Showing papers on "Thunderstorm published in 1991"

Kinematic, Dynamic, and Thermodynamic Analysis of a Weakly Sheared Severe Thunderstorm over Northern Alabama

Abstract: A kinematic, dynamic, and thermodynamic analysis of a weakly sheared, airmass thunderstorm observed over northern Alabama is presented. Most notable is the fact that the dominant cell in this storm closely resembles the Byers and Braham model for warm-based, airmass storms. Several phenomena never documented for this storm-type are discussed. One of these is a strong and deep downdraft observed at midlevels with an associated “weak-echo” trench. Its origin appears to be related to a wake entrainment process. A midlevel inflow which causes a visible constriction in the storm cloud is also observed. This inflow results in a division of the thermal buoyancy into two maxima in the vertical: one associated with the precipitation core and the other with strong positive vertical motions in the growing cumulus turret. In addition, a downdraft separate from that seen at midlevels develops at low levels and causes a microburst outflow at the surface. This downdraft appears to be initiated by precipitation ...

A numerical study of thunderstorm electrification: Model development and case study

Abstract: A numerical model was developed for examining the thunderstorm electrification process in which it is assumed that the electrification is entirely due to noninductive charge transfer between colliding ice crystals and hail. Since this ice-hail charge mechanism is very dependent on particle sizes and distributions, an explicit microphysical framework is used. To maintain simplicity, the electrification model is kinematic; thus the temperature and velocity fields are input into the electrification model. The cloud model of Taylor (1989) was used to generate the temperature and velocity fields to examine the July 19, 1981, Cooperative Convective Precipitation Experiment thundercloud. Using these fields, the electrification model produced time-dependent ice particle concentrations, radar reflectivities, charge, and vertical electric field distributions in good general agreement with those observed. The model produced a maximum electric field strength of 1.27 kV/cm, which is on the order of that needed for lightning initiation, and this maximum occurred very close to the time of the observed discharge. Thus, the ice-hail charge mechanism appears to have played an important role in the electrical development of the July 19 cloud.

Electrical and Kinematic Structure of the Stratiform Precipitation Region Trailing an Oklahoma Squall Line.

Abstract: An electric field sounding through the transition zone precipitation minimum that trailed an Oklahoma squall line on 18 June 1987 provides information about the electrical structure within a midlatitude trailing stratiform cloud. A single-Doppler radar analysis concurrent with the flight depicts a kinematic structure dominated by two mesoscale flow regimes previously identified in squall-line systems: a strong midlevel, front-to-rear flow coinciding with the stratiform cloud layer and a descending rear inflow that sloped from 6.5 km AGL at the stratiform cloud's trailing edge to 1.5 km AGL at the convective line. Electric field magnitudes as high as 113 kV m−1 were observed by the electric field sounding, which reveals an electric field structure comparable in magnitude and complexity to structures reported for convective cells of thunderstorms. The charge regions inferred with an approximation to Gauss' law have charge density magnitudes of 0.2–4.1 nC m−3 and vertical thicknesses of 130–1160 m; ...

On the Interpretation of Single-Doppler Velocity Patterns within Severe Thunderstorms

Abstract: Although the flow field within a severe thunderstorm is complex, it is possible to simulate the basic features using simple analytical flow models (such as uniform flow, axisymmetric rotation, axisymmetric divergence). Combinations of such flow models are used to produce simulated Doppler velocity patterns that can be used as “signatures” for identifying quasi-horizontal flow features within severe thunderstorms. Some of these flow features are: convergence in the lower portions of a storm and divergence in the upper portions associated with a strong updraft, surface divergence associated with a wet or dry downdraft, mesocyclone (rotating updraft), flow around an updraft obstacle, and tornado. Recognition of the associated Doppler velocity patterns can aid in the interpretation of single-Doppler radar measurements that include only the radial component of flow in the radar viewing direction.

Correlating Lightning to Severe Local Storms in the Northeastern United States

Abstract: Two tornado events and an intense downburst episode were investigated in an attempt to relate cloud-to-ground lightning rates with the occurrence of severe local storms. The State University of New York at Albany lightning detection system was used to yield characteristic lightning rate tendencies and particular lightning signatures that were associated with severe storms in the northeastern United States. Tornadoes and large hail occurred about 10–15 min after a pronounced peak in the 5-min cloud-to-ground lightning rate. In the downburst event, very destructive winds occurred just after the 5-min rate peaked. Because these severe local storm activities followed well-defined peaks in the 5-min cloud-to-ground lightning rate, it may be possible that the 5-min rates could be used operationally to forecast severe weather.

