Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 829 AM EDT Tue May 01 2018 Valid 00Z Wed May 02 2018 - 00Z Wed May 09 2018 ...Locally heavy rain possible later this week over the western islands... Upper ridging is forecast to remain quasi-stationary to the southeast of Hawai'i into next week, strengthening over the next day or so through Friday before easing this weekend as a front pushes through late this weekend into early next week. For the next couple of days, moisture plume associated with the former front just to the southeast of the Big Island will move back to the northwest as the upper ridge to the southeast builds back into the area. Farther to the northwest, an upper low will slide eastward along 30N and enhancing the rainfall across the island chain (especially northwest of the Big Island) for the balance of the work week. Global models and ensembles indicate some potential for locally heavy rains as evidenced by the "MAX" values per the 00Z GEFS reforecast QPF Thu-Fri. Flash flooding may be an issue with persistent/training rain/convection with LIs around zero to -2. The threat for heavy rainfall should begin to wane by Sunday night as the upper trough lifts out to the northeast and heights build again in the wake of the frontal passage. North to northeast winds will increase and precipitable water values will fall over most of the region, except perhaps the Big Island. Shower activity should be limited to windward locations in a much more stable atmosphere. Fracasso