Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 827 AM EDT Fri Sep 23 2016 Valid 00Z Sat Sep 24 2016 - 00Z Sat Oct 01 2016 Not many differences in the forecast from yesterday. An upper low northeast of the islands will drift slowly northeastward away from Hawaii while a few weak embedded impulses should sporadically enhance moisture and lift over the islands. One such impulse is occurring now with heavy rain currently occurring across the eastern half of the Big Island and Maui. Precipitable water values are expected to remain near 1.75 inches to 2 inches across the Big Island from today thru Saturday night. On Sunday, a front passes well north of the islands possibly disrupting the trade flow. As another large high pressure system builds across the central to eastern Pacific, the trade flow becomes well established early next week as precipitable water values drop again to between 1.25 to 1.5 inches through the period. Kocin