windward/mauka locations. As a drier air mass works across the state starting this weekend and into early next week, PWs should fall into the 1.0-1.3 inch range. This along with a weakening of the trades into the 10-20 kt range should keep shower coverage and intensity a bit more limited than seen through much of this week. Ryan