More intense storm events over NJ anticipated

chance for 100-year storms could occur 45%-50% more often

New Jersey Department of Environmental Protection (NJ DEP) has released a research summary and two studies by the Northeast Regional Climate Center, a National Oceanic and Atmospheric Administration (NOAA) partner, confirming 2.5%-10% increases in precipitation across New Jersey over the last 20 years. Further increases in precipitation intensity through the end of this century due to climate change are projected.

"This science provides us another opportunity to ensure communities become more resilient," said NJ DEP Commissioner Shawn LaTourette who acknowledged that more frequent and intense storms of Tropical Storms Henri and Ida are a reality today.

He elaborated, "By building upon our scientific understanding, we can take wise steps… from planning more resilient development, to enhancing stormwater and flood control infrastructure and beyond. We all have the power to ensure that what we build today will stand the test of time and a changing climate."

Highlights from study findings

  • Data obtained through 1999 does not accurate reflect current rainfall intensity conditions, which influence planning and development policy.

  • The study "Changes in Hourly and Daily Extreme Rainfall Amounts in NJ since the Publication of NOAA Atlas 14 Volume" fills in 20 years of climate data gaps for the state. It also addresses changing measurements of storm intensity by incorporating the past two decades of data into the current analyses.

  • The study "Projected Changes in Extreme Rainfall in New Jersey based on an Ensemble of Downscaled Climate Model Projections" reports that precipitation is likely to increase by more than 20% by the year 2100 from the baseline established in 1999.

  • More frequent storms, such as the 2-year and 10-year, 24-hour storms are expected to see increases in precipitation intensity of 5%-15% on average across the state by the end of the century.

  • A high likelihood that precipitation intensity will increase throughout the century in all parts of the state exists, but greater projected changes will be in the northern part of the state than in the southern and coastal areas.

Director of the Northeast Regional Climate Center and professor of Earth and Atmospheric Sciences at Cornell University, Dr. Arthur DeGaetano said, “It is crucial the most recent rainfall observations and state-of-the-art climate model simulations of future rainfall be incorporated into decisions regarding flood potential, infrastructure design and resiliency planning.”

Both reports went through a peer review by the NJ DEP Science Advisory Board’s standing committee for Climate and Atmospheric Sciences.