April 13th, 2019 Hamilton and Greenwood, Mississippi Tornadoes

Hamilton and Greenwood, Mississippi Dangerous Nighttime Tornadoes

A single supercell thunderstorm produced two large and damaging tornadoes in the communities of Hamilton and Greenwood, Mississippi on Saturday night. These tornadoes were especially dangerous, due to the fact that they moved through the county around 11PM CDT on a Saturday night. The first tornado was rated a high-end EF-2 with winds estimated at 130 mph, and the second tornado was an EF-1. A total of 19 injuries were reported along with one fatality. The lone fatality was the result of a tree that fell on a trailer, killing the tenant. 

Synopsis: 

The Mid-South was under a Slight Risk (2/5) to Enhanced Risk (3/5) of severe thunderstorms for at least 3 days preceding the event. There was some uncertainty as to where severe storms would develop, but there was never a doubt that the ingredients necessary for severe weather were there. Around 7PM that evening, the Storm Prediction Center coordinated a Tornado Watch with our office. The tornado watch included a handful of counties in northeastern Mississippi, one of which was Monroe County, MS.

Meteorological Setup:

At the surface, a deepening low pressure system was located just west of Oxford, Mississippi with a warm front lifting into Monroe County around 10PM. The majority of the evening was rather quiet, with just a few strong storms in Chickasaw County around 1030PM. As the warm front continued to lift northward, a single supercell storm rode along the warm front. This storm first produced a tornado near Starkville, MS, or about 35 miles south of Monroe County. As the storm moved north, rotation had actually weakened and a tornado was no longer ongoing. However, the wind signature was still strong. As the storm moved into our warning area, a severe thunderstorm warning was issued around 1047PM and had the special wording of "Possible Tornado," as the storm showed slight signs of wrapping up again. The storm continued to move north into Monroe County with very little rotation evident on radar. 

About 15 minutes later, or 11:04PM, the storm started to show signs of converging motion, but rotation still appeared rather weak. By 11:06PM, the storm went from nearly no rotation to a very tight circulation. At 11:07PM, the correlation coefficient (CC product, Bottom left) showed a Tornado Debris Signature (TDS). This signature immediately verified that the tornado was now on the ground and doing lots of damage. At 11:09PM, a follow-up statement to the warning upgraded the warning to a confirmed damaging tornado with the wording, "This is a PARTICULARLY DANGEROUS SITUATION, TAKE COVER NOW!" The tornado continued northward into the town of Hamilton, wreaking havoc and lofting debris over 11.3 miles and nearly 20 minutes. The Tornado dissipated just to the east of the KGWX radar and the town of Quincy.

Around the same time as the other one dissipated, a second tornado from the same storm touched down north of Gattman, MS and traveled north northeast for approximately 13 miles before lifting. Another Tornado Debris Signature was observed with this tornado on radar. (Shown in lower left pane in image below) The tornado primarily damaged trees and a roof near the town of Splunge. No injuries or fatalities occurred with this tornado. 

Our office conducted a storm survey the following day and found damage with the first tornado to be consistent with up to 130 mph winds, or a strong EF-2 tornado. The second tornado that was surveyed, was found to have caused damage in the EF-1 range or 95 mph. 

Radar loop of both tornadoes as they moved north northeast through Monroe County between 11:00 and 11:45 PM CDT. Tornado Debris Signature can be seen in lower left panel, shown as a blue dot.