Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 152 AM EDT Thu Jul 15 2021 Valid 00Z Fri Jul 16 2021 - 00Z Fri Jul 23 2021 High pressure centered at the mid-latitudes dominates the north central Pacific through this weekend into the middle of next week. Trade winds remain moderate to brisk through this period. The trade flow and layer relative humidity periodically 50-70 percent maintains widely scattered windward terrain/mountain focused showers each day into early next week, with maxima expected in the volcanoes of Maui and the Big Island, as well as the mountains of Kauai. Local enhancements may occur with each low amplitude tropical wave that passes through the islands. The airmass will have precipitable water values predominantly 1.25 to 1.5 inches, increasing to slightly above 1.5 inches in the vicinity of tropical waves. A few models hint at higher amplitude tropical waves possible in the latter portion of next week, when potential for greater moisture and associated rainfall may develop. Petersen