Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 251 AM EST Fri Nov 13 2020 Valid 00Z Sat Nov 14 2020 - 00Z Sat Nov 21 2020 Today's guidance offers fairly similar ideas for the overall pattern evolution through the period though with some embedded detail uncertainties. From late this week through the weekend, high pressure north of the state on Friday will progress eastward while an upper weakness or low develops over the state. This evolution should favor some slackening of initially strong trades and support a moderate increase of moisture over/near the Big Island. As a result rainfall amounts may increase and there could be some land/sea breeze influence if background flow weakens sufficiently. After Sunday the upper weakness should gradually shear out/drift eastward while the surface pattern will favor a couple fronts dropping south toward the state. High pressure behind each front should help to maintain trade flow with a windward shower focus. There are timing differences for the first front expected to reach the islands around Tuesday-Wednesday with the 00Z ECMWF faster than the 00Z GFS. Interestingly the GFS is considerably slower than its run from 24 hours ago while the ECMWF has been more steady. Latest 00Z runs of both models suggest that the next front to approach from the north late in the week may not quite reach the islands. For most of next week the GEFS/ECMWF means show precipitable water values within a half standard deviation on either side of normal while the operational runs show some embedded pockets of greater or less moisture. Rausch