Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 726 AM EST Mon Nov 09 2015 Valid 00Z Tue Nov 10 2015 - 00Z Tue Nov 17 2015 The 9/00Z forecast cycle maintains a consistent forecast across the central and subtropical Pacific---including Hawai'i. A persistence-type forecast (for precipitation and wind speeds) remains a constant --- through a good portion of the work week. A strong ridge of high pressure in the central and east central Pacific should remain anchored between 30N and 40N --- and weaken slightly as the the weather forecast moves into next weekend. Anticipate a steady east-northeast tradewind flow and occasional strong gusts. The deterministic guidance continues with the idea that an acceleration of the Subtropical Jet over Hawai'i is in the offing --- and spreading downstream into the Mainland (along the southern California coast). This upper-level feature may end up generating more mid-level cloud cover and increase the areal coverage of precipitation for the highest elevations. based on the ECMWF solution --- this westerly jet-level air stream will 'max out" in the 100kt-110kt range --- next weekend. For the extended medium range day 6-7 (and beyond), a distinct split-flow pattern emerges downstream over the Mainland, with Hawai'i settled beneath an expanding Subtropical Jet axis and broad ridging building into the forecast area from the west and northwest. An active Polar Jet Stream remains over the mid-latitude Pacific along 45N-50N. The 9/00Z ECENS/GEFS ensembles continue to grapple with the amplitude of the wave pattern along 140W with the first Arctic outbreak of the season spreading southward across the northeast Pacific. A 70/30 blend of these two respective ensemble means --- would cover the differences downstream and north of the Islands Vojtesak