The Eulerian and Lagrangian correlation structures of 13 convective ra
instorms were investigated using rainfall data from the 1987 Convectiv
e Initiation Downburst Experiment in Denver, Colorado. One minute rain
fall data were available for two superposed raingage networks: 46 rain
gages on the portable automated mesonet (PAM) network at a mean spacin
g of 10.6 km and 31 additional raingages on the Federal Aviation Admin
istration Lincoln Laboratory Operational Weather Studies (FLOWS) netwo
rk at a mean spacing of 2.4 km. Eulerian correlation coefficients are
low and often negative for high-resolution 1 min rainfall data. Correl
ation increases with time-averaging, beyond 10-15 min for single rain
cells on the FLOWS network and small-mesoscale rainstorms on the PAM n
etwork. The average speed of rain cells and small-mesoscale rainstorms
was found to be 76.5 and 56.4 km hr(-1), respectively. Storm kinemati
c is identified as the cause of data scatter and low Eulerian correlat
ions, Convective rainstorms are essentially uncorrelated in the Euleri
an reference frame at a typical raingage spacing of 2-3 km for rain ce
lls and 10-15 km for small mesoscale rainstorms. A spatial cross-corre
lation analysis in a Lagrangian reference frame moving with the center
of mass of the storm separates the kinematic component from the struc
tural component of a rainfall field. The spatial cross correlations in
the Lagrangian rainfall field show considerable improvement over the
Eulerian spatial correlation plots, and data scatter is greatly reduce
d. The increase in correlation coefficients from Eulerian to Lagrangia
n reference frames typically ranged from 0.5 to 1.1.