meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did no ...

, training denotes repeated areas of

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

, typically associated with

thunderstorm A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are some ...

s, that move over the same region in a relatively short period of time. Training thunderstorms are capable of producing excessive

fall totals, often causing

flash flooding A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, or tropical storm, or by meltwater from ice or snow flowing ov ...

. The name ''training'' is derived from how a

train In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often ...

and its cars travel along a

track Track or Tracks may refer to: Routes or imprints * Ancient trackway, any track or trail whose origin is lost in antiquity * Animal track, imprints left on surfaces that an animal walks across * Desire path, a line worn by people taking the shorte ...

(moving along a single path), without the track moving.

Formation

Showers and thunderstorms along thunderstorm trains usually develop in one area of stationary

instability In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds. Not all systems that are not stable are unstable; systems can also be mar ...

, and are advanced along a single path by prevailing winds. Additional showers and storms can also develop when the

gust front An outflow boundary, also known as a gust front, is a storm-scale or mesoscale boundary separating thunderstorm-cooled air ( outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually ...

from a storm collides with warmer air outside of the storm. The same process repeats in the new storms, until overall conditions in the surrounding atmosphere become too stable for support of thunderstorm activity. Showers and storms can also develop along

stationary fronts A stationary front (or quasi-stationary front) is a weather front or transition zone between two air masses when both air mass is advancing into the other at speeds exceeding 5 knots (about 6 miles per hour or about 9 kilometers per hour) at the gr ...

, and winds move them down the front. The showers that often accompany thunderstorms are usually thunderstorms that are not completely developed.

Hazards

A series of storms continually moving over the same area, dumping heavy rains, can cause flash flooding. Each storm usually produces heavy rain, and after a significant amount of rain falls from the storms which have moved over the same area, flooding occurs.

Thunderstorm training

''Thunderstorm training'' is used to refer specifically to training occurring with thunderstorms. It forms when storms tend to backbuild. This type of training can quickly cause

flash flood A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, or tropical storm, or by meltwater from ice or snow flowing ...

ing, especially if the thunderstorms are strong.

References

{{Reflist

External links

MCS Movement and Behavior
by Stephen Corfidi

by Mike Evan Precipitation Weather hazards Mesoscale meteorology Severe weather and convection fr:Orage#Orages en V ou en série