Hawaii Extended Forecast Discussion NWS Weather Prediction Center College Park MD 238 AM EST Fri Jan 10 2020 Valid 00Z Sat Jan 11 2020 - 00Z Sat Jan 18 2020 ...Wet pattern for Hawaii... Latest models and ensembles support periods of heavier rainfall over the state through the weekend into next week. This is as an upper trough/low now just to the east of the area shifts westward over the region underneath a blocking upper ridge settled to the north of the islands. During the weekend this upper low energy should combine with a shortwave approaching from the west to yield a better defined upper low west of the main islands that may then track northwest/north. Recent GFS/GEFS runs have been somewhat stronger with this re-developing upper low versus most other guidance, but differences are now smaller than prior days to bolster forecast confidence with the overall pattern. System amplitude and slow progression would hold an axis of high precipitable water values over the islands for multiple days offers the potential for periods of heavy rain into early next week and Flash Flood watches have been issued for favored areas of the islands. Temperatures are cold enough aloft to also support winter weather advisories for Mauna Loa and Mauna Kea. Meanwhile east-central Pacific high pressure will support brisk trades during the next few days, with a gradual trend from easterly to southeasterly in response to surface troughing/low pressure to the west and northwest of the state. Some wind and small craft advisories along with some high surf and offshore gale warnings have also already been issued for portions of the islands and maritime interests. Please refer to updated information from NWS WFO Honolulu for these hazards. Weakening of the east-central Pacific high and a front coming into the picture off to the northwest should allow for trades to slacken into later next week, but frontal approach may support renewed lead moisture surge northward into the state heading into next weekend. Schichtel