Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
754 AM EDT Fri Oct 02 2015

Valid 00Z Sat Oct 03 2015 - 00Z Sat Oct 10 2015

Current Hawai'i forecasts were on track with the 2/00Z model cycle
guidance.

The 2/00Z ECMWF/GFS did a decent job of depicting the northward
migration of a mid-level circulation invof 29.5N 149.5W and the
southward decent of its associated cold front. At 6/12Z (day 4),
the deterministic ECMWF migrates the mid-level front through the
central part of the state with the deterministic GFS a slower
solution --- placing the trough/front west of Kauai.

Another key feature of this pattern is a compact mid-level
circulation invof 13N 156.5W. This feature remains intact and
south of the Islands until the passage of the mid-latitude
mid-level front. Between 6/12Z and 7/12Z, this features slowly
drift northward of 17N and across the eastern half of the state.

The deterministic 'differences' between the 2/00Z GFS/ECMWF would
suggest using a blend of the these 2 solutions to 'anchor' the
aforementioned  synoptic-scale and sub-synoptic scale weather
features in the day 4-6 time frame ---for now. The moisture and
energy exchanges between the Tropics and mid latitudes invof
Hawai'i have been difficult to predict in these time frames.
However, the fact remains---the GFS/ECMWF equally identify these
features---and continued scrutiny is warranted, for a prolonged
period of unsettled weather.

Vojtesak