Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 801 AM EDT Mon Apr 11 2016 Valid 00Z Tue Apr 12 2016 - 00Z Tue Apr 19 2016 A closed high is forecast to build to the north and then northeast of the region as its surface reflection maintains/strengthens the trades midweek. Precipitable waters will mostly ebb and flow between 0.9 and 1.4 inches which suggests scattered light to isolated heavier showers in windward areas and possible leeward areas due to the stronger trades. Later this week into the weekend, ensembles show lowering heights over Hawai'i as a deep trough or upper low develops around 30N/145W. 00Z GFS/ECMWF/Canadian showed this well but the 06Z GFS was much quicker/weaker. Associated tail end of the surface front may push through the area next Sun-Mon with a backing and increase of the trades and a modest surge in PW values, but the ensembles are not yet sold on a scenario as strong as the 00Z GFS/ECMWF/Canadian. ECMWF ensembles were more amplified than the GEFS/CMC ensembles and generally favor their deeper solution. Fracasso