Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 716 AM EST Wed Jan 10 2018 Valid 00Z Thu Jan 11 2018 - 00Z Thu Jan 18 2018 Model and ensemble guidance remains fairly stable with respect to the forecast through the next seven days. A cold front initially approaching Kauai will stall and weaken to a mere trough over the next couple days. This front may be accompanied by areas of mostly light rainfall. As the sharpening upper shortwave supporting this front crosses the islands over the next two days and interacts with a weak upper feature already near the Big Island, expect an increase in moisture/rainfall in the vicinity of the Big Island through about Thursday night. Eastward progression of the shortwave will lead to a drier trend Friday into the weekend. From now into the weekend any shower activity will likely have a greater than average dependence on sea/land breeze effects given the surface trough over the islands the next couple days and a weak ridge taking its place into the weekend. A weak and relatively dry front approaching from the northwest early in the weekend may just barely reach the northwestern islands before an upper ridge building east-northeast toward/across the state helps to push it back to the northeast. Model/ensemble consensus shows the surface ridge gradually strengthening with a farther north axis by next Monday-Wednesday, leading to more typical trade flow and windward focus for showers. At the moment there is a fairly good signal that trades may strengthen further around next Wednesday or shortly thereafter as a stronger high builds across the central Pacific. Rausch