Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 803 AM EDT Wed Aug 12 2015 Valid 00Z Thu Aug 13 2015 - 00Z Thu Aug 20 2015 ...'Hilda' remains a feature of the Hawai'i sensible weather pattern... Please refer to the official Central Pacific Hurricane Center (CPHC) forecasts for the latest information regarding 'Hilda' and the storm's sensible weather impacts. From the 12/00Z model cycle --- the deterministic GFS/ECMWF initialized several sub-synoptic scale features that were identifiable on satellite --- and not related to 'Hilda'. Will discuss these--- both of which could provide some sensible weather impacts for the Islands. The 12/00Z deterministic GFS/ECMWF/Canadian runs and the ECENS mean maintain a nearly-stationary, shallow mid-level circulation (will call it a TUTT cell) --- currently near 30N 160W --- through ---at least--- early Sunday (16/12z). The GFS/ECMWF maintain this feature for much of the 7-day forecast period in its current position. A second initialized feature of the pattern was located near 15N 161W and the ECMWF/Canadian --- in rather unique fashion --- allow this weak wave (will call it a disturbance embedded within the ITCZ) --- to migrate northward across the western half of the state and infuse this moisture/energy with the TUTT cell to its north. The third unique aspect of the 12/00Z deterministic model initialization --- was how the GFS solution --- appears to incorporate some of the residual mid-level moisture/vorticity from the northern periphery of 'Hilda' into the TUTT cell and allows the disturbance embedded within the ITCZ to continue migrating westward--- limiting its interaction with the TUTT cell whatsoever. For the sub-synoptic scale features --- recommend a blend of the 12/00Z GEFS/ECENS means to encompass the broad range of possible deterministic solutions invof Hawai'i this 7-day forecast period. Vojtesak