Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 750 AM EDT Fri Jul 04 2014 Valid 00Z Sat Jul 05 2014 - 00Z Sat Jul 12 2014 The 4/00Z forecast cycle yielded good results with the GEFS-ECENS means in decent agreement with the flow pattern aloft through day 6. Their corresponding 4/00z deterministic GFS-ECMWF runs handle the surface pattern with good continuity and reliability. A mid-latitude surface cyclone and its surface front---migrating along 47N 150W @ 7/00Z---will temporarily disrupt the subtropical ridge and decrease tradewind intensity for about 48 hours. By Wednesday (9/12z), both deterministic runs show an impressive post-frontal strengthening of the surface high invof 42N 148.5W. See no reason to doubt that the tradewinds return, in earnest mid-week. For day 5-7, the deterministic ECMWF and GFS indicate an active ITCZ along 10N latitude and a tropical disturbance migrating along the western periphery of the subtropical ridge---from just west of the Marianas Islands into Japan/South Korea region of eastern Asia. But their details lack continuity and differ significantly with respect to forward speed and intensity. Therefore, a blend of the GEFS-ECENS for the day 6-7 period should yield decent results with a gradual westward migration of the surface high in the mid-latitude Pacific along 40N from 148.5W to 160W longitude into next Friday (day 7). Vojtesak