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version 4.0
August 13, 2004

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Table of Contents

INTRODUCTION

A : BASIC DEFINITIONS

A1) What is a hurricane, typhoon, or tropical cyclone?
A2) What is "Cape Verde" hurricane?
A3) What is a super-typhoon? What is a major hurricane ? What is an intense hurricane ?
A4) What is an easterly wave and what causes them?
A5) What is a tropical disturbance, tropical depression, tropical storm?Updated
A6) What is a sub-tropical cyclone?
A7) What is an extratropical cyclone ?Updated
A8) What is storm surge and how is it different from tidal surge ?
A9) What is a "CDO" ?
A10) What is a TUTT ?
A11) What is the "eye" ? How is it formed and maintained ? What is the "eyewall" ? What are "spiral bands" ? Updated
A12) What is a moat in a hurricane ?
A13) What is UTC ? How can I tell at what time a satellite picture was taken ?New
A14) How do I convert from mph to knots (or m/s), from inches of mercury to millibars (or hPa), or from degrees of latitude to miles (or kilometers) ?
A15) How do tropical cyclones form ?
A16) Why do tropical cyclones require at least 80°F ocean temperatures to form ?New
A17) What is the Saharan Air Layer (SAL) ? How does it affect tropical cyclones ?New

B : TROPICAL CYCLONE NAMES

B1) Why are tropical cyclones named?
B2) What are the upcoming tropical cyclone names ?Updated
B3) What names have been retired in the Atlantic and East Pacific basin?Updated
B4) What is the origin of the word 'hurricane' ?


C : TROPICAL CYCLONE MODIFICATION AND MYTHS

C1) Doesn't the low pressure in the tropical cyclone center cause the storm surge?
C2) Doesn't the friction over land kill tropical cyclones?
C3) Aren't big tropical cyclones also intense tropical cyclones?
C4) Has there ever been an attempt or experiment to reduce the strength of a hurricane ?
C5) Why don't we try to destroy tropical cyclones by: (pick one or more)
  1. seeding them with silver iodide ?
  2. placing a substance on the ocean surface ?
  3. nuking them ?
  4. adding water absorbing substances ?
  5. cooling the surface waters with icebergs or deep ocean water?New
  6. other means ?
C6) During a hurricane are you supposed to have the windows and doors on the storm side closed and the windows and doors on the lee side open ?
C7) Should I tape my windows when a hurricane threatens?


D : TROPICAL CYCLONE WINDS AND ENERGY

D1) How are Atlantic hurricanes ranked?
D2) How are Australian tropical cyclones ranked?
D3) Why do tropical cyclones' winds rotate counter-clockwise (clockwise) in the Northern (Southern) Hemisphere?
D4) What does "maximum sustained wind" mean ? How does it relate to gusts in tropical cyclones ?New
D5) How does the damage that hurricanes cause increase as a function of wind speed?
D6) Why are the strongest winds in a hurricane typically on the right side of the storm?
D7) How much energy does a hurricane release?
D8) What are "concentric eyewall cycles" (or "eyewall replacement cycles") and why do they cause a hurricane's maximum winds to weaken ?
D9) What causes each hurricane to have a different maximum wind speed for that given minimum sea-level pressure?
D10) Why do hurricane force winds start at 64 knots ?New

E : TROPICAL CYCLONE RECORDS

E1) Which is the most intense tropical cyclone on record?
E2) Which tropical cyclone intensified the fastest?
E3) Which tropical cyclone has produced the highest storm surge?
E4) What are the largest rainfalls associated with tropical cyclones?
E5) Which are the largest and smallest tropical cyclones on record?
E6) Which tropical cyclone lasted the longest?
E7) What is the farthest a tropical cyclone has traveled?New
E8) What tropical cyclones have been at Category Five the longest?New
E9) Which tropical cyclones have caused the most deaths and most damage?
E10) What are the average, most, and least tropical cyclones occurring in each basin?Updated
E11) In what years did the Atlantic basin develop the greatest and fewest tropical cyclones ?Updated
E12) For the USA, what are the 30 most intense, 30 costliest, and 30 highest death toll hurricanes on record ?Updated
E13) What tropical storms and hurricanes have moved from the Atlantic to the Northeast Pacific or visa versa?


F : TROPICAL CYCLONE FORECASTING

F1) What regions around the globe have tropical cyclones and who is responsible for forecasting there?
F2) What are those track and intensity models that the Atlantic forecasters are talking about in the Inter-Governmental messages?
F3) What are the various forecasts that are being issued for seasonal tropical cyclone activity around the world ?
F4) What is Prof. Gray's seasonal hurricane forecast for this year and what are the predictive factors?
F5) What is the official U.S. Government (NOAA) seasonal hurricane outlook for the Atlantic basin for this year and what are the predictive factors ?
F6) How has the official U.S. Government (NOAA) seasonal hurricane outlook done in previous years ?Updated
F7) How accurate are the forecasts from the National Hurricane Center ?New
F8) How is storm surge forecast ?New

