Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 830 AM EDT Wed May 23 2018 Valid 00Z Thu May 24 2018 - 00Z Thu May 31 2018 Models and ensembles reasonably agree that subtropical ridging will shift over Hawaii as a surface high axis stretches east-west along 32-36N. This will maintain locally breezy trades that may increase Thu-Fri as the surface high bridges to the north of the state. With a relatively stable air mass and precipitable water values near average, expect generally light windward showers through the weekend. Guidance offers similar pattern evolution themes into early-mid next week, but now differ a bit more with advent and approach of an amplifying mid-upper level trough and surface frontal system to the northwest of the state. The latest ECMWF/UKMET dig this system more than the GFS/Canadian and that may be more reasonable considering the amplitude of the upstream ridge common to most guidance. Accordingly, slow system approach would lead to weakening/veering/moistening trades and wetter flow onset, but details remain uncertain given forecast spread. Schichtel