Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
249 AM EST Wed Mar 02 2022

Valid 00Z Thu Mar 03 2022 - 00Z Thu Mar 10 2022

Latest models and ensembles continue to show an amplifying upper
trough moving through the main islands from about late Wednesday
through Thursday, accompanied by a surface trough along with low
pressure development northeast of the state.  The upper trough
should increase shower activity to some degree while consensus
maintains the idea that the best potential for some enhanced
totals will be over and near the Big Island as a pocket of greater
deep moisture approaches/arrives from the southeast in advance of
the upper trough.  Expect generally northerly low level winds
behind the surface trough/low pressure Thursday-Friday and then a
brief return to more typical but relatively light trades for the
weekend with weak high pressure to the north.  Most showers should
be on the light side given below average precipitable water
values.  Another amplifying shortwave and a leading surface front
should arrive from the west early next week, once again disrupting
trade flow and increasing rainfall.  Slower trend in the GFS over
the past day has narrowed the timing spread for the front but the
broader envelope of models and ensemble members would suggest
considerable uncertainty remains for specifics of the upper
trough, leading front, and associated rainfall.  At the very
least, the fact that this latter upper trough should amplify a
little farther west than its predecessor would offer potential for
somewhat higher rainfall totals than with the short-term system.

Rausch