Mitigation against extreme windstorms

Abstract: This paper treats various manifestations of atmospheric wind in relation to the effects these have on human safety and comfort. We concentrate on more recent advances in our knowledge of the geophysical structure and behavior of extreme windstorms. Particular attention is given to severe thunderstorms and their attendant mesoscale offspring, tornadoes and downbursts, as well as the extratropical and tropical cyclones. It appears that the highest credible wind speed estimates in any of these windstorms so far are for tornadoes, about 135 m s−1; these have been derived from photogrammetric analyses of eyewitness photography and remote sensing from in situ and portable Doppler radars. On the other hand, it is found from extensive aerial and ground poststorm damage surveys that the vast majority of all tornadoes have peak wind speeds no higher than those measured by sparse surface networks and reconnaissance aircraft in mature hurricanes. New in situ and remote sensing (Doppler radars) weather observing networks currently being deployed across the United States and other countries, combined with greater public awareness, may significantly alter our current assessment of the climatology of extreme windstorms in these areas. Advances in the field of wind engineering are shown to afford cost-effective techniques for mitigating against extreme windstorms, including tornadoes. However, the rather unique sociopolitical framework of building codes and practices in the United States presently hinders effective technology transfer and mitigation practice. Important implications of these findings accrue to forecasts and warnings of forest fires and airborne dispersal (loss of containment) of toxic materials, including nuclear processing by-products.

Climatological Characteristics and Objective Prediction of Thunderstorms over Alaska

Abstract: Archived lightning data from the Bureau of Land Management automated network of direction-finding stations in Alaska were examined to determine the seasonal, diurnal, and spatial distributions of cloud-to-ground lightning, including the effects of the underlying topography on the timing, location, and magnitude of the lightning activity. The interior of Alaska was found to exhibit a continental type climate with a pronounced afternoon maximum in lightning activity and no significant nocturnal activity. Over 90% of the strikes were found to occur during June and July, the time of maximum solar insulation. A relatively high incidence of positive flashes was found during all phases of thunderstorm occurrence. High flash accumulations over mountainous regions clearly revealed the affinity of lightning activity for elevated terrain. Maximum activity was found to occur earliest in the higher elevations, moving to lower elevations later in the day. Linear screening regression analysis and the Model Outp...

Aircraft overflight measurements of Midwest severe storms : implications on geosynchronous satellite interpretations

Abstract: The instrumented NASA ER-2 aircraft overflew severe convection with IR V features for the first time in the midwest United States during May 1984. Measurements taken by the ER-2 were: visible and IR imagery, high-frequency passive microwave (92, 183 GHz) imagery, nadir lidar backscattered return, and flight altitude information. The May 7 and May 13, 1984 cases are analyzed in detail and the various data sources are combined and compared with GOES imagery. The high resolution aircraft IR imagery shows that thermal couplets are considerably more pronounced than in GOES imagery. In one of the cases (May 7, 1984) the minimum cloud-top IR temperature was located upshear of the overshooting cloud top in the lidar height field. The IR temperatures in the downshear anvils were as much as 5 C warmer than the ambient air temperatures, implying that the upwelling IR radiance comes from about 0.5-1.0 km below the cloud top. The in situ ER-2 measurements of temperature and air velocity 3-4 km above the overshooting tops showed very intense temperature and vertical velocity, perturbations. These perturbations are suggestive of lee waves generated by the overshooting tops or a cold dome above the squall line possibly due to tropopause lifting by the storms.

Microphysical and radiative characteristics of convective clouds during COHMEX

Abstract: This paper has two purposes: first, to document the structure and evolution of two strong thunderstorms in Alabama using radar multiparameter data; and second, to relate the inferred microphysics to the resulting upwelling microwave radiance observed concurrently by high altitude aircraft. These measurements were collected during the COHMEX field program in the summer of 1986. The radar analysis includes a description of the parameters reflectivity Z, differential reflectivity Z(DR), linear depolarization ratio LDR, and hail signal HS for two thunderstorm cases on July 11, 1986. The simultaneous aircraft data include passive microwave brightness temperature, T(B), measurements at four frequencies ranging from 18 to 183 GHz, as well as visible and infrared data. The remote radar observations reveal the existence of large ice particles within the storms, which is likely to have caused the observed low microwave brightness temperatures. By relating the evolution of the radar measureables to the microwave T(B)s it has been found that knowledge of the storm microphysics and its evolution is important to adequately understand the microwave T(B)s.

