Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
758 AM EDT Thu Oct 16 2014
Valid 00Z Fri Oct 17 2014 - 00Z Fri Oct 24 2014
... 'Ana' heading towards Hawai'i this weekend ...
The 16/00Z ECENS/GEFS and their deterministic runs offered no
surprises with respect to the anticipated track and forward speed
of 'Ana' during the next 3 days---passing south of the state---but
close enough to generate substantial periods of very heavy
rainfall and strong, gusty winds on Saturday and Sunday. This
closely matches the Central Pacific Hurricane Center (CPHC)
forecast---heading into Monday morning. Please refer to the CPHC
for the latest forecasts and most current information concerning
The deterministic 16/00z GFS/ECMWF solutions begin to differ from
their means on day 4 (Monday) as the tropical system interacts
with a migratory mid-latitude surface ridge originating in the
western Aleutians. The result is a timing difference---and at what
longitude---a northward re-curvature occurs with the system
(roughly west of Kauai and east of French Frigate Shoals).
For days 5-7, recommend using a blend of the 11/00Z GEFS/ECENS
means considering the deterministic 11/00Z GFS closely fit the
ECENS/GEFS solution and the system's entrainment in the
mid-latitude westerlies. The deterministic ECMWF would suggest the
system stalls invof 24N 163W on Tuesday and Wednesday.