An areal flood advisory is a weather alert issued to inform the public about potential flooding across a broad geographical area. These advisories signal conditions that could lead to minor flooding. Staying informed allows for timely action to mitigate risks.
Understanding Areal Flood Advisories
An areal flood advisory indicates general flooding of streets, low-lying zones, and areas with poor drainage. It does not signify immediately life-threatening situations, unlike a Flash Flood Warning, which denotes imminent danger from rapid water rises, or a Flood Warning, which concerns riverine flooding. This advisory is issued when flooding is expected to cause minor inconvenience or nuisance.
The geographical scope of an areal flood advisory is broader than a specific river basin, encompassing a wider region where conditions are favorable for widespread minor flooding. These advisories usually remain in effect for a few hours, though they can be extended depending on ongoing weather patterns and water levels. An areal flood advisory is considered the lowest level of flood alert, indicating less severe flooding compared to a warning.
Common Causes of Areal Flooding
Areal flooding results from specific meteorological and environmental conditions. Prolonged moderate to heavy rainfall is a common cause, as the ground becomes saturated and can no longer absorb additional water. Rapid snowmelt over already saturated ground can also contribute to this type of flooding.
Urban areas are particularly susceptible to areal flooding due to their high concentration of impervious surfaces like roads and buildings. These surfaces prevent water from soaking into the ground, leading to overwhelmed storm drains and increased runoff. The inability of drainage systems to handle the volume of water causes it to accumulate in low-lying areas and streets.
Responding to an Areal Flood Advisory
When an areal flood advisory is issued, taking practical safety measures is prudent. A fundamental safety guideline is “Turn Around, Don’t Drown,” emphasizing that one should never drive or walk through flooded roads. Just six inches of moving water can cause a person to lose balance, and one foot of moving water can sweep a vehicle away. Monitoring local weather updates through reliable sources is also important to stay aware of current conditions and forecasts.
Avoiding walking through floodwaters is advisable, as they can conceal hazards such as debris, open manholes, or even downed power lines. Securing outdoor items that could be swept away by water, like patio furniture or trash cans, can help prevent damage and reduce hazards. Awareness of potential road closures and planning alternative routes is also beneficial. While areal advisories do not indicate immediate life-threatening situations, exercising caution and awareness is important to prevent accidents and minor property damage.