Changes in Extreme Precipitation in the Northeast United States: 1979–2014

Abstract Extreme precipitation can have significant adverse impacts on infrastructure and property, human health, and local economies. This paper examines recent changes in extreme precipitation in the northeast United States. Daily station data from 58 stations missing less than 5% of days for the years 1979–2014 from the U.S. Historical Climatology Network were used to analyze extreme precipitation, defined as the top 1% of days with precipitation. A statistically significant (95% confidence level) increasing trend of the threshold for the top 1% of extreme precipitation events was found (0.3 mm yr−1). This increasing trend was due to both an increase in the frequency of extreme events and the magnitude of extreme events. Rainfall events ≥ 150 mm (24-h accumulation) increased in frequency from 6 events between 1979 and 1996 to 25 events between 1997 and 2014, a 317% increase. The annual daily maximum precipitation, or the highest recorded precipitation amount in a given year, increased by an average of 1.6 mm yr−1, a total increase of 58.0 mm. Decreasing trends in extreme precipitation were observed east of Lake Erie during the warm season. Increasing trends in extreme precipitation were most robust during the fall months of September, October, and November, and particularly at locations further inland. The analysis showed that increases in events that were tropical in nature, or associated with tropical moisture, led to the observed increase in extreme precipitation during the fall months.

Download Full-text

A Dynamical and Statistical Characterization of U.S. Extreme Precipitation Events and Their Associated Large-Scale Meteorological Patterns

Journal of Climate ◽

10.1175/jcli-d-15-0910.1 ◽

2017 ◽

Vol 30 (4) ◽

pp. 1307-1326 ◽

Cited By ~ 16

Author(s):

Siyu Zhao ◽

Yi Deng ◽

Robert X. Black

Keyword(s):

United States ◽

Extreme Precipitation ◽

Large Scale ◽

Warm Season ◽

Base Function ◽

Regional Patterns ◽

Statistical Characterization ◽

Climate System Model ◽

Extreme Precipitation Events ◽

Precipitation Events

Abstract Regional patterns of extreme precipitation events occurring over the continental United States are identified via hierarchical cluster analysis of observed daily precipitation for the period 1950–2005. Six canonical extreme precipitation patterns (EPPs) are isolated for the boreal warm season and five for the cool season. The large-scale meteorological pattern (LMP) inducing each EPP is identified and used to create a “base function” for evaluating a climate model’s potential for accurately representing the different patterns of precipitation extremes. A parallel analysis of the Community Climate System Model, version 4 (CCSM4), reveals that the CCSM4 successfully captures the main U.S. EPPs for both the warm and cool seasons, albeit with varying degrees of accuracy. The model’s skill in simulating each EPP tends to be positively correlated with its capability in representing the associated LMP. Model bias in the occurrence frequency of a governing LMP is directly related to the frequency bias in the corresponding EPP. In addition, however, discrepancies are found between the CCSM4’s representation of LMPs and EPPs over regions such as the western United States and Midwest, where topographic precipitation influences and organized convection are prominent, respectively. In these cases, the model representation of finer-scale physical processes appears to be at least equally important compared to the LMPs in driving the occurrence of extreme precipitation.

Download Full-text

Climatology and Environmental Characteristics of Extreme Precipitation Events in the Southeastern United States

Monthly Weather Review ◽

10.1175/mwr-d-14-00065.1 ◽

2015 ◽

Vol 143 (3) ◽

pp. 718-741 ◽

Cited By ~ 48

Author(s):

Benjamin J. Moore ◽

Kelly M. Mahoney ◽

Ellen M. Sukovich ◽

Robert Cifelli ◽

Thomas M. Hamill

Keyword(s):

