Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 830 AM EDT Wed Aug 31 2016 Valid 00Z Thu Sep 01 2016 - 00Z Thu Sep 08 2016 ...A weakening Hurricane Madeline still a threat to clip the Big Island tonight... ...Major Hurricane Lester may impact the Hawai`ian islands by this weekend... A quick look at the infrared satellite imagery this morning showed two tropical cyclones generally moving westward toward the Hawai`ian island chain. The mid/upper-level pattern remains favorable for westward propagating features given the building heights over the mid-latitudes. First, Hurricane Madeline which has weakened quite a bit since yesterday since remains a threat to affect the Big Island during the next 24 to 36 hours. Given a track south of the island, the strongest winds and storm surge would be impact this region. Additionally, heavy rainfall is likely, particularly in regions of upslope trajectories. For more information on the latest forecast track of precipitation potential, please visit the Central National Hurricane Center and local Hawai`ian forecast office websites. Among the two tropical cyclones, Hurricane Lester definitely looks more impressive on satellite imagery given a pronounced eye structure. The National Hurricane Center has this system gradually lifting a little more northward come Friday with a rather expansive cone of uncertainty for the weekend. At this point in time, the southern end of this envelope encompasses the Big Island but the other extreme takes it north of the islands. The ATCF guidance shows this spread with a majority of the members generally within the center. Regardless, this system should continue to be monitored given the threat for damaging winds, dangerous storm surge, and heavy rainfall. Please visit the National Hurricane Center website for the latest track guidance. Rubin-Oster