Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 810 AM EDT Fri Jul 07 2017 Valid 00Z Sat Jul 08 2017 - 00Z Sat Jul 15 2017 The guidance shows relatively good agreement at 500 hPa and the surface over the next week. A large mid-level subtropical high that is northwest of the Islands should remain in place through the end of the week and then expand eastward around the 35th parallel into Tuesday. A TUTT cell/mid- to upper-level low is apparent at 500 hPa which the guidance slowly retrogrades northeast to north of Hawai'i. Trade winds should increase in magnitude from Sunday onward as the tail end of a front retrogrades as an inverted trough north and northwest of the 50th state. Precipitable water values should remain near 1.25"/close to average through Sunday night. The signal remains strong for an axis of enhanced moisture to reach the Islands Tuesday and Wednesday with precipitable water values of ~1.75" as the remnants of a northeast Pacific tropical cyclone attempt (currently near 19N 128W) move westward past the 140th meridian within a sheared environment to the south of the TUTT cell, possibly moving by Hawai'i as a "screaming eagle" feature. Windward showers, with some local enhancement early next week as precipitable water increases with the surface trough passage. Moisture from the system will be slow to lower on Thursday and Friday, which should continue enhanced shower activity in the wake of the system. Roth