Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
724 AM EST Wed Feb 15 2017

Valid 00Z Thu Feb 16 2017 - 00Z Thu Feb 23 2017

Quasi-zonal flow within the mid-latitudes will initially dominate
while a sprawling 588-dm mid-level ridge should dominate over the
island chain. Eventually the pattern is expected to amplify
although the strongest band of height falls will remain well north
of Hawai`i. However, this system will bring a shift in the winds
as a baroclinic zone sweeps through the region by Saturday as the
flow becomes more north-northeasterly over the weekend. Given the
modest pressure gradient setting up, expect breezy conditions to
prevail as 20 to 30 knot north-northeasterly winds persist. As the
surface anticyclone shifts eastward, the winds turn a bit more
north of east as a trade wind regime re-establishes its presence.
This should continue throughout the remainder of the forecast. In
terms of precipitation, the best chances will be with the passage
of a cold front over the weekend. Models agree on the coverage
being rather scattered given the best forcing remains well north
of the islands. Overall, the handling of this pattern has been
quite good across the board with only low-end scatter in the
ensemble spaghetti plots.


Rubin-Oster