What is the difference between a tornado and a hurricane?

Tornadoes and hurricanes appear to be similar in their general structure. Both are characterized by extremely strong horizontal winds swirling around the center, strong upward motion dominating the circulation with some downward motion in the center. The tangential winds far exceed the radial inflow or the vertical motion, and can cause much damage. Hurricanes always rotate counterclockwise in the northern hemisphere (clockwise in the southern), the direction of their rotation being determined by the Earth's rotation. This is almost always true of tornadoes too, although on rare occasions "anticyclonic" tornadoes spinning in the opposite direction do occur (tornadic circulation is determined by the local winds). This is where the similarities end.

The most obvious difference between tornadoes and hurricanes is that they have drastically different scales. They form under different circumstances and have different impacts on the environment. Tornadoes are "small-scale circulations", the largest observed horizontal dimensions in the most severe cases being on the order of 1 to 1.5 miles. They most often form in association with severe thunderstorms which develop in the high wind-shear environment of the Central Plains during spring and early summer, when the large-scale wind flow provides favorable conditions for the sometimes violent clash between the moist warm air from the Gulf of Mexico with the cold dry continental air coming from the northwest. However, tornadoes can form in many different circumstances and places around the globe. Hurricane landfalls are often accompanied by multiple tornadoes. While tornadoes can cause much havoc on the ground (tornadic wind speeds have been estimated at 100 to more than 300 mph), they have very short lifetimes (on the order of minutes), and travel short distances. They have very little impact on the evolution of the surrounding storm, and basically do not affect the large-scale environment at all. Hurricanes, on the other hand, are large-scale circulations with horizontal dimensions from 60 to well over 1000 miles in diameter. They form at low latitudes, generally between 5 and 20 degrees, but never right at the equator. They always form over the warm waters of the tropical oceans (sea-surface temperatures must be above 26.5° C, or about 76° F) where they draw their energy. They travel thousands of miles, persist over several days, and, during their lifetime, transport significant amounts of heat from the surface to the high altitudes of the tropical atmosphere. While their sporadic occurrence prevents them from drastically impacting the large-scale circulation, they still affect it in ways which must be accounted for and need to be better understood.

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Hurricane Isaias Impacts the US East Coast
Hurricane Isaias Precipitation History, July 29 to August 4, 2020 This animation shows IMERG rain rates (blue-yellow shading) and accumulations (green shading) observed from July 2 to August 4, 2020 along Tropical Storm Isaias’ track from the tropical Atlantic into the Caribbean and then northward along the Atlantic coast. The red line shows the location of the center of Isaias, as tracked by the National Hurricane Center and then smoothed in time for the animation. Parts of the Bahamas received over 30 centimeters (~1 foot) of rainfall during Isaias’ passage, where it made landfall on August
IMERG Hurricane Hanna 7-27-20 cropped
Hanna formed from a westward propagating tropical easterly wave that entered the southeast corner of the Gulf of Mexico on Tuesday July 21st. The wave provided a focus for shower and thunderstorm activity, which then led to the formation of an area of low pressure over the central Gulf of Mexico. The National Hurricane Center (NHC) found that this low had developed a closed circulation by the evening of Wednesday July 22nd, making it Tropical Depression #8. Over the next 24 hours, the depression slowly organized and intensified over the central Gulf before reaching tropical storm intensity on
GPM Hurricane Douglas 7-25-20
Hurricane Douglas continued to approach the Hawaiian islands during this GPM overpass early in the morning (02:11 UTC) of July 25, 2020. Douglas had previously strengthened to a Category 4 hurricane the day before, but had substantially weakened over cooler waters throughout the day. Regardless, the GMI and DPR instruments recorded rain rates near 50 millimeters/hour (~2 inches/hour) near Douglas` center. The Central Pacific Hurricane Center advised residents of Hawaii to expect hurricane-strength winds and rainfall starting Saturday evening and lasting through Monday. View fullscreen in STORM
IMERG rainfall totals from Japan, July 3 - 9 2020
From July 3-9, 2020, NASA’s IMERG algorithm continued to observe the heavy precipitation that fell as part of the seasonal Meiyu-Baiu rains (“plum rains”) in east Asia. Weekly totals reached their regional maxima over the island of Kyushu in southern Japan. About half of the island of Kyushu received over 45 cm (~18 inches) of rain. The majority of Honshu, Japan’s main island, as well as Shikoku to its south, were also impacted by the rains, receiving from 10-25 cm, depending on the location. Additionally, large areas of eastern China were also covered by the plum rains during this weekly
IMERG rainfall totals from Japan, June 29 - July 5, 2020
This animation shows NASA IMERG rain rates (blue shading) and accumulations (green shading) near Kyushu island, in the southwest of Japan from June 29 - July 5, 2020. Devastating floods and landslides swept through parts of Kyushu on July 4, 2020, resulting in over 40 deaths and orders for hundreds of thousands of people to evacuate their homes according to media reports. Download video (right-click -> Save As) The rains that triggered the flooding occurred in the context of the Meiyu-Baiu rainy season, which arrives in east Asia every year from June to mid-July. “Meiyu” and “Baiu” are the