Beginning on April 25th, 2011 a multi day multi state tornado violent tornado outbreak would begin to impact portions of the Plains, Ohio Valley, Tennessee Valley and primarily the South. Over the course of 4 days, from April 25th, 2011 through April 28th, 2011, 358 tornadoes would be confirmed in 21 states.
The worst of the outbreak would begin to unfold on April 27th, 2011. The Storm Prediction Center had issued it’s rare high risk for portions of Mississippi, Alabama, Tennessee and Georgia. A moderate risk and slight risk was outlined for a large area stretching from Arkansas and portions of Florida all the way to the Miami Valley and even up into portions of New York.
A very powerful weather system developed and moved towards the Ohio and Tennessee Valley by the morning of April 27th. An unusually strong jet stream combined with the strength of this system and very warm and moist air out ahead of the system would lead to an unusually dangerous atmosphere, particularly across portions of the South.
A strong squall line with embedded tornadoes impacted a large portion of Alabama and Mississippi during the early morning hours of April 27th, 2011. This intense squall line left thousands of people without power and also knocked out power to numerous outdoor weather warning sirens in the area (this is why we believe so strongly in having multiple methods of receiving weather warnings). This line of storms also took out telephone lines and caused several NOAA weather radio transmitter sites to go offline.
As the squall line shifted out of the area by mid morning hours, the atmosphere had ample time to heat up and destabilize. By the mid afternoon hours, the atmosphere was a ticking time bomb across portions of Mississippi. Storms began developing as early as 2:00 PM and there was so much rotation and wind shear in the atmosphere, every storm began to rotate and take on a hook echo characteristic. You can see that visually by looking at this radar loop from later in the day as tornado producing storms moved towards Central Alabama.
By 3:00 PM CDT, the tornado outbreak was in full progress with a large damaging tornado, later rated an EF4, moving into the City of Cullman, Alabama. The tornado did extensive damage in Cullman, a city with nearly 20,000 people. The tornado in Cullman damaged 867 residences and 94 businesses! Here is a picture of the tornado as it moved into Cullman captured via local television outlet’s tower cam.
As if one large violent tornado hitting a large population center was not enough, the day would only get worse with a very long tracked and long lived supercell producing violent tornadoes in Tuscaloosa, Birmingham and tracking all the way into North Carolina. This violent supercell originated in Newton County, Mississippi at 2:54 PM CDT and traveled 380 miles before finally weakening in Macon County, North Carolina at 10:18 PM CDT. Here’s an amazing image with radar captures overlaid of the entire track of that intense supercell.
The National Weather Service Offices did an amazing job on April 27th, 2011 issuing hundreds of tornado and severe thunderstorm warnings stretching from New York all the way to the Gulf Coast. Here is a look at the most concentrated portion of the outbreak and the numerous warnings that were issued across portions of the South. Red boxes indicate tornado warnings, yellow severe thunderstorm warnings and green flash flood warnings.
The multi day tornado outbreak left 346 people dead, 325 of those deaths being caused by tornadoes. The April 27th tornado outbreak was really a worse case scenario with multiple large and violent, long lived tornadoes impacting large metropolitan areas.
Could another large tornado impact the Miami Valley or impact a large metropolitan area in Ohio? The answer to that is that it is absolutely possible. At some point in time, another large tornado will strike a metropolitan area in the Ohio Valley. That is why self preparedness is so important. We learned valuable lessons following the April 27th tornado outbreak, and one of the most important lessons was that all of us need multiple methods of receiving weather warnings. We can’t just rely on outdoor weather warning sirens, we can’t just rely on NOAA weather radios. A combination of multiple devices and methods to receive weather warnings is the best practice. If you don’t own a NOAA weather radio, they can be purchased at most retail stores and they can and do save lives!