All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 136 6 0
PDF Downloads 18 2 0

Thunderstorm Potential of Cold Air Cumulonimbi

Christopher A. Biltoft2d Weather Wing, Air Weather Service, RAF Croughton, England

Search for other papers by Christopher A. Biltoft in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Cumulonimbi are often reported in cold air during winter months in northern Europe but thunderstorms are observed much less frequently. This suggests that some cold air cumulonimbi cannot develop into thunderstorms. The possibility of identifying cumulonimbi lacking thunderstorm potential is investigated. Threshold height and temperature values are found for cold air thunderstorms. Approximately 10% of soundings associated with cold air cumulonimbi have values below this threshold. Also, chi-square tests of a Revised Stability Index based on threshold values indicate that some cumulonimbi are not unstable through sufficient depth to develop into thunderstorms. A stability cutoff value is established which separates “stable” cumulonimbi from others which have the potential to become thunderstorms.

Abstract

Cumulonimbi are often reported in cold air during winter months in northern Europe but thunderstorms are observed much less frequently. This suggests that some cold air cumulonimbi cannot develop into thunderstorms. The possibility of identifying cumulonimbi lacking thunderstorm potential is investigated. Threshold height and temperature values are found for cold air thunderstorms. Approximately 10% of soundings associated with cold air cumulonimbi have values below this threshold. Also, chi-square tests of a Revised Stability Index based on threshold values indicate that some cumulonimbi are not unstable through sufficient depth to develop into thunderstorms. A stability cutoff value is established which separates “stable” cumulonimbi from others which have the potential to become thunderstorms.

Save