Colorado State University

Team Members

Group Photos

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Group photo 1
December 2022 (left to right) Alex, Rung, Tyler, Jen, Chelsea, Angelie, Ting-Yu, and Michael
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Group photo 2
October 2021 (left to right) Michael, Ali, Chelsea, Alex, Ting-Yu, Phil, Tyler, Chandra, Rung, Ellie, and Jen
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Group photo 3
January 2020 (left to right) Naufal, Jen, Alex, Chelsea, Ellie, Jon, Ali, Ting-Yu, Dandan, Kate, Brianna, Chandra, Rung, Jhordanne, and Michael
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Group photo 4
Halloween 2019 (left to right) Naufal, Michael, Ben, Rung, Alex, Jon, Ali, Jen, Ellie, Chandra, Jhordanne, Chelsea, Ting-Yu, and Dandan

Please click the photo to find more info about each member

Michael Bell,
Phil Klotzbach,
Research Scientist III
Brenda Dolan,
Research Scientist III
Jen DeHart,
Research Scientist I
C. Chelsea Nam,
Postdoctoral Fellow
Tyler Barbero,
M.S. Student
Alex DesRosiers,
Ph.D. Candidate
Angelie Nieves-Jiménez,
M.S. Student
Chandra Pasillas,
Ph.D. Candidate
Rung Panasawat-wong,
Ph.D. Candidate

Brief intro of each member



Professor Michael Bell is the principal investigator of the CSU Tropical Weather and Climate Research Group. He became interested in studying the atmosphere and tropical cyclones (TCs) growing up in coastal Florida and being impacted by hurricanes. After obtaining a B.A. degree from the University of Florida, he moved to Colorado to pursue math and meteorology, and worked at NCAR as a researcher and airborne radar support scientist. He completed his M.S. thesis at Colorado State University on TC intensity theory and Ph.D. dissertation at Naval Postgraduate School (NPS) in Monterey, California on air-sea interaction in TCs. Dr. Bell became an assistant professor at University of Hawaii in 2012, and returned to Colorado in 2016 to join the faculty at CSU where he currently teaches and researches atmospheric science. He is the recipient of the NSF CAREER, ONR Young Investigator, and White House PECASE Awards for his research in tropical meteorology, TCs, field experiments, radar observations, and numerical modeling. He enjoys hiking, canoeing, and music, and serves on the Board of Directors for the Fort Collins Area Swim Team.



Chelsea Nam is a postdoctoral fellow studying convective structure and evolution during tropical cyclone genesis. To better understand the complex, multi-scale tropical cyclogenesis, she uses a number of different datasets and methods including radar (airborne, shipborne) data, ensemble high-resolution mesoscale models (WRF and CM1) and large-scale reanalyses. She graduated from her PhD at Colorado State University (CSU) in 2021 working with Dr. Michael Bell. She received a B.S in earth science from Seoul National University (SNU) at South Korea in 2015, and her M.S in atmospheric science from SNU in 2017. During her Master’s, she researched TC risk in statistical and climatological perspective working with Dr. Chang-Hoi Ho and Dr. Doo-Sun R. Park. She has a passion for teaching; she completed the graduate teaching certificate program at CSU while serving an instructor for the undergraduate Intro course for atmospheric science at CSU in 2019 and as a teaching assistant for Atmospheric Dynamics II course in 2020.


Jennifer is a Research Scientist I. In her research, Jennifer uses a combination of polarimetric radar observations and mesoscale models to understand the processes responsible for heavy tropical rainfall in a variety of weather systems. Prior to arriving at CSU, Jennifer received her Ph.D. from the University of Washington, where she worked with Prof. Robert Houze, Jr. to understand how external forcings affect the three-dimensional structure of tropical cyclones. Throughout her career, Jennifer has been fortunate to participate in several field campaigns, including VORTEX2, HS3, OLYMPEX, and the upcoming PRECIP campaign in 2021. In her free time, Jennifer enjoys traveling and eating delicious food.


Phil Klotzbach is a Research Scientist in the Department of Atmospheric Science at Colorado State University. He received his Ph.D. in Atmospheric Science from CSU in 2007. Klotzbach has been employed in the Department of Atmospheric Science for the past twenty years and was co-author on the Atlantic basin hurricane forecasts with Dr. William Gray through 2005. He became first author on the seasonal hurricane forecasts in 2006. Klotzbach developed the two-week forecasts currently being issued during the peak months of the hurricane season between August-October. He has authored over 50 articles in peer-reviewed journals such as Journal of Climate and Weather and Forecasting. Klotzbach graduated from Bridgewater State College with a BS degree in Geography in 1999. He then attended Colorado State University where he received his Masters degree in Atmospheric Science in 2002. After receiving his Masters degree, Klotzbach thru-hiked the Appalachian Trail from Georgia to Maine (2100+ miles). He has also climbed all 54 14,000 foot peaks in Colorado, and has completed nine marathons and six ultra-marathons.