United States ◽

Extreme Precipitation ◽

Southeastern United States ◽

Warm Season ◽

Stage Iv ◽

Flow Patterns ◽

Water Vapor Transport ◽

Cool Season ◽

Extreme Precipitation Events ◽

Precipitation Events

Abstract This paper documents the characteristics of extreme precipitation events (EPEs) in the southeastern United States (SEUS) during 2002–11. The EPEs are identified by applying an object-based method to 24-h precipitation analyses from the NCEP stage-IV dataset. It is found that EPEs affected the SEUS in all months and occurred most frequently in the western portion of the SEUS during the cool season and in the eastern portion during the warm season. The EPEs associated with tropical cyclones, although less common, tended to be larger in size, more intense, and longer lived than “nontropical” EPEs. Nontropical EPEs in the warm season, relative to those in the cool season, tended to be smaller in size and typically involved more moist, conditionally unstable conditions but weaker dynamical influences. Synoptic-scale composites are constructed for nontropical EPEs stratified by the magnitude of vertically integrated water vapor transport (IVT) to examine distinct scenarios for the occurrence of EPEs. The composite results indicate that “strong IVT” EPEs occur within high-amplitude flow patterns involving strong transport of moist, conditionally unstable air within the warm sector of a cyclone, whereas “weak IVT” EPEs occur within low-amplitude flow patterns featuring weak transport but very moist and conditionally unstable conditions. Finally, verification of deterministic precipitation forecasts from a reforecast dataset based on the NCEP Global Ensemble Forecast System reveals that weak-IVT EPEs were characteristically associated with lower forecast skill than strong-IVT EPEs. Based on these results, it is suggested that further research should be conducted to investigate the forecast challenges associated with EPEs in the SEUS.

Download Full-text

Spatial Distribution and Temporal Change of Extreme Precipitation Events on the Koshi Basin of Nepal

Journal on Geoinformatics, Nepal ◽

10.3126/njg.v17i1.23007 ◽

2018 ◽

Vol 17 (1) ◽

pp. 38-46

Author(s):

Sanjeevan Shrestha ◽

Tina Baidar

Keyword(s):

Adverse Effect ◽

Spatial Distribution ◽

Extreme Events ◽

Extreme Precipitation ◽

Temporal Change ◽

Extreme Weather Events ◽

Extreme Precipitation Events ◽

Increasing Trend ◽

Koshi Basin ◽

Precipitation Events

Climate change, particularly at South Asia region is having a huge impact on precipitation patterns, its intensity and extremeness. Mountainous area is much sensitive to these extreme events, hence having adverse effect on environment as well as people in term of fluctuation in water supply as well as frequent extreme weather events such as flood, landslide etc. So, prediction of extreme precipitation is imperative for proper management. The objective of this study was to assess the spatial distribution and temporal change of extreme precipitation events on Koshi basin of Nepal during 1980-2010. Five indicators (R1day, R5 day, R > 25.4 mm, SDII and CDD) were chosen for 41 meteorological stations to test the extreme events. Inverse distance weighting and kriging interpolation technique was used to interpolate the spatial patterns. Result showed that most extreme precipitation events increased up to mountain regions from low river valley; and then it decreased subsequently up to Himalayan regions (south to north direction). However, there is high value of indices for lowland Terai valley also. Most of the indices have hotspot with higher value at north western and southern part of the study area. For temporal change, most of the extreme precipitation indices showed increasing trend within 30 years’ period. The spatial distribution of temporal change in indices suggests that there is increasing trend in lowland area and decreasing trend in mountainous and Himalayan area. So, adaptive measure should be adopted through proper land use planning, especially at those hotspot areas and their tributaries; to reduce adverse effect of extreme precipitation events.

Download Full-text

The Seasonal Nature of Extreme Hydrological Events in the Northeastern United States

Journal of Hydrometeorology ◽

10.1175/jhm-d-14-0237.1 ◽

2015 ◽

Vol 16 (5) ◽

pp. 2065-2085 ◽

Cited By ~ 40

Author(s):

Allan Frei ◽

Kenneth E. Kunkel ◽

Adao Matonse

Keyword(s):

