Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
820 AM EDT Sun Apr 07 2019

Valid 00Z Mon Apr 08 2019 - 00Z Mon Apr 15 2019

A cold front currently nearing Kauai will stall and dissipate over
the next few days as precipitable water values increase to
1.20-1.40 inches. Mainly light showers are expected area-wide with
embedded moderate amounts. Trades will increase Monday as high
pressure moves eastward to the north of the state and strengthens
to near 1040mb late Tue near 38N/140W (very strong for this time
of year -- about +2.5 stnd dev). Concurrently, models and
ensembles show an upper low developing to the east of the area
(east of 150W) that is forecast to retrograde westward as upper
ridging bridges over the upper low from the Dateline in the
tropics to the mid-latitudes. Ensembles are well-clustered aloft
but differ on 1) how much moisture to wrap back into the area from
the deep tropics and 2) if the closed low will continue westward
or stall over the eastern islands. Expect an increase in rainfall
to at least the Big Island and Maui around Saturday that may push
westward next Sunday. This may pose a heavy rain threat for parts
of the islands.


Fracasso