scholarly journals Observations of Extreme Short-Term Precipitation Associated with Supercells and Mesovortices

2019 ◽  
Vol 148 (1) ◽  
pp. 159-182 ◽  
Author(s):  
Erik R. Nielsen ◽  
Russ S. Schumacher
Keyword(s):  
Flash Flood ◽  
Stage Iv ◽  
The United States ◽  
Surface Boundary ◽  
Short Term ◽  
Central Plains ◽  
Hourly Rainfall ◽  
High Precipitation ◽  
Rain Rates ◽  
Term Rain

Abstract Extreme hourly rainfall accumulations (e.g., exceeding 75 mm h−1) in several noteworthy flash flood events have suggested that the most intense accumulations were attendant with discrete mesoscale rotation or rotation embedded within larger organized systems. This research aims to explore how often extreme short-term rain rates in the United States are associated with storm-scale or mesoscale vortices. Five years of METAR observations and three years of Stage-IV analyses were obtained and filtered for hourly accumulations over 75 and 100 mm, respectively, clustered into events, and subjectively identified for rotation. The distribution of the short-term, locally extreme events shows the majority of the events were located along the Atlantic and Gulf of Mexico coastlines with additional events occurring in the central plains and into the Midwest. Nearly 50% of the cases were associated with low-level rotation in high-precipitation supercells or mesoscale vortices embedded in organized storm modes. Rotation events occurred more clearly in the warm sector, while nonrotation events tended to occur along a surface boundary. The rotation events tended to produce higher hourly accumulations over a larger region, but were associated with somewhat stronger synoptic-to-mesoscale forcing for ascent and more total column moisture. These results support recent modeling results suggesting that rotationally induced dynamic vertical pressure perturbations should not be ignored when it comes to extreme precipitation and can potentially enhance the short-term rain rates.

Investigation of PR and TMI Version 6 and Version 7 Rainfall Algorithms in Landfalling Tropical Cyclones Relative to the NEXRAD Stage-IV Multisensor Precipitation Estimate Dataset

2013 ◽  
Vol 52 (12) ◽  
pp. 2809-2827 ◽  
Author(s):  
Joseph P. Zagrodnik ◽  
Haiyan Jiang
Keyword(s):  
Tropical Cyclones ◽  
Stage Iv ◽  
Tropical Rainfall Measuring Mission ◽  
Heavy Rain ◽  
Light Rain ◽  
Hourly Rainfall ◽  
Wide Range ◽  
Landfalling Tropical Cyclones ◽  
Rain Rates ◽  
Rainfall Estimates

AbstractRainfall estimates from versions 6 (V6) and 7 (V7) of the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) 2A25 and Microwave Imager (TMI) 2A12 algorithms are compared relative to the Next Generation Weather Radar (NEXRAD) Multisensor Precipitation Estimate stage-IV hourly rainfall product. The dataset consists of 252 TRMM overpasses of tropical cyclones from 2002 to 2010 within a 230-km range of southeastern U.S. Weather Surveillance Radar-1988 Doppler (WSR-88D) sites. All rainfall estimates are averaged to a uniform 1/7° square grid. The grid boxes are also divided by their TMI surface designation (land, ocean, or coast). A detailed statistical analysis is undertaken to determine how changes to the TRMM rainfall algorithms in the latest version (V7) are influencing the rainfall retrievals relative to ground reference data. Version 7 of the PR 2A25 is the best-performing algorithm over all three surface types. Over ocean, TMI 2A12 V7 is improved relative to V6 at high rain rates. At low rain rates, the new ocean TMI V7 probability-of-rain parameter creates ambiguity in differentiating light rain (≤0.5 mm h−1) and nonraining areas. Over land, TMI V7 underestimates stage IV more than V6 does at a wide range of rain rates, resulting in an increased negative bias. Both versions of the TMI coastal algorithm are also negatively biased at both moderate and heavy rain rates. Some of the TMI biases can be explained by uncertain relationships between rain rate and 85-GHz ice scattering.

