Dynamics and Predictability of Large-Scale, High-Impact Weather and Climate Events

Abstract. Their economic and social importance emphasized by the survey of Department of Disaster Relief, Ministry of Civil Affairs of the People’s Republic of China, two different typical patterns of precipitation anomaly in the southern part of China during the 1982/1983 and 2009/2010 cold seasons coincided with the canonical El Niño and positive North Atlantic Oscillation (NAO) and with the El Niño Modoki and negative NAO, respectively. A better understanding of how a particular type of El Niño and a specific phase of NAO worked together to cause the relevant anomalous atmospheric circulation over the East Asia in the two high impact weather and climate cases was an interesting issue and could improve the prediction skill of natural hazards to a certain extent. In conclusion, superimposing on the remote and local Rossby wave responses in the atmosphere induced by the El Niño Modoki-related condensational heat sink over the South China Sea, the downstream extension of the negative NAO was well established by a NAO-induced stationary Rossby wave train along the Asian subtropical jet and played a major role in the persistent dry conditions in the Southwest China for the 2009/2010 boreal winter. On the contrary, for the 1982/1983 boreal winter, the canonical El Niño weakened the downstream extension of the positive NAO, and induced by the canonical El Niño-related condensational heat sink over the western equatorial Pacific Ocean, the remote and local Rossby wave responses in the atmosphere played a leading role in the sustained wet conditions in the South China.

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Advanced Data Assimilation and Predictability Studies on High-Impact Weather and Climate

Advances in Meteorology ◽

10.1155/2010/121763 ◽

2010 ◽

Vol 2010 ◽

pp. 1-2

Author(s):

Zhaoxia Pu ◽

Song-You Hong ◽

Yaohui Li ◽

Hann-Ming Henry Juang

Keyword(s):

Data Assimilation ◽

High Impact ◽

Weather And Climate ◽

High Impact Weather

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Modeling high-impact weather and climate: lessons from a tropical cyclone perspective

Climatic Change ◽

10.1007/s10584-013-0954-6 ◽

2013 ◽

Vol 129 (3-4) ◽

pp. 381-395 ◽

Cited By ~ 69

Author(s):

James M. Done ◽

Greg J. Holland ◽

Cindy L. Bruyère ◽

L. Ruby Leung ◽

Asuka Suzuki-Parker

Keyword(s):

Tropical Cyclone ◽

High Impact ◽

Weather And Climate ◽

High Impact Weather

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Weather regimes in South East Asia: Sub-seasonal predictability of the regimes and the associated high impact weather

10.5194/egusphere-egu21-7411 ◽

2021 ◽

Author(s):

Paula Gonzalez ◽

Emma Howard ◽

Simon Thomas ◽

Thomas Frame ◽

Oscar Martinez-Alvarado ◽

...

Keyword(s):

East Asia ◽

Large Scale ◽

High Impact ◽

Lead Times ◽

South East Asia ◽

Synoptic Scale ◽

Seasonal Predictability ◽

Weather Regimes ◽

Predictive Skill ◽

High Impact Weather

<div> <p>This work considers the sub-seasonal predictability of two sets of weather regimes for South East Asia: a two-tiered assignment, that first considers large-scale patterns and then assigns synoptic-scale regimes, and a flat classification, which only considers the synoptic scale. In the two-tiered approach, the tier 1 large-scale regimes, which capture ENSO and seasonal variations, are each partitioned into South East Asia regional clusters that capture synoptic variability.&#160;&#160;&#160;</p> </div><div> <p>The sub-seasonal predictability of both the standard and tiered regimes is assessed using UKMO GloSea5 hindcasts and forecasts for lead times of up to 5 weeks. We find that the GloSea5 system presents an accurate representation of the regimes&#8217; climatology and a good level of skill for their assignment. Nonetheless, the predictability depends on the specific regimes and some significant forecast drifts are also identified. Additionally, the predictive skill of high impact precipitation events obtained statistically from the prediction of the regimes is assessed and compared with the probabilistic precipitation forecasts of the GloSea5 ensemble.&#160;&#160;&#160;&#160;</p> </div><div> <p>A description of the regime classification methodology and their connections to seasonal and synoptic phenomena will be discussed in a separate presentation, titled &#8220;Weather regimes in South East Asia: connections with synoptic phenomena and high impact weather&#8221; and presented by Emma Howard.&#160;</p> </div>

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Weather regimes in South East Asia: connections with synoptic phenomena and high impact weather

10.5194/egusphere-egu21-7472 ◽

2021 ◽

Author(s):

Emma Howard ◽

Paula Gonzalez ◽

Simon Thomas ◽

Thomas Frame ◽

Oscar Martinez-Alvarado ◽

...