Mass fluxes in New Mexico mountain thunderstorms from radar and aircraft measurements

Abstract: We have obtained the vertical and detrained mass fluxes through the life cycles of four thunderstorms using measurements from four Doppler radars and an instrumented aircraft. The storms formed over the Magdalena Mountains of central New Mexico, and remained near the mountains through their entire life. Updraughts appeared to entrain a certain amount of surrounding radar-invisible air. Thermodynamic considerations suggest that this air came from neighbouring towering cumulus clouds rather than directly from the environment. Entrained air did not immediatly mix with cloud-base air, but tended to maintain its own identity in ascent. Levels with decreasing parcel buoyancy induced significant detrainment from the updraught. Downdraughts were confined primarily to levels below 7–8 km above mean sea level. The net mass flux entering or leaving the underside of the thunderstorms equalled that supplied by the mountain upslope flow. Since this net flux is a combination of updraughts and downdraughts, unstable air at low levels is gradually replaced by stable downdraught air, thus ensuring the demise of the storm.

Electric fields and current densities under small Florida thunderstorms

Abstract: Results are presented of measurements of the electric field E and Maxwell current density that were performed simultaneously under and near small Florida thunderstorms. It is shown that the amplitude of JM is of the order of 1 nA/sq cm or less in the absence of precipitation and that there are regular time variations in JM during the intervals between lightning discharges that tend to have the same shapes after different discharges in different storms. It is argued that the major causes of time variations in JM between lightning discharges are currents that flow in the finitely conducting atmosphere in response to the field changes rather than rapid time variations in the strength of cloud current sources. The displacement current densities that are computed from the E records dominate JM except when there is precipitation, when E is large and steady, or when E is unusually noisy.

An Analysis of a Mesocyclone–Induced Tornado Occurrence in Northern California

Abstract: One documented F2 tornado and several other unconfirmed tornadoes were reported in California's Sacramento Valley on 24 September 1986. The synoptic pattern which occurred that day was one long-recognized by California operational meteorologists as being associated with severe weather in the state. The present study documents this event and shows that the parent thunderstorm had supercellular characteristics and that the tornado was mesocyclone-induced. As is the case elsewhere when severe thunderstorms are observed, the mesoscale environment established a focus for late morning and early afternoon deep convection. A quasi-stationary leeside trough acted in concert with local channeling effects to promote the advection of relatively moist air to the northern portions of the Valley. This channeled flow contributed to low-level shear which was much stronger than that evident in the Oakland hodograph and one which was comparable to that found with supercell and mesocyclone development elsewhere in t...

Surface wind convergence as a short-term predictor of cloud-to-ground lightning at Kennedy Space Center

Abstract: Cloud-to-ground lightning is a significant forecast problem at the Kennedy Space Center (KSC) in Florida. In this study, cloud-to-ground lightning is related in time and space to surface convergence for 244 days during the convective seasons of 1985 and 1986 over a 790 sq-km network at KSC. The method uses surface convergence, particularly the average over the area, to identify the potential for new, local thunderstorm growth, and it can be used to specify the likely time and location of lightning during the life cycle of the convection. A threshold of 75 x 10 to the -6th/s change in divergence is the main criterion used to define a convergence event, and a set of flashes less than 30 min apart defines a lightning event. Time intervals are found from the study to be approximately 1 h from beginning convergence to first flash, and another hour to the end of lightning. The influences of low-level winds and midlevel moisture in determining the location and intensity of convection are discussed. This is the first known dynamically-based forecast method for lightning prediction. The technique, currently in use at KSC, has been shown to be a systematic, quantitative tool for predicting lightning onset in situations where conventional analysis tools such as radar and satellite are limited.

