Evaluating the skill of satellite data on the individuation of extreme precipitation events in Calabria (southern Italy)

Daily Data ◽

In this study, the skill of TRMM Multi-Satellite Precipitation Analysis (TMPA) data to locate spatially and temporally extreme precipitation has been tested over Calabria, a region in southern Italy.Calabria is a very challenging region for hydrometeorology studies, as i) it is a mainly mountainous region with complex orography; ii) it is surrounded by sea, providing&#160; an abundance of available moisture; iii) it belongs to the Mediterranean region, a hot-spot for climate change.TMPA, which provides daily data at a 0.25&#176; resolution (i.e., about 25 km at southern Italy latitudes), was tested with regards to three extreme precipitation events that occurred between 1998 and 2019, i.e., the years of TMPA&#8217;s operational time frame. The first event, taking place on 07-12/09/2000, lasted for several days and involved most of Calabria. The second (01-04/07/2006) was a very localized midsummer event, which hit a very small area with destructive consequences. Finally, the 18-27/11/2013 event was a ten-day long heavy precipitation event that hit the region in spots.TMPA daily data were compared against validated and homogenized rain gauge data from 79 stations managed by the Multi-Risk Functional Centre of the Regional Agency for Environmental Protection. TMPA was evaluated both in relative and absolute terms: i) the relative skill was tested by checking if TMPA evaluated correctly the presence of extreme precipitation, defined as daily precipitation passing the 99th percentile threshold; ii) the absolute skill was tested by checking if TMPA reproduced correctly the cumulated precipitation values during the events.TMPA proved sufficiently able to locate areas subject to heavy cumulated precipitation during large spatially distributed events over the region. However, it showed difficulties in reproducing very localized events, as the 2006 case study was not detected at all, showing that 25-km spatial resolution and daily time resolution proved inadequate to resolve this type of rainfall event.Results might give insights into the possibility of using satellite data for real-time monitoring of extreme precipitation, especially since the transition from the old TMPA to the new Integrated Multi-satellitE Retrievals for GPM (IMERG) set was completed in January 2020.&#160;Acknowledgments:The Project INDECIS is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462).

The effect of climate change on urban drainage: an evaluation based on regional climate model simulations

Water Science & Technology ◽

10.2166/wst.2006.592 ◽

2006 ◽

Vol 54 (6-7) ◽

pp. 9-15 ◽

Cited By ~ 41

Author(s):

M. Grum ◽

A.T. Jørgensen ◽

R.M. Johansen ◽

J.J. Linde

Keyword(s):

Climate Change ◽

Extreme Precipitation ◽

Climate Model ◽

Regional Climate ◽

Rain Gauge ◽

Urban Drainage ◽

Rainfall Extremes ◽

The Future ◽

That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps: Firstly, hourly rainfall intensities from 16 point rain gauges are averaged to create a rain gauge equivalent intensity for a 25 × 25 km square corresponding to one grid cell in the climate model. Secondly, the differences between present and future in the climate model is used to project the hourly extreme statistics of the rain gauge surface into the future. Thirdly, the future extremes of the square surface area are downscaled to give point rainfall extremes of the future. The results and conclusions rely heavily on the regional model's suitability in describing extremes at time-scales relevant to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change.

Evaluating extreme precipitation events on the Iberian Peninsula using TRMM satellite data

10.3390/chycle-2017-04880 ◽

2017 ◽

Cited By ~ 1

Author(s):

Margarida Liberato ◽

Riccardo Hénin ◽

Alexandre Ramos ◽

Célia Gouveia

Keyword(s):

Iberian Peninsula ◽

Satellite Data ◽

Extreme Precipitation ◽

On the links between sub-seasonal clustering of extreme precipitation and high discharge in Switzerland and Europe

10.5194/hess-2021-625 ◽

2021 ◽

Author(s):

Alexandre Tuel ◽

Bettina Schaefli ◽

Jakob Zscheischler ◽

Olivia Martius

Keyword(s):

