Springtime showers and thunderstorms dumped heavy rains over parts of
northwestern Arkansas and south central Missouri over the weekend.
Hardest hit was northwestern Arkansas where two children were swept
away by flood waters west of Huntsville, Arkansas. A stationary front
draped across central Arkansas from northern Texas to the Mid-Atlantic
region provided the focus for strong storms as southerly winds pumped
low-level moisture up from the Gulf of Mexico.
This image shows an instantaneous snapshot of the storms that led to the flooding taken by the Tropical Rainfall Measuring Mission (TRMM) satellite. The image was taken at 06:30 UTC on 24 April 2004. It shows the horizontal distribution of rain intensity as seen from above by the TRMM satellite. Rain rates in the center swath are from the TRMM Precipitation Radar (PR), the first and only precipitation radar in space, and rain rates in the outer swath are from the TRMM Microwave Imager (TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner VIRS).
TRMM shows three different mesoscale convective systems known as MCSs:
one over south central Texas, one over north central Texas and one along
the Oklahoma-Arkansas border. MCSs typically contain showers and/or
thundershowers along their leading edge that contain strong updrafts and
produce heavy rain (as seen by the red areas) followed by or adjacent to
areas of stratiform rain with weaker rainrates (green areas). The
southernmost MCS has a horseshoe type shape indicative of a mature MCS
whereby strong winds entering the rear of the system deform the storms
along the leading edge into a bow shape. Convection in the middle MCS
is more linear and very intense as shown by the dark red areas indicative
of a squall line. The third MCS that is farthest north has a broad area
of stratiform rain (green area) of moderate intensity centered on the
An additional image shows a vertical slice taken by the TRMM PR through the
central MCS looking east. It shows intense rainrates associated with the
leading edge convection. The leading edge is made up of many convective
elements as evidenced by the cellular nature of the intense echoes (dark
red areas) associated with the numerous protruding towers (green and
yellow areas extending vertically).
TRMM is a joint mission between NASA and the Japanese space agency JAXA.
Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang