Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
810 AM EDT Wed May 09 2018

Valid 00Z Thu May 10 2018 - 00Z Thu May 17 2018

An amplified pattern will move across the central Pacific over the
next few days; however, models are still persistent that the
height falls will occur well north of Hawai'i. There is an
inverted trough centered over the island chain that will move over
the region by Thursday and linger through Saturday. This inverted
trough could bring an uptick in scattered showers but for now the
06Z GFS, 00Z ECMWF, and the 00Z CMC do not indicate a significant
or noticeable increase versus the typical showers driven by trade
winds. By Sunday, ridging will build back across the area. Winds
will initially be light and variable through the end of the work
week and strengthen by the weekend. The ECMWF seems to be most
aggressive with the increase of wind speed--showing a sustained 20
to 25 knots. The GFS and CMC are weaker with winds sustained at 10
to 15 knots. Given that all three models show an inverted trough,
tend to lean toward the ECMWF with wind speeds. As the ridge
builds in, winds are expected to slightly weaken. Scattered
showers will persevere throughout the week--with coverage reduced
by early next week as a consequence of the ridge.

Reinhart