Why do tornadoes have such high wind speeds? Tornadoes are devastating, mainly because of their potential to produce high wind speeds.
While some tornadoes can only be about 40mph, some exceed 300mph. And the extent of damage depends directly on the speed they achieve.
But, the question is, “how are tornadoes spun up to such high wind speeds?”
Tornadoes have high wind speeds due to warm and humid air merging with colder and drier air, leading to robust updrafts and vigorous rotation inside the funnel.
What is the Average Wind Speed Inside a Tornado?
Before answering the question, “What causes the high wind speeds associated with tornadoes?” it is important to learn about their average wind speed.
Here is a bit more about it:
| Scale | Description | Speed |
| F5 | Incredible Tornado | 261mph to 318mph |
| F4 | Devastating Tornado | 207mph to 260mph |
| F3 | Severe Tornado | 158mph to 2026mph |
| F2 | Significant Tornado | 113mph to 157mph |
| F1 | Moderate Tornado | 73mph to 112mph |
| F0 | Gale Tornado | 40mph to 72mph |
How Do You Measure Tornado Wind Speeds?
Many different techniques are used to measure the wind speed in a tornado, and the highest recorded by Doppler Radar was 135m/s.
Here are some more details about the event:
| Date | 3/5/1999 |
| Record Value | 135 m/s |
| Geospatial location | Bridge Creek |
| Length of record | Since 1996 |
| Elevation | 1365ft |
Doppler on Wheels, a mobile radar system like the one used by the University of Oklahoma, has successfully detected tornado wind speeds reaching approximately 302 mph above the Earth’s surface.
An Important Consideration
Be aware that this wind speed measurement is not considered the fastest “recorded” speed.
It is mainly because the winds are not directly measured by instruments but instead calculated using computerized Doppler wind algorithms.
Why Do Tornadoes Have Such High Wind Speeds?
Tornadoes rank among the most formidable natural occurrences on our planet.
They possess the ability to produce awe-inspiring gusts of wind at astonishing velocities.
Scientists and the general public have always been fascinated by the extraordinary speed displayed by tornadoes.
Here are some factors contributing to tornadoes achieving high wind speeds:
Wind Shear
Wind shear plays a crucial role in the creation and progression of tornadoes, making it an essential meteorological element.
The diversity in wind velocity and orientation at different altitudes fosters the ideal conditions for the development of tornadoes.
In areas characterized by robust wind shear, the amplification of horizontal air rotation in the lower atmosphere occurs.
How Does It Work?
When wind shear generates rotational energy, its interaction with updrafts and downdrafts within a thunderstorm can lead to the vertical stretching and intensification of this energy.
The formation of a mesocyclone occurs as a result of this procedure, which gives rise to a rotating updraft spanning several miles in diameter.
The mesocyclone plays a vital role in the formation of tornadoes.
Wind shear is a crucial factor that enables the mesocyclone to sustain its rotation, creating the swirling column of air commonly linked with tornadoes.
The Connection between the Wind Shear and Wind Speed
Numerous research studies have presented compelling evidence regarding the correlation between wind shear and the intensity of tornadoes.
A study revealed a significant connection between wind shear and the intensity of tornadoes.
The research indicated that tornadoes with increased wind shear values had a higher probability of generating stronger winds and resulting in more substantial destruction.
An Example to Consider
The United States’ Great Plains, commonly known as Tornado Alley, encounters a distinct blend of weather conditions promoting tornadoes’ development.
An environment abundant in wind shear is formed by the collision of warm, moist air originating from the Gulf of Mexico and cool, dry air originating from the Rocky Mountains.
Fact: As per the National Oceanic and Atmospheric Administration (NOAA), Tornado Alley encounters a significant number of tornadoes because of the advantageous wind shear conditions.
Supercell Thunderstorms
Tornadoes primarily arise from supercell thunderstorms, which are easily recognizable due to their unique structure and defining features.
Supercells are thunderstorms that showcase a continuous rotating updraft and possess remarkable longevity and exceptional organization.
Storms of this nature often manifest in regions distinguished by:
- Intense wind shear
- Ample moisture
- Atmospheric instability
The Connection with the Mesocyclone
The mesocyclone, a rotating updraft within a supercell, creates an ideal environment for forming tornadoes.
