When hurricanes hit: what the warnings mean
It’s hurricane season, which can mean major disruptions to your supply chain (and your life, if you live in the path of a major storm). Several different agencies, from the US Coast Guard to the National Oceanic and Atmospheric Administration, issue warnings and advisories about major storms.
Here’s what you need to know about these advisories and what they mean for your business.
When a storm becomes a hurricane
The difference between a storm, a tropical storm, and a hurricane is based on wind speeds.
- Gail force winds are winds that reach sustained speeds or frequent gusts of 39-54 mph.
- A tropical storm occurs when the sustained surface wind speed is 39-73 mph.
- A storm becomes a hurricane when the sustained surface wind reaches 74 mph or more.
The Saffir-Simpson Hurricane Wind Scale rates a hurricane’s sustained wind speed to determine its strength and potential for damage. Major hurricanes are classified as Category 3 or higher.
Here are the official category descriptions from NOAA’s National Hurricane Center:
- Category 1: Sustained winds of 74-95 mph. Very dangerous winds will produce some damage. Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
- Category 2: Sustained winds of 96-110 mph. Extremely dangerous winds will cause extensive damage. Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.
- Category 3: Sustained winds of 111-129 mph. Devastating damage will occur. Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
- Category 4: Sustained winds of 130-156 mph. Catastrophic damage will occur. Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
- Category 5: Sustained winds of 157 mph or higher. Catastrophic damage will occur. A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
Hurricane and storm warnings are issued by the National Hurricane Center. They include advisories (issued for tropical storms and hurricanes, with information about the location, intensity, and speed of the storm) and bulletins (issued between advisories with updated information about the storm).
The National Hurricane Center defines their advisories as follows:
- Tropical Storm Watch: An announcement that sustained winds of 39-73 mph are possible within 48 hours.
- Tropical Storm Warning: An announcement that sustained winds of 39-73 mph are expected within 36 hours.
- Hurricane Watch: An announcement that sustained winds of 74 mph or higher are possible. The watch is issued 48 hours in advance of the anticipated onset.
- Hurricane Warning: An announcement that sustained winds of 74 mph or higher are expected. The warning is issued 36 hours in advance of the anticipated onset and can remain in effect when dangerously high water or waves continue, even if winds subside.
The US Coast Guard classifies port conditions during hurricanes at four different levels, with mandated procedures for port operations at each level. In addition, the ports have procedures in place for hurricanes as well, which includes securing hazardous materials and implementing container stacking plans.
Once ports are closed, they are not allowed to reopen until the US Coast Guard Captain of the Port determines that it’s safe to resume operations.
Here are the US Coast Guard Hurricane Port Conditions definitions:
- Port Condition Whiskey: A heightened condition in which gale force winds are possible within 72 hours. All commercial vessels and barges greater than 500 gross tons and all oceangoing barges and their supporting tugs shall report to the Coast Guard Captain of the Port their intention to depart or remain in port.
- Port Condition X-Ray: A readiness condition in which gale force winds are possible within 48 hours. Vessels more than 500 gross tons and oceangoing barges and their supporting tugs should make preparations to leave the port or have received permission from the Coast Guard COTP to remain in port.
- Port Condition Yankee: A warning condition in which gale force winds are possible within 24 hours. All affected ports are under vessel traffic control measures. All vessels greater than 500 gross tons and oceangoing barges and their supporting tugs with permission to remain in port should make their final mooring arrangements.
- Port Condition Zulu: A danger condition in which gale force winds are possible within 12 hours. The port is closed and all port operations are suspended except for vessel movements and activities specifically authorized by the Coast Guard COTP.
Information about specific ports
General information about hurricane storm conditions and related port preparedness actions are also provided by the ports and the U.S. Coast Guard.
- Port of Mobile: the US Coast Guard Mobile Homeport site lists current port conditions and severe weather port contingency plans.
- Port of Jacksonville: Marine Safety Information Bulletins (MSIB) for specific hurricanes are posted on their news page and on their Homeport site.
- Port of Miami: Also includes Port Everglades. Hurricane conditions and port condition preparedness procedures are posted on the Port of Miami Homeport site.
- Port of Tampa Bay: Port status information is available no the St. Petersburg sector Homeport site.
- Port of Savannah: Port conditions and hurricane preparedness guides are posted on the Port of Savannah Homeport site.
- Port of New Orleans: New Orleans Homeport site lists current port conditions and their hurricane contingency port plan. Updates are also available on their website.
- Port of North Carolina: Marine Safety Information Bulletins, contingency plans, and port conditions are posted on the North Carolina Homeport site. Check the North Carolina Ports website for specifics on port closures.
- Port of Charleston: Port status information is available on the Charleston Homeport Site. South Carolina Ports also publishes advisories on their website.
- Port of Houston: Port conditions and hurricane season documents and forms are available on the Houston-Galveston Homeport site.
- Port of Virginia: Port conditions and contingency plans are available on the Hampton Roads Homeport site. Operations alerts are also on the Port of Virginia website.
Of course, if you live in the path of an oncoming hurricane, you’re not just concerned about taking care of your cargo. Taking care of your family and your home is even more important.
Here’s a few resources that can help:
- Check out weather forecasts and storm maps from the National Hurricane Center.
- Get radio broadcasts about National Weather Service warnings, watches, forecasts and other hazard information from NOAA Weather Radio All Hazards on receivers capable of picking up the signal, such as VHF marine radios.
- Learn what to do before, during, and after a hurricane from this resource provided by the Department of Homeland Security.
- Check the hurricane safety tips and resources from the National Weather Service.