Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
708 AM EST Sat Mar 10 2018

Valid 00Z Sun Mar 11 2018 - 00Z Sun Mar 18 2018

...Heavy rain likely next week...

With a 1040mb high near 40N/180 Saturday afternoon moving just
south of eastward, pressure gradient will keep trades brisk even
as the high weakens to about 1030mb by Tuesday afternoon. To the
south, sharpening mid-level energy and an associated weak surface
low or at least trough axis should lift northeastward just west of
or near Hawai'i. With precipitable water values about 1.75 inches
but perhaps nearing 2 inches (which is about +2 to +4 standard
deviations) moderate to heavy rainfall is likely for at least part
of the region next Tue-Fri. The GFS/ECMWF differ on the location
and amount of rainfall but ingredients will be in place. By next
Saturday, models/ensembles show another upper trough or closed low
near 25N/180 which should allow heights over Hawai'i to rise,
helping to diminish the heavy rain threat.


Fracasso