5 Tornadoes across southeast Colorado - 4/27/2012
Early morning tornadoes like those that occurred on April 27, 2012 are rare in Colorado. The last recorded significant after midnight tornado in southeast Colorado occurred at 1:30 AM on April 30th, 1942 across Bent and Kiowa counties. The April 27th tornadoes were spawned by a strong storm system interacting with low level moisture which was pulled westward from the central plains into southeast Colorado by the approaching storm system. No matter what time of day, conditions can be right for powerful storms to develop.
Meteorologists from the National Weather Service in Pueblo surveyed the storm damage across southeast Colorado during Friday, April 28th. Preliminary findings indicate five tornadoes occurred; two in Prowers County, two in Kiowa County, and one in Bent County.
What lessons can be learned from this episode...
From interviews with government officials and the victims of the tornadoes...
1) People should have multiple ways to receive vital weather information.
2) People should stay informed with the latest weather information via NOAA All Hazards Weather Radio, local commercial radio and TV stations, and the NWS Pueblo web site. This episode was being advertised by the National Weather Service and the media a few days in advance. The timing of the severe weather was especially concerning, being around and after midnight.
3) We discovered that some people had their NOAA All Hazards Weather Radio receivers turned off during the episode. It is important to put your device in standy-by mode, so it will be able to alert and awaken you when a tornado or severe thunderstorm warning is issued by the National Weather Service.
4) Government officials can alert citizens of impending severe weather via a phone call. It is important to have a corded phone in your dwelling. Cordless phones that work with a base-station (which uses electricity) are vulnerable to power failures. If you have a base-station that has battery back up, the battery could potentially be bad, which would be a single point of failure for your cordless phone system. If you have a mobile device, make sure you register it with you local government, so your device is on the list to receive emergency weather calls.
5) Remember, sirens are OUTDOOR warning devices. There is no guarantee you will hear an outdoor warning siren in the middle of the night when you are asleep.
The National Weather Service in Pueblo is in the process of evaluating the services we provided to the people or Baca, Bent, Prowers, and Kiowa Counties the night of April 27th.
Estimated start time... 1:45 a.m.
Location... 4.4 miles east of McClave to 6 miles northeast of McClave (Bent County)
Estimated highest peak wind...125 mph (EF2)
Average path width... 200 yards
Path length... 6.2 miles
At its peak, the tornado was approximately 300 yards in width, causing low end EF2 damage. A dwelling and metal building were struck...causing extensive damage to the buildings and even driving part of a cornstalk into a wooden stump (see below)
Four metal power poles were taken down. The one below, in the direct path of the tornado, was bent at a 90 degree angle at its base...
The tornado moved north and did extensive damage to a ranch. Horses were tossed into corrals where they were not normally kept. A well-built metal barn sustained EF2 damage (possibly from a suction vortex rotating around the main circulation) while the residence only a few dozen feet away was virtually untouched.
Tornado # 2
Estimated start time... 1:50 a.m.
Location... 8 miles southwest of Lamar
Estimated highest peak wind...120 mph (EF2)
Average path width... 200 yards
Path length... 2 miles (difficult to determine due short grass and lack of structures and trees)
A hog farm was hit, with 18 hog barns completely destroyed. There were no hogs on the farm at the time. Below is an aerial image taken by Denver TV media helicopter of the hog barns that were destroyed. The large feed bins were scattered to the north-northwest for approximately 1/3 mile, with a small debris field more than one mile long.
Below is a typical hog barn...
Below is a hog barn southwest of Lamar after the tornado...
Below is a ground photo of the destroyed 18 hog barns...
Estimated start time... 1:58 a.m.
Location... 3.75 miles southeast to 9 miles northeast of Lamar
Estimated highest peak wind...120 mph (low end EF2)
Average path width... 100 yards
Path length... 21 miles (difficult to determine due lack of structures toward the end of the path)
Injuries...fatalities... 7 minor injuries
This tornado damaged or destroyed five dwellings. Two communications towers were toppled and a power substation was damaged near the beginning of the path...as seen below...
The tornado moved north-northeast and caused EF1 damage to this dwelling below. Two people suffered minor injuries.
The tornado moved north and damaged a house, and tossed a double-wide mobile home over 100 feet. There were five minor injuries. A motor home was also flipped and destroyed.
The tornado then moved north into Kiowa County and did EF1 damage to a ranch...
Paths of tornadoes 4 and 5
Estimated start time... 2:33 a.m.
Location... 1.5 miles south of Chivington to Chivington (Kiowa County)
Estimated highest peak wind...105 mph (high end EF1)
Average path width... 100 yards
Path length... 2 miles
Injuries...fatalities... 1 minor injury
This tornado hit a mobile home and a church.
Below is a photo of the mobile house...
Estimated start time... 2:40 a.m.
Location... 3 miles northeast of Chivington (Kiowa County)
Estimated highest peak wind...115 mph (low end EF2)
Average path width... 50 yards
Path length... 1 mile (difficult to determine due to short grass and lack of structures and trees)
A tornado struck an unoccupied mobile home and other ranch buildings. The mobile home had tie downs which were augered more than a foot into the ground. It was lofted approximately 30 feet, and bent around a truck. Below is a photo of the wreckage...including the severely bent frame of the mobile home.
Here is one auger and tie-down pulled out of the ground...
Below is the radar imagery of the line of supercell thunderstorms as seen from the Pueblo Doppler radar approaching the Lamar area at 149 AM. The supercell on the left struck the hog farm southwest of Lamar.
The doppler velocity imagery at the same time (below) shows two distinct circulations to the south of the Lamar. Bright green pixels (signifying strong winds flowing towards the radar) next to bright red pixels (signifying strong winds flowing away from the radar) indicates strong rotation in that area. One circulation center (or mesocyclone) was located approximately 7 miles south southwest of Lamar, while the newer broader rotation (or mesocyclone) signature was just starting to spin up to its southeast.
By 158 AM, these storms had moved to the north at around 50 mph and were located just to the east of Lamar. Reflectivity imagery below shows the strongest storm (in the red and white colors) to the east of the city of Lamar.
Dopper Velocity at this same time (shown below) shows a very tight circulation center (bright green to blue colors immediately adjacent to bright red to pink colors) just to the southeast of Lamar associated with the strong mesocyclone. It is at this time a tornado was reported to the National Weather Service by law envorcement 3.75 miles southeast of Lamar. Radar estimated 70 mph of inbound velocities immediately adjacent to 70 mph of outbound velocities.
At 238 AM, this same storm continued tracking to the north northeast to near Chivington (Kiowa County). Below is the reflectivity image of this storm.
Doppler velocity imagery (below) from the Pueblo radar continues to show a tight circulation center with this storm. More tornado damage was reported in the Chivington area.