Investigating the 2017 U.S. Northern Great Plains Drought
During the spring and summer of 2017 Montana, North Dakota and South Dakota experienced a devastating drought that sparked wildfires, destroyed livestock and reduced agricultural production, resulting in economic losses that exceeded one billion dollars. Neither the drought’s swift onset nor its severity were forecast.
In response to a request by the National Integrated Drought Information System (NIDIS), NOAA and CIRES researchers at the ESRL Physical Sciences Laboratory investigated the drought. Their study, entitled The Causes, Predictability, and Historical Context of the 2017 U.S. Northern Great Plains Drought, was recently posted online at drought.gov. The findings suggest that rapid onset of the drought in the spring and summer of 2017 was mainly due to failed rains.
Observed May–July precipitation over eastern Montana was found to be the lowest on record, and precipitation averaged over Montana, North Dakota and South Dakota was the third lowest on record dating back to at least 1895. Failed rains led to the third largest soil moisture decline for any three-week period over eastern Montana since at least 1916.
The researchers conducted climate model simulations, which revealed that droughts with intensity similar to that of 2017 are 20% more likely due to anthropogenic influences. Anthropogenic influences increase the likelihood of droughts in July because of long-term reductions in soil moisture, also known as aridification. Aridification is affected by increases in evapotranspiration associated with rising temperatures.
Below average May–July 2017 precipitation was not predicted in advance of the season. Cumulative precipitation deficits were only predictable through sequences of up to three-day forecasts. Sequences of longer than five-day forecasts provided no indication that the seasonal evolution of precipitation would be different from average.
The goals of the study were to inform forecasters on current drought prediction capabilities, to quantify how drought risk changes in a warming world and to aid to policy makers better define drought risk.
A companion impact assessment, Flash Drought: Lessons Learned From the 2017 Drought Across the U.S. Northern Plains and Canadian Prairies, completed by NIDIS in partnership with the federal, state, tribal, academic and Canadian partners, was also made available.
The authors of The Causes, Predictability, and Historical Context of the 2017 U.S. Northern Great Plains Drought are: Andrew Hoell, Judith Perlwitz, and Jon Eischeid of the ESRL Physical Sciences Laboratory.
Posted: June 10, 2019
Related story: Climate Change to Make Events Like 2017 Northern Plains Flash Drought More Likely
During the spring and summer of 2017 Montana, North Dakota and South Dakota experienced a devastating drought that sparked wildfires, destroyed livestock and reduced agricultural production, resulting in economic losses that exceeded one billion dollars. Neither the drought’s swift onset nor its severity were forecast.
In response to a request by the National Integrated Drought Information System (NIDIS), NOAA and CIRES researchers at the ESRL Physical Sciences Laboratory investigated the drought. Their study, entitled The Causes, Predictability, and Historical Context of the 2017 U.S. Northern Great Plains Drought, was recently posted online at drought.gov. The findings suggest that rapid onset of the drought in the spring and summer of 2017 was mainly due to failed rains.
Observed May–July precipitation over eastern Montana was found to be the lowest on record, and precipitation averaged over Montana, North Dakota and South Dakota was the third lowest on record dating back to at least 1895. Failed rains led to the third largest soil moisture decline for any three-week period over eastern Montana since at least 1916.
The researchers conducted climate model simulations, which revealed that droughts with intensity similar to that of 2017 are 20% more likely due to anthropogenic influences. Anthropogenic influences increase the likelihood of droughts in July because of long-term reductions in soil moisture, also known as aridification. Aridification is affected by increases in evapotranspiration associated with rising temperatures.
Below average May–July 2017 precipitation was not predicted in advance of the season. Cumulative precipitation deficits were only predictable through sequences of up to three-day forecasts. Sequences of longer than five-day forecasts provided no indication that the seasonal evolution of precipitation would be different from average.
The goals of the study were to inform forecasters on current drought prediction capabilities, to quantify how drought risk changes in a warming world and to aid to policy makers better define drought risk.
A companion impact assessment, Flash Drought: Lessons Learned From the 2017 Drought Across the U.S. Northern Plains and Canadian Prairies, completed by NIDIS in partnership with the federal, state, tribal, academic and Canadian partners, was also made available.
The authors of The Causes, Predictability, and Historical Context of the 2017 U.S. Northern Great Plains Drought are: Andrew Hoell, Judith Perlwitz, and Jon Eischeid of the ESRL Physical Sciences Laboratory.
Posted: June 10, 2019
Related story: Climate Change to Make Events Like 2017 Northern Plains Flash Drought More Likely