Mountain Thunderstorms and Forest Fires

Fuquay, D. M.

doi:10.1080/00431672.1962.9926981

Cited by 9 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These observations support earlier ones [Talman, 1931;Watson Watt, 1931;Fuquay, 1962;Hiser, 1973;Few, 1974] indicating that lightning can occur in regions of thunderclouds where the precipitation intensity is low. In the studies reported here, significant amounts of both polarities of charge were encountered in the vicinity of the precipitation echo that the balloon passed near the cloud base.…”

Section: Concludi -Ng Remarksmentioning

confidence: 99%

Thunderstorm on July 16, 1975, over Langmuir laboratory: A case study

Winn¹,

Moore²,

Holmes³

et al. 1978

J. Geophys. Res.

104

View full text Add to dashboard Cite

The electric field along the path of an instrumented balloon was closely coupled to the wind profile and to the radar echo structure of a weak thunderstorm over Langmuir Laboratory on July 16, 1975. The balloon ascended at 3.5 m/s into the southern part of the storm, where a stable layer had stopped the cloud's vertical convection at 6.4 km above sea level. At lower altitudes, near the cloud base, the balloon rose past two nearby oppositely charged regions which were associated with a precipitation echo and with an outflow of air from the storm. When the balloon ascended into clear air through the top of the lower cloud at 6.4‐km altitude, its motion indicated a sharp change in wind direction, and its electric field meter showed an abrupt decrease in field intensity, probably from a screening layer at the cloud boundary. Above 7.5 km the balloon encountered a slanted and charged downdraft just before entering the northern part of the storm under its anvil cloud. This downdraft, which had a velocity of about 6 m/s, was a prominent and persistent feature of the cloud's circulation. It held the balloon at a nearly constant altitude of 7.7 km for 10 min while carrying it 3 km toward the center of the storm. When the electric field meter descended, after release from the balloon, it encountered the downdraft a second time, 24 min after its first encounter. Electric field measurements suggest that the downdraft was carrying a negative charge. Our measurements on this storm also contain evidence for vertical transport of horizontal momentum and for a net positive charge in the upper part of the storm.

show abstract

Section: Concludi -Ng Remarksmentioning

confidence: 99%

Thunderstorm on July 16, 1975, over Langmuir laboratory: A case study

Winn¹,

Moore²,

Holmes³

et al. 1978

J. Geophys. Res.

104

View full text Add to dashboard Cite

show abstract

“…Of particular concern are days with high-based thunderstorms that generate numerous lightning strikes but little or no rainfall at the surface (Colson 1960;Hall 2005). Fuquay (1962) determined that the average summer thunderstorm in the northern Rocky Mountains has a cloud base near 3650 m MSL and generates rainfall amounts of less than 1.3 mm. In the current study, dry thunderstorms are defined as those with cloud-to-ground lightning strikes that occur with less than 2.5 mm of rainfall at the surface.…”

Section: Introductionmentioning

confidence: 99%

Model-Generated Predictions of Dry Thunderstorm Potential

Rorig

McKay

Ferguson

et al. 2007

Journal of Applied Meteorology and Climatology

View full text Add to dashboard Cite

Dry thunderstorms (those that occur without significant rainfall at the ground) are common in the interior western United States. Moisture drawn into the area from the Gulfs of Mexico and California is sufficient to form high-based thunderstorms. Rain often evaporates before reaching the ground, and cloud-to-ground lightning generated by these storms strikes dry fuels. Fire weather forecasters at the National Weather Service and the National Interagency Coordination Center try to anticipate days with widespread dry thunderstorms because they result in multiple fire ignitions, often in remote areas. The probability of the occurrence of dry thunderstorms that produce fire-igniting lightning strikes was found to be greater on days with high instability and a deficit of moisture at low levels of the atmosphere. Based on these upper-air variables, an algorithm was developed to estimate the potential of dry lightning (lightning that strikes the ground with little or no rainfall at the surface) when convective storms are expected. In the current study, this algorithm has been applied throughout the western United States, with modeled meteorological variables rather than the observed soundings that have previously been used, to develop a predictive scheme for estimating the risk of dry thunderstorms. Predictions of the risk of dry thunderstorms were generated from real-time forecasts using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5) for the summers of 2004 and 2005. During that period, 240 large lightning-caused fires were ignited in the model domain. Of those fires, 40% occurred where the probability of dry lightning was predicted to be equal to or greater than 90% and 58% occurred where the probability was 75% or greater.

show abstract

“…3) Thus far, the paradigm has provided little insight into why the tallest clouds, which are surrounded by highly conductive air and whose upper parts are too cold for the formation of precipitation, exhibit the greatest electrical activity (Shackford 1960;Fuquay 1962;Uman and Krider 1989). 4) A recent and surprising finding, not accounted for by the paradigm, is that the ratio of the total lightning flash rate to the Wilson conduction current, which flows from the upper atmosphere to the top of the cloud, is almost constant over a wide range of storm intensities (Blakeslee et al 1989).…”

Section: Potential Anomaliesmentioning

confidence: 99%

“…6) A situation that is not easy to fit into the paradigm is the common observation that a heavy fall of precipitation is often accompanied by little or no lightning. 7) An uncommon and neglected anomaly is the occasional thundercloud that produces lightning with little or no precipitation (Fuquay 1962;Magono 1980). On the other hand, radar observations show that the lightning is sometimes followed by the rapid formation of precipitation (Moore et al 1964).…”

Section: Potential Anomaliesmentioning

confidence: 99%

The Atmospheric Electricity Paradigm

Vonnegut

1994

Bull. Amer. Meteor. Soc.

View full text Add to dashboard Cite

Remarkable aspects of the thundercloud are its intense electrification, precipitation, and convection. A satisfactory understanding of how a thunderstorm works will require a continuing series of investigations to explore the complicated interrelationships among these phenomena. Until now the major effort has been devoted to studies of how precipitation causes electrification.For a century, investigations of thunderstorms have been dominated by the idea that lightning is produced by a charge-separation process within the cloud caused by falling precipitation. The origin of this idea, its implications, present status, and probable future are examined in the light of T. S. Kuhn's views on the nature of scientific progress. Despite some achievements, the results of research based on the precipitation theory have proved disappointing. For example, they have shed little light on important problems such as the factors that determine the polarity of the cloud electric dipole and the role that electricity plays in meteorological processes. During this century, with the discovery of cosmic rays and the ionization they produce in the air above the cloud, it has become apparent that other processes, which do not involve contact charge separation or falling precipitation, are also causing electrification.Thunderstorms exercise great influence, for both good and bad, on many human activities. In view of their great environmental importance, it is surprising how little is known about them and how little effort is being made to understand how they work. It is urged that the present limited thunderstorm research activities be expanded to include new, and possibly more productive, approaches.

show abstract

Mountain Thunderstorms and Forest Fires

Cited by 9 publications

References 0 publications

Thunderstorm on July 16, 1975, over Langmuir laboratory: A case study

Thunderstorm on July 16, 1975, over Langmuir laboratory: A case study

Model-Generated Predictions of Dry Thunderstorm Potential

The Atmospheric Electricity Paradigm

Contact Info

Product

Resources

About