According to a study, 1.75 hurricanes strike the United States on an average in a year

Storm clouds hovering over the Gulf coast of the United States coalesced into a Category 4 hurricane, christened Harvey, and battered the state of Texas in what could be the worst natural disaster to hit the United States mainland in a decade. The tropical storm made landfall on 28 August, with wind speeds touching 215km per hour.

When a hurricane makes landfall, it pushes a wall of water inland, inundating large swathes of land, spawning further showers. Hurricanes in the Atlantic are classified as categories one to five according to wind speed using the Saffir-Simpson Hurricane Scale.

Category 4 hurricanes have wind speeds ranging from 209kmph to 251kmph, while those exceeding 252kmph are bracketed as Category 5 storms. Hurricane Katrina, one of the deadliest natural calamities to hit the United States in recent history, was initially a Category 3 tropical storm, but notched Category 5 speeds at its peak, wreaking havoc in the State of New Orleans, where the levees in place were ill equipped to weather a storm of such ferocity.

The United States' east coast has been particularly prone to high intensity storms.

A NASA report predicts that most storms brew during the six-month window from June to November. Hurricanes have become a regular fixtures for many States, with a large chunk of their budgets spent in reconstructing property and mending lives torn apart by the winds.

Hurricane Katrina claimed over 1200 lives and caused $108 billion in damages, making it one of the costliest storms in history. New York, the world's financial nerve centre was not exempt from the vagaries of nature, as it was left submerged by Hurricane Sandy, a storm that made landfall in 2012, crippling the city's transportation system, and paralysing global markets. Despite being a Category 1 storm, Sandy cost $71.4 billion in damages. New York has the third largest GDP among American states, behind California and Texas.

A study undertaken by the Hurricane Research Division of the Atlantic Oceanographic and Meteorological Laboratory found that according to historical data, 1.75 hurricanes strike the United States on an average in a year. It further inferred that 88% of all major hurricanes have hit either Florida or Texas.

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The loss of life and property could be further compounded by the blow to the environment as the floodwaters of Hurricane Harvey recede in the oil-rich Texas. An Exxon Mobil refinery in Baytown, on the outskirts of Houston was damaged, and a statement released by the company said that a roof at the facility "partially sank," releasing chemical fumes into the atmosphere.

The floods have interrupted 16% of U.S. refining capacity. Texas produced 1.2 billion barrels of oil in 2014, accounting for 36% of total U.S. output. However, there has been no major spike in crude prices owing to a glut in supply that is not reciprocated by global demand.

With Hurricane Harvey still yet to relent, meteorologists are charting the course it might take. Forecasters warn that the flood may cause yet more damage if it moves into low-lying Louisiana, which is yet another important state for the energy industry. Refineries in the New Orleans-Baton Rouge region have an operating capacity of 2.6 million barrels a day, according to the Oil Price Information Service. A single day of disruption can set refineries in the state back by $121.4 million at present rates.