Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 809 AM EDT Mon Jul 29 2019 Valid 00Z Tue Jul 30 2019 - 00Z Tue Aug 06 2019 ...Erick forecast to move south of Hawai'i late this week... ...Flossie expected to move close to Hawai'i early to mid next week... A subtropical ridge north of the archipelago moves westward and weakens as it moves west of the International Dateline. Trade winds are expected to continue with clouds and showers generally favoring windward and mountain locations, with some weakening of the Trades expected from Wednesday onward as the surface high weakens. Per the latest track from the National Hurricane Center, Erick strengthens into a major hurricane in a couple of days before weakening thereafter, expected to pass south of the Big Island next Thursday-Friday as a weakening tropical storm. Its approach could result in increased winds, cloudiness, and precipitation chances across much of the state. Confidence remains low this far out on exact rainfall amounts, but there is potential for some heavier rain especially for windward slopes of the Big Island and Maui. Trades should weaken a bit this coming weekend in the wake of Erick, with showery activity again favoring the windward regions. Thereafter, Flossie is forecast to approach the island of Hawai'i early to mid next week, though there are timing differences seen in the guidance partially related to the pattern across the northeast Pacific. While the 06z GFS is an outlier with a pair of mid-level lows offshore the Pacific Northwest...a blend of the 00z Canadian, 00z ECMWF, 06z GEFS mean, and 00z ECMWF ensemble mean should deal with this issue effectively. This generally fits the NHC track being closest to the 00z ECMWF guidance with Flossie itself. See NHC forecasts and discussions for the latest information and forecast philosophy on Erick and Flossie. Roth