Spring 2011 Tornado Outbreak

Forecasters knew it was going to be a bad day when the Storm Prediction Center (SPC) forecasted the possibility of a  "high risk" severe weather day...to hear tornado sirens were screaming just after sunrise on April 26th, 2011. The National Weather Service (NWS) estimated there was a total of 312 tornadoes during the entire outbreak starting at 8:00 a.m. EDT April 26th to 8:00 a.m. April 28th, 2011.  During the 24-hour period alone, from April 27th to April 28th, the NWS estimated there were a total of 226 tornadoes (yes, this many is JUST 24-hours).
Considering the amount of tornadoes and the strength of theme over such a large area, just about 90% of them issued Tornado Warnings and Watches. The public was well aware of the unfolding events, even a day before it all unveiled. The people were educated and warned but they just could not outrun the wrath and strength of these tornadoes. Just think: if we today, did not have the technology and information from storms past imagine how many more fatalities there would have been? The fact that people know what tornadoes are, what their destruction could cause, and how to try to keep safe, is enough to say that Meteorologists are doing their jobs. 
This event was surpassed the record books! The largest previous number of tornadoes in one single event spawned 148 tornadoes in April 1974!
At least 344 people were killed throughout the entire April 2011 outbreak, and 334 fatalities in just the 24-hour people between the 27th to the 28th,  with thousands injured. This is the most people kill

• This is the most people killed by tornadoes in a two-day period since April 5-6, 1936, when 454 people were killed, mostly in Tupelo, Mississippi, and Gainesville, Georgia.

• This is the deadliest single day for tornadoes since the March 18, 1925, tornado outbreak that had 747 fatalities across 7 states (including the Tri-State Tornado). (NWS). 

I spoke to a friend and fellow Meteorologist earlier (Thursday May 2nd), and he told me of a Tweet from Jim Cantore's (of the Weather Channel) Twitter account: @JimCantore Jim Cantore

I just spoke with mayors office. 373 missing in Tuscaloosa county (Alabama). 323 are from the city of Tuscaloosa. This is STRICTLY missing persons.

Heats and prayers go out to all of those affected. 


All must be wondering: how did such a deadly outbreak come about?
I was looking at the weather maps a day or so before and I remember thinking that these maps were not showing a pretty station...I knew, we all knew it was going to be bad. The only thing was that we did not know it was going to be THIS bad...EF-5 tornadoes are extremely rare, and to have one of these completely threw us for a loop. I was watching the TV (The Weather Channel who had some incredible coverage) as well as streaming a few local Alabama new stations on my computer. When these Meteorologists (who thought they've seen it all) saw what was unfolding, their mouths dropped and you could see the tears building up but could not show the emotion because they knew the damage that was being done, but could not do anything about it. I felt the same way. I think I can safely say that we all did.

These storms were from a series of supercells (typically thunderstorms that rotate around a vertical axis. Such storms ofter produce severe weather at ground level including damaging winds, large hail and/or tornadoes.

Supercell Formation

 Most strong and violent tornadoes are produced by supercells) as part of a strong cold front that
was pushing through the area. The ingredients were perfect for a tornadic scenario to play out. The temperatures were very warm, Gulf moisture was being pumped in, and upper level jet streaks were sinking to the surface (thus creating the wind shear profiles). Referring to the video below, the cloud pattern showed evidence for severe weather to break. There is a pool of stable cool air (a stable airmass) along the North (you can see it as a swirl of clouds along the top of the image). While this pool of air was rotating, moist air from the Gulf and the Atlantic was being pushed north and west.

                                                                                                                           

This is where the 'collision' of the two air masses was located was enough energy to create severe weather. As you continue to watch, through the afternoon hours of the time lapse (peak daytime heating) you see the clouds over the southeast grow, almost explode, as the energy in this collision peaks, creating very strong storms. The last ingredient that really helped to stir the pot was the jet stream. It is difficult to see (and it move past rather quick, but if you rewind back to the 27th), you will see what looks like a narrow band of fast moving air/wind that blew from the north and east, between the two air masses: this was a split jet streak (this split is what allowed for tornadoes to and unsettled weather to occur all the way up to the mid-Atlantic and Plains states).

Split Jet Stream

The winds near the surface were blowing from south and east, and the jet stream was blowing from the west (you can close your eyes and see the different wind directions occurring!), creating quite powerful shear, or small-scale wind circulations, which helped to create these supercell storms form before the cold front boundary. The storms moved east and north with the jet stream guiding the way. The upper-level low was very slow to move allowed for storm-after-storm to affect the same area for a much longer time then typically as well as the assisting in the energy building to generate such strong and long lived storms/tornadoes.

The following images is what forecasters were looking for to warn the public that was in immanent danger. Meteorologists look for what looks like a hook in the RADAR imagery. This hook formation shows how the wind profiles change and creation of a vertical tornado vortex.

Long Track Tornadoes (Red Boxes)

Barrow County, AL

Typically, when looking at a RADAR image, the darker colors; red and yellows, mean the heavier the rain or hail. In this case, the bright colors are the aggregate signature of car parts, shredded tree branches, pieces of houses, dirt, and debris that has been sucked up thousands of feet into the sky by the tornado vortex. The blue circles in both images show the area of this specific tornado. The image below is the same RADAR and location. This RADAR is under a different lens; the storm base velocity. The colors in this image are mainly red and green (sometimes purple and white). This RADAR can detect certain storm characteristics such as tornado vortex signatures and the relative storm motion.

