What is a hurricane?

What is a Hurricane?

A hurricane is a type of tropical cyclone, which is a generic term for a low pressure system that generally forms in the tropics. The cyclone is accompanied by thunderstorms and, in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface. Tropical cyclones are classified as follows:

Tropical Depression
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 mph (33 kt) or less. Sustained winds are a 1-minute average wind measured at about 33 ft (10 meters) above the surface. While 1 knot = 1 nautical mile per hour or 1.15 statute miles per hour and is abbreviated as "kt".

Tropical Storm
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (34-63 kt)

Hurricane
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (64 kt) or higher

Hurricanes are categorized according to the strength of their winds using the Saffir-Simpson Hurricane Scale. A Category 1 storm has the lowest wind speeds, while a Category 5 hurricane has the strongest. These are relative terms, because lower category storms can sometimes inflict greater damage than higher category storms, depending on where they strike and the particular hazards they bring. In fact, tropical storms can also produce significant damage and loss of life, mainly due to flooding.

Hurricane Names

When the the winds from these storms reach 39 mph (34 kts), the cyclones are given names. Years ago, an international committee developed names for Atlantic cyclones (The History of Naming Hurricanes). In 1979 a six year rotating list of Atlantic storm names was adopted — alternating between male and female hurricane names. Storm names are used to facilitate geographic referencing, for warning services, for legal issues, and to reduce confusion when two or more tropical cyclones occur at the same time. Through a vote of the World Meteorological Organization Region IV Subcommittee, Atlantic cyclone names are retired usually when hurricanes result in substantial damage or death or for other special circumstances.

(Thanks to the NHC.)

Hurricane & Tropical Storm

MM_XSLTransform error.
http://phonebook.com/rss/hurricane.com.xml is not a valid XML document.
DOMDocument::loadXML() [domdocument.loadxml]: Space required after the Public Identifier in Entity, line: 1
DOMDocument::loadXML() [domdocument.loadxml]: SystemLiteral " or ' expected in Entity, line: 1
DOMDocument::loadXML() [domdocument.loadxml]: SYSTEM or PUBLIC, the URI is missing in Entity, line: 1
DOMDocument::loadXML() [domdocument.loadxml]: Opening and ending tag mismatch: hr line 7 and body in Entity, line: 9
DOMDocument::loadXML() [domdocument.loadxml]: Opening and ending tag mismatch: body line 4 and html in Entity, line: 9
DOMDocument::loadXML() [domdocument.loadxml]: Premature end of data in tag html line 2 in Entity, line: 10 in file http://phonebook.com/rss/hurricane.com.xml.

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL /rss/hurricane.com.xml was not found on this server.</p>
<hr>
<address>Apache/2.2.9 (Debian) PHP/5.2.6-1+lenny4 with Suhosin-Patch mod_ssl/2.2.9 OpenSSL/0.9.8g Server at phonebook.com Port 80</address>
</body></html>

Advisory

National Hurricane Center (Atlantic)

Active tropical cyclones in the Atlantic, Caribbean, and the Gulf of Mexico

Hurricane EARL Public Advisory Number 38A-Issued at 800 PM EDT FRI SEP 03 2010

Hurricane EARL Forecast/Advisory Number 38-Issued at 2100 UTC FRI SEP 03 2010

Hurricane EARL Forecast Discussion Number 38-Issued at 500 PM EDT FRI SEP 03 2010

Hurricane EARL Wind Speed Probabilities Number 38-Issued at 2100 UTC FRI SEP 03 2010

Hurricane EARL Graphics-

Hurricane EARL 5-Day Uncertainty Track Image

5-Day Uncertainty Track last updated Fri, 03 Sep 2010 23:45:26 GMT

Hurricane EARL 34-Knot Wind Speed Probabilities

Wind Speed Probabilities last updated Fri, 03 Sep 2010 21:09:32 GMT

Hurricane EARL Probabilistic Storm Surge Graphics-

Hurricane EARL Probabilistic Storm Surge Graphics Image

Tropical Depression FIONA 5-Day Uncertainty Track Image

5-Day Uncertainty Track last updated Fri, 03 Sep 2010 23:55:24 GMT

Tropical Depression FIONA 34-Knot Wind Speed Probabilities

Wind Speed Probabilities last updated Fri, 03 Sep 2010 21:09:59 GMT

Tropical Depression FIONA 5-Day Track, Uncertainty Cone, Warnings (.shp)-GIS Data last updated Fri, 03 Sep 2010 23:54:39 GMT

Tropical Depression FIONA Best Track Information (.shp)-GIS Data last updated Fri, 03 Sep 2010 20:33:56 GMT

Tropical Depression FIONA Best Track Information (.kmz)-GIS Data last updated Fri, 03 Sep 2010 20:33:56 GMT

Tropical Depression FIONA Forecast Information (.shp)-GIS Data last updated Fri, 03 Sep 2010 20:33:56 GMT

Tropical Depression FIONA Wind Speed Probabilities - 0.5 Degree Multiple Basins (.shp)-GIS Data last updated Fri, 03 Sep 2010 21:10:03 GMT

Tropical Depression FIONA Wind Speed Probabilities - 0.1 Degree Multiple Basins (.shp)-GIS Data last updated Fri, 03 Sep 2010 21:10:10 GMT

Atlantic Tropical Weather Outlook-
000
ABNT20 KNHC 032353
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT FRI SEP 3 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANE
EARL...LOCATED ABOUT 155 MILES SOUTH-SOUTHWEST OF NANTUCKET
MASSACHUSETTS...AND ON RECENTLY DOWNGRADED TROPICAL DEPRESSION
FIONA...LOCATED ABOUT 100 MILES SOUTH-SOUTHWEST OF BERMUDA.

SHOWERS AND THUNDERSTORMS HAVE INCREASED IN ASSOCIATION WITH THE
REMNANT LOW OF GASTON...WHICH IS LOCATED ABOUT HALFWAY BETWEEN THE
CAPE VERDE ISLANDS AND THE LESSER ANTILLES. ENVIRONMENTAL
CONDITIONS ARE CONDUCIVE FOR GRADUAL DEVELOPMENT...AND A TROPICAL
DEPRESSION COULD RE-FORM DURING THE NEXT COUPLE OF DAYS AS THE
SYSTEM MOVES WESTWARD AT AROUND 10 MPH. THERE IS A HIGH CHANCE
...60 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE AGAIN
DURING THE NEXT 48 HOURS.

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN AREA OF LOW PRESSURE
LOCATED BETWEEN THE WEST COAST OF AFRICA AND THE CAPE VERDE ISLANDS
HAVE CHANGED LITTLE THIS EVENING. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR SOME SLOW DEVELOPMENT DURING THE NEXT
COUPLE OF DAYS. THERE IS A MEDIUM CHANCE...30 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT
MOVES NORTHWESTWARD NEAR 10 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER ROBERTS/BRENNAN

Hurricane Home

Education & Information

Hurricane Related

Headlines