Aggressive Hurricane Season and Extreme Rainfall on Virginia’s Horizon

As a heat wave hits Virginia this week, twin challenges fueled by climate change could also send the state deadly and damaging weather that increases pollution to waterways, according to two recently released reports. 

The National Oceanic and Atmospheric Administration issued its May hurricane forecast, predicting 8 to 13 hurricanes this season in the Atlantic. This marks the most aggressive May outlook ever produced by NOAA.  

At the same time, Climate Central reports that a warming planet will send extreme rainfall across Virginia, raising risks of floods and threatening efforts to repair key waterways across the Chesapeake Bay watershed. 

The Climate Central report details how much more rainfall is likely to fall in each Virginia city or county during severe storms if the climate warms by 3.6 °F (2 °C). That includes Charlottesville, 21.7 percent; Norfolk, 12.8 percent; Petersburg, 17.9 percent; Fredericksburg, 22 percent; Alexandria, 20 percent; Richmond, 17.6 percent; Roanoke City, 19.7 percent; and Virginia Beach, 17.4 percent. 

The predictions underscore the urgency of Virginia’s investment in flood protection, wastewater upgrades, tree conservation and efforts to clean up polluted waters. These forecasts come after Virginia’s governor pulled the state out of two major efforts to reduce the effects of climate change impacts including the Regional Greenhouse Gas Initiative and clean car standards approved by the General Assembly, which mandated a gradual shift to electric vehicles. 

Warmer ocean waters serve as a key ingredient for hurricanes, and scientists expect the lingering above-average temperatures in the Atlantic to increase the intensity and frequency of one of nature’s deadliest storms this hurricane season. Experts attribute these record-breaking temperatures to the ocean’s absorption of heat caused by increases in fossil fuel emissions.  

Further inland, the increasing frequency of heat waves within rivers threatens plants and animals like trout and salmon, in addition to accelerating the creation of toxic algal blooms. 

A warming planet also means heavier and increased rainfall. For every 1°F of warming, the air can hold an extra 4 percent of moisture, according to Climate Central’s report called “Extreme Precipitation in a Warming Climate.”

As a result, heavy downpours, flooding, and stormwater runoff that overwhelms overburdened sewer systems, erodes backyard streams, and pollutes local waters will increase. One inch of rain falling on an acre of hardened surface, such as streets and parking lots, produces 27,000 gallons of runoff, according to the Chesapeake Bay Foundation (CBF). Stormwater passing over such surfaces often picks up oil, grease, dirt, and nutrients (nitrogen and phosphorus) and flows into nearby waterways.  

The state’s most recent “Dirty Waters” list declared more than 75 percent of Virginia’s estuaries and tidal rivers and 86 percent of Virginia’s lakes impaired. 

It’s a new chapter in a continuing trend. Between 1958 and 2021, Climate Central noted, the heaviest storms now drop 60 percent more rain in the Northeast (including Pennsylvania, Maryland, the District of Columbia, New York, and West Virginia) and 37 percent more in the Southeast (including Virginia).  

This increases the chances of heavier downpours that contribute to flash floods like those that killed an 85-year-old woman in Buchanan County in August 2021.  

Climate Central reported that flood damage costs in Virginia totaled roughly $855 million in 2020 and that figure could exceed $1 billion by 2050 as global temperatures continue to rise.  

Joe Wood, CBF Virginia Senior Scientist, issued the following statement:  

“Virginians experience climate change threats in many ways. As we head into what is forecasted to be another abnormally warm summer, Virginians must also contend with heavier downpours, damaging floods, and dangerous hurricanes.  

“More rainfall across Virginia has ripple effects across the Bay watershed, not to mention homes and businesses. The increasing frequency of severe storms causes more dangerous and costly flooding, overburdening sewer systems as well as local waterways that receive more polluted stormwater. Runoff from sweltering impervious surfaces is laden with pollutants which degrade Bay species, and lead to algal blooms that choke underwater life. Heat waves in rivers pose similar threats to plants and animals who depend on cooler, cleaner water to thrive.” 

“It’s critical to support local and state efforts to preserve and expand the state’s trees, which are natural sponges that soak up rainfall and pollutants. Trees alongside streams and streets, particularly city streets devoid of shade within what are known as urban heat islands, come with environmental benefits and benefits for communities disproportionately impacted by climate change. It’s also urgent to continue efforts to control emissions of climate-warming greenhouse gases.”