Details:

Journal Title:
Weather and Forecasting
Personal Author:
Chavez, Ivan ; Milrad, Shawn M. ; Halperin, Daniel J. ; Mroczka, Bryan ; Tyle, Kevin R.
Chavez, Ivan ; Milrad, Shawn M. ; Halperin, Daniel J. ; Mroczka, Bryan ; Tyle, Kevin R. Less -
NOAA Program & Office:
NWS (National Weather Service)
Description:
Florida annually leads the United States in lightning-caused fatalities. While many studies have examined the lightning frequency maximum near Cape Canaveral, relatively little attention has been paid to the western Florida peninsula, which features a similar warm-season lightning event density. Of particular concern are first cloud-to-ground (FCG) lightning events in developing thunderstorms, which are difficult to predict with sufficient lead time and can catch people off guard. This study performs an environmental analysis of warm-season (May–September) FCG events (2014–21) across the western Florida peninsula using high-resolution model analysis data, including a comparison to null (No CG) days. FCG events and No CG days are first identified from ground-based lightning data and partitioned into nine synoptic-scale flow regimes. Next, spatiotemporal distributions of FCG events are elucidated for the western Florida peninsula. An ingredients-based analysis shows that the convective environment one hour before FCG events during strong south-southeast flow features the largest amounts of moisture, but the smallest instability values and weak midtropospheric lapse rates, primarily due to warm advection and moisture transport from the Atlantic Ocean. Environments one hour before FCG events in all nine flow regimes feature markedly greater instability values, larger relative humidity values, and steeper midtropospheric lapse rates than do No CG days. Results emphasize that instability and moisture are the key ingredients for warm-season FCG events in the region. Convective parameter statistical distributions and composite soundings populate an online dashboard that can be used by regional forecasters to better predict FCG events and increase alert lead times. Significance Statement Florida annually leads the United States in lightning fatalities. Of particular concern are first cloud-to-ground (FCG) lightning events, which are difficult to forecast and can catch people off guard especially during outdoor recreational activities and labor. We investigate the environmental characteristics of warm-season FCG events across the western Florida peninsula. Among nine regional flow patterns, some are associated with a less moist and more unstable atmosphere one hour before an FCG event, while other regimes exhibit a more moist and less unstable atmosphere. However, regardless of flow pattern, FCG events consistently feature substantially greater instability and moisture than do null events. Key findings are displayed on an online dashboard, to better inform regional forecasters.
Keywords:
[+]
Atmospheric Science
Source:
Weather and Forecasting, 37(10), 1867-1883
DOI:
https://doi.org/10.1175/waf-d-22-0005.1
ISSN:
0882-8156;1520-0434;
Format:
PDF
Publisher:
American Meteorological Society
Document Type:
Journal Article
Rights Information:
Other
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:227493987d0a7dbe8b65cf8f2e46105f54671d88838a4ebfaf6b160a731da596
Download URL:
https://repository.library.noaa.gov/view/noaa/52818/noaa_52818_DS1.pdf
File Type:

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