Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 817 AM EDT Fri Aug 19 2016 Valid 00Z Sat Aug 20 2016 - 00Z Sat Aug 27 2016 The upper level pattern at the beginning of the period will feature an upper level ridge and the accompanying surface high well northeast of the islands. A large scale trough over the north-central Pacific, along with a weak inverted trough from the tropics, will serve to lower 500mb heights and a break in the ridging north of the islands by Sunday and into the beginning of next week. The ridging tries to become re-established north of the islands by the end of the forecast period next Thursday, with the EC mean showing more ridging than the GEFS mean, which has some signs of a lingering trough west of the islands. There should be a weakening of the normal trade wind pattern from the trough and thus a smaller surface pressure gradient from Sunday to Tuesday. The veering winds to a more southeasterly flow should advect higher PWs into the region early next week and increase the coverage of showers and storms. Hamrick