Extreme Precipitation ◽

Temporal Structure ◽

Extreme Precipitation Event ◽

Precipitation Event ◽

Discharge Data ◽

High Discharge ◽

Temporal Clustering ◽

The Impact ◽

Abstract. River discharge is impacted by the sub-seasonal (weekly to monthly) temporal structure of precipitation. One example is the successive occurrence of extreme precipitation events over sub-seasonal timescales, referred to as temporal clustering. Its potential effects on discharge have received little attention. Here, we address this question by analysing discharge observations following extreme precipitation events either clustered in time or occurring in isolation. We rely on two sets of precipitation and discharge data, one centered on Switzerland and the other over Europe. We identify "clustered" extreme precipitation events based on the previous occurrence of another extreme precipitation within a given time window. We find that clustered events are generally followed by a more prolonged discharge response with a larger amplitude. The probability of exceeding the 95th discharge percentile in the five days following an extreme precipitation event is in particular up to twice as high for situations where another extreme precipitation event occurred in the preceding week compared to isolated extreme precipitation events. The influence of temporal clustering decreases as the clustering window increases; beyond 6–8 weeks the difference with non-clustered events is negligible. Catchment area, streamflow regime and precipitation magnitude also modulate the response. The impact of clustering is generally smaller in snow-dominated and large catchments. Additionally, particularly persistent periods of high discharge tend to occur in conjunction with temporal clusters of precipitation extremes.

Simulating extreme precipitation over the Arabian Peninsula using a convective-permitting sub-seasonal reforecast product

10.5194/egusphere-egu2020-4059 ◽

2020 ◽

Author(s):

Thang M. Luong ◽

Christoforus Bayu Risanto ◽

Hsin-I Chang ◽

Hari Prasad Dasari ◽

Raju Attada ◽

...

Keyword(s):

Extreme Events ◽

Extreme Precipitation ◽

Arabian Peninsula ◽

Flash Flood ◽

Value Added ◽

Rain Gauge ◽

Potential Predictability ◽

Simulated Precipitation ◽

Despite being one of the driest places in the world, the Arabian Peninsula (AP) occasionally experiences extreme precipitation events associated with organized convections. On 25 November 2009, for instance, a cutoff low driven rainfall exceeding 140 mm over a 6-hour period triggered a flash flood event in Jeddah, Saudi Arabia, claiming hundreds of lives and substantially damaging infrastructure. Similar extreme precipitation events have occurred in subsequent years. To assess the potential predictability of extreme precipitation in the Arabian Peninsula, we perform retrospective forecast simulations for several extreme events occurring over the period 2000 to 2018, out to a sub-seasonal timescale (3-4 weeks). Using the Advanced Research version of Weather Research and Forecasting Model (WRF-ARW), we dynamically downscale 11 ensemble members of the European Centre for Medium-Range Weather Forecasts (ECMWF) sub-seasonal reforecasts at convective-permitting resolution (4 km). WRF simulated precipitation is evaluated against various precipitation products, including the Global Precipitation Measurement (GPM) system, Climate Prediction Center morphing technique (CMORPH), and the Saudi Ministry of Water and Electricity(MOWE) and the Presidency of Meteorology and Environment(PME) regional rain gauge measurements. The convective-permitting WRF simulations substantially improve the representation of precipitation relative to the ECMWF reforecast, in terms of spatial distribution and timing. A specific focus in the presentation of the results will be on the potential value added by the use of convective-permitting modeling (CPM) to forecasting extreme events at sub-seasonal timescales. The predictability of the synoptic pattern could be the key for CPM sub-seasonal-type forecast for the AP.