Keyword(s):

East Asia ◽

Large Scale ◽

High Impact ◽

Precipitation Forecast ◽

South East Asia ◽

Weather Regimes ◽

Modes Of Variability ◽

Synoptic Weather ◽

High Impact Weather ◽

Second Tier

<div> <p>&#160;</p> </div><div> <p>A tiered set of weather regimes describing variability in 850&#160;hPa&#160;winds in South East Asia (SEA) is presented and compared to a corresponding non-tiered set of weather regimes. The tiered regimes are calculated in two parts: the first tier computed by applying EOF/K-means clustering on a planetary scale domain which partitioning seasonal variation and ENSO, and the second tier obtained by EOF/K-means clustering on a smaller SE Asia regional domain, partitioning the synoptic variability within each of the&#160;first tier&#160;regimes. This identifies synoptic weather phenomena with multi-day persistence. In contrast, the un-tiered (&#8220;flat&#8221;) clustering approach uses a standard EOF/K-means classification in the regional domain without conditional dependence on large-scale, with the number of regimes set to match the tiered regimes.&#160;&#160;</p> </div><div> <p>These regimes are used to study the likelihood of extreme precipitation depending on synoptic circulation. We consider the conditional probability depending on regime type of synoptic weather events including cold surges, phases of the MJO and BSISO, tropical cyclones, Borneo Vortices and equatorial waves. We then study the regime-conditioned probability of high percentile TRMM precipitation. We find that a perfect regime forecast would have greater skill than the GloSEA5 precipitation forecast for lead times longer than approximately one week. The tiered regimes distinguish a greater fraction of considered modes of variability, while the flat regimes better distinguish the precipitation variability.&#160;&#160;</p> </div><div> <p>The predictability of these regimes will be discussed in a separate presentation, titled &#8220;Weather regimes in South East Asia: Sub-seasonal predictability of the regimes and the associated high impact weather&#8221; and presented by Paula Gonzalez.&#160;</p> </div>

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A methodology to conduct wind damage field surveys for high-impact weather events of convective origin

Natural Hazards and Earth System Science ◽

10.5194/nhess-20-1513-2020 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1513-1531 ◽

Cited By ~ 5

Author(s):

Oriol Rodríguez ◽

Joan Bech ◽

Juan de Dios Soriano ◽

Delia Gutiérrez ◽

Salvador Castán

Keyword(s):

Field Studies ◽

High Impact ◽

Strong Wind ◽

Field Surveys ◽

Weather Events ◽

Straight Line ◽

High Impact Weather ◽

Strong Winds ◽

Wind Events ◽

The One

Abstract. Post-event damage assessments are of paramount importance to document the effects of high-impact weather-related events such as floods or strong wind events. Moreover, evaluating the damage and characterizing its extent and intensity can be essential for further analysis such as completing a diagnostic meteorological case study. This paper presents a methodology to perform field surveys of damage caused by strong winds of convective origin (i.e. tornado, downburst and straight-line winds). It is based on previous studies and also on 136 field studies performed by the authors in Spain between 2004 and 2018. The methodology includes the collection of pictures and records of damage to human-made structures and on vegetation during the in situ visit to the affected area, as well as of available automatic weather station data, witness reports and images of the phenomenon, such as funnel cloud pictures, taken by casual observers. To synthesize the gathered data, three final deliverables are proposed: (i) a standardized text report of the analysed event, (ii) a table consisting of detailed geolocated information about each damage point and other relevant data and (iii) a map or a KML (Keyhole Markup Language) file containing the previous information ready for graphical display and further analysis. This methodology has been applied by the authors in the past, sometimes only a few hours after the event occurrence and, on many occasions, when the type of convective phenomenon was uncertain. In those uncertain cases, the information resulting from this methodology contributed effectively to discern the phenomenon type thanks to the damage pattern analysis, particularly if no witness reports were available. The application of methodologies such as the one presented here is necessary in order to build homogeneous and robust databases of severe weather cases and high-impact weather events.

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Introduction to the special issue: Compound weather and climate events

Weather and Climate Extremes ◽

10.1016/j.wace.2021.100381 ◽

2021 ◽

pp. 100381

Author(s):

Jakob Zscheischler ◽

Jana Sillmann ◽

Lisa Alexander

Keyword(s):

Special Issue ◽

Weather And Climate ◽

Climate Events

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