This image circled in blue, shows the location of the tornado in this area. The bright green within the red shows the divergence and strong updraft (inflow of air) occurring at the surface. If you refer to a few posts back, I listed an image that showed the components of and the inflow and outflow of air through a tornado. Most of the time, "debris balls" will form from out the tornadoes. Like mentioned before, debris can be picked up on the RADAR images. Debris from this tornado traveled nearly 20 miles (in the air) and fell outside of Tuscaloosa! Click this link to check out the 3-D base velocity of the Barnesville Tornado.

Storm Reports:

SPC Storm Reports 4/27/11

 There were 13 confirmed tornadoes through the southeast. The following are the stats of each:

Tornado 1 (Pickens County)                                  
Event Date: 4/27/11                                                
Event Type: EF-2 Tornado                                      
Est. Peak Winds(MPH): ~ 125                                
Injuries/Fatalities: Unknown                                      
Damage Path Length(miles): @ least 3                      
Width: .8 mile                                                          

Tornado 2 (Coaling Tornado, Tuscaloosa/Jefferson)
Event Date: 4.27/11
Event Type: EF-3 Tornado
Peak Winds: Up to 155
Injuries/Fatalities: Unknown
Damage Path: 18.3
Width: 200 yds.

Tornado 3 Cahaba Heights Tornado (Jefferson )        

Event Date: 4/27/11                                                    

Event Type: EF-2 Tornado                                          

Est. Peak Winds: Up to 120 mph                                

Injuries/Fatalities: Unknown                                         

Damage Path Length (miles): 7.9                                  

Width: 200 yds.                                                           

Tornado 4 Odenville Tornado (St.Clair County)
Event Date: 4/27/11
Event Type: EF-2
Est. Peak Winds: Up to 120
Injuries/Fatalities: Unknown
Damage Path Length (miles): 3.9
Width: 200 yds

Tornado 5  Hackleburg Tornado (Marion County)

Event Date: 4/27/11

Event Type: EF-5 Tornado

Est. Peak Winds: > 200 mph

Injuries/Fatalities: @ least 25+, many injuries

Damage Path (miles): 25.2

Tornado 6 Shotsville Tornado (Marion County)

Event Date: 4.27/11

Event Type: Potentially > EF-3

Est. Peak Winds: > 140 mph

Injuries/Fatalities: 6 and rising

Damage Path (miles): 19.1

Tornado 7 (Sumter/Pickens County)
Event Date: 4/27/11

Event Type: EF-3

Est. Peak Winds: ~ 140

Injuries/Fatalities: Unknown

Damage Path (miles): @ least 9

Tornado 8 Tuscaloosa/ Birmingham Tornado
Event Date: 4/27/11

Event Type: High End EF-4

Est. Peak Winds: @ least 165-200 mph

Injuries/Fatalities: @ least 65 rising

Damage Path (miles): 80.3 miles

Width: 1.5 miles

Tornado 9 Haleyville (Marion/Winston Counties)
Event Date: 4/27/11

Event Type: Potentially > EF-3

Est. Peak Winds: ~> 140 mph

Injuries/Fatalities: 

Damage Path (miles): 31.8

Tornado 10 Sawyerville/Eoline (Greene/Hale/Bibbs Counties)
Event Date: 4/27/11

Event Type: EF-3

Est. Peak Winds: ~ 145

Injuries/Fatalities: at least 7 fatalities +, many injured

Damage Path (miles): 71.3 

Width: 1 mile

Tornado 11 (Jefferson/St.Clair/Calhoun/Etowah/Cherokee Counties)
Event Date: 4/27/11

Event Type: Potentially > EF-3

Est. Peak Winds: ~ >180mph

Injuries/Fatalities: Numerous fatalities, many injured

Damage Path (miles): 72 

Width: up to 1.25 miles

Tornado 12 Wateroak Tornado (Hale/Bibb Counties)
Event Date: 4/27/11

Event Type: EF-1

Est. Peak Winds: ~ 105

Injuries/Fatalities: Many injured

Damage Path (miles): 5.5

Width: 150 yds.

Tornado 13 Lake Martin Tornado (Elmore/Tallapoosa/Chanbers Counties)
Event Date: 4/27/11

Event Type: Potentially > EF-3

Est. Peak Winds: ~ > 170 mph

Injuries/Fatalities: at least 9 fatalities +, many injured

Damage Path (miles): 44.1 miles

Width: 1/2 mile

NWS/NOAA Confirmed Tornado Track in Alabama

The listed storm reports above are from the southeast alone. There were dozens of other confirmed tornadoes   throughout the Plains, Mid-Atlantic, and extending up to New York.

Thank goodness for technology...all the lives that were saved (many more people could have perished if they were not told) and just the educational value now; we have so much information and footage of what happened as we can study, educate and save that many more lives now. It is such a tragedy that all those lives and all the destruction had to occur  in order for people to know the wrath of Mother Nature.
Just a note: May is the peak for the tornado season...hopefully his outbreak is not indicative of a very active season.

For more updated information, check the NWS website: www.nws.noaa.gov. 

More specifically: http://www.noaanews.noaa.gov/april_2011_tornado_information.html