What is the difference between a tornado and a hurricane?

Both tornadoes and hurricanes are characterized by extremely strong horizontal winds that swirl around their center and by a ring of strong upward motion surrounding downward motion in their center. In both tornadoes and hurricanes, the tangential wind speed far exceeds the speed of radial inflow or of vertical motion.

Hurricanes always and tornadoes usually rotate counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. The Earth's rotation determines this direction for the storms' rotation in each hemisphere. Local winds are sometimes able to cause a tornado to form that spins in the opposite direction from the typical direction for that hemisphere.

The most obvious difference between a tornado and hurricane is that a hurricane's horizontal scale is about a thousand times larger than a tornado. In addition, hurricanes and tornadoes form under different circumstances and have different impacts on the atmosphere.

Tornadoes are small-scale circulations, that are rarely more than a few hundred feet across when they touch the ground. Most tornadoes grow out of severe thunderstorms that develop in the high wind-shear environment of the United States Central Plains during spring and early summer.  Many tornadoes form when the large-scale wind flow leads to a violent clash between moist, warm air traveling north from the Gulf of Mexico and cold, dry, continental air coming from the United States Northwest. Tornadoes can also form in many other locations and from other forcing factors. For example, a hurricane making landfall may trigger many tornadoes to form.

Tornado wind speeds may reach 100 to 300 mph and cause havoc on the ground, but tornadoes typically last only a few minutes and rarely travel more than 10 or 20 miles along the ground. Tornadoes have little impact on storms that spawn them or collectively on the global circulation of the atmosphere.

Hurricanes, on the other hand, are large-scale circulations that are 60 to over 1,000 miles across. Hurricanes form near the Equator, generally between 5 and 20 degrees latitude, but never right on the Equator. Hurricanes always form over the warm waters of the tropical oceans and generally where the sea-surface temperature exceeds 26.5°C (76°F).

A hurricane may travel thousands of miles and persist over several days or weeks. During its lifetime, a hurricane will transport a significant amount of heat up from the ocean surface and into the upper troposphere or even lower stratosphere. Even though hurricanes form only sporadically, they do affect the global atmosphere's circulation in measurable ways, although this is still an active area of research.

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top image for Sahara 2024
Most people live in places where it rains much more often than it does in the Sahara Desert. For this reason, it can be challenging to make sense of news reports of major storms in the Sahara. NASA satellite data and rainfall statistics can give the needed context. Below is a discussion of three news stories about rainfall in or near the Sahara Desert during August and September 2024. These news stories described storm runoff, infrastructure damage, and the rain's impact on the ecosystems at the edge of the desert. Areas with significant impacts are shown in green in Figure 1. Figure 1. A map
Screenshot of IMERG rain rates on October 29, 2024
During the 10-day period from Oct. 26 through Nov. 4, 2024, parts of central-eastern and southern Spain saw unusually heavy flooding that resulted in heavy infrastructure damage and over 200 fatalities, according to the Associated Press. In this animation, NASA’s IMERG multi-satellite data product shows estimated rain rates (blue/yellow shading) and accumulations (green/purple shading) from the flooding rainfall. Cloudiness is also shown in white/gray shading, from geosynchronous infrared satellite observations. Download video (right-click -> "Save As") The flooding was caused by heavy
Map IMERG rainfall totals from Milton.
While the GPM Core Observatory’s instruments show exceptional detail in Milton’s rainfall structure in several overpasses throughout the week, the IMERG global multi-satellite product provides a broader overview of precipitation along Milton’s track as a continuous picture from development through landfall. Download this video (right-click -> "save as") The above animation shows IMERG precipitation rates (in blue/yellow shading) and accumulations (in green/purple shading) from Oct. 5-10, 2024. Cloudiness is shown in shades of white/gray using infrared geosynchronous satellite data. While
GPM data shows precipitation within Hurricane Milton over the Gulf of Mexico on Oct. 7, 2024.
Updated Oct. 10, 2024 Click here for a visualization of IMERG precipitations and totals from Hurricane Milton. After forming in the Bay of Campeche, Hurricane Milton underwent a remarkable period of rapid intensification with its central pressure falling from 1007 mb (29.74 inches of mercury, inHg) at 11:00 a.m. EDT Oct. 5 to 897 mb (26.49 inHg) at 8:00 p.m. EDT on Oct. 7. At this time Milton became the fifth most intense hurricane in the Atlantic Basin on record in terms of central pressure, just behind Hurricane Rita (2005) on that list, and only the sixth storm in the Atlantic to have a
Map of IMERG rainfall totals from Hurricane Helene.
After tracking through the eastern Gulf of Mexico and battering much of the west coast of Florida with strong winds and storm surge, Hurricane Helene made landfall in the Big Bend region of Florida’s northwest coast at 11:10 pm EDT about 10 miles west-southwest of Perry, Florida, as a powerful Category 4 hurricane with maximum sustained winds reported at 140 mph by the National Hurricane Center (NHC). Hurricane Idalia, a strong Category 3 storm at the time, also made landfall in the Big Bend last year. Animation of NASA IMERG precipitation rates and totals from Hurricane Helene from Sept. 23 -