Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
806 AM EDT Tue Mar 12 2019

Valid 00Z Wed Mar 13 2019 - 00Z Wed Mar 20 2019

Surface high pressure will be positioned north of the islands for
the remainder of the week and will be shifting eastward as a
trough passes to the north over the weekend. High pressure will
return to the north and west of Hawaii by Monday. A
mid/upper-level weakness evident across the eastern Hawaiian
Islands is forecast to slowly drift eastward through the next few
days. Shower activity will generally be sparse and the trade winds
are forecast to gradually weaken through midweek as the pressure
gradient across the region weakens.

A cold front will push southward over the state by Saturday
evening which will only result in a slight increase in shower
activity since the moisture associated with this system is
limited. Additionally, while the strongest height falls, cold
advection in the wake of the front should generally remain north
of the state, a period of gusty north to northwesterly winds is
likely. By Monday, a surface high should once again rebuild just
north of Hawaii with upper ridging west of Hawaii expanding east
across the state. This will bring a return to more typical
conditions and 10-20 kt trades. Subsidence associated with the
ridge will dry the air mass further, with PWs dropping well below
1 inch by early next week.


Campbell