Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 821 AM EDT Tue May 16 2017 Valid 00Z Wed May 17 2017 - 00Z Wed May 24 2017 Upper low centered to the east of the region is forecast to very slowly slide eastward through the rest of the week as the subtropical ridge wobbles around 170E-180. Light windward showers will be of minor concern for the rest of the week with generally dry conditions elsewhere. A stalled front will weaken well north of the region, but its moisture axis will remain. By the weekend into next week, an upper low will track eastward between 40-50N, allowing heights to lower a bit to the north of Hawai'i. A cold front associated with the upper low just south of the Aleutians will drop southeastward toward the area this weekend into next week, but the models/ensembles differ on how far south this may progress. The 00Z ECMWF and Canadian were farther south than about 75% of the ensemble members while the 00Z-06Z GFSs were closer to the ensemble means. Prefer a solution in the middle for now, given the expected amplification of the upper ridge into SW Canada next week which may support a sharper/deeper upstream trough. Fracasso