A fairly complete article from Figaro ... Continuation of events to follow ...
Hurricane Irene has arrived in the United States
INFOGRAPHIC - Hurricane Irene was downgraded to category 1 before arriving in North Carolina. Local authorities have ordered the evacuation of coastal areas, which thousands of Americans have evacuated as a precaution.
It is a state of emergency on the East Coast of the United States, where 65 million residents and tourists are threatened by the gigantic hurricane Irene, which weakened on Saturday morning. Irene arrived at 8 a.m. (14 p.m. in Paris) on the North Carolina coast, near Cape Lookout, and should reach New York on Sunday. Heavy rain and strong gusts of wind fell early in the morning at Kill Devils Hill, a few miles from the eye of the storm. The city became ghost, the inhabitants had sheltered in their houses covered preventively with wooden panels.
Scalded by the Katrina disaster in 2005, the authorities fear major destruction in a densely populated area of more than 1000 km between North Carolina and Massachusetts. "Everything indicates that Irene will be a historic hurricane," Barack Obama warned in a recorded message from his vacation spot on Martha's Vineyard Island on the East Coast. He cut his vacation short by a day to return to Washington Friday evening, shortly before midnight.
Evacuation of coastal areas
Irene must then follow the East Coast and continue on Sunday towards Washington, New York and Boston. From North Carolina to Massachussetts, authorities have declared a state of emergency or issued hurricane warnings, and tens of thousands have been ordered to leave the coast. In Baltimore, authorities have distributed sandbags to residents to build makeshift dikes. In New York, Mayor Michael Bloomberg urged residents of the most dangerous areas to evacuate as soon as possible.
Norfolk's naval base, the largest in the world, has moved its ships to sea, where they are at less risk of damage. Because of the exceptional size of the hurricane, which presents cyclonic conditions over a radius of 150 km and strong winds over more than 460 km, the NHS fears a significant rise in water in the coastal areas. Some cities in the Mid Atlantic states, such as Norfolk, Baltimore, Ocean City, New York, and even Boston could be flooded. The region's soils are already saturated with water after heavy rains during the summer. The National Oceanic and Atmosperic Administration (NOAA) forecasts 12 to 24 cm of precipitation along the East Coast this weekend.
Less powerful than Hurricane Katrina which devastated Louisiana in 2005 (the hurricane was category 4 with winds of 200 km / hour on its arrival in this state), but as wide, Irene was demoted on Saturday morning in category 1 (on a scale from 1 to 5) by the National Hurricane Center of Miami (NHC) with winds reaching up to 150 km / hour. But the Center points out that the hurricane still remains dangerous. “The risks remain the same. What matters is the size and duration of the storm, not so much the wind speed. ”
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Two key factors: water temperature and earth temperature
Hurricane Irene is the ninth major meteorological phenomenon to have crossed the North Atlantic area since the beginning of the year. The previous one, Harvey, in early August, had remained a tropical storm. Irene has been classified as a hurricane for the past few days and has already killed 5 people while crossing the Caribbean. The Miami-based National Hurricane Center (NHC) forecast 2011 (until October) to be an "average" year with 11 tropical storms, 6 hurricanes and two major hurricanes.
If the trajectory forecasts of these immense whirling air masses (500 to 1000 km in diameter) over the ocean are now rather reliable - the knowledge of the temperature of the water which "feeds" the force of the storm is a key factor just like the level of atmospheric pressure - forecasts of their route when they land are much more difficult to establish. The hurricane can, almost to its pleasure, increase or decrease in intensity. The NHC has also refused, when preparing its forecasts before the cyclone season, to issue opinions on the issue.
Winds of 150 km / h
Irene has several particularities: "born" on August 15, from a low pressure wave from Africa which crossed the Atlantic, this storm is the first of the year to win the hurricane "stripes" in this region of the world. In addition, this phenomenon is one of the few to climb north to reach Cape Hatteras and New York. The last hurricane to have done so is Gloria, in 1985. On Saturday, Irene was downgraded from category 2 to category 1 on the Saffir-Simpson scale, which has five, with winds of 150 km / h. He is expected to reach New York on Sunday.
The next tropical storm in the North Atlantic will be called Jose, the next Katia. Everyone hopes that we will not see the 21st first name, Whitney, chosen by a committee led by the World Meteorological Organization. In 2012, the first tropical storm will be named Alberto, followed by Beryl, then Chris… The series of appellations is ready until 2016
Source: http://www.lefigaro.fr/environnement/20 ... caines.php
Nasa video: http://www.youtube.com/watch?v=UkSQDd5ueh4
