Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 720 AM EST Wed Nov 06 2019 Valid 00Z Thu Nov 07 2019 - 00Z Thu Nov 14 2019 With the passage of a front supported by departing dynamics aloft, expect weak high pressure to the northwest of the islands to support mostly northeast winds through Thursday while generally light showers will favor windward/mountain locales. Then dissipation of the high as a front approaches from the northwest should weaken background flow and allow for more land/sea breeze influence. Today there is better agreement that the upper trough whose southern periphery will pass over the islands during the weekend will be progressive enough during that time frame for any flow separation to occur northeast of the islands. There are still a few ensemble members and show this happening farther west than the main cluster of models/means but there has been a definite trimming away of the western part of the prior day's envelope. The one difference of note is that the 00-06Z GFS and 00Z GEFS mean/UKMET are more amplified with the upper trough than the ECMWF/CMC and their ensemble means. Thus would favor a compromise at least halfway toward the ECMWF cluster for the upper trough and associated frontal position. Likewise anticipate some increase in moisture/rainfall with the front but perhaps not quite to the extent seen in the GFS. Weak high pressure behind the weekend/early week front may be sufficient to re-establish at least modest trade flow for at least a portion of the early-mid week period. GEFS/ECMWF means have been fairly consistent in depicting a moderate drying trend with precipitable water values settling in the 1.25-1.50 inch range. The 00Z ECMWF is in this neighborhood but with different details, while the latest GFS runs keep more moisture over the main islands. Preference would lean to the majority cluster. Another front should begin to approach from the northwest by next Wednesday. Rausch