Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 715 AM EST Sun Nov 04 2018 Valid 00Z Mon Nov 05 2018 - 00Z Mon Nov 12 2018 Initially moderate to brisk trades will weaken over the coming days as supporting eastern Pacific high pressure drifts to the northeast and a central Pacific front approaches. Enhancement to shower activity due to the proximity of a compact upper low to the eastern main islands should become less pronounced with time as the upper low lifts away to the north. Some shower activity (windward and/or sea breeze focus depending on exact strength of trades) will likely continue but with lighter amounts as somewhat drier air moves in from the east early in the week. Aside from the 00Z CMC and its ensembles, there is better clustering for the forecast evolution during the latter half of the week through the weekend. Latest ECMWF/GFS runs and their ensemble means along with the UKMET to a fair degree support an open upper trough whose progression is sufficient to bring the leading frontal boundary through the main islands during the weekend. This front and corresponding increase of deep moisture would yield a potential for a period of enhanced rainfall most likely in the late week/early weekend time frame. Based on the full range of guidance the 06Z GFS/00Z GEFS mean and 00Z ECMWF/ECMWF mean provide the most agreeable scenario for a specific forecast. The 00Z GFS and to a greater degree FV3 GFS offer faster progression of the upper trough and surface front. Even accounting for the faster progression the 00Z GFS seems to be on the light side with its rainfall along the front. History of guidance's handling of central Pacific flow over recent days tempers confidence so far in spite of the improved consensus. Another day or so with some stability in the guidance would certainly help to increase forecast confidence. Rausch