Lightning Cessation Guidance Published in Atmosphere

Over the summer, Dr. Ari Preston and alumnus John Drugan ’20 published research about using radar and total lightning data to develop lightning cessation guidance for isolated cells in the Washington, D.C. area. Lightning ranks as one of the deadliest weather phenomena. Most deaths occur before or mainly after peak lightning activity. This is because these flashes occur at times when lightning has not yet become threatening (e.g., first flash) or is no longer deemed threatening (e.g., last flash). The commonly used 30-30 rule, where the second “30” refers to the wait time in minutes before resuming outdoor activities after the most recent lightning flash, can be a lengthy amount of time to wait, and can delay business operations including aviation, construction, sports, and community events. Developing lightning cessation guidance can therefore assist outdoor safety measures.

map showing research location around Washington, DC
The red circles extend 200 km from the KLWX and KDOX radar sites. All 23 non-severe storms were within 150 km (black circle) of the DCLMA center.

A total of 23 non-severe thunderstorms during the 2015–2017 warm seasons are analyzed. Radar and lightning data are superimposed using the Warning Decision Support System–Integrated Information (WDSS-II) software to develop cessation algorithms. Horizontal reflectivity and the hydrometeor classification algorithm to locate graupel are used for each convective cell. Results show that the three best-performing cessation algorithms use thresholds of (1) horizontal reflectivity ≥ 40 dBZ at −5 ◦C, (2) horizontal reflectivity ≥ 35 dBZ at −10 ◦C, and (3) graupel at −15 ◦C. Lightning is not expected 15 minutes after the threshold is no longer met for each algorithm. These algorithms are recommended for use only for isolated cells in the Washington, D.C. area. Further study is needed to draw conclusions for other convective cell types and different geographic regions.

Table showing the rane and average lightning advisory cancellation time for each cessation algorithm.

47th Annual Northeastern Storm Conference a Success

Held in Burlington, VT March 11-13, 2022, the 47th Annual Northeastern Storm Conference was a resounding success.

Students, Faculty and Alumni Involvement in 2022 AMS Annual Meeting

This past January, Atmospheric Sciences students, faculty, and alumni presented a poster and chaired a Town Hall event at the 102nd American Meteorological Society (AMS) Annual Meeting. They promoted The Climate Consensus, Inc., a multi-institution climate outreach network, and invited other universities to join in this effort. Current Atmospheric Sciences student Gabrielle Brown, and Atmospheric Sciences faculty Dr. Janel Hanrahan, represented Northern Vermont University. They presented the poster authored by 16 students and faculty from eight universities, and co-chaired the Town Hall Meeting. They were joined by four Atmospheric Sciences alumni who are serving as representatives for their own graduate institutions. Arianna Varuolo-Clarke, currently working on her Ph.D. at Columbia University, and one of the founding members of the NVU Climate Consensus group, represented Columbia University as a Town Hall panelist. Andrew Westgate, who’s working on his Ph.D. at University of Wisconsin-Milwaukee, co-chaired the Town Hall Meeting. Two other Atmospheric Sciences graduates served as panelists for this event. Allison LaFleur represented Purdue University where she’s working on her Ph.D. Lauren Cornell represented the SUNY College of Environmental Science and Forestry where she’s working on her M.S. degree. The Climate Consensus currently has representatives from eight universities and is planning to expand over the next year.

Several Atmospheric Sciences students traveled to Houston to attend the AMS Student Conference. This was a great opportunity to present their research and network with atmospheric sciences professionals. Gabrielle Brown was selected for “Outstanding Student Conference Poster: Presenter” for her poster titled The Impact of Climatological Base Period Choice on the Communication of Climate Trends.

For those of us who were still able to attend #AMSStudent2022 in Houston, we had a great time! #AMS2022