G : TROPICAL CYCLONE CLIMATOLOGY

G1) When is hurricane season?
G2) How does El Niño-Southern Oscillation affect tropical cyclone activity around the globe?
G3) What may happen with tropical cyclone activity in a 2xCO2 world?
G4) Are we getting stronger and more frequent hurricanes, typhoons, and tropical cyclones in the last several years?
G5) Why do tropical cyclones occur primarily in the summer and autumn?
G6) What determines the movement of tropical cyclones?
G7) Why doesn't the South Atlantic Ocean experience tropical cyclones?Updated
G8) Does an active June and July mean the rest of the season will be busy too?
G9) Why do hurricanes hit the East coast of the U.S., but never the West coast?
G10) How much lightning occurs in tropical cyclones?
G11) What is the 20th century hurricane record for each U.S. coastal state and county?
G12) What is my chance of being struck by a tropical storm or hurricane?
G13) What is my chance of having a tropical storm or hurricane strike by each month?
G14) What is the average number of tropical storms and hurricanes to affect my town?
G15)What is the peak number of tropical storms and hurricanes to affect my town?
G16)I'm vacationing in the Caribbean/the Bahamas/Central America/Miami or elsewhere in the tropics during hurricane season. What's my chance of getting hit by a hurricane ? New

H : TROPICAL CYCLONE OBSERVATION

H1) What is the Dvorak technique and how is it used?
H2) Who are the "Hurricane Hunters" and what are they looking for?
H3) What is it like to fly into a hurricane?
H4) Can I get a seat on a hurricane flight?
H5) What's it like to go through a hurricane on the ground ? What are the early warning signs of an approaching tropical cyclone ?New
H6) Are there hurricanes on other planets ? New
H7) How does the ocean respond to a hurricane and how does this feedback to the storm itself? New


I : REAL TIME INFORMATION

I1) Where can I get real-time advisories for tropical cyclones?
I2) Where can I get real-time tropical weather analyses?
I3) Where can I get real-time ship and buoy data?
I4) Where can I get real-time sea surface temperature data?
I5) Where can I get real-time satellite pictures and satellite products?
I6) Where can I get real-time radar data?
I7) Where can I get real-time hurricane aircraft reconnaissance data?
I8) Where can I get real-time forecasts of tropical cyclone motion?
I9) What computer software is available for tracking tropical cyclones?
I10) How can I get hurricane information when I'm not at my computer ? New

J : HISTORICAL INFORMATION

J1) Where can I get historical data on tropical cyclones ?
J2) What journals have regular articles on tropical cyclones ?
J3) What books have been written about tropical cyclones ?
J4) What fictional books,plays, and movies have been written involving tropical cyclones ?New
J5) What refereed articles were written in recent years on tropical cyclones ?
J6) What are some important dates in the history of hurricanes and hurricane research ? New


K : HURRICANE PREPARATION

K1) What steps should I take when a hurricane watch/warning is posted?
K2) What can I do to make my home/business more disaster resistant?
K3) What kind of hurricane shutters are available ?

L : HURRICANES versus TORNADOES

L1) How are tropical cyclones different from tornadoes?
L2) Why do tropical cyclones spawn tornadoes?
L3) What percentage of tropical cyclones spawn tornadoes?
L4 What parts of a tropical cyclone are most favored for tornado formation?
L5) How long after landfall are TC tornadoes a threat? Updated
L6) Are TC tornadoes weaker than midlatitude tornadoes?Updated
L7) What is the largest known outbreak of TC tornadoes?
L8) What is the deadliest single TC-spawned tornado?
L9) What is the most damaging single TC-spawned tornado?
L10) Why are TC tornadoes especially difficult to deal with?
L11) Which states are most vulnerable to TC tornadoes outbreaks? New
L12) What about Florida ? They get the most hurricane strikes; do they also get a lot of TC tornadoes ? New
L13) How does the damage from hurricanes compare to tornadoes ? New

Introduction
This FAQ (Frequently Asked Questions) web site attempts to address various questions regarding hurricanes, typhoons and tropical cyclones that have been posed to us as hurricane researchers over the years. While it is not intended to be a technical guide, references are given throughout the FAQ for those that would like additional, detailed information. Also, there is no guarantee that all that is in here is completely accurate (we're human!). If you do see an item that needs correction, or if you have any additional questions that you think should be added to this FAQ, please
contact us directly.

Hopefully, this FAQ site can help answer some of the questions that you may have about the characteristics of these catastrophic storms, how they are monitored and forecasted, and what are some of research topics that are being addressed today.

We'd like to thank various people for helping to put together this FAQ: Sim Aberson, Jack Beven, Gary Padgett, Tom Berg, Julian Heming, Gary Gray, Frank Woodcock, Stephen Caparotta, Steven Young, D. Walston, James Lewis Free, Jon Gill, Miles Lawrence, Robert A. Black, Bill McCaul, Bart Hagemeyer, Frank Marks, Joe Cione and John Guiney, all provided substantial bits to this FAQ. Many thanks also to Jan Null for providing the first .html version of the FAQ.

Chris Landsea principal author
Stan Goldenberg co-author
Neal Dorst webmaster
Erica Rule outreach coordinator

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