Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
620 AM EST Wed Jan 30 2019

Valid 00Z Thu Jan 31 2019 - 00Z Thu Feb 07 2019

An upper low initially now just east of the state near 21N 151
will reflect as low pressure/inverted troughing at the surface.
The gradient between this feature and high pressure to the
northwest will generate brisk to strong northerly to northeasterly
winds over the islands through Thursday. By Friday the upper low
will shear out. Increasing dominance of high pressure to the north
should promote more easterly trades by the weekend and early next
week as the strong supporting surface high pressure center
gradually shifts eastward and upper ridging builds over the state.
Moisture rotating around the upper low east of the state will
bring areas of generally light to moderate rainfall with a focus
over north/northeast-facing terrain through mid-late week. By the
weekend and early next week showers will likely focus over
eastward-facing locales. In this pattern, recent ECMWF runs bring
a bit more late week central Pacific shortwave energy southward
across the islands aloft during the weekend versus overall
guidance consensus that is somewhat farther east, but the latest
model and ensemble trend is more toward the ECMWF idea. This would
lead to more of a temporary disruption in trades and a few more
showers.

Schichtel