Spatial distribution of visible lightning on jupiter

Abstract: An analysis of Voyager images of Jupiter is used to evaluate the horizontal spatial distribution of visible lightning over most of one hemisphere. Essentially all the detectable activity is confined to very narrow latitude bands at 13.5 N and 49 N. The active regions at 49 N are the brightest, most numerous, and periodic in longitude. Activity at this latitude is long-lived and is most likely associated with moist convective regions deep in Jupiter's atmosphere. The longitudinal periodicity of the lightning storms may represent the effects of a planetary scale atmospheric wave trapped at the depth of the moist convection.

Acoustic signature of thunder from seismic records

Abstract: Thunder, the sound wave through the air associated with lightning, transfers sufficient energy to the ground to trigger seismometers set to record regional earthquakes The acoustic signature recorded on seismometers, in the form of ground velocity as a function of time, contains the same type features as pressure variations recorded with microphones in air At a seismic station in Kislovodsk, USSR, a nearly direct lightning strike caused electronic failure of borehole instruments while leaving a brief impulsive acoustic signature on the surface instruments The peak frequency of 25–55 Hz is consistent with previously published values for cloud-to-ground lightning strikes, but spectra from this station are contaminated by very strong wind noise in this band A thunderstorm near a similar station in Karasu triggered more than a dozen records of individual lightning strikes during a 2-hour period The spectra for these events are fairly broadband, with peaks at low frequencies, varying from 6 to 13 Hz The spectra were all computed by multitaper analysis, which deals appropriately with the nonstationary thunder signal These independent measurements of low-frequency peaks corroborate the occasional occurrences in traditional microphone records, but a theory concerning the physical mechanism to account for them is still in question Examined separately, the individual claps in each record have similar frequency distributions, discounting a need for multiple mechanisms to explain different phases of the thunder sequence Particle motion, determined from polarization analysis of the three-component records, is predominantly vertical downward, with smaller horizontal components indicative of the direction to the lightning bolt In three of the records the azimuth to the lightning bolt changes with time, confirming a significant horizontal component to the lightning channel itself

The Development of the Piedmont Front and Associated Outbreak of Severe Weather on 13 March 1986

Abstract: An investigation was conducted of the mesoscale evolution of a quasi-stationary front, termed the Piedmont front owing to its location through the central Carolinas, and an associated outbreak of severe weather on 13 March 1986. Space-time relationships between mesoscale processes associated with the evolution of the surface front and the initiation of severe thunderstorms were studied utilizing the enhanced surface and upper-air observation networks deployed during the field phase of GALE. Surface streamline patterns, frontogenesis, and moisture-flux divergence were computed employing an objective analysis scheme. Following the arrival at the Carolina coast of a coastal front, the Piedmont front rapidly developed along an axis of dilatation over the eastern margin of the Piedmont, while the coastal front gradually dissipated over the nearshore waters. A differential cloud cover across the Piedmont front resulted in enhanced solar insolation on the warm side of the front that strengthened frontog...

Surface wind convergence as a short-term predictor of cloud-to-ground lightning at Kennedy Space Center: A four-year summary and evaluation

Abstract: Since 1986, USAF forecasters at NASA-Kennedy have had available a surface wind convergence technique for use during periods of convective development. In Florida during the summer, most of the thunderstorm development is forced by boundary layer processes. The basic premise is that the life cycle of convection is reflected in the surface wind field beneath these storms. Therefore the monitoring of the local surface divergence and/or convergence fields can be used to determine timing, location, longevity, and the lightning hazards which accompany these thunderstorms. This study evaluates four years of monitoring thunderstorm development using surface wind convergence, particularly the average over the area. Cloud-to-ground (CG) lightning is related in time and space with surface convergence for 346 days during the summers of 1987 through 1990 over the expanded wind network at KSC. The relationships are subdivided according to low level wind flow and midlevel moisture patterns. Results show a one in three chance of CG lightning when a convergence event is identified. However, when there is no convergence, the chance of CG lightning is negligible.

Severe Weather Flying

Abstract: Focusing on detection and avoidance of severe weather, this book teaches pilots how to lessen their chances of being caught in extreme weather conditions. Written so that anyone can understand complex meteorological terms, it attempts to bring across the most crucial principles that pilots can use to fly more wisely. Different weather conditions, including lightning, icing, and wind shear, and their effect on flying are discussed in detail.

