Strange Storms: Rainfall Extremes From the Remnants of Hurricane Ida (2021) in the Northeastern US

Abstract

On 1 September 2021, the remnants of Hurricane Ida transformed into a lethal variant of tropical cyclone in which unprecedented short‐duration rainfall from clusters of supercells produced catastrophic flooding in watersheds of the Northeastern US. Short‐duration rainfall extremes from Ida are examined through analyses of polarimetric radar fields and rain gauge observations. Rainfall estimates are constructed from a polarimetric rainfall algorithm that is grounded in specific differential phase shift (KDP) fields. Rainfall accumulations at multiple locations exceed 1000‐year values for 1–3 hr time scales. Radar observations show that supercells are the principal agents of rainfall extremes. Record flood peaks occurred throughout the eastern Pennsylvania—New Jersey region; the peak discharge of the Elizabeth River is one of the most extreme in the eastern US, based on the ratio of the peak discharge to the sample 10‐year flood at the gaging station. As with other tropical cyclones that have produced record flooding in the Northeastern US, Extratropical Transition was a key element of extreme rainfall and flooding from Ida. Tropical and extratropical elements of the storm system contributed to extremes of atmospheric water balance variables and Convective Available Potential Energy, providing the environment for extreme short‐duration rainfall from supercells.

Rainfall Frequency Analysis Based on Long‐Term High‐Resolution Radar Rainfall Fields: Spatial Heterogeneities and Temporal Nonstationarities

“…A. Smith et al. (2023)) are important for enhancing the application of radar rainfall data sets to rainfall frequency studies.…”

“…A. Smith et al. (2023)). Rainfall extremes from these storms are not captured by systematic rain gauge networks used for rainfall frequency studies (Bonin et al.…”

“…A. Smith et al. (2023)). In many settings and for many storms, rain gauge networks simply do not sample extremes, especially for convective rainfall.…”

A New Framework for Evaluating Model Simulated Inland Tropical Cyclone Wind Fields

“…Hurricane Ida (2021), a destructive Category 4 hurricane, is the second most‐damaging hurricane to hit Louisiana in history (Beven et al., 2021). The post‐landfall remnants of Ida also caused catastrophic damages from flooding and thunderstorms across the Northeastern states (Smith et al., 2023). Here we use Ida as an example to show the evaluation framework.…”

Flood preparedness and utilization of early warning systems among households in selected flood-prone areas in Tagum City, Davao Del Norte

“…Bangladesh faces recurring challenges with severe floods, causing extensive damage and displacing populations, exacerbating poverty, and hindering long-term development efforts (Rashid et al, 2022). The United States, as seen in events like Hurricane Harvey, experiences devastating economic losses, displacement of residents, and long-term environmental repercussions due to flooding (Smith et al, 2023). Every year, many cities in the Philippines face potential threats from floods.…”