Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
724 AM EST Fri Dec 09 2016

Valid 00Z Sat Dec 10 2016 - 00Z Sat Dec 17 2016

Troughing to the northwest of the region will sustain a few more
days of showery conditions with some embedded heaver amounts.
Southerly flow will veer to northwesterly as a cold front pushes
into the region early next week. Blend of the recent GFS/ECMWF
should suffice. As that upper trough and sfc front pull away from
Hawai'i, weak ridging and drier conditions are forecast to
overspread the area on Wednesday/Thursday. Trades will become
southeasterly next Thursday into Friday as the ensembles show
strongly digging heights along 165W and an increasing probability
of a closed low. This could potentially set up another heavy
rainfall pattern for the 50th state, though some differences in
the GFS/ECMWF ensembles are evident -- the former were
deeper/slower than the latter though the 00Z deterministic ECMWF
was slower than its ensemble mean and closer to the 00Z GFS/GEFS
mean. GEFS mean QPF from an M-climate perspective shows values
above the 99.5 percentile next Friday, meaning it is quite unusual
for the GEFS mean to be this wet at this lead time this time of
year.


Fracasso