Price et al. (2011) Using Lightning Data to Better Understand and Predict Flash Floods in the Mediterranean

Identification

• Journal: Surveys in Geophysics
• Year: 2011
• Date: 2011-09-16
• Authors: Colin Price, Yoav Yair, A. Mugnai, K. Lagouvardos, María Carmen Llasat, Silas Michaelides, Uri Dayan, Stefano Dietrich, Francesco Di Paola, Eli Galanti, Luís Garrote, N. Harats, Dimitrios Katsanos, M. Kohn, V. Kotroni, Montserrat Llasat-Botija, Barry Lynn, Luis Mediero, Efrat Morin, K. Nicolaides, S. Rozalis, K. Savvidou, Baruch Ziv
• DOI: 10.1007/s10712-011-9146-y

Research Groups

• Tel Aviv University, Tel Aviv, Israel
• The Open University of Israel, Ra’anana, Israel
• National Research Council, ISAC, Rome, Italy
• National Observatory of Athens, Athens, Greece
• University of Barcelona, Barcelona, Spain
• Cyprus Meteorological Service, Nicosia, Cyprus
• Hebrew University of Jerusalem, Jerusalem, Israel
• Technical University of Madrid, Madrid, Spain

Short Summary

The EU FP6 FLASH project (2006-2010) investigated using lightning data to improve the understanding and prediction of flash floods in the Mediterranean, demonstrating its utility for real-time storm monitoring, enhancing satellite rainfall estimates, and improving short-term nowcasts and medium-range forecasts.

Objective

• To better understand and predict flash floods in the Mediterranean region by leveraging lightning observations, developing nowcasting and forecasting tools, and analyzing the associated meteorological and hydrological processes.

Study Configuration

• Spatial Scale: Mediterranean region and Europe, with 23 specific flash flood case studies spanning from Spain to Israel. Hydrological modeling focused on catchments ranging from 0.5 km² to 1,020 km².
• Temporal Scale: The project spanned 4 years (2006-2010). Data (lightning, satellite imagery) were updated every 15 minutes. Nowcasting tools provided predictions up to 3 hours, while forecasting tools extended to a few days.

Methodology and Data

• Models used:
  • Mesoscale Meteorological Models: MM5 (Version 3), WRF (Weather Research and Forecasting model).
  • Hydrological Models: CASURA (SCS curve number rainfall-runoff model with Kinematic wave routing), RIBS (Real-time Interactive Basin Simulator).
• Data sources:
  • Lightning data: ZEUS ground-based VLF detection network, satellite observations (LEO satellites, optical sensors).
  • Rainfall data: Surface rain gauge measurements, radar estimated rainfall, satellite microwave retrievals (AMSU sensor), METEOSAT cloud-top infrared imagery.
  • Synoptic data: ECMWF reanalysis.
  • Topography data: Digital Elevation Model (DEM).
  • Societal impact data: Systematic database of news items and flood events.

Main Results

• Real-time regional lightning observations are highly effective for detecting, monitoring, and tracking intense thunderstorm activity over large spatial scales.
• Lightning data significantly improve satellite-based rainfall estimations, particularly by "filling in the gaps" from coarse temporal sampling of Low Earth Orbiting satellites through a developed lightning-based "morphing" methodology.
• Nowcasting tools for intense convection were developed, showing a Probability of Detection (POD) of 0.46 for 30-minute lead times and a low false alarm rate of 0.03 for 30-minute nowcasts.
• Assimilating lightning data into numerical models (MM5) qualitatively improved initial conditions and 1-2 day forecasts of heavy precipitation.
• New Mediterranean-specific synoptic indicators (Modified K-Index (MKI) and Dynamic Rain Index (DRI)) were developed, providing better localized representation of flash flood risk.
• A Lightning Potential Index (LPI) was developed using WRF model microphysical parameters, showing reasonable agreement with observed lightning activity.
• Hydrological models (CASURA, RIBS) accurately simulated peak river discharge in studied catchments using radar rainfall data.
• Analysis of societal impacts revealed a rising trend in damages and social impact from floods in the Mediterranean, underscoring the need for improved public awareness and risk reduction.

Contributions

• Established the first comprehensive project (EU FP6 FLASH) dedicated to utilizing lightning observations for flash flood understanding and prediction in the Mediterranean.
• Developed a novel lightning-based "morphing" methodology to combine microwave rainfall retrievals with continuous lightning data, addressing temporal gaps in satellite observations.
• Introduced a Lightning Potential Index (LPI) derived from WRF model microphysical parameters for forecasting electrical activity.
• Created new Mediterranean-specific synoptic indicators (MKI, DRI) for improved flash flood risk forecasting.
• Demonstrated the practical application of lightning data for real-time nowcasting, improving initial conditions for medium-range weather models, and enhancing satellite rainfall estimates.
• Established a systematic database of natural hazard news and flood events in the Mediterranean, contributing to the understanding of societal impacts and vulnerability trends.
• Developed extensive educational outreach materials and platforms to increase public awareness of flash floods and thunderstorms.

Funding

• European Union FP6 FLASH project (2006-2010), with a total budget of €1.2 million.

Citation

@article{Price2011Using,
  author = {Price, Colin and Yair, Yoav and Mugnai, A. and Lagouvardos, K. and Llasat, María Carmen and Michaelides, Silas and Dayan, Uri and Dietrich, Stefano and Paola, Francesco Di and Galanti, Eli and Garrote, Luís and Harats, N. and Katsanos, Dimitrios and Kohn, M. and Kotroni, V. and Llasat-Botija, Montserrat and Lynn, Barry and Mediero, Luis and Morin, Efrat and Nicolaides, K. and Rozalis, S. and Savvidou, K. and Ziv, Baruch},
  title = {Using Lightning Data to Better Understand and Predict Flash Floods in the Mediterranean},
  journal = {Surveys in Geophysics},
  year = {2011},
  doi = {10.1007/s10712-011-9146-y},
  url = {https://doi.org/10.1007/s10712-011-9146-y}
}