Hurricane Information
Hurricane Preparedness Guide
The South Carolina Emergency Management Division's 2018 Hurricane Preparedness Guide can be viewed
here and should be reviewed and kept on hand in the event of a hurricane. It contains useful preparation tips including evacuation maps and an emergency supply checklist.
Storm Definitions
Tropical Disturbance
A tropical wave or easterly wave defined as a cluster of clouds and thunderstorms moving through the tropics.
Tropical Depression
When the tropical wave develops a rotary, cyclonic circulation with sustained winds to 38 mph.
Tropical Storm
Once winds within a tropical system reach 39 miles per hour and the distinct low pressure area is well defined by a rotating circulation, the system is considered a tropical storm and is given a name.
Hurricane
A hurricane has sustained winds exceeding 74 miles per hour or greater, dangerously high water and rough seas. Hurricanes are categorized by severity using the Saffir/Simpson Scale:
Saffir/Simpson Hurricane Scale
Category One
Winds 74-95 MPH
Or storm surge 4-5 feet above normal.*
Category Two
Winds 96-110 MPH
Or storm surge 6 feet above normal.*
Category Three
Winds 111-129 MPH
Or storm surge 9-12 feet above normal.*
Category Four
Winds 130-156 MPH
Or storm surge 13-18 feet above normal.*
Category Five
Winds 157 MPH and greater
Or storm surge greater than 18 feet above normal.*
*Actual storm surge values will vary considerably depending on coastal configurations and other factors.
Watches and Warnings
When a tropical storm or hurricane threatens, the National Hurricane Center will issue advisories based on the projected time until landfall of the storm.
Watch
A tropical storm or hurricane watch means that tropical storm or hurricane conditions pose a possible threat in a specified region within 36 hours. You should begin preliminary preparations. Stay tuned to local news or the weather channel for updates.
Warning
A tropical storm or hurricane warning means that tropical storm or hurricane conditions are expected in a specified region within 24 hours. All preparations should be completed. Stay tuned to local news or the weather channel for evacuation orders and additional instructions.
Emergency Operations Center Operating Conditions
OPCON 5
Day-to-day operations to include normal training and exercises.
OPCON 4
Possibility of an emergency or disaster situation that may require a partial or full activation of the Charleston Municipal Emergency Operations Center.
OPCON 3
Disaster or emergency situation likely or imminent. Full or partial activation of the Charleston Municipal Emergency Operations Center.
OPCON 2
Disaster or emergency situation in effect; maximum preparedness level; full activation of the Charleston Municipal Emergency Operations Center.
OPCON 1
Disaster or emergency situation in effect; full-fledged emergency response operations on-going; highest state of emergency operations.
