SOME OPERATIONAL ASPECTS OF USING LIGHTNING DATA

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SOME OPERATIONAL ASPECTS OF USING LIGHTNING DATA
IN FORECASTING OF SEVERE STORMS B. Antonescu,
A. Tanase, S. Burcea, Aurora Stan-Sion National
Meteorological Administration, Bucharest, Romania
Corresponding author bogdan.antonescu_at_meteo.inm
h.ro
1. INTRODUCTION From August 2002 a lightning
detection network (LDN) SAFIR 3000 has been
operating in Romania (Figure 1).
2. RESULTS
In order to determine the accuracy of the
forecasting of first cloud-toground lightning,
were calculated several statistical quantities
Fals Alarme Ratio (FAR), Probability of Detection
(POD) and Critical Success Index (CSI) (Figure
2).
Figure 1 The configuration of lightning detection
network
Figure 2 FAR,POD and CSI for the four criteria
Figure 3 The Lead Times for the four criteria
Preliminary results show that the best criterias,
for the forecast of the first cloud-to-ground,
was 35 dBZ at the heigt of the -10C izotherm and
40 dBZ at the same height. The 35 dBZ criteria
has 88,4 POD and 79,3 CSI and the 40 dBZ has
86,3 POD and 65,5 CSI. The lead times for all
criteria are shown in Figure 3.
The aim of this study is to analize the
operational use of lightning data in forecasting
the severe storms, especially the moment of the
first lightning. Lightning data provided by LDN
together with radar data soundings and outputs
from numerical models were used for anticipating
the onset of electrical activity. In this study
are examined 60 thunderstorm cases form south
Romania region, from 2003 to 2005, using four
combination of reflectivity thresholds and
environmental temperature 35 dBZ and 40 dBZ and
the height of the -10C and -15C, for one volume
scan. The height of the isotherms were those
recorded from 00 and 12 UTC from Bucharest
soundings, for the thunderstorms from 2003 to
2004. For 2005 the height was estimated using the
output of ALADIN model and the real sounding.

3. CONCLUSIONS
Based on the statistical parameters and lead
times it was found that the best criteria for the
forecast of the beginning of cloud-to-ground
activity is the presence of an 35 dBZ echo at the
height of the -10C izotherm, with a lead time of
17 minutes. In the future we want to explore a
series of thermodinamical parameters (CAPE, CIN,
relative humidity 925-500 hPa, etc.), for
indicating the potential of lightning activity in
a given day For the moment, a statistical
forecast indicating the probaility of occurrence
of lightning in a area around Bucharest is in
experimental use at ANM.