The Above-Anvil Cirrus Plume: An Important Severe Weather Indicator in Visible and Infrared Satellite Imagery

Abstract

Intense tropopause-penetrating updrafts and gravity wave breaking generate cirrus plumes that reside above the primary anvil. These “above anvil cirrus plumes” (AACPs) exhibit unique temperature and reflectance patterns in satellite imagery, best recognized within 1-min “super rapid scan” observations. AACPs are often evident during severe weather outbreaks and, due to their importance, have been studied for 35+ years. Despite this research, there is uncertainty regarding why some storms produce AACPs but other nearby storms do not, exactly how severe are storms with AACPs, and how AACP identification can assist with severe weather warning. These uncertainties are addressed through analysis of severe weather reports, NOAA/National Weather Service (NWS) severe weather warnings, metrics of updraft cloud height, intensity, and rotation derived from Doppler radars, as well as ground-based total lightning observations for 4583 storms observed by GOES super rapid scanning, 405 of which produced an AACP. Datasets are accumulated throughout storm lifetimes through radar object tracking. It is found that 1) AACP storms generated 14 times the number of reports per storm compared to non-AACP storms; 2) AACPs appeared, on average, 31 min in advance of severe weather; 3) 73% of significant severe weather reports were produced by AACP storms; 4) AACP recognition can provide comparable warning lead time to that provided by a forecaster; and 5) the presence of an AACP can increase forecaster confidence that large hail will occur. Given that AACPs occur throughout the world, and most of the world is not observed by Doppler radar, AACP-based severe storm identification and warning would be extremely helpful for protecting lives and property.

Understanding Hail in the Earth System

“…Satellite‐derived techniques have evolved to also address the limitations of in situ observations (e.g., Bedka et al, ; Bedka, Murillo, et al, ; Punge et al, ). However, these techniques remain a proxy measurement for hail that is not necessarily well correlated with observed hail at the surface, though appears to often capture the more intense storms (Cecil & Blankenship, ; Ferraro et al, ; Bedka et al, ). While the potential for these techniques to assist in operational nowcasting is clear, there is also a role to play in providing global estimates of hail frequency (e.g.…”

Towards objective identification and tracking of convective outflow boundaries in next-generation geostationary satellite imagery

“…To highlight the OFBs and the presence of dust, horizontal reflectivity and the correlation coefficient are used (Van Den Broeke and Alsarraf, 2016). Finally, for information on the full 3D dynamics of the case study, a numerical model representation of the environment was collected from the High Resolution Rapid Refresh system (HRRR; Benjamin et al, 2016). The combination of these model and observation datasets is employed to confirm the presence of a distinct convective OFB rather than some other quasi-linear feature, such as a bore or elevated cloud layer.…”

Using Overshooting Top Area to Discriminate Potential for Large, Intense Tornadoes

“…The satellite-based approach proposed here does not suffer from these coverage limitations. Finally, this approach provides the opportunity for examining possible OTA-severe weather relationships (including for hail and severe wind intensity; e.g., Bedka et al, 2018;Punge et al, 2017) in other regions of the world, particularly those with little or no radar coverage.…”