Wind

Wind-related Hazards

Severe wind conditions, such as those associated with strong storms, hurricanes, or high wind events, can lead to significant hazards. Residents are encouraged to stay informed and prepared in the event of an emergency by visiting www.CalvertCountyMd.gov/BeAwarePrepare and signing up for Calvert County Alert to receive timely information about various emergency and non-emergency situations in the county. Citizens can also download the free Calvert Prepare app to their mobile device to access emergency information, alerts and preparedness guidance on the go.

Downed Trees & Power Lines

Falling trees or tree limbs can cause extensive damage to homes, vehicles and other structures. Downed trees and power lines can block roadways and pose direct injury risks to individuals. High winds can cause trees to fall suddenly, leaving little time to move to safety. Trees that fall on utility lines may disrupt essential services like electricity.

Downed power lines pose a significant risk of electrocution to humans and animals. A live wire can charge the ground around it, making it dangerous to approach or touch anything that is in contact with the wire, including water, metal fences, and even trees. Learn more about downed power lines, including how to report them to your utility provider.

Flooding

Tidal flooding, often referred to as storm surge or coastal flooding, is a significant concern in coastal and low-lying areas, particularly during strong wind events such as hurricanes, tropical storms and nor'easters. High winds from these weather systems can push water onshore more forcefully than normal, leading to flooding in coastal regions.

In the event of significant flooding conditions, sand and sandbags will be made available for Calvert County residents to protect their property. The Calvert County Department of Public Safety urges citizens to take necessary precautionary actions to protect flood-prone property. View Calvert County Government Press Releases at www.calvertcountymd.gov/News to see if sandbags are currently available or for other safety recommendations.

Weather Alerts

The National Weather Service (NWS) issues several types of alerts related to wind conditions, each indicating a different level of risk or expected impact. These alerts help individuals and communities prepare for and respond to hazardous wind conditions.

  • Wind Advisory: This alert is issued when sustained wind speeds of 25 to 39 mph are expected for at least an hour, or wind gusts of 35 to 57 mph for any duration. It signals that winds are strong enough to cause minor damage, like downing small branches or blowing around unsecured objects, and could make driving difficult, especially for high-profile vehicles.
  • High Wind Watch: This is issued when there is the potential for sustained wind speeds of 40 mph or more for at least one hour, or wind gusts of 58 mph or higher for any duration. The watch is typically issued 12 to 48 hours before the anticipated onset of high winds. A watch means that high wind conditions are possible, giving people time to prepare.
  • High Wind Warning: Issued when sustained wind speeds of 40 mph or more are expected to last for at least one hour, or wind gusts will reach 58 mph or higher for any duration. This warning indicates that high winds are imminent or occurring, posing a significant threat to life and property. Actions should be taken to secure property and ensure safety.
  • Wind Chill Advisory: This alert is issued when wind chill temperatures are expected to be significant but not extreme. The specific criteria for issuing a Wind Chill Advisory vary by region, taking into account the local climate and what is considered unusually cold.
  • Wind Chill Watch: Issued when there is the potential for a combination of very cold air and strong winds to create dangerously low wind chill values, typically within 12 to 48 hours. This watch alerts people to the possibility of extreme conditions that could lead to frostbite and hypothermia.
  • Wind Chill Warning: This is issued when dangerously low wind chill temperatures are expected, posing a threat to life if precautions are not taken. The criteria for a Wind Chill Warning vary by region but are designed to highlight conditions that could lead to frostbite or hypothermia in a short amount of time.

Wind Restrictions for Bridges

In Maryland, wind restrictions on bridges are implemented to ensure the safety of vehicles during strong wind events. The Maryland Transportation Authority (MDTA) is responsible for managing these restrictions. These restrictions are typically based on wind speeds and can affect different types of vehicles.

While specific restrictions can vary and are subject to change, they generally follow a tiered system, depending on the severity of the wind conditions:

  • Wind Warnings: These are typically issued when wind speeds are high enough to warrant caution but not high enough to trigger the phased restrictions. During a wind warning, drivers are alerted to potential high winds on the bridge and are advised to drive with caution. Specific criteria for wind warnings can vary, but they generally serve as a preliminary alert that conditions are becoming hazardous.
  • Phase I: Typically initiated when wind speeds or gusts are between 30-39 mph (48-62 km/h). Vehicles vulnerable to high winds, such as box trucks, large SUVs and vehicles towing trailers are advised to use caution.
  • Phase II: Initiated when wind speeds or gusts reach 40-49 mph (64-79 km/h). At this stage, house trailers, empty box trailers or any vehicle that, in the opinion of law enforcement personnel, may not safely cross the bridge are prohibited from crossing.
  • Phase III: The most severe restrictions, implemented when wind speeds exceed 50 mph (80 km/h). During Phase III, only automobiles, pickup trucks, flatbed trailers, commercial buses and heavy-laden tractor/trailers are permitted to cross. Furthermore, external factors such as the direction of the wind or the presence of precipitation can lead to variations in these restrictions.
  • Traffic Holds/Bridge Closure: When wind speeds become dangerously high, or other hazardous conditions are present (such as ice or visibility issues), the MDTA may temporarily hold traffic or close the bridge entirely. This measure is taken to prevent accidents when it's deemed too dangerous for any vehicles to cross. Traffic holds can be of varying duration, depending on the severity of the weather conditions and how quickly they improve.
    • Bridge Closure: This is the most extreme measure, used when conditions are considered too dangerous for vehicle travel across the bridge. Closures are announced to the public via various channels, including traffic reports, social media, and the MDTA's website.

For motorists planning to travel across bridges, it's essential to check the latest travel advisories and weather conditions before setting out, especially during high winds or storms. The MDTA provides updates about current wind conditions and restrictions through local traffic reports, social media and the MDTA website.