Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
735 AM EDT Sun May 01 2016

Valid 00Z Mon May 02 2016 - 00Z Mon May 09 2016

The 1 May/00Z forecast cycle maintains a very consistent approach
--- with a break (weakness) in the Subtropical Ridge developing
later Thursday and continuing into next Saturday (8/12Z) --- at
the very least.

The deterministic details still have a 'ways to go' with the
outcome along this 'break or weakness'--- and the 1/00Z ECMWF
appeared to be a less likely solution versus the Canadian and GFS
--- between 150W-160W longitude.

The solutions differ --- in the same regions of the Pacific (at
high latitude) --- not unlike previous model cycles. A temporary
'reshuffling' of the pattern has been set into motion --- with
some questions concerning a storm track shift in the Bering Sea.
So much so --- that by 7/12z (day6) --- the ECENS is briefly
out-of-phase with the NAEFS/GEFS and Canadian ensemble packages
along 170W longitude (along 50N).

Downstream, would think something closer to the 1/00Z
deterministic GFS/Canadian and their corresponding means look like
much better 'placeholders' for the east Pac and Gulf of Alaska.
For Hawai'i and the central subtropical Pacific, this depicts an
inverted trough axis and 'wavy' surface trough along 160W
(Canadian/GFS) days 6-7  --- rather than a deep cutoff low
scenario next weekend (the ECMWF solution is a good day faster
with its development).

The more likely outcome for days 6-7?--- a disruption of the trade
winds for next weekend due to the pronounced signal for weakness
in the entire Subtropical Ridge ---from west to east. And the
emergence of a cutoff at 500 mbs (around day8?)--- just not at the
'quicker pace' of the deterministic 1/00Z ECMWF.  

Vojtesak