Orographic effect on extreme precipitation statistics peaks at hourly time scales

<p>Temporal clustering of extreme precipitation events on subseasonal time scales is a type of compound event, which can cause large precipitation accumulations and lead to floods. We present a novel count-based procedure to identify subseasonal clustering of extreme precipitation events. Furthermore, we introduce two metrics to characterise the frequency of subseasonal clustering episodes and their relevance for large precipitation accumulations. The advantage of this approach is that it does not require the investigated variable (here precipitation) to satisfy any specific statistical properties. Applying this methodology to the ERA5 reanalysis data set, we identify regions where subseasonal clustering of annual high precipitation percentiles occurs frequently and contributes substantially to large precipitation accumulations. Those regions are the east and northeast of the Asian continent (north of Yellow Sea, in the Chinese provinces of Hebei, Jilin and Liaoning; North and South Korea; Siberia and east of Mongolia), central Canada and south of California, Afghanistan, Pakistan, the southeast of the Iberian Peninsula, and the north of Argentina and south of Bolivia. Our method is robust with respect to the parameters used to define the extreme events (the percentile threshold and the run length) and the length of the subseasonal time window (here 2 &#8211; 4 weeks). The procedure could also be used to identify temporal clustering of other variables (e.g. heat waves) and can be applied on different time scales (e.g. for drought years). <span>For a complementary study on the subseasonal clustering of European extreme precipitation events and its relationship to large-scale atmospheric drivers, please refer to Barton et al.</span></p>

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Clustering of Regional-Scale Extreme Precipitation Events in Southern Switzerland

Monthly Weather Review ◽

10.1175/mwr-d-15-0205.1 ◽

2016 ◽

Vol 144 (1) ◽

pp. 347-369 ◽

Cited By ~ 22

Author(s):

Yannick Barton ◽

Paraskevi Giannakaki ◽

Harald von Waldow ◽

Clément Chevalier ◽

Stephan Pfahl ◽

...

Keyword(s):

Time Scales ◽

Extreme Precipitation ◽

Wave Breaking ◽

Large Scale ◽

Statistical Significance ◽

Regional Scale ◽

Breaking Waves ◽

Temporal Clustering ◽

Extreme Precipitation Events ◽

Precipitation Events

Abstract Temporal clustering of extreme precipitation events on subseasonal time scales is of crucial importance for the formation of large-scale flood events. Here, the temporal clustering of regional-scale extreme precipitation events in southern Switzerland is studied. These precipitation events are relevant for the flooding of lakes in southern Switzerland and northern Italy. This research determines whether temporal clustering is present and then identifies the dynamics that are responsible for the clustering. An observation-based gridded precipitation dataset of Swiss daily rainfall sums and ECMWF reanalysis datasets are used. Also used is a modified version of Ripley’s K function, which determines the average number of extreme events in a time period, to characterize temporal clustering on subseasonal time scales and to determine the statistical significance of the clustering. Significant clustering of regional-scale precipitation extremes is found on subseasonal time scales during the fall season. Four high-impact clustering episodes are then selected and the dynamics responsible for the clustering are examined. During the four clustering episodes, all heavy precipitation events were associated with an upper-level breaking Rossby wave over western Europe and in most cases strong diabatic processes upstream over the Atlantic played a role in the amplification of these breaking waves. Atmospheric blocking downstream over eastern Europe supported this wave breaking during two of the clustering episodes. During one of the clustering periods, several extratropical transitions of tropical cyclones in the Atlantic contributed to the formation of high-amplitude ridges over the Atlantic basin and downstream wave breaking. During another event, blocking over Alaska assisted the phase locking of the Rossby waves downstream over the Atlantic.

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Spatiotemporal variations of extreme precipitation events at multi-time scales in the Qinling-Daba mountains region, China

Quaternary International ◽

10.1016/j.quaint.2019.07.029 ◽

2019 ◽

Vol 525 ◽

pp. 89-102 ◽

Cited By ~ 3

Author(s):

Yiting Shao ◽

Xingmin Mu ◽

Yi He ◽

Wenyi Sun ◽

Guangju Zhao ◽

...

Keyword(s):

Time Scales ◽

Extreme Precipitation ◽

Spatiotemporal Variations ◽

Extreme Precipitation Events ◽

Precipitation Events

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Projected changes in extreme precipitation at sub-daily and daily time scales

10.17077/etd.na49-82ap ◽

2019 ◽

Author(s):

Alex Morrison

Keyword(s):

Time Scales ◽

Extreme Precipitation ◽

Projected Changes ◽

Daily Time

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Climatology of Extreme Precipitation in Japan for Different Time Scales

SOLA ◽

10.2151/sola.2011-040 ◽

2011 ◽

Vol 7 ◽

pp. 157-160 ◽

Cited By ~ 6

Author(s):

Junya Miyajima ◽

Fumiaki Fujibe

Keyword(s):

Time Scales ◽

Extreme Precipitation ◽

Different Time Scales

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Intraseasonal and Interannual Variability of Extreme Dry and Wet Events over Southeastern South America and the Subtropical Atlantic during Austral Summer

Journal of Climate ◽

10.1175/2008jcli2257.1 ◽

2009 ◽

Vol 22 (7) ◽

pp. 1682-1699 ◽

Cited By ~ 48

Author(s):

Michel N. Muza ◽

Leila M. V. Carvalho ◽

Charles Jones ◽

Brant Liebmann

Keyword(s):

