National Weather Service - Little Rock, Arkansas...Heavy Rain/Severe Weather on April 3-4, 2008 (Pg1)

	Excessive rain occurred during the latter half of March in northern and western Arkansas. Amounts were generally 200 to 500 percent of normal!
In the picture: Percent of normal rainfall during the last 14 days of March, 2008.

There was so much rain that extensive flooding occurred along area tributaries. As April began, flooding was ongoing along portions of the Black and lower White Rivers in eastern Arkansas.
In the picture: North of Newport (Jackson County), the winding Black River flooded surrounding farmland on 03/27/2008. Click to enlarge.

Link of Interest

More on the Flooding

Record Rainfall in March

There was much concern as this event began, with not only heavy rain expected...but also severe weather.

	The event began with a warm front moving north from the Gulf Coast region on the 3rd. The front was followed by above normal temperatures (in the 70s to near 80 degrees in central and southern Arkansas) and abundant moisture. There was plenty of fuel for developing thunderstorms.
In the picture: Temperatures warmed markedly during the afternoon of 04/03/2008 as a warm front lifted northward through Arkansas. By 4 pm CDT, temperatures in central and southern sections of the state were in the 70s to around 80 degrees.

In addition to an unstable atmosphere, isolated tornadoes were expected with winds turning with height. The tornadoes came to fruition.

In the picture: The weather pattern at 600 pm CDT on 04/03/2008. Helicity (representing the potential for rotating winds) was high (over 200 m2/s2) from Arkansas into the Ohio Valley, and CAPE (Convective Available Potential Energy...or a measure of instability) was ample enough (over 1500 J/kg) to support thunderstorm development. In addition, there was diffluence aloft (at 30,000 feet). Winds spread out overhead, which pulled in air from below (creating lift). Severe storms were most likely where areas of helicity, CAPE and diffluence overlapped.

	A large area of showers and thunderstorms developed near the stalled front in northern and western Arkansas during the evening of the 3rd. Out ahead of the precipitation, a lone supercell (storm with rotating updrafts) popped up in central sections of the state.
In the picture: The WSR-88D (Doppler Weather Radar) showed a lone supercell in central Arkansas at 910 pm CDT on 04/03/2008. The storm had no competition for available energy, which is often a dangerous scenario. In this case, the supercell became tornadic.

Rotation within the storm strengthened markedly as it approached Benton (Saline County) from the west. Extensive damage was reported from Benton to Hurricane Lake...or just northwest of Bryant (all in Saline County).
In the picture: The WSR-88D (Doppler Weather Radar) showed strong rotation to the west of Benton (Saline County) at 915 pm CDT on 04/03/2008. More specifically, strong inbound winds (green and blue colors) were adjacent (gate-to-gate) to strong outbound winds (red, yellow and purple colors).

Link of Interest