Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
814 AM EDT Wed Aug 29 2018

Valid 00Z Thu Aug 30 2018 - 00Z Thu Sep 06 2018

Hawaii should gradually begin to dry out today as the moisture
plume to the east of Tropical Depression Lane shifts westward away
from the islands, and a drier air mass overspreads the region from
the north. Models/ensembles show broad agreement that a large and
expansive upper ridge initially centered over the Pacific Ocean
well north of Hawaii will begin to quickly break down late this
week through the weekend, allowing an upper level low to drift
westward in the general direction of Hawaii. While low-level
easterlies of 20-25 kt will persist into late week, the
approaching upper low will disrupt the trades by this weekend,
with generally light and variable winds expected. A gradual
increase in moisture and convective instability will accompany the
upper low, thus would expect a gradual increase in shower activity
by early next week, which may affect areas beyond the typical
windward locations due to the lack of trades in the vicinity of
the low. By the middle of next week model consensus suggests that
the upper low may weaken as some of the energy gets absorbed into
an amplifying upper trough over the north central Pacific,
bringing a gradual resumption of the trades across Hawaii.

The latest model guidance consensus along with the official
forecast track from the National Hurricane Center is for Tropical
Storm Miriam to remain well east of the Hawaiian Islands as it
turns northward near 140W later this week.

Ryan