\label{fig:ciMon} Same as Fig. \ref{fig:prMon} except for convective instability (CI) measured by near surface moist static energy ($h_s$) minus 700hPa saturated moist static energy ($h^{*}_{700hPa}$),  i.e. $h_s - h^{*}_{700hPa}$.  Only grids significant at the level 0.05 of the two-side Student's t-test are shaded.