Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EST Fri Nov 29 2019

Valid 00Z Sat Nov 30 2019 - 00Z Sat Dec 07 2019

Expect high pressure over the central Pacific to support strong
trade winds this weekend and into the start of next week.  This
high will weaken early next week but another high to its west will
build in and should maintain fairly brisk trades through at least
Thursday.  Late in the week spread gradually increases regarding
position/extent of the high.  The 00Z GEFS mean appears to be on
the extreme side of the envelope in terms of how much the
southwest side of the high gives way to lower pressures to the
west (ahead of an upper trough between 180-170W longitude).

Typically windward/mountain-focused showers may be enhanced for a
time during the weekend as a band of moisture associated with an
old front drops south over the state.  Guidance as a whole
suggests an increase of precipitable water values for the latter
half of next week but not to the degree of the GEFS mean, favoring
a compromise among remaining solutions as the best option.  Some
shower activity will likely continue through the week but heaviest
rainfall should remain to the south and west of the main islands
given that guidance shows the main islands themselves remaining
under or just east of the axis of a mean ridge aloft.

Rausch