Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 807 AM EDT Sat Oct 01 2016 Valid 00Z Sun Oct 02 2016 - 00Z Sun Oct 09 2016 Very gradual weakening of surface high pressure to the northeast of the state should promote a similar trend for trade flow over the coming days. Depending on the strength of mid-level troughing just north/northwest of the region, around mid-late week a surface trough might develop nearby and lead to further weakening of the trades or a more southeastward orientation. Compared to other current guidance the 00z/06z GFS runs are strongest aloft and likewise most pronounced with surface troughing. With some differences in details guidance generally suggests that trades should become easterly once again next weekend as high pressure becomes elongated along or just north of 30N latitude. There is still reasonable agreement that moisture and areas of enhanced rainfall will be increasing this weekend and persist into at least Wednesday-Thursday. Some of this moisture will be associated with the remnants of Ulika. Some spread exists in exactly how far northwestward the highest precipitable water values reach but GFS/ECMWF runs agree that the Big Island should see a period with PWATs reaching or exceeding 2 inches. The weakness aloft will likely play a part in enhancing moisture/rainfall. A drying trend should begin by Friday-Saturday though with a fair amount of uncertainty over exact timing and extent. Rausch