Stages of Development
from disturbance to hurricane
Tropical Storm:
If sustained wind speeds increase to at least 35 knots, a tropical depression is upgraded to a tropical storm. Surface wind speeds vary between 35 and 64 knots and the storm becomes more organized. Tropical storms resemble the appearance of hurricanes due to the intensified circulation.

Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.