Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
250 AM EST Tue Mar 01 2022

Valid 00Z Wed Mar 02 2022 - 00Z Wed Mar 09 2022

Light winds with some degree of surface troughing over the area
will continue to allow for some land/sea breeze influence on
shower activity into Wednesday.  Guidance is consistent in showing
an amplifying upper trough moving through the state from about
late Wednesday through Thursday, with some sharpening of the
surface trough and low pressure development northeast of the
state.  The upper trough should increase shower activity, with
latest guidance now signaling the best potential for enhanced
totals over and near the Big Island as a pocket of greater deep
moisture approaches/arrives from the southeast in advance of the
upper trough.  Today's models have converged for the forecast of
the upper trough/surface low northeast of the state after
Thursday, with sufficient northward progression to yield a day or
so of northerly low level winds late in the week followed by a
brief period of light trades during the weekend when a weak
surface high exists just to the north of the islands.  Guidance
continues to show the arrival of another amplifying shortwave and
leading surface front early next week, once again disrupting trade
flow and increasing rainfall.  Frontal timing and to what extent
showers are enhanced will depend on upper trough details whose
scale is too small to have good predictability several days out in
time.  For now an intermediate solution appears reasonable,
between the faster 00Z GFS (which would have an earlier return to
trade flow) and other guidance that is slower to varying degrees.

Rausch