Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
730 AM EST Fri Nov 10 2017

Valid 00Z Sat Nov 11 2017 - 00Z Sat Nov 18 2017

Water vapor imagery loops shows an active southern stream upper
level trough/low to the northwest of the Hawaiian islands. Latest
GFS/ECMWF and their ensemble members cluster well over the next
week, bolstering forecast confidence. Guidance reasonably agrees
to track the southern stream feature generally eastward over the
weekend as lead weakened island trades increasingly advect
deepened moisture into the state in response to fuel some enhanced
showers. The trough/low is slated to dig southeastward toward/east
of the Big Island next week as an amplifying mid-upper level ridge
strongly builds over the north-central Pacific. This may allow
infusion of some northern stream energy into the lower latitude
system whose further digging and amplification acts to steadily
decrease moisture and showers over the state next week in the wake
of system passage. Strong high pressure building to the north of
the state next week in this pattern will meanwhile act to increase
island trades to moderate then brisk levels mid-late week, in a
pattern with only limited windward terrain precipitaion.

Schichtel