South America ◽

Interannual Variability ◽

Time Scales ◽

Extreme Precipitation ◽

Precipitation Anomaly ◽

South Atlantic ◽

Southeastern Brazil ◽

The South ◽

Extreme Precipitation Events ◽

Precipitation Regimes

Abstract Intraseasonal and interannual variability of extreme wet and dry anomalies over southeastern Brazil and the western subtropical South Atlantic Ocean are investigated. Precipitation data are obtained from the Global Precipitation Climatology Project (GPCP) in pentads during 23 austral summers (December–February 1979/80–2001/02). Extreme wet (dry) events are defined according to 75th (25th) percentiles of precipitation anomaly distributions observed in two time scales: intraseasonal and interannual. The agreement between the 25th and 75th percentiles of the GPCP precipitation and gridded precipitation obtained from stations in Brazil is also examined. Variations of extreme wet and dry anomalies on interannual time scales are investigated along with variations of sea surface temperature (SST) and circulation anomalies. The South Atlantic SST dipole seems related to interannual variations of extreme precipitation events over southeastern Brazil. It is shown that extreme wet and dry events in the continental portion of the South Atlantic convergence zone (SACZ) are decoupled from extremes over the oceanic portion of the SACZ and there is no coherent dipole of extreme precipitation regimes between tropics and subtropics on interannual time scales. On intraseasonal time scales, the occurrence of extreme dry and wet events depends on the propagation phase of extratropical wave trains and consequent intensification (weakening) of 200-hPa zonal winds. Extreme wet and dry events over southeastern Brazil and subtropical Atlantic are in phase on intraseasonal time scales. Extreme wet events over southeastern Brazil and subtropical Atlantic are observed in association with low-level northerly winds above the 75th percentile of the seasonal climatology over central-eastern South America. Extreme wet events on intraseasonal time scales over southeastern Brazil are more frequent during seasons not classified as extreme wet or dry on interannual time scales.

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Retrospective Sub-Seasonal Forecasts of Extreme Precipitation Events In The Arabian Peninsula Using Convective-Permitting Modeling

10.21203/rs.3.rs-733656/v1 ◽

2021 ◽

Author(s):

Christoforus Bayu Risanto ◽

Hsin-I Chang ◽

Thang M. Luong ◽

Christopher L. Castro ◽

Hari P. Dasari ◽

...

Keyword(s):

Time Scales ◽

Red Sea ◽

West Coast ◽

Extreme Precipitation ◽

Lead Time ◽

Arabian Peninsula ◽

Lead Times ◽

The West ◽

Extreme Precipitation Events ◽

Precipitation Events

Abstract This paper is to demonstrate the potential of extreme cool-season precipitation forecasts in the Arabian Peninsula (AP) at sub-seasonal time scales, identify the region and periods of forecast opportunity, and investigate the predictability of synoptic-scale forcing at sub-seasonal time scales. To this end, we simulate 18 extreme precipitation events using the convective-permitting weather research and forecasting (CP-WRF) model with lateral boundary forcing from the European Centre of Medium-range Weather Forecasts sub-seasonal to seasonal reforecasts (ECMWF S2S reforecasts). The simulations are initiated at one-, two-, and three-week lead times. At all lead times, the CP-WRF improved the mean accumulated precipitation in the extratropical synoptic regimes over the west coastal and central AP and the central Red Sea. Based on categorical statistics with a threshold of 20-mm accumulated precipitation over 7 days, the CP-WRF accurately forecasted the precipitation over Jeddah, the west coast of AP, and the central Red Sea up to three weeks lead time. The relative operating characteristic curve reconfirmed the high forecasting skill of the CP-WRF, with an area under the curve above 0.5 in most of the events at all lead times. Finally, the correlation coefficients between the ECMWF and ECMWF reanalysis interim 500-hPa geopotential heights were higher in the events associated with the extratropical synoptic regime than in those associated with the tropical synoptic regime, regardless of lead time. Therefore, the convective-permitting model can potentially improve the accuracy of extreme winter precipitation forecasts at two-and three-week lead times over Jeddah, the west coast of AP, and the central Red Sea in the extratropical synoptic regime.

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A novel method to identify sub-seasonal clustering episodes of extreme precipitation events and their contributions to large accumulation periods

10.5194/hess-2021-67 ◽

2021 ◽

Author(s):

Jérôme Kopp ◽

Pauline Rivoire ◽

S. Mubashshir Ali ◽

Yannick Barton ◽

Olivia Martius

Keyword(s):

Time Scales ◽

Extreme Precipitation ◽

Time Window ◽

Heat Waves ◽

Reanalysis Data ◽

Data Set ◽

The North ◽

Extreme Precipitation Events ◽

Compound Event ◽

Precipitation Events

Abstract. Temporal (serial) clustering of extreme precipitation events on sub-seasonal time scales is a type of compound event. It can cause large precipitation accumulations and lead to floods. We present a novel, count-based procedure to identify episodes of sub-seasonal clustering of extreme precipitation. We introduce two metrics to characterise the frequency of sub-seasonal clustering episodes and their relevance for large precipitation accumulations. The procedure does not require the investigated variable (here precipitation) to satisfy any specific statistical properties. Applying this procedure to daily precipitation from the ERA5 reanalysis data set, we identify regions where sub-seasonal clustering occurs frequently and contributes substantially to large precipitation accumulations. The regions are the east and northeast of the Asian continent (north of Yellow Sea, in the Chinese provinces of Hebei, Jilin and Liaoning; North and South Korea; Siberia and east of Mongolia), central Canada and south of California, Afghanistan, Pakistan, the southwest of the Iberian Peninsula, and the north of Argentina and south of Bolivia. Our method is robust with respect to the parameters used to define the extreme events (the percentile threshold and the run length) and the length of the sub-seasonal time window (here 2–4 weeks). This procedure could also be used to identify temporal clustering of other variables (e.g. heat waves) and can be applied on different time scales (sub-seasonal to decadal). The code is available at the listed GitHub repository.

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