The Extreme Precipitation Index (EPI): A Coupled Dynamic–Thermodynamic Metric to Diagnose Midlatitude Floods Associated with Flow Reversal

Weather and Forecasting ◽

10.1175/waf-d-18-0156.1 ◽

2019 ◽

Vol 34 (5) ◽

pp. 1257-1276 ◽

Cited By ~ 1

Author(s):

Shawn M. Milrad ◽

Eyad H. Atallah ◽

John R. Gyakum ◽

Rachael N. Isphording ◽

Jonathon Klepatzki

Keyword(s):

Extreme Precipitation ◽

Western Europe ◽

Potential Temperature ◽

Precipitation Index ◽

Flow Reversal ◽

Precipitation Event ◽

Day Range ◽

Extreme Precipitation Index ◽

Abstract The extreme precipitation index (EPI) is a coupled dynamic–thermodynamic metric that can diagnose extreme precipitation events associated with flow reversal in the mid- to upper troposphere (e.g., Rex and omega blocks, cutoff cyclones, Rossby wave breaks). Recent billion dollar (U.S. dollars) floods across the Northern Hemisphere midlatitudes were associated with flow reversal, as long-duration ascent (dynamics) occurred in the presence of anomalously warm and moist air (thermodynamics). The EPI can detect this potent combination of ingredients and offers advantages over model precipitation forecasts because it relies on mass fields instead of parameterizations. The EPI’s dynamics component incorporates modified versions of two accepted blocking criteria, designed to detect flow reversal during the relatively short duration of extreme precipitation events. The thermodynamic component utilizes standardized anomalies of equivalent potential temperature. Proof-of-concept is demonstrated using four high-impact floods: the 2013 Alberta Flood, Canada’s second costliest natural disaster on record; the 2016 western Europe Flood, which caused the worst flooding in France in a century; the 2000 southern Alpine event responsible for major flooding in Switzerland; and the catastrophic August 2016 Louisiana Flood. EPI frequency maxima are located across the North Atlantic and North Pacific mid- and high latitudes, including near the climatological subtropical jet stream, while secondary maxima are located near the Rockies and Alps. EPI accuracy is briefly assessed using pattern correlation and qualitative associations with an extreme precipitation event climatology. Results show that the EPI may provide potential benefits to flood forecasters, particularly in the 3–10-day range.

Characteristics and Synoptic Patterns of Regional Extreme Rainfall over the Central and Eastern Tibetan Plateau in Boreal Summer

Atmosphere ◽

10.3390/atmos12030379 ◽

2021 ◽

Vol 12 (3) ◽

pp. 379

Author(s):

Jun Sun ◽

Xiuping Yao ◽

Guowei Deng ◽

Yi Liu

Keyword(s):

Tibetan Plateau ◽

South Asian ◽

Extreme Precipitation ◽

Extreme Rainfall ◽

Precipitation Event ◽

South Asian High ◽

Eastern Tibetan Plateau ◽

Line Type ◽

In this research, the observation datasets from 106 gauge stations over the central and eastern areas of the Tibetan Plateau (TP) and the ERA (ECMWF Re-Analysis)-Interim reanalysis datasets in the summers of 1981–2016 are used to study the characteristics and synoptic patterns of extreme precipitation events over the TP. By using a modern statistical method, the abnormal circulation characteristics at high, middle, and low latitudes in the Northern Hemisphere during extreme precipitation events over the central-eastern Tibetan Plateau are discussed, and the physical mechanisms related to the extreme precipitation events are investigated. The results show that the largest amount of extreme precipitation is found in the southern and eastern areas of the TP, where the frequency of daily extreme rainfall events (exceeding 25 mm) and the frequency of all extreme precipitation events both show obvious quasi-biweekly oscillation. When the daily extreme precipitation event threshold over the TP is met and more than 5 stations show daily extreme precipitation at the same time, with at least three of them being adjacent to each other, this is determined as a regional extreme precipitation event. As such, 33 regional daily extreme precipitation events occur during the summer periods of 1981–2016. According to the influence system, the 33 regional extreme precipitation events can be divided into three types, namely the plateau trough type, the plateau shear line type, and the plateau vortex type. For the plateau trough type, the South Asian high is anomalously strong at 100 hPa. For the other two types, the South Asian high is slightly weaker than usual. For the plateau shear line type, the development of the dynamic disturbance is the strongest, reaching 200 hPa. In the plateau trough type and plateau vortex type, the water vapor is transported by the westerly belt and the southwesterly flow from the Bay of Bengal.

