Two major heavy rain/flood events in the mid-Atlantic: June 2006 and September 2011

Abstract

In June 2006, significant flooding and flash flooding impacted much of the mid-Atlantic region as a continuous supply of deep tropical moisture moved north from the subtropical Atlantic ahead of a slowmoving cold front. A 3-day period of heavy rain resulted in nearly 38.1 cm (15 in) of rain across portions of the northern mid-Atlantic with record flooding along the mainstem Susquehanna and Delaware Rivers. In September 2011, moisture associated with the remnants of Tropical Storm Lee resulted in a 24-h period of heavy rain over which rainfall totals approached 30.3 cm (12 in) across portions of central New York and northern Pennsylvania. Numerous river-stage records that were set in the June 2006 event were shattered along the mainstem Susquehanna River during the September 2011 flood. Damage estimates resulting from the flooding in both events were >2 billion dollars, and 22 lives were lost. Multiple counties across the northern mid-Atlantic were declared disaster areas. Both flood events were investigated to identify the similar meteorological features and patterns responsible for extreme rainfall. Several crucial similarities were identified that likely combined to produce historic socioeconomic and environmental impacts. One of the similarities was that each event had a well-established atmospheric river in place that provided the uninterrupted supply of deep tropical moisture. Additionally, although these events displayed many of the large-scale characteristics identified in previous flash flood classification schemes, both events were associated with the presence of coastal fronts that appeared to make these cases different from many otherwise similar and previously documented flood cases.

Hydrological Model Diversity Enhances Streamflow Forecast Skill at Short‐ to Medium‐Range Timescales

“…The North Branch Susquehanna River (NBSR) basin in the U.S. Middle Atlantic Region was selected as the study area (Figure ; Nelson, ). Severe weather and flooding hazards are an important concern in the NBSR, for example, the City of Binghamton, New York, has been affected by multiple damaging flood events over recent years (Gitro et al, ; Jessup & DeGaetano, ). In the NBSR, four different U.S. Geological Survey (USGS) daily gauge stations were selected as the forecast locations (Figure ).…”

Relative effects of statistical preprocessing and postprocessing on a regional hydrological ensemble prediction system

“…Furthermore, different regional EPSs have been designed and implemented for research purposes, to meet specific regional needs, and/or for real-time forecasting applications. Two examples, among several others (Zappa et al, 2008(Zappa et al, , 2011Hopson and Webster, 2010;Demuth and Rademacher, 2016;Addor et al, 2011;Golding et al, 2016;Bennett et al, 2014;Schellekens et al, 2011), are the Stevens Institute of Technology's Stevens Flood Advisory System for short-range flood forecasting (Saleh et al, 2016) and the National Center for Atmospheric Research (NCAR) System for Hydromet Analysis, Research, and Prediction for medium-range streamflow forecasting (NCAR, 2017). Further efforts are underway to operationalize global ensemble flood forecasting and early warning systems, e.g., through the Global Flood Awareness System (Alfieri et al, 2013;Emerton et al, 2016).…”

Using the Multisensor Advected Layered Precipitable Water Product in the Operational Forecast Environment

“…In addition, the operational TPW product also has a tendency of being most sensitive to low-level moisture contributions (Forsythe et al 2015;LeRoy et al 2016), which could mask important moisture plumes at higher levels. This notwithstanding, the blended TPW product repeatedly has shown its operational utility leading up to, and during, high-impact hydrologic events (e.g., Moore et al 2012;Cordeira et al 2013;Gitro et al 2014).…”