Discriminating downburst-producing and hail-bearing thunderstorms using total lightning and weather radar observations T. Rigo (1), M. Aran (1), J. Bech (2), C. Farnell (1), J. Mateo (1), N. Pineda (1), R. Ripoll (1), and A. Serra (1) (1) Meteorological Service of Catalonia, Barcelona ([email protected]), (2) Department of Astronomy and Meteorology. University of Barcelona. Barcelona ([email protected]) Objectives • generation of a preliminary data base of severe weather convective events (hail and wind) for Catalonia • development of a methodology for the validation of the events • first characterization of key elements for the identification of both types of phenomena STARTING POINT Starting: 2 existing DDBB LOCATION LAT LON YYYY MM DD HH TYPE Rupit 42.03 2.47 2001 10 20 14 TORNADO Sant Miquel de Pineda 42.1 2.49 2001 10 20 15 TORNADO Montgat 41.47 2.28 2001 11 16 15 TORNADO Solsona 41.98 1.52 2002 10 21 18 TORNADO Castelldefels 41.28 1.97 2005 9 7 16.3 TORNADO Santa Colomba de Cervello 41.37 2.02 2006 2 21 16.45 TORNADO Tarragona 41.12 1.25 2006 8 16 15.5 TORNADO Castelldefels 41.27 1.97 2006 9 13 10.3 TORNADO San Feliu de Llobregat 41.38 2.05 2006 9 13 11 TORNADO Santa Coloma de Cervello 41.37 2.02 2006 9 13 14 TORNADO Puiggros 41.55 0.9 2007 8 6 HAIL Juneda 41.53 0.82 2007 8 6 HAIL Arbeca 41.53 0.93 2007 8 6 HAIL Golmes 41.63 0.93 2007 8 6 HAIL Castellnou de Seana 41.65 0.98 2007 8 6 HAIL Vilanova de Bellpuig 41.62 0.97 2007 8 6 HAIL Sitges 41.25 1.8 2007 8 12 20 TORNADO Mollerussa 41.62 0.62 2007 9 17 HAIL Tarragona 41.12 1.25 2008 1 16 14.15 WIND Bescano 41.97 2.75 2008 3 22 HAIL salt 41.98 2.79 2008 3 22 HAIL Palafolls 41.67 2.75 2008 3 22 HAIL Malgrat de Mar 41.65 2.75 2008 3 22 HAIL Santa Coloma de Gramanet 41.43 2.21 2008 4 17 17.3 TORNADO Salou 41.07 1.13 2008 7 12 HAIL Puigverd de Lleida 41.53 0.73 2008 9 11 HAIL El Masnou 41.48 2.3 2008 10 3 HAIL Parets del Valles 41.58 2.23 2008 10 3 HAIL Garraf 41.25 1.9 2008 10 17 17 TORNADO Solivella 41.45 1.18 2008 11 2 3.3 WIND Reus 41.16 1.11 2008 11 2 3.3 WIND Salou 41.08 1.14 2008 11 2 3.3 WIND Sarral 41.45 1.25 2008 11 2 4 TORNADO LEspluga de Francoli 41.39 1.1 2008 11 2 4 WIND Vilassar de Mar 41.51 2.39 2008 11 2 10.3 WIND el Prat de Llobregat 41.33 2.1 2008 12 26 11 WIND Vacarisses 41.6 1.92 2009 1 24 2 WIND La Palma 41.4 1.97 2009 1 24 6 WIND Abrera 41.52 1.9 2009 1 24 6 WIND Sant Boi de Llobregat 41.34 2.04 2009 1 24 9 WIND Cantallops 42.42 2.92 2009 2 1 15 TORNADO Starting: SMC data SPOTTERS Question: Could we have a good database of severe weather convective events for Catalonia? (non-tornadic strong winds > 20 m/s tornadic winds hail size > 2 cm) STARTING POINT PRELIMINARY DATABASE Preliminary DataBase Preliminary DataBase Once we have the preliminary fields, verification is needed However, the first set of events allow to identify different regions affected by severe weather phenomena PRELIMINARY DATABASE VALIDATION Validation of the events DB RECORD LON LAT YEAR MONTH DAY HOUR MINUTE DATABASE 41.72 0.59 2014 9 4 23 30 SINOBAS/ESWD • XEMA (AWS) • Radar animations Validation of the events DB RECORD LON LAT YEAR MONTH DAY HOUR MINUTE DATABASE 41.32 0.87 2013 6 18 13 45 SINOBAS • XEMA (AWS) • Radar animations INCORRECT HOUR OR LOCATION MORE POINTS TO ADD Validation of the events DB RECORD LON LAT YEAR MONTH DAY HOUR MINUTE DATABASE 41.12 1.25 2014 12 8-9 18 0 ESWD • XEMA (AWS) • Radar animations Adding new episodes SMC DATABASE: hail-pad reports, watchers, remote sensing and AWS observations… Only few cases have been added in the first phase Some cases were OK in the first database, but many others need corrections (time and/or location). A residual set of