Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 804 AM EDT Sun May 24 2015 Valid 00Z Mon May 25 2015 - 00Z Mon Jun 01 2015 Heading into the first part of next week, guidance expects energy feeding into the mean upper trough northeast of the state to pull the overall trough axis a little westward. This evolution encourages a retreat of the eastern side of high pressure northwest of the islands, leading to a lighter trend for north/northeasterly winds initially affecting the area. Therefore shower activity generally focused over windward terrain may at times become influenced by sea and land breeze boundaries during the first half of the week. A surface trough may disrupt trade flow during the latter half of the weak but overall from late week into next weekend the surface pattern should become more supportive of light to moderate trades and windward focused rainfall. Expect lowest precipitable water values of the period to be northwest of the Big Island early in the week. After that time individual model runs show potential for pockets of PWATs reaching at least 1.50 inches but with disagreement on timing and location. Note that from Thu night onward 00z/06z GFS runs become more amplified than most other guidance, first with the trough to the northeast/north of the state and then by Sun with the southern edge of the westerlies to the north/northwest. Thus at the very least GFS runs could be a little premature with the northwestward migration of higher PWATs. Rausch