Cloud-to-Ground Lightning Characteristics in Mesoscale Convective Systems, April-September 1986

Abstract: : Cloud-to-ground (CG) lightning characteristics were examined in 25 Mesoscale Convective Systems (MCSs) that occurred during the warm season of 1986. Lightning strike locations were superimposed on infrared (IR) satellite imagery to examine lightning ground strike patterns relative to cold cloud-tops of MCSs. Lightning strikes frequently indicated thunderstorms more than 1 hr before cold clouds were apparent on IR satellite imagery. Time series of the area within various temperature contours were compared to time series of positive and negative flash rates. The patterns of variations in negative cloud- to-ground flash rates appeared most similar to variations in the area within temperatures of -60 deg C to -70 deg C on satellite imagery. Positive flashes occurred in two different modes, a stratiform/dissipating mode and a convective mode. In the stratiform/dissipating mode, positive flashes occurred during the mature and dissipating stages of an MCS and peaked near or after the peak in negative flash rates. Ground strike locations were generally dispersed across a large area and were usually associated with either a dissipating convective region or a stratiform region on radar and with decaying and warming cloud-top temperatures on satellite imagery. The stratiform/dissipating mode appeared during all months on the warm season.

Lightning to the upper atmosphere: A vertical light pulse from the top of a thunderstorm as seen by a payload bay TV camera of the space shuttle

Abstract: An examination and preliminary analysis of video images of thunderstorms as seen by a payload bay TV camera of the Space Shuttle provided examples of lightning in the stratosphere above thunderstorms. These images were obtained on several recent Shuttle flights while conducting the Mesoscale Lightning Experiment (MLE). MLE was an experiment to obtain night time images from space of large storm complexes with lightning. These images are used to provide data for the design of specialized instrumentation which will provide quantitative measurements of global lightning. Eight video sequences were selected because they illustrate near vertical discharges in the stratosphere above thunderstorms. Although there are previous reports in the literature, these are the first images from the viewpoint of an orbiting spacecraft. The written material is primarily a companion to a video presentation.

High Plains Severe Weather—Ten Years After

Abstract: More than a decade ago, a study was published that identified a short list of precursor conditions for severe thunderstorms on the High Plains of the United States. The present study utilizes data from the summer months of ten convective seasons to estimate how well the criteria fare as a method of forecasting severe weather days in that region. Results indicate that the technique produces a relatively high success rate in terms of detecting severe weather days for most years studied. False alarms are a bit high in an absolute sense (36% overall), but fall well within acceptable limits in the real world, where the philosophy of “better to overwarn, than underforecast” prevails.

Observations of turbulent boundary-layer interaction with a thunderstorm outflow — A possible wake region energy source

Abstract: Laboratory and numerical model simulations of turbulent circulations within the wake regions of thunderstorm outflows have been done with the assumption that there is no turbulence within the ambient airmass. Furthermore, many observational studies have used Doppler radar data that have been filtered so that turbulent structures are reduced in amplitude or eliminated altogether. This study presents unique Doppler radar observations of the collision of a roll-like boundary-layer circulation with a gust flow. The boundary-layer circulation is seen to interact with the circulation within the gust flow head and to reappear within the wake region. It is suggested that the ambient boundary layer may be an energy source for the generation and/or maintenance of turbulence in the wake region.

The spatial variations of lightning during small Florida thunderstorms

Abstract: Networks of field mills (FM's) and lightning direction finders (LDF's) were used to locate lightning over the NASA KSC on three storm days. Over 90 percent of all cloud-to-ground (CG) flashes that were detected by the LDF's in the study area were also detected by the LDF's. About 17 percent of the FM CG events could be fitted to either a monopole or a dipole charge model. These projected FM charge locations are compared to LDF locations, i.e., the ground strike points. It was found that 95 percent of the LDF points are within 12 km of the FM charge, 75 percent are within 8 km, and 50 percent are within 4 km. For a storm on 22 Jul. 1988, there was a systematic 5.6 km shift between the FM charge centers and the LDF strike points that might have been caused by the meteorological structure of the storm.

