Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
244 AM EST Sat Mar 13 2021

Valid 00Z Sun Mar 14 2021 - 00Z Sun Mar 21 2021

Drier air will be moving through the state today even as a
lingering area of low pressure along the cold front wavers just
east of the Big Island. This may support some areas of modest
rainfall over Maui and Molokai per the 00Z CAMs. By Sunday through
next week, Pacific pattern will be driven by initially strong but
weakening upper ridging moving into the Bering Sea, forming the
middle part of an omega block configuration over the middle and
high latitudes. To its south, over the subtropics, weak troughing
will persist near/over Hawai'i but with a trend toward some
ridging by next weekend. Despite the frontal boundary hung up near
the region this week and area of low pressure, overall heavy
rainfall threat will be lower owing to drier air in the lowest
half of the atmosphere and lower precipitable water values
(1.0-1.5 inches vs over 1.5 inches earlier in the week). 7-day
totals per the guidance continue to vary but do show multi-inch
totals for some windward areas on breezy northeast trades
(disrupted early from the weak area of low pressure). Models
differ on how much moisture could return from the south later next
week (GFS more aggressive than the ECMWF), but for now would favor
a consensus/middle ground solution that may become clearer after
the short term front dissipates.

Fracasso