Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
826 AM EDT Tue May 08 2018

Valid 00Z Wed May 09 2018 - 00Z Wed May 16 2018

Flat mid-latitude flow will gradually give way to more notable
amplification across the central Pacific by Thursday/Friday.
However, models agree on such height falls remaining well north of
the Hawai`ian island chain. In the wake, broad ridging returns to
the region by Sunday into early next week given further
amplification in the higher latitudes.

At the surface, an anticyclone is expected to slide eastward in
time with related trade winds slowly slackening in strength by
later in the week. By early Friday, some of the guidance shows an
inverted trough extending across Kauai before flattening in
response to the approach of the next dome of high pressure. This
latter feature will ensure a re-strengthening of the trades by the
weekend with sustained winds approaching 20 to 25 knots at times.
Such strength should come down a bit into next week as the
synoptic pressure gradients begin to weaken. Overall, the regime
over the next 7 days will support trade driven showers,
particularly during the multiple spikes in tropospheric moisture
expected this week. Precipitable water values come down by Sunday
which should gradually reduce the coverage of showers.


Rubin-Oster