Use of an expert system to predict thunderstorms and severe weather

Abstract: To assist the battlefield commander, the U.S. Army Atmospheric Sciences Laboratory has developed a rule-based expert system that can advise weather forecasters on the possibility of thunderstorm activity and other severe weather phenomena. This expert system, the Thunderstorm Intelligence Prediction System (TIPS), provides expedient conclusions about the weather that are derived from a large sum of data. During the spring and summer thunderstorm season of 1990 TIPS was tested at 14 different sites across the United States© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Forcing mechanisms of thunderstorm downdrafts

Abstract: The role of various forcing mechanisms of thunderstorm downdrafts has been explored. Four case studies of downdrafts are presented. Radar data from five closely spaced radars are used to conduct direct triple Doppler calculations of the full three-dimensional wind field in three of the cases; data from three closely spaced radars are used in the remaining case. Differential reflectivity measurements are used to diagnose the presence of ice in the downdraft regions. Data from a dense array of surface mesonet stations are used to diagnose the thermodynamic characteristics and origin levels of outflow air from the downdrafts. A one-dimensional parcel-following model, which incorporates evaporation, melting and entrainment, and which is strongly constrained by detailed radar and surface observations, is used to diagnose the relative importance of various forcing mechanisms. The studied downdrafts, while originating at different altitudes, ranging from 2 km to 4.5 km, are found to be forced by the same basic mechanisms: cooling due to the evaporation of precipitation inside the cell and precipitation loading. The deeper downdrafts are nearly neutrally thermally buoyant above 2 km and are driven downwards by precipitation loading. The evaporation of precipitation is crucial to the maintenance of neutral buoyancy. The intensity of the modelled downdrafts is insensitive to whether the entrainment source is cloudy or outside environmental air. This is because the positive buoyancy of entrained cloudy air is offset by the supply of rapidly evaporating cloud droplets into the downdraft. Cloud droplet evaporation is found to contribute about 40% of the total evaporation if entrainment occurs from primarily inside the cloud. In the two downdrafts with deep origins, near 4.5 km AGL, engulfment of outside air into the upper levels of the downdrafts is observed. Ice phase precipitation is found to be unimportant in the forcing of these downdrafts. A very narrow, less than 1 km horizontal scale, region of mixed phase precipitation is present in one of the downdrafts at one observation time. The melting of ice is found to be of secondary importance compared to other forcing mechanisms. Ice phase precipitation is not observed in the three remaining downdrafts. Three of the downdrafts, exhibiting different origin levels and intensities, occur simultaneously within a 10 km region illustrating the variety of events that can develop in virtually identical environments. The studied downdrafts occur in moist, low-cloud base environments which contrast with those common in the High Plains and western USA, where the dominant forcing mechanisms probably differ. Thesis Supervisor: Dr. Earle Williams Title: Associate Professor of Meteorology

Solar cycle variations in atmospheric noise at HF

Abstract: Data are presented showing a clear solar cycle dependence of HF background noise. The background noise at HF originates from two sources: electrical discharges in the atmosphere and galactic noise. The atmospheric component may enter the receiving system via the ground wave from local thunderstorms but the dominant component at mid latitudes is frequently the result of skywave propagation from distant thunderstorms. Given the marked changes which occur in the ionosphere (and hence radiowave propagation) over a solar cycle it is not surprising that there are corresponding changes in the background noise level at HF. >

New Results for Lightning Activity on Venus and Jupiter, and Predictions of Lightning Activity on Neptune

Abstract: One goal of planetary lightning research is the identification of the specific conditions that produce lightning on each planet. On Earth, lightning activity is produced by condensates in cumuliform water clouds. On Venus, there are no water clouds, yet there is abundant evidence of lightning. On Jupiter, water-rich air parcels sink rather than rise because water vapor is much denser than the ambient atmosphere. Yet Jupiter shows two, 100,000 km long, lines of thunderstorms. In this paper, a summary is presented of recent analyses of spacecraft data that give us clues about the conditions that produce lightning on Venus and Jupiter.

Thunderstorm monitoring and lightning warning, operational applications of the Safir system

Abstract: During the past years a new range of studies have been opened by the application of electromagnetic localization techniques to the field of thunderstorm remote sensing. VHF localization techniques were used in particular for the analysis of lightning discharges and gave access to time resolved 3-D images of lightning discharges within thunderclouds. Detection and localization techniques developed have been applied to the design of the SAFIR system. This development's main objective was the design of an operational system capable of assessing and warning in real time for lightning hazards and potential thunderstorm hazards. The SAFIR system main detection technique is the long range interferometric localization of thunderstorm electromagnetic activity; the system performs the localization of intracloud and cloud to ground lightning discharges and the analysis of the characteristics of the activity.