Temperature scaling of extreme precipitation events – an application of the new DWD event catalogue

10.5194/ems2021-452 ◽

2021 ◽

Author(s):

Tanja Winterrath ◽

Ewelina Walawender ◽

Katharina Lengfeld ◽

Elmar Weigl ◽

Andreas Becker

Keyword(s):

Extreme Precipitation ◽

Ambient Air ◽

Precipitation Intensity ◽

Convective Precipitation ◽

Precipitation Event ◽

Precipitation Regimes ◽

Temperature Scaling ◽

First Results ◽

According to the Clausius-Clapeyron equation on saturation vapour pressure a temperature increase of 1&#160;K allows an atmospheric air mass to hold approximately 7&#160;% more water vapour thus increasing its potential for heavy precipitation. Several published measurement studies on the relation between precipitation intensity and temperature, however, revealed an increase of even up to twofold the CC rate for short-term precipitation events. Model conceptions explain this scaling behaviour with increasing temperature by different intensification pathways of convective processes and/or a transition between stratiform and convective precipitation regimes that both can hardly be verified by point measurements alone. In this presentation, we present first results of the correlation between ambient air temperature and different attributes of the Catalogue of Radar-based Heavy Rainfall Events (CatRaRE) recently published by Deutscher Wetterdienst (DWD). This object-oriented event catalogue files and characterizes extreme precipitation events that have occurred on German territory since 2001. It is based on the high-resolution precipitation climate data set RADKLIM of DWD, i.e. contiguous radar-based reflectivity measurements adjusted to hourly station-based precipitation totals and corrected for typical measurement errors applying specific climatological correction methods. Our analysis gives new insights into potential explanations of the observed temperature scaling relating not only precipitation intensity but characteristic event properties like area, duration, and extremity indices with ambient temperature data. With this approach, extreme precipitation events can be analysed in a comprehensive way that is significant in the context of potential impact. The presented analysis moreover allows testing the hypothesis of regime changing based on objective precipitation event criteria that are typical for different precipitation types. We will briefly present the methodological background of CatRaRE with special focus on the event attributes used in the analysis of Clausius-Clapeyron scaling and give first results on the retrieved temperature dependencies of extreme precipitation events.

Subseasonal to Seasonal Extreme Precipitation Events in the Contiguous United States: Generation of a Database and Climatology

Journal of Climate ◽

10.1175/jcli-d-20-0580.1 ◽

2021 ◽

pp. 1-47

Author(s):

Ty A. Dickinson ◽

Michael B. Richman ◽

Jason C. Furtado

Keyword(s):

United States ◽

New England ◽

Extreme Precipitation ◽

Extreme Event ◽

Significant Risk ◽

Optimal Number ◽

Precipitation Event ◽

Hybrid Index ◽

AbstractExtreme precipitation across multiple timescales is a natural hazard that creates a significant risk to life, with a commensurately large cost through property loss. We devise a method to create 14-day extreme event windows that characterize precipitation events in the contiguous United States (CONUS) for the years 1915 through 2018. Our algorithm imposes thresholds for both total precipitation and the duration of the precipitation to identify events with sufficient length to accentuate the synoptic and longer time scale contribution to the precipitation event. Kernel density estimation is employed to create extreme event polygons which are formed into a database spanning from 1915 through 2018. Using the developed database, we clustered events into regions using a k-means algorithm. We define the “Hybrid Index”, a weighted composite of silhouette score and number of clustered events, to show the optimal number of clusters is 14. We also show that 14-day extreme precipitation events are increasing in the CONUS, specifically in the Dakotas and much of New England. The algorithm presented in this work is designed to be sufficiently flexible to be extended to any desired number of days on the subseasonal-to-seasonal (S2S) timescale (e.g., 30 days). Additional databases generated using this framework are available for download from our GitHub. Consequently, these S2S databases can be analyzed in future works to determine the climatology of S2S extreme precipitation events and be used for predictability studies for identified events.

