A retrospective and prospective examination of the 1960s U.S. Northeast
Drought
Abstract
As the most severe drought over the Northeastern United States (NEUS) in
the past century, the 1960s drought had pronounced socioeconomic and
natural impacts. Although it was followed by a persisting wet period,
the conditions leading to the 1960s extreme drought could return in the
future, along with its challenges to water management. To project the
characteristics and potential consequences of such a future drought,
pseudo-global warming simulations using the Weather Research and
Forecasting Model are performed to simulate the dynamical conditions of
the historical 1960s drought, but with modified thermodynamic conditions
under the RCP8.5 scenario in the early (2021-2027), middle (2041-2047)
and late (2091-2097) 21st century. Our analysis focuses on essential
hydroclimatic variables including temperature, precipitation,
evapotranspiration, soil moisture, snowpack and surface runoff. In
contrast to the historical 1960s drought, similar dynamical conditions
will generally produce more precipitation, increased soil moisture and
evapotranspiration, and reduced snowpack. However, we also find that
although wet months get much wetter, dry months may become drier,
meaning that wetting trends are most significant in wet months but are
essentially negligible for extremely dry months with negative monthly
mean net precipitation. For these months, the trend towards wetting
conditions provides little relief from the effects of extreme dry
months. These conditions may even aggravate water shortages due to an
increasingly rapid transition from wet to dry conditions. Other
challenges emerge for residents and stakeholders in this region,
including more extreme hot days, record-low snow pack, frozen ground
degradation and subsequent decreases in surface runoff.