Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
312 AM EST Wed Jan 06 2021

Valid 00Z Thu Jan 07 2021 - 00Z Thu Jan 14 2021

Upper ridging will remain over the island chain through early
Friday, promoting a rather quiet pattern. Trades will weaken again
Friday as the pressure gradient relaxes well ahead of a front to
the north. With precipitable water values between about 0.8-1.1
inches, light windward and mountain showers are forecast this
week. Ensembles indicate troughing dipping into the area Saturday,
associated with a surface front that will attempt to sink toward
the islands. Weak trades will turn northeasterly as the weakening
boundary passes, though it appears most of the moisture should
stay just east of Hawai'i. Precipitable water values may rise
slightly to about 1.2-1.3 inches over the weekend which may
enhance shower activity. By next week, another trough may approach
the region from the northwest Tue into next Wed. At the same time,
moisture may attempt to lift northward from the deep tropics just
east of the Big Island. For now, a model/ensemble consensus should
suffice, though the ECMWF ensembles generally have a more
amplified pattern from the Pacific eastward which may have more
credence given the ridge building into western North America. 

Fracasso