Evaluation of thunderstorm indices from ECMWF analyses, lightning data and severe storm reports

Abstract

This study describes the environmental atmospheric characteristics in the vicinity of different types of severe convective storms in Europe during the warm seasons in 2006 and 2007. 3406 severe weather events from the European Severe Weather Database ESWD were investigated to get information about different types of severe local storms, such as significant or weak tornadoes, large hail, damaging winds, and heavy precipitation. These data were combined with EUCLID (European Cooperation for Lightning Detection) lightning data to distinguish and classify thunderstorm activity on a European scale into seven categories: none, weak and 5 types of severe thunderstorms. Sounding parameters in close proximity to reported events were derived from daily high-resolution T799 ECMWF (European Centre for Medium-range Weather Forecasts) analyses. We found from the sounding-derived parameters in Europe: 1) Instability indices and CAPE have considerable skill to predict the occurrence of thunderstorms and the probability of severe events. 2) Low level moisture can be used as a predictor to distinguish between significant tornadoes or non-severe convection. 3) Most of the events associated with wind gusts during strong synoptic flow situations reveal the downward transport of momentum as a very important factor. 4) While deep-layer shear discriminates well between severe and non-severe events, the storm-relative helicity in the 0-1 km and especially in the 0-3 km layer adjacent to the ground has more skill in distinguishing between environments favouring significant tornadoes and wind gusts versus other severe events. Additionally, composite parameters that combine measurements of buoyancy, vertical shear and low level moisture have been tested to discriminate between severe events.

Sounding‐derived parameters associated with tornadic storms in Catalonia

“…The highest values of SRH 03 are in EF2 soundings, as is also commented on the above‐mentioned article and in Kaltenböck et al . (). Four of the five EF2 soundings of our database surpassed an SRH 03 of 180 m 2 s −2 (not shown).…”

“…One additional parameter relevant in previous studies was also included: SBCAPE (e.g. Kaltenböck et al, ; Taszarek and Kolendowicz, ). All of them are listed and referenced in Table .…”

Anomalous electric field changes and high flash rate beneath a thunderstorm in northeast India

“…Steiger et al (2007) found that a total lightning hole was associated with an intense, non-tornadic supercell; whereas none of the supercells exhibited a lightning hole in their observations over Dallas-Fort Worth, Texas. Kaltenböck et al (2009) also have reported more CG lightning during days with severe weather, especially with hail, wind and precipitation events from organized and clustered thunderstorm systems.…”

Impact of ASCAT Soil Moisture Assimilation on Regional Precipitation Forecasts: A Case Study for Austria

“…Nowadays, high-resolution models are resolving features such as synoptic forcing and local influences like orography and convergence zones which are predominant for thunderstorm initiation (Kaltenb€ ock et al 2009). Moreover, the need for proper soil moisture representation is well understood.…”