Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 823 AM EDT Thu Jul 03 2014 Valid 00Z Fri Jul 04 2014 - 00Z Fri Jul 11 2014 .General Synopsis... Prominent upper-level ridge in the Subtropics (west-to-east aligned axis) will gradually weaken along 25N-30N and 150W-160W during the weekend---as long wave troughing in the Gulf of Alaska and north central Pacific Ocean takes shape this weekend. .Model Preferences... Thoughts were to follow a blend of the 3/00Z ECENS-GEFS solutions through day 7...with their corresponding deterministic runs providing utility with the wind and rainfall forecasts through Sunday (day 3). A quick glance on water vapor over the Pacific indicates weakness aloft and/or broad troughing along 10N-20N latitude from 120W-160W longitude. Embedded cyclonic flow invof the ITCZ and a light southerly component to the flow tending to drift high clouds northward into CWA...but having little to no impact on the current sensible weather. .Short Term... Northeast of the Hawai'ian Islands, the subtropical surface high will slowly migrate north-northeastward and build into the west central coast of North America---and the 3/00Z ECENS and GEFS ensemble packages appeared straight-forward with this solution through day 3-4. Where the deterministic runs differ from the means are in two locations in the Pacific---the Gulf of Alaska (invof 50N 150W) and in the tropical southeast Pacific (invof 20N 130W). Both geographical locations provide 'weakness' in the Subtropical Ridge. In particular, upper-level troughing east-southeast of Hawai'i offers the best prospects for subtle change---in terms of sensible weather---heading into next week. .Medium Range... Challenge will be to determine the outcome of the subtropical ridge alignment next week in the subtropical Pacific, with subtle 'influence' from the northern periphery of the ITCZ attempting to drift northward and approach Hawai'i from the south. Some of the details are obscured by the means, though the prevailing ensemble means indicate a broad area of lower heights moving northward along 20N between day 5-7. Vojtesak