events has been removed VALIDATION FIRST ANALYSIS OF THE CORRECTED DATABASE Analysis of the events: SMC Spotters www.meteo.cat/observacions/xom_vigilancia Analysis: Synoptic charts - (A) passage of a mid-level trough (W to E) in (60 % of events). Not deep trough (35 % of A cases). at 700 hPa W winds. Local convergences at SRF mainly trigger convection (03/10/2008) - (B) ridge at mid-tropo over the Iberian pen. (25% of events). Short wave crossing through N Catalonia. Small CIN with high contrast 500 vs 850 hPa. Convection triggered in the mountains (10/04/2011) A B 500 hPa A B 850 hPa Analysis: Synoptic charts - (A) Omega configuration (21/02/2006) - (B) Depression NE Europe. At 500 hPa trough at NW of Iberian pen. SRH0–3 km > 150 m2/s2. Cut-off low over the Iberian peninsula (02/11/2008) - (C) secondary low near the Catalan coast (12/08/2007) A B C 500 hPa A B C 850 hPa Analysis: Thermodynamics • LI < -3 & tmp 850-500 hPa > 28°C are good indicators for hail diam > 2.5 cm. • CAPE not good indicator • PW significative values for summer season Analysis: Thermodynamics • sRH(0-3km) - in 14/31 shows high values • EHI & CAPE not representative Analysis: Lightning jump TRACK RADAR LIGHTNING FLASHES RIGO ET AL, 2010 Analysis: Lightning jump LIGHT. FLASHES RADAR TRACK LJ FLASH RATE IC PHENOMENON OBSERVATION CG Metzger & Nuss, 2013 Nuss, & Metzger Analysis: Lightning jump LIGHT. FLASHES RADAR TRACK LJ FLASH RATE IC PHENOMENON OBSERVATION CG Metzger & Nuss, 2013 Nuss, & Metzger Analysis: Lightning jump GENERAL 72 events Before Ontime After < t0-10 min t0-10/t0+10 >t0+10 %IC 29.2 11.1 6.9 %CG 2.8 20.8 6.9 BOTH=IC+CG %BOTH 45.8 19.4 13.9 %NO 22.2 48.6 72.2 HAIL 33 events WIND 8 events TORNADO 31 events Before Ontime After Before Ontime After Before Ontime After < t0-10 min t0-10/t0+10 >t0+10 < t0-10 min t0-10/t0+10 >t0+10 < t0-10 min t0-10/t0+10 >t0+10 %IC 27.3 6.1 9.1 %IC 25 25 0 %IC 32.3 12.9 6.5 %CG 3.0 21.2 12.1 %CG 12.5 0 0 %CG 0.0 25.8 3.2 %BOTH 63.6 24.2 9.1 %BOTH 37.5 0 0 %BOTH 29.0 19.4 22.6 %NO 6.1 48.5 69.7 %NO 25 75 100 %NO 38.7 41.9 67.7 Analysis: MSG BT IR V-SHAPE 2012/07/05 2012/03/21 2013/08/24 Brunner et al, 2007 MSG Brunner Observation Analysis: MSG BT IR V-SHAPE GENERAL 49 events Over Close Far <10 km 10-30 km >30 km %NO 46.9 14.3 26.5 %YES 53.1 85.7 73.5 HAIL 21 events WIND 5 events TORNADO 23 events Over Close Far Over Close Far Over Close Far <10 km 10-30 km >30 km <10 km 10-30 km >30 km <10 km 10-30 km >30 km %NO 19.0 4.8 23.8 %NO 20 20 40 %NO 78.3 21.7 26.1 %YES 81.0 95.2 76.2 %YES 80 80 60 %YES 21.7 78.3 73.9 - Preliminary version of blended data base developed - Predominant synoptic patterns identified - Lightning jump (LJ) analysis over 72 cases performed - 80% of cases (95% for hail) present LJ 10’ before (nowcasting potential) - For non hail events LJ not so clear for cases studied - Satellite IR V-Shape structure analysis over 49 cases performed - 80% of hail and donwburst cases this feature was identified within 10 km FINAL REMARKS - Improve the database number of cases: AWS, watchers, remote sensing… - Consider all the phenomenon observed for each event - Identify key signatures using remote sensing (new DB improvement) - Development of automatic algorithms for improving nowcasting and diagnosis of severe weather FUTURE WORK MAX WIND GUST MAX REFLECTIV. 31st August 2015 31st August 2015 THANKS FOR YOUR ATTENTION Objectives Long range (future): • Improvement of the data base with new cases and more information • systematical application of the methodology of validation of new events • analysis of the key elements associated with hail or winds phenomena, and developing of models for operational purpose.