When the storm pulls in warm, humid air and quickly pushes it upwards, it comes across the rotating mesocyclone.
The interplay between the updraft and the mesocyclone amplifies the rotation, resulting in the conversion of energy from the surroundings into the forming tornado.
In a research conducted by Brooks and Doswell (2001), an examination was carried out on tornado environments in the United States.
The study revealed a robust correlation between supercells and noteworthy tornadoes.
According to the research, it was emphasized that almost 95% of tornadoes categorized as EF2 or above were generated by supercell thunderstorms.
An Example to Consider
A prime example of supercell thunderstorms is the well-known tornado outbreak that took place on April 27, 2011, in the southeastern region of the United States.
The occurrence of this outbreak led to the formation of 358 tornadoes, causing substantial destruction and loss of human lives.
The occurrence emphasized the strength and devastating potential of supercell thunderstorms and the tornadoes they produce.
Rear-Flank Downdraft
The intensification of tornadoes is significantly influenced by the rear-flank downdraft (RFD) within a supercell thunderstorm.
The RFD is a section of cooler air that descends at the back of the supercell storm.
It is positioned on the opposite side of the forward flank, which is where the primary updraft occurs.
The connection between the RFD and the updraft is a crucial phenomenon referred to as the “tornado cyclone interaction.”
The Concept of Occlusion
The descending movement of the RFD and its interaction with the updraft results in the tightening and acceleration of the rotating mesocyclone within the supercell.
The tightening process is commonly known as “occlusion,” wherein the RFD envelops the mesocyclone, resulting in a more condensed and focused rotation zone.
Consequently, the mesocyclone’s rotational velocity escalates, resulting in the formation and strengthening of the tornado.
What Does the Research Say?
Research has yielded valuable findings regarding the influence of RFD on the intensity of tornadoes and the velocity of winds.
As an example, research conducted by Wurman et al. (2007) explored the characteristics of tornadoes and the accompanying mesocyclones.
They did it by utilizing cutting-edge radar and sensor technologies.
The study emphasized that tornadoes with more powerful RFDs demonstrated increased rotational velocities and stronger winds.
An Example to Consider
One instance that demonstrates the impact of the RFD on tornado development is the El Reno tornado, which took place on May 31, 2013, in Oklahoma, United States.
The tornado was incredibly massive and destructive, measuring a maximum width of 2.6 miles and estimated wind speeds exceeding 295 mph.
The examination of this tornado incident unveiled the existence of a formidable RFD that played a role in the escalation and expansion of the tornado.
Fact: Having a strong Rear Flank Downdraft (RFD) within a supercell thunderstorm is a vital factor in amplifying the wind velocities witnessed in tornadoes.
Low Level Jet
A low-level jet (LLJ) is a common meteorological phenomenon that plays a role in the development of tornadoes, especially during nighttime and early morning periods.
LLJs are powerful, slender streams of air that manifest in the lower atmosphere, typically found at altitudes ranging from 1,000 to 3,000 feet above the Earth’s surface.
The jets transport a plentiful amount of warm, damp air from the Gulf of Mexico and various other moisture sources.
They supply the essential ingredients for the formation of intense thunderstorms.
The LLJ amplifies the wind shear near a storm, raising the likelihood of tornado development and the resulting intense wind speeds.
Convective Available Potential Energy (CAPE)
CAPE plays a crucial role in the formation and strength of tornadoes, making it an essential meteorological factor.
CAPE quantifies the quantity of energy accessible for the formation of convection and storm activity in the atmosphere.
Elevated CAPE values suggest a significant possibility of robust updrafts within thunderstorms, which play a crucial role in the development of tornadoes.
Fact: The storm that generated the Joplin tornado had an exceptionally elevated CAPE value, suggesting the existence of substantial energy ready for convection.
Takeaway
Why do tornadoes have such high wind speeds? Tornadoes exhibit exceptionally strong wind velocities as a result of a convergence of various elements.
The meeting of heated, damp air and cooler, arid air generates an unsteady atmosphere, resulting in the development of formidable updrafts.
Comprehending the intricate mechanisms that contribute to the creation of tornadoes and their remarkable velocity is essential in order to anticipate and alleviate their destructive consequences.
