Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
817 AM EDT Sat Aug 09 2014

Valid 00Z Sun Aug 10 2014 - 00Z Sun Aug 17 2014

Please refer to the Central Pacific Hurricane Center (CPHC) for
the latest information and updates concerning 'Julio'.

Overview and Model Preferences...
9/00Z ECENS/GEFS guidance seemed to cover the Pacific
synoptic-scale pattern and features of interest without much
fanfare through day 7. In my opinion, thought the outcome of
'Iselle' from 100W to 160W (over the last 10 days worth of
forecasts) gives the GFS some 'deserved' credence to the overall
broad-scale forecast sequence---past and present. And more
importantly, that which lies ahead for the mid-latitude Pacific. 

Broad but formidable upper-level longwave anchoring invof the
eastern Aleutians extends equatorward to approximately 30N 160W
and serves as steering guide for remnant Subtropical moisture and
dynamics through day 7. More recent 9/00Z deterministic details of
the interaction between Subtropics and mid latitudes were
muddled--though the mid-latitude forecast aloft from 4-5 days
ago---and even back 10 days has been right-on with the upper-level
longwave trough in the north central Pacific and anomalous upper
low invof southern Bering Sea.

This mid-latitude feature will be a key factor going forward for
at least the next 8 days across the mid-latitude Pacific, and
anticipate the Subtropical moisture plume will have lingering
effects--not only for the Subtropics--but also for the western
Canadian shoreline and AK Panhandle periodically as mid-level warm
advection precipitation events develop through time.    

For Hawai'i
Active weather in place through the weekend---mainly western half
of the state---with remnant dynamics from 'Iselle' stalled invof
20N 160W. Thought the 9/00z deterministic GFS handled the sensible
weather features for days 2-3 and directed any effects towards
east-facing and north-facing shores and slopes--with a track
paralleling the entire chain.

Vojtesak