Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 729 AM EDT Mon Mar 21 2016 Valid 00Z Tue Mar 22 2016 - 00Z Tue Mar 29 2016 The 00z ECMWF and 06z GFS are in very good agreement with each other and their ensemble means, so both are considered useful this period. The 00z UKMET and 00z Canadian have progression issues with cyclones across the northern Pacific (with both outpacing the other guidance, including ensemble means), with the 00z Canadian becoming a strong outlier with an upper trough northeast of Hawai'i from Friday onward, which eventually distorts its surface pressure/wind patterns across the 50th state by Saturday. A frontal zone/shear line moving across the Papahanaumokuakea Marine National Monument on Thursday moves into the main islands by Friday and shifts eastward due to the upper trough northeast of the state thereafter, stalling close to the Big Island Friday afternoon into Monday. A large, deep cyclone moving across the western Pacific drags a cold front into the northwestern archipelago (west-northwest of Kauai) by late Wednesday. The result is a series of disruptions to the trade wind regime with enhanced moisture and rain chances (possibly heavy) between Tuesday and Friday near Kauai. It is unclear at this time how significantly the Big Island would be impacted by heavy rain this weekend, with the 00z ECMWF showing a greater chance of the occurrence than the 06z GFS. Stay tuned. Roth