Climatology of Flood-Producing Storms and Their Associated Rainfall Characteristics in the United States

2019 ◽  
Vol 147 (11) ◽  
pp. 3861-3877 ◽  
Author(s):  
Erin Dougherty ◽  
Kristen L. Rasmussen
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Flash Flood ◽  
Stage Iv ◽  
The United States ◽  
Early Summer ◽  
Storm Events ◽  
Rainfall Characteristics ◽  
High Rainfall ◽  
Slow Rise

Abstract Floods are one of the deadliest weather-related natural disasters in the continental United States (CONUS). Given that rainfall intensity and the amount of CONUS population exposed to floods is expected to increase in the future, it is critical to understand flood characteristics across the CONUS. Therefore, the purpose of this study is to develop a flood-producing storm climatology over the CONUS from 2002 to 2013 to better understand rainfall characteristics of these storms and spatiotemporal differences across the country. Flood reports from the NCEI Storm Events Database are grouped by causative meteorological event and are merged with a database of stream-gauge-indicated floods to provide a robust indication of significant hydrologic events with a meteorological linkage. High-resolution Stage IV rainfall data were matched to 5559 flood episodes across the CONUS to identify rainfall characteristics of flood-producing storms in a variety of environments. This storm climatology indicates that flash flood–producing storms frequently occur with high rainfall accumulations in the summer east of the Rockies. Slow-rise flood-producing storms frequently occur in the spring–early summer (winter), with high rainfall accumulations over the northern and central CONUS (Pacific Northwest) due to rain-on-snowmelt, synoptic systems, and mesoscale convective systems (atmospheric rivers). Hybrid flood-producing storms, sharing characteristics of flash and slow-rise floods, frequently occur in spring–summer and have high rainfall accumulations in the central CONUS, Northeast, and mid-Atlantic. Results from this climatology may provide useful for emergency managers, city planners, and policy makers seeking efforts to protect their communities against risks associated with flood-producing storms.

Changes in Future Flash Flood–Producing Storms in the United States

2020 ◽  
Vol 21 (10) ◽  
pp. 2221-2236 ◽  
Author(s):  
Erin Dougherty ◽  
Kristen L. Rasmussen
Keyword(s):  
United States ◽  
Climate Models ◽  
Flash Flood ◽  
Global Climate ◽  
The United States ◽  
Flash Floods ◽  
Global Climate Models ◽  
Future Climate ◽  
South Central ◽  
Rain Rates

AbstractFlash floods are high-impact events that can result in massive destruction, such as the May 2010 flash floods in the south-central United States that resulted in over $2 billion of damage. While floods in the current climate are already destructive, future flood risk is projected to increase based on work using global climate models. However, global climate models struggle to resolve precipitation structure, intensity, and duration, which motivated the use of convection-permitting climate models that more accurately depict these precipitation processes on a regional scale due to explicit representation of convection. These high-resolution convection-permitting simulations have been used to examine future changes to rainfall, but not explicitly floods. This study aims to fill this gap by examining future changes to rainfall characteristics and runoff in flash flood–producing storms over the United States using convection-permitting models under a pseudo–global warming framework. Flash flood accumulated rainfall increases on average by 21% over the United States in a future climate. Storm-generated runoff increases by 50% on average, suggesting increased runoff efficiency in future flash flood–producing storms. In addition to changes in nonmeteorological factors, which were not explored in this study, increased future runoff is possible due to the 7.5% K−1 increase in future hourly maximum rain rates. Though this median change in rain rates is consistent with Clausius–Clapeyron theory, some storms exhibit increased future rain rates well above this, likely associated with storm dynamics. Overall, results suggest that U.S. cities might need to prepare for more intense flash flood–producing storms in a future climate.

scholarly journals Flash Flood Verification: Pondering Precipitation Proxies

2018 ◽  
Vol 19 (11) ◽  
pp. 1753-1776 ◽  
Author(s):  
Gregory R. Herman ◽  
Russ S. Schumacher
Keyword(s):  
Flash Flood ◽  
Stage Iv ◽  
Extreme Rainfall ◽  
Heavy Precipitation ◽  
The United States ◽  
Superior Performance ◽  
The West ◽  
Rainfall Frequency ◽  
Precipitation Analysis ◽  
Spatially Varying

