From the National Weather Service this is the Mokulele Airlines look at the extended forecast for the Hawaiian Islands:
Today's guidance maintains good continuity with the general pattern during the period. For the first half of the week there will be very moist southeasterly flow over the state, between a deep-layer ridge to the north/northeast of the area and a trough off to the west. As has been the case in recent days there is good agreement on the potential for heavy rainfall over the windward portions of the Big Island. However differences still exist for the magnitude of rainfall totals over the northwestern islands with the GFS again heaviest. An intermediate solution appears most reasonable as the mass field discrepancies seen 24 hours ago have dampened out but the GFS still brings slightly higher precipitable water values to the northwestern islands versus other guidance. Meanwhile the UKMET implies potential for meaningful rainfall to reach a little farther east than the ECMWF/CMC--plus the 00Z ECMWF trended wetter than the prior run. From Thursday onward anticipate lighter rainfall and a continued primary focus over windward areas. Near to slightly below normal precipitable water values will settle into the area through early next week while an upper ridge to the north will drop down closer to the islands before weakening. At the same time orientation of surface high pressure will adjust trades back to a more easterly direction while the gradient will be sufficient to maintain fairly brisk wind speeds.