United States ◽

Extreme Precipitation ◽

Extreme Event ◽

Warm Season ◽

The United States ◽

Cold Season ◽

Northeastern United States ◽

Extreme Precipitation Events ◽

Extreme Hydrological Events ◽

Precipitation Events

Abstract Recent analyses of extreme hydrological events across the United States, including those summarized in the recent U.S. Third National Climate Assessment (May 2014), show that extremely large (extreme) precipitation and streamflow events are increasing over much of the country, with particularly steep trends over the northeastern United States. The authors demonstrate that the increase in extreme hydrological events over the northeastern United States is primarily a warm season phenomenon and is caused more by an increase in frequency than magnitude. The frequency of extreme warm season events peaked during the 2000s; a secondary peak occurred during the 1970s; and the calmest decade was the 1960s. Cold season trends during the last 30–50 yr are weaker. Since extreme precipitation events in this region tend to be larger during the warm season than during the cold season, trend analyses based on annual precipitation values are influenced more by warm season than by cold season trends. In contrast, the magnitude of extreme streamflow events at stations used for climatological analyses tends to be larger during the cold season: therefore, extreme event analyses based on annual streamflow values are overwhelmingly influenced by cold season, and therefore weaker, trends. These results help to explain an apparent discrepancy in the literature, whereby increasing trends in extreme precipitation events appear to be significant and ubiquitous across the region, while trends in streamflow appear less dramatic and less spatially coherent.

Download Full-text

Simulation of Extreme Precipitation in Four Climate Regions in China by General Circulation Models (GCMs): Performance and Projections

Water ◽

10.3390/w13111509 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1509

Author(s):

Mengru Zhang ◽

Xiaoli Yang ◽

Liliang Ren ◽

Ming Pan ◽

Shanhu Jiang ◽

...

Keyword(s):

Extreme Precipitation ◽

General Circulation ◽

Global Climate ◽

Summer Precipitation ◽

General Circulation Models ◽

Cumulative Distribution ◽

Extreme Precipitation Events ◽

Increasing Trend ◽

The Future ◽

Semi Arid

In the context of global climate change, it is important to monitor abnormal changes in extreme precipitation events that lead to frequent floods. This research used precipitation indices to describe variations in extreme precipitation and analyzed the characteristics of extreme precipitation in four climatic (arid, semi-arid, semi-humid and humid) regions across China. The equidistant cumulative distribution function (EDCDF) method was used to downscale and bias-correct daily precipitation in eight Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models (GCMs). From 1961 to 2005, the humid region had stronger and longer extreme precipitation compared with the other regions. In the future, the projected extreme precipitation is mainly concentrated in summer, and there will be large areas with substantial changes in maximum consecutive 5-day precipitation (Rx5) and precipitation intensity (SDII). The greatest differences between two scenarios (RCP4.5 and RCP8.5) are in semi-arid and semi-humid areas for summer precipitation anomalies. However, the area of the four regions with an increasing trend of extreme precipitation is larger under the RCP8.5 scenario than that under the RCP4.5 scenario. The increasing trend of extreme precipitation in the future is relatively pronounced, especially in humid areas, implying a potential heightened flood risk in these areas.

Download Full-text

Changes in Intense Precipitation over the Central United States

Journal of Hydrometeorology ◽

10.1175/jhm-d-11-039.1 ◽

2012 ◽

Vol 13 (1) ◽

pp. 47-66 ◽

Cited By ~ 137

Author(s):

Pavel Ya. Groisman ◽

Richard W. Knight ◽

Thomas R. Karl

Keyword(s):

United States ◽

Extreme Precipitation ◽

Heavy Precipitation ◽

The Past ◽

Extreme Precipitation Events ◽

Intense Precipitation ◽

Central United States ◽

Extreme Rain ◽

Rain Events ◽

Precipitation Events

Abstract In examining intense precipitation over the central United States, the authors consider only days with precipitation when the daily total is above 12.7 mm and focus only on these days and multiday events constructed from such consecutive precipitation days. Analyses show that over the central United States, a statistically significant redistribution in the spectra of intense precipitation days/events during the past decades has occurred. Moderately heavy precipitation events (within a 12.7–25.4 mm day−1 range) became less frequent compared to days and events with precipitation totals above 25.4 mm. During the past 31 yr (compared to the 1948–78 period), significant increases occurred in the frequency of “very heavy” (the daily rain events above 76.2 mm) and extreme precipitation events (defined as daily and multiday rain events with totals above 154.9 mm or 6 in.), with up to 40% increases in the frequency of days and multiday extreme rain events. Tropical cyclones associated with extreme precipitation do not significantly contribute to the changes reported in this study. With time, the internal precipitation structure (e.g., mean and maximum hourly precipitation rates within each preselected range of daily or multiday event totals) did not noticeably change. Several possible causes of observed changes in intense precipitation over the central United States are discussed and/or tested.

