Composites of (n = 44) Forbush decrease events over a t _±40 day period not coincident within a t _±7 day period of GLEs from 1983 to 1995 for: a) the CR flux (%), and b) cloud cover (%). The mean anomalies (solid black lines) are plotted together with the ±1.96 SEM values (blue dashed lines) for each of the t _±40 days of the composite. Based on PDFs of 10,000 MC simulations at each t value two-tailed confidence intervals are calculated at the p = 0.05 and p = 0.01 levels (dashed and dotted red lines respectively).