Thunderstorm climatology based on lightning detector data, Manitoba, Canada
Case studies are presented of the most active lightning storms of 1985 and 1986. Relationships between meteorological parameters and lightning strike distribution are presented. The relationship may prove useful in the suppression of lightning
Cloud-to-ground lightning signatures of long-lived tornadic supercells on 27-28 April 2011
Alabama ; Climatic hazard ; Geographical information system ; Lightning ; Mississippi ; Natural hazards ; Tornado ; United States of America ; Weather type
This study integrates past research methodologies, data from the National Lightning Detection Network (NLDN), and geographic information system techniques to assess the lightning and severe weather hazard relationship for the 27–28 April 2011 United
States tornado outbreak. NLDN and Doppler radar data are used to examine the cloud-to-ground (CG) lightning characteristics associated with 7 supercell thunderstorms that produced long-track, significant and/or violent tornadoes. Analyses indicate that CG
lightning flashes alone do not provide enough information for the detection of a lightning jump prior to tornadogenesis. All 7 supercells were dominated by negative-polarity CG lightning flashes; which is expected due to the geographic location and elevated
low-level moisture found in the outbreak environment. The correlation between low-level mesocyclone strength and total CG lightning flash rate was varied and inconsistent among all storms despite their formation and sustenance in similar environmental
Visualizing summertime lightning patterns on Colorado Fourteeners
Applied climatology ; Colorado ; Hiking ; Lightning ; Mountain climate ; Preventive measure ; Rainstorm ; Risk ; Seasonal variability ; Social geography ; Summer ; United States of America
This article explores temporal and spatial patterns of cloud-to-ground lightning strikes to Colorado Fourteeners, the popularly summited set of mountains that exceed 4,267 m (14,000 ft). It describes the Fourteener concept, examines trends
in lightning fatalities and injuries, and reviews thunderstorm climatology across the greater Colorado landscape. Three measures characterize lightning activity for fifty-four Fourteeners: (1) overall strikes received, (2) lightning days, and (3) the time
of day when lightning first strikes. The results can help avoid lightning when making long-term plans to visit Fourteeners and can heighten awareness when on Fourteeners. In addition to lightning avoidance, the article contributes to mountain geography
Diurnal variations in the characteristics of cloud-to-ground lightning activity in the Great Lakes region of the United States
Cloud-to-ground (CG) lightning observations for the warm season thunderstorms (May-September) of 1989 and 1990 were analyzed for the Great Lakes region. Diurnal variations in the frequency, spatial extent, flash density, amplitude, and polarity
of CG lightning flashes are considered. Identifying the diurnal variations of lightning activity will improve the understanding of the characteristics of thunderstorms that occur at different times of the day. A large degree of intraseasonal (i.e., month
to month) variation was observed in the diurnal patterns for several of the lightning parameters.
Diurnal patterns in lightning activity in northern tropical Africa
Africa ; Atmospheric circulation ; Convection ; Diurnal variation ; Lightning ; Remote sensing ; Tropical zone
The AA. analyze summertime lightning incidence data across northern tropical Africa from the TRMM satellite sensor during 1998–2011. They use harmonic analyses to detect the spatial patterns in diurnal variations of lightning activity across
the study area. The results are in conformity with previous studies examining diurnal patterns of convective weather processes in this region, with most lightning activity concentrated over land areas. The peak time of lightning activity over most
of the study area was during late afternoon hours. The peak time of lightning activity was observed during early morning hours in some coastal areas, such as Cameroon, which can be a result of local-level convergence between the land and sea breeze. A general
progression in the time of lightning activity from late afternoon to early evening hours was observed throughout the interior of the study area, which may be attributed to land-surface heating and associated mesoscale convective systems, and to upper-level
Lightning at the Master's : an evaluation of April thunderstorms in and near the Augusta national golf club
This research investigates what meteorological factors contributed to lightning production and thunderstorm development in and surrounding Richmond County, Georgia, during the month of April from 1995 to 2003. Discriminant analysis is utilized
in order to identify what meteorological variables correlated most significantly with lightning production in thunderstorms. Additionally, composite synoptic analyses of environmental conditions associated with thunderstorm days and a case study of the 2
highest lightning activity days in April are also presented.
Climate, lightning, and wildfire in the national forests of the southeastern United States : 1989-1998
The AA. compiled the record of wildfires from each national forest unit in the southeastern United States for the period 1989 to 1998, then regressed annual fire numbers against lightning flash densities and measures of climatic drought (seasonal
precipitation and Palmer Drought Severity Index, PDSI, values). Lightning-caused fires were most common in Florida, where seasonally-dry winters and high lightning-flash density elevate fire risk. Overall regression models consistently identified fire season
Lightning and special peat bog phenomena on Andøya, northern Norway
, 5 similar phenomena have been recorded in Norway, and pieces of earth displaced from their original locations have been reported in Britain, Germany and the United States. Lightning is hypothesized to have caused these phenomena.
Locating convection in landfalling tropical cyclones : a GIS-based analysis of radar reflectivities and comparison to lightning-based observations
Researchers have utilized radar reflectivity returns and lightning flashes separately and together to locate convection with tropical cyclones (TCs). This study employs a GIS to delineate regions of high radar reflectivity values within 45
lightning flash locations. Results indicate that the GIS-based radar analysis may be identifying TC regions that are electrically active. Both the radar- and lightning-based analyses show that convection shifts from the right to the front of the storm
Discussion of various misconceptions of students and the general public that include : water always freezes at O deg. C.; on days of high humidity, the air is heavy due to water vapor content; lightning does not strike the same place twice
On August 28, 1981, the Crow Canyon drainage basin in central Nevada was burned by a lightning-generated wildfire that destroyed the vegetation cover consisting primarily of juniper trees, sagebrush, and desert grasses. The geomorphic impact
The AA. investigate spatial variations in the incidence of anthropogenic and natural (lightning-ignited) fire in the central Appalachian Mountains of Virginia and West Virginia using a record of wildland fires that occurred on federal lands between
Caucasus ; Cluster analysis ; Data collection ; European part of Russia ; Hydrometeorology ; Instrumentation ; Lightning ; Natural hazards ; Preventive measure ; Weather type
Dans cette quatrième section consacrée aux peuples, aux lieux et aux régions, on trouvera les articles suivants : 1-Geography written in lightning : race, sexuality, and regulatory aesthetics in the birth of a nation ; 2-Geoeconomic imaginations