Download Full-text

ENSO and Wintertime Extreme Precipitation Events over the Contiguous United States

Journal of Climate ◽

10.1175/2007jcli1705.1 ◽

2008 ◽

Vol 21 (1) ◽

pp. 22-39 ◽

Cited By ~ 48

Author(s):

Siegfried D. Schubert ◽

Yehui Chang ◽

Max J. Suarez ◽

Philip J. Pegion

Keyword(s):

United States ◽

West Coast ◽

Extreme Precipitation ◽

East Coast ◽

Daily Precipitation ◽

Precipitation Variability ◽

The West ◽

Extreme Precipitation Events ◽

The Impact ◽

Precipitation Events

Abstract In this study the authors examine the impact of El Niño–Southern Oscillation (ENSO) on precipitation events over the continental United States using 49 winters (1949/50–1997/98) of daily precipitation observations and NCEP–NCAR reanalyses. The results are compared with those from an ensemble of nine atmospheric general circulation model (AGCM) simulations forced with observed SST for the same time period. Empirical orthogonal functions (EOFs) of the daily precipitation fields together with compositing techniques are used to identify and characterize the weather systems that dominate the winter precipitation variability. The time series of the principal components (PCs) associated with the leading EOFs are analyzed using generalized extreme value (GEV) distributions to quantify the impact of ENSO on the intensity of extreme precipitation events. The six leading EOFs of the observations are associated with major winter storm systems and account for more than 50% of the daily precipitation variability along the West Coast and over much of the eastern part of the country. Two of the leading EOFs (designated GC for Gulf Coast and EC for East Coast) together represent cyclones that develop in the Gulf of Mexico and occasionally move and/or redevelop along the East Coast producing large amounts of precipitation over much of the southern and eastern United States. Three of the leading EOFs represent storms that hit different sections of the West Coast (designated SW for Southwest coast, WC for the central West Coast, and NW for northwest coast), while another represents storms that affect the Midwest (designated by MW). The winter maxima of several of the leading PCs are significantly impacted by ENSO such that extreme GC, EC, and SW storms that occur on average only once every 20 years (20-yr storms) would occur on average in half that time under sustained El Niño conditions. In contrast, under La Niña conditions, 20-yr GC and EC storms would occur on average about once in 30 years, while there is little impact of La Niña on the intensity of the SW storms. The leading EOFs from the model simulations and their connections to ENSO are for the most part quite realistic. The model, in particular, does very well in simulating the impact of ENSO on the intensity of EC and GC storms. The main model discrepancies are the lack of SW storms and an overall underestimate of the daily precipitation variance.

Download Full-text

Listening to Stakeholders: Initiating Research on Sub-seasonal to Seasonal Heavy Precipitation Events in the Contiguous U.S. by First Understanding What Stakeholders Need

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-20-0313.1 ◽

2021 ◽

pp. 1-35

Author(s):

Olivia VanBuskirk ◽

Paulina Ćwik ◽

Renee A. McPherson ◽

Heather Lazrus ◽

Elinor Martin ◽

...

Keyword(s):

United States ◽

Environmental Management ◽

Predictive Models ◽

Extreme Precipitation ◽

Heavy Precipitation ◽

Role Playing ◽

Extreme Precipitation Events ◽

Rainfall Extremes ◽

Actionable Science ◽

Precipitation Events

AbstractHeavy precipitation events and their associated flooding can have major impacts on communities and stakeholders. There is a lack of knowledge, however, about how stakeholders make decisions at the sub-seasonal to seasonal (S2S) timescales (i.e., two weeks to three months). To understand how decisions are made and S2S predictions are or can be used, the project team for “Prediction of Rainfall Extremes at Sub-seasonal to Seasonal Periods” (PRES2iP) conducted a two-day workshop in Norman, Oklahoma, during July 2018. The workshop engaged 21 professionals from environmental management and public safety communities across the contiguous United States in activities to understand their needs for S2S predictions of potential extended heavy precipitation events. Discussions and role-playing activities aimed to identify how workshop participants manage uncertainty and define extreme precipitation, the timescales over which they make key decisions, and the types of products they use currently. This collaboration with stakeholders has been an integral part of PRES2iP research and has aimed to foster actionable science. The PRES2iP team is using the information produced from this workshop to inform the development of predictive models for extended heavy precipitation events and to collaboratively design new forecast products with our stakeholders, empowering them to make more-informed decisions about potential extreme precipitation events.

