Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
809 AM EDT Mon Jul 14 2014
Valid 00Z Tue Jul 15 2014 - 00Z Tue Jul 22 2014
Through Tue expect a band of enhanced deep moisture to continue
drifting westward across the islands, bringing locally heavier
rainfall that should be best focused over windward terrain.
Heights aloft are still forecast to be fairly high which could
temper coverage of heaviest activity slightly. There will be a
drying trend after Tue, though perhaps to a lesser extent for a
time near the Big Island, while a deep layer ridge settling to the
northeast/north of the region will support moderate trades.
A weakness aloft will pass over the islands late this week. Once
the axis of this feature reaches just west of the state, guidance
has been indicating another surge of higher PW values and
potential for increased rainfall coverage/intensity by around
Sun-Mon. There is still a fair amount of model and ensemble
spread regarding the timing of this moisture and max PW values,
though at least among latest GFS/ECMWF runs there is less of a
timing difference than yesterday. Would prefer an average of
latest guidance based on typical model error 6-7 days out in time
and the current envelope of solutions.