Abstract Quantitative precipitation estimate (QPE) exceedances of numerous different heavy precipitation thresholds—including spatially varying average recurrence interval (ARI) and flash flood guidance (FFG) thresholds—are compared among each other and against reported and warned flash floods to quantify existing deficiencies with QPEs and to identify best practices for using QPE for flash flood forecasting and analysis. QPEs from three different sources—NCEP Stage IV Precipitation Analysis (ST4), Climatology Calibrated Precipitation Analysis (CCPA), and Multi-Radar Multi-Sensor (MRMS) QPE—are evaluated across the United States from January 2015 to June 2017. In addition to evaluating different QPE sources, threshold types, and magnitudes, QPE accumulation interval lengths from hourly to daily are considered. Systematic errors with QPE sources are identified, including a radar distance dependence on extreme rainfall frequency in MRMS, spurious occurrences of locally extreme precipitation in the complex terrain of the West in ST4, and insufficient QPEs for many legitimate heavy precipitation events in CCPA. Overall, flash flood warnings and reports corresponded to each other far more than any QPE exceedances. Correspondence between all sources was at a maximum in the East and worst in the West, with ST4, CCPA, and MRMS QPE exceedances locally yielding maximal correspondence in the East, Plains, and West, respectively. Surprisingly, using a fixed 2.5 in. (24 h)−1 proxy outperformed shorter accumulation exceedances and the use of ARIs and FFGs. On regional scales, different ARI exceedances achieved superior performance to the selection of any fixed threshold; FFG exceedances were consistently too rare to achieve optimal correspondence with observed flash flooding.

Cultural Awareness of Students in Communication Sciences and Disorders: A Mixed-Methods Study

2020 ◽  
Vol 5 (5) ◽  
pp. 1231-1242
Author(s):  
Celeste Domsch ◽  
Lori Stiritz ◽  
Jay Huff
Keyword(s):  
United States ◽  
Study Abroad ◽  
Cultural Awareness ◽  
Qualitative Data ◽  
The United States ◽  
Self Report ◽  
Global Awareness ◽  
Short Term ◽  
Term Study ◽  
Short Term Study

Purpose This study used a mixed-methods design to assess changes in students' cultural awareness during and following a short-term study abroad. Method Thirty-six undergraduate and graduate students participated in a 2-week study abroad to England during the summers of 2016 and 2017. Quantitative data were collected using standardized self-report measures administered prior to departure and after returning to the United States and were analyzed using paired-samples t tests. Qualitative data were collected in the form of daily journal reflections during the trip and interviews after returning to the United States and analyzed using phenomenological methods. Results No statistically significant changes were evident on any standardized self-report measures once corrections for multiple t tests were applied. In addition, a ceiling effect was found on one measure. On the qualitative measures, themes from student transcripts included increased global awareness and a sense of personal growth. Conclusions Measuring cultural awareness poses many challenges. One is that social desirability bias may influence responses. A second is that current measures of cultural competence may exhibit ceiling or floor effects. Analysis of qualitative data may be more useful in examining effects of participation in a short-term study abroad, which appears to result in decreased ethnocentrism and increased global awareness in communication sciences and disorders students. Future work may wish to consider the long-term effects of participation in a study abroad for emerging professionals in the field.

The Future of Muslim Education in the United States: An Agenda for Research

2003 ◽  
Vol 20 (3-4) ◽  
pp. 46-82
Author(s):  
Fathi Malkawi
Keyword(s):  
United States ◽  
The United States ◽  
American Education ◽  
Future Trends ◽  
Muslim Community ◽  
Short Term ◽  
The Future ◽  
Muslim Education ◽  
Future Plans

This paper addresses some of the Muslim community’s concerns regarding its children’s education and reflects upon how education has shaped the position of other communities in American history. It argues that the future of Muslim education will be influenced directly by the present realities and future trends within American education in general, and, more importantly, by the well-calculated and informed short-term and long-term decisions and future plans taken by the Muslim community. The paper identifies some areas in which a wellestablished knowledge base is critical to making decisions, and calls for serious research to be undertaken to furnish this base.

