Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
322 AM EST Sun Dec 18 2022

Valid 00Z Mon Dec 19 2022 - 00Z Mon Dec 26 2022

An anomalous closed upper low, with a sub 990-mb surface low,
develops by Sunday evening near 35 degrees north, and drifts
farther southeastward to near 30 degrees north on Monday, with a
well defined cold front passing through the entire state by
Tuesday morning.  Light and variable winds on Sunday morning will
increase from south to southwest ahead of the front going into
Sunday night, perhaps gusting over 40 mph at times with gale force
winds over the coastal waters.  These winds will then veer to the
west and northwest once the front moves through, and will continue
to be quite breezy through Tuesday night before abating and
becoming more variable going into the middle of the week.

There will also be a surge of deep tropical moisture northward
ahead of the front starting Sunday night and lasting through early
Tuesday morning, with the potential for 3-6 inches of rainfall
with locally higher totals across the central and southern
Islands, and the risk of flooding will be present across
vulnerable areas.  This low pressure system then lifts northward
by midweek, with a weak surface high trying to build in across the
Islands by the end of the week and into the weekend, with drier
conditions for most locations except for terrain enhanced showers
across the Big Island as a more typical trade wind pattern tries
to return by the end of the week.
 
Hamrick