Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 834 AM EDT Thu Sep 27 2018 Valid 00Z Fri Sep 28 2018 - 00Z Fri Oct 05 2018 The tail end of a baroclinic zone and associated per-frontal trough were noted just to the north of Kauai fostering the development of northeastward progressing showers; which is forecast to increase in coverage and intensity as the frontal zone progresses closer to Kauai and Oahu. Precipitable water values of 2 to 2.25 inch over the region will increase the possibility for periods of heavy rain as this will be 1 to 2 standard deviations above average for late September. Surface high pressure will build over the region to the north and reduce the coverage of precipitation. The Central Pacific Hurricane Center is currently advertising a 70 percent chance for tropical cyclone development during the next 5 days. While impacts would stay well south of the island chain, enhanced trades are expected with sustained winds in the 15 to 20 knot range. Into early next week, a mid-latitude longwave trough crossing the International Dateline will lift up this wave with a position well west of Hawai`i. From Friday onward, conditions should be much drier except for some scattered trade driven shower activity. Model guidance suggests the next cold front approaches the northern islands but any precipitation would arrive shortly after. Campbell/Rubin-Oster