“Of Sound Mind and Body”

2019 ◽  
pp. 64-86
Author(s):  
Frank E. Vandervort ◽  
Vincent J. Palusci
Keyword(s):  
United States ◽  
Substance Abuse ◽  
Social Problem ◽  
Drug Testing ◽  
The United States ◽  
Developmental Trajectory ◽  
Prenatally Exposed ◽  
Short Term ◽  
Mind And Body ◽  
Sound Mind

Substance abuse is a major medical and social problem. Estimates suggest that each year some 15 percent of the 4 million babies born in the United States are exposed to drugs or alcohol. Research demonstrates that exposure to these substances is harmful to the children in both the short term and across their developmental trajectory. This chapter summarizes the harms that might result from such prenatal exposure and considers the ways that both federal and state law respond to this. The chapter argues for universal drug testing of newborns in an effort to ascertain whether they have been prenatally exposed to such substances so that treatment and other services can be provided.

scholarly journals An Exploratory Qualitative Study of Patient and Caregiver Perspectives of Ambulatory Kidney Palliative Care

2021 ◽  
pp. 104990912098612
Author(s):  
Alycia A. Bristol ◽  
Sobaata Chaudhry ◽  
Dana Assis ◽  
Rebecca Wright ◽  
Derek Moriyama ◽  
...  
Keyword(s):  
Palliative Care ◽  
Kidney Disease ◽  
Chronic Kidney Disease Stage ◽  
Stage Iv ◽  
The United States ◽  
Qualitative Description ◽  
Disease Stage ◽  
Structured Interviews ◽  
Care Clinic ◽  
Clinical Model

Objectives: The ideal clinical model to deliver palliative care to patients with advanced kidney disease is currently unknown. Internationally, ambulatory kidney palliative care clinics have emerged with positive outcomes, yet there is limited data from the United States (US). In this exploratory study we report perceptions of a US-based ambulatory kidney palliative care clinic from the perspective of patient and caregiver attendees. The objective of this study was to inform further improvement of our clinical program. Methods: Semi-structured interviews were conducted to elicit the patient and caregiver experience. Eleven interviews (8 patients with chronic kidney disease stage IV or V and 3 caregivers) were analyzed using qualitative description design. Results: We identified 2 themes: “Communication addressing the emotional and physical aspects of disease” and “Filling gaps in care”; Subthemes include perceived value in symptom management, assistance with coping with disease, engagement in advance care planning, program satisfaction and patient activation. Significance of Results: Qualitative analysis showed that attendees of an ambulatory kidney palliative care clinic found the clinic enhanced the management of their kidney disease and provided services that filled current gaps in their care. Shared experiences highlight the significant challenges of life with kidney disease and the possible benefits of palliative care for this population. Further study to determine the optimal model of care for kidney palliative care is needed. Inclusion of the patient and caregiver perspective will be essential in this development.

scholarly journals Decline in Marriage Associated with the COVID-19 Pandemic in the United States

2020 ◽  
Vol 6 ◽  
pp. 237802312098032
Author(s):  
Brandon G. Wagner ◽  
Kate H. Choi ◽  
Philip N. Cohen
Keyword(s):  
United States ◽  
The United States ◽  
Cumulative Number ◽  
Short Term ◽  
Know How ◽  
The Social ◽  
Reporting Delays ◽  
Social Upheaval ◽  
Near Future ◽  
Do So

In the social upheaval arising from the coronavirus disease 2019 (COVID-19) pandemic, we do not yet know how union formation, particularly marriage, has been affected. Using administration records—marriage certificates and applications—gathered from settings representing a variety of COVID-19 experiences in the United States, the authors compare counts of recorded marriages in 2020 against those from the same period in 2019. There is a dramatic decrease in year-to-date cumulative marriages in 2020 compared with 2019 in each case. Similar patterns are observed for the Seattle metropolitan area when analyzing the cumulative number of marriage applications, a leading indicator of marriages in the near future. Year-to-date declines in marriage are unlikely to be due solely to closure of government agencies that administer marriage certification or reporting delays. Together, these findings suggest that marriage has declined during the COVID-19 outbreak and may continue to do so, at least in the short term.

Sign in / Sign up

Export Citation Format

Share Document