A Diagnostic Examination of Consecutive Extreme Cool-Season Precipitation Events at St. John’s, Newfoundland, in December 2008

Weather and Forecasting ◽

10.1175/2010waf2222371.1 ◽

2010 ◽

Vol 25 (4) ◽

pp. 997-1026 ◽

Cited By ~ 7

Author(s):

Shawn M. Milrad ◽

Eyad H. Atallah ◽

John R. Gyakum

Keyword(s):

Extreme Precipitation ◽

Trajectory Analysis ◽

Precipitation Amount ◽

Precipitation Event ◽

Cool Season ◽

Typing Method ◽

Weakly Stable ◽

Baroclinic Zone ◽

Abstract St. John’s, Newfoundland, Canada (CYYT), is frequently affected by extreme precipitation events, particularly in the cool season (October–April). Previous work classified precipitation events at CYYT into categories by precipitation amount and a manual synoptic typing was performed on the 50 median extreme precipitation events, using two separate methods. Here, consecutive extreme precipitation events in December 2008 are analyzed. These events occurred over a 6-day period and produced over 125 mm of precipitation at CYYT. The first manual typing method, using a backward-trajectory analysis, results in both events being classified as “southwest,” which were previously defined as the majority of the backward trajectories originating in the Gulf of Mexico. The second method of manual synoptic typing finds that the first event is classified as a “cyclone,” while the second is a “frontal” event. A synoptic analysis of both events is conducted, highlighting important dynamic and thermodynamic structures. The first event was characterized by strong quasigeostrophic forcing for ascent in a weakly stable atmosphere in association with a rapidly intensifying extratropical cyclone off the coast of North America and transient high values of subtropical moisture. The second event was characterized by primarily frontogenetical forcing for ascent in a weakly stable atmosphere in the presence of quasi-stationary high values of subtropical moisture, in association with a northeast–southwest-oriented baroclinic zone situated near CYYT. In sum, the synoptic structures responsible for the two events highlight rather disparate means to produce an extreme precipitation event at CYYT.

Dynamics of widespread extreme precipitation events and the associated large-scale environment using AMeDAS and JRA-55 data

Journal of Climate ◽

10.1175/jcli-d-21-0064.1 ◽

2021 ◽

pp. 1-44

Author(s):

Ryosuke Shibuya ◽

Yukari Takayabu ◽

Hirotaka Kamahori

Keyword(s):

Extreme Precipitation ◽

Large Scale ◽

Diabatic Heating ◽

Height Anomaly ◽

East China ◽

Precipitation Event ◽

Production Term ◽

Western Japan ◽

AbstractThis study examines disastrous historical precipitation cases that generate extreme precipitation simultaneously over a wide area in Japan (as in July 2018), defined as widespread extreme precipitation events. A statistically significant large-scale environment conducive for widespread extreme precipitation events over western Japan is investigated based on composite analysis. During a widespread precipitation event, a zonally elongated positive anomaly of the column-integrated water vapor extends from East China to western Japan. In the lower troposphere, a dipole of a geopotential height anomaly exists with positive and negative values at the east and west of the precipitation area, respectively. It is found that the negative geopotential anomaly is enhanced over East China at two days before the event and moves toward the precipitating area mainly due to the PV production term by diabatic heating, in analogy of a diabatic Rossby wave. The temporal evolution of the dynamical forced vertical velocity is well in phase with that the PV production term, inferring the importance of the coupling between the dynamical forced motion and diabatic heating. This result provides a physical understanding of the reason why both the background moisture and the baroclinicity are essential in the composited atmospheric fields and another view to the importance of the feedback parameter between the dynamical motion and diabatic heating.