Download Full-text

EXTREME EVENTS OF PRECIPITATION AND OCCURRENCES OF FLOODING, RUNOFF AND INUNDATION IN THE METROPOLITAN REGION OF CURITIBA, BRAZIL

Geografia em Questão ◽

10.48075/geoq.v14i02.25902 ◽

2021 ◽

Vol 14 (2) ◽

Author(s):

Nathan Felipe da Silva Caldana ◽

Leonardo Rodrigues ◽

Luis Gustavo Batista Ferreira ◽

Marcelo Augusto De Aguiar e Silva

Keyword(s):

Extreme Events ◽

Rural Areas ◽

Extreme Precipitation ◽

Rainfall Variability ◽

Metropolitan Region ◽

Severe Damage ◽

Extreme Precipitation Events ◽

Urban And Rural Areas ◽

Precipitation Events

Extreme precipitation events cause severe damage in both urban and rural areas. The objective of this work was to analyze rainfall variability, understand the dynamics of extreme precipitation events and to find out the occurrence of floods, runoff and inundation in the Metropolitan Region of Curitiba (MRC). Data from 39 rainfall stations distributed in the MRC area were used, as well as data by municipality of occurrence of flooding, runoff or inundation, from 1976 to 2018. Extreme precipitation events were identified in all months, most frequently in the summer. Totaling 48 decrees of emergency or public calamity and 397,516 people affected by one of the three socioenvironmental disasters.

Download Full-text

Influence of the Madden–Julian Oscillation on Forecasts of Extreme Precipitation in the Contiguous United States

Monthly Weather Review ◽

10.1175/2010mwr3512.1 ◽

2011 ◽

Vol 139 (2) ◽

pp. 332-350 ◽

Cited By ~ 37

Author(s):

Charles Jones ◽

Jon Gottschalck ◽

Leila M. V. Carvalho ◽

Wayne Higgins

Keyword(s):

United States ◽

Extreme Precipitation ◽

Western Hemisphere ◽

Boreal Winter ◽

Lead Times ◽

Madden Julian Oscillation ◽

Extreme Precipitation Events ◽

Skill Scores ◽

Probabilistic Forecasts ◽

Precipitation Events

Abstract Extreme precipitation events are among the most devastating weather phenomena since they are frequently accompanied by loss of life and property. This study uses reforecasts of the NCEP Climate Forecast System (CFS.v1) to evaluate the skill of nonprobabilistic and probabilistic forecasts of extreme precipitation in the contiguous United States (CONUS) during boreal winter for lead times up to two weeks. The CFS model realistically simulates the spatial patterns of extreme precipitation events over the CONUS, although the magnitudes of the extremes in the model are much larger than in the observations. Heidke skill scores (HSS) for forecasts of extreme precipitation at the 75th and 90th percentiles showed that the CFS model has good skill at week 1 and modest skill at week 2. Forecast skill is usually higher when the Madden–Julian oscillation (MJO) is active and has enhanced convection occurring over the Western Hemisphere, Africa, and/or the western Indian Ocean than in quiescent periods. HSS greater than 0.1 extends to lead times of up to two weeks in these situations. Approximately 10%–30% of the CONUS has HSS greater than 0.1 at lead times of 1–14 days when the MJO is active. Probabilistic forecasts for extreme precipitation events at the 75th percentile show improvements over climatology of 0%–40% at 1-day lead and 0%–5% at 7-day leads. The CFS has better skill in forecasting severe extremes (i.e., events exceeding the 90th percentile) at longer leads than moderate extremes (75th percentile). Improvements over climatology between 10% and 30% at leads of 3 days are observed over several areas across the CONUS—especially in California and in the Midwest.

Download Full-text