Brenda is a Research Scientist III at Colorado State University. She received her Ph.D. in Atmospheric Science from CSU in 2009. Brenda's research focuses on precipitation and microphysical processes using polarimetric radar, satellites, and disdrometers. Brenda's research interests include radar analysis and algorithms, observational integration and validation of cloud-resolving models, precipitation processes, and cloud physics. She is an expert in polarimetric radar, having developed one of the first hydrometeor identification algorithms for short-wavelength radars (X- and C-band). Additionally, she has worked with a wide variety of radars from around the world including ground, ship, and satellite-based radars from Ka- to S-band. Brenda enjoys field work and has participated in over 10 field projects as a radar or mission scientist. She works at the interface of cloud resolving models and observations, using them synergistically to improve observational retrievals and better model representation of physical processes. In her spare time, Brenda can be found baking, skiing, hiking, camping, or taking flying adventures with her pilot husband and two kids.



Angelie Nieves-Jiménez is an M.S. student born and raised in San Juan, Puerto Rico. Angelie graduated from the University of Puerto Rico at Mayagüez with a B.S. in Industrial Engineering. Her motivation to study Atmospheric Sciences during her undergraduate studies was complemented by her work as a SOARS Protégé for four years at the National Center for Atmospheric Research (NCAR). Angelie is interested in expanding her knowledge of tropical cyclone rapid intensification and associated rainfall. One of her main goals is to inspire the future generation and give back to her island by increasing education in this discipline and guiding the people when natural hazards are imminent. In her spare time, Angelie enjoys spending time with her family, friends, and her dog Nova in Puerto Rico and eating Puerto Rican fried food.


Alex is a Ph.D. student at Colorado State University. He was born and raised in Tampa Florida and obtained his Bachelor's Degree in Environmental Engineering from the University of Florida. An affinity for the outdoors has made Colorado an excellent new home. Alex’s current research aims to identify internal mechanisms driving rapid intensification in recent Atlantic storms. In situ data such as the NOAA P-3 Tail Doppler Radar will be used to capture these mechanisms in action. This research also incorporates machine learning techniques to lessen the time and effort it takes to quality control radar data. The end goal is a better understanding of how rapid intensity changes occur in order to provide more information for modelers and forecasters.


Tyler Barbero is a first year M.S. student originally from Santa Clara, California. He received his B.S. in Ocean and Atmospheric Sciences and minor in Mathematics from Scripps Institution of Oceanography and the University of California San Diego. His undergraduate research involved looking at dust dynamics and transport in Southern California but his interests took a turn when he interned at the Geophysical Fluid Dynamics Laboratory (GFDL) on a project investigating tropical cyclone (TC) track biases in GFS, IFS and GFDL SHiELD models. He plans to continue this research into his Masters and also explore other interests which include tropical waves, large-scale atmospheric and oceanic controls on TCs among others. Alongside research, Tyler aspires to teach and through this, inspire in people the same enthusiasm he has for this field. For pastime activities, he enjoys rock climbing, surfing (when near an ocean), and unwinding with a beer (or two) after a long week.


Chandra Pasillas is a Ph. D. candidate co-advised by Michael Bell and Christian Kummerow. She is working to advance geostationary nighttime multi-spectral imaging for low cloud detection with applications towards improving fog forecasting and tropical cyclone forecasting through the use of derived motion winds.Chandra received her Bachelors’ of Science in Meteorology from the United States Air Force Academy in 2004, and then entered the United States Air Force (USAF) as a weather officer. She obtained her Masters’ of Science in Atmosphere Science from the Naval Post-graduate School where she studied the impacts of time latency and satellite selection to the USAF’s World Wide Merged Cloud Analysis (WWMCA) product under Dr. Tom Murphree. In addition to her current research, Chandra is interested in bringing research products into operations capacity to provide today’s forecasters with the best tools available for informing leaders and aviators of adverse weather impacts.

Rung Panasawatwong  


Rung is a Ph.D. candidate co-advised by Michael Bell and Kristen Rasmussen. She's originally from Bangkok, Thailand and is receiving the Thai Government Scholarship. She is interested in extreme-rainfall producing storms in the Tropical East Asia Region. She received her Bachelors and Master of Science degrees from Massachusetts Institute of Technology, where she studied climate sensitivity to CO2 and reversing rainfall trends over Southeast Asia. Currently, she is working with an ingredient framework to study extreme storms, using radar observations and reanalysis data to study the climatology of extreme storms in preparation for the PRECIP field campaign in 2021 in Taiwan and Japan. Outside of work, she’s interested in different cultures and foreign languages. She can speak Thai and English fluently, and can hold conversations in Japanese.

Group Alumni/ Past Members

Shannon McElhinney  

  • M.S. in 2014
  • Thesis: Observations of Supergradient Winds in the Tropical Cyclone Boundary Layer
  • Current Affilation: Geophysical Fluid Dynamics Laboratory, Princeton, NJ

  • Ph.D. in 2022
  • Thesis: Investigation of Relationships Between Tropical Cyclone Structure and Intensity Change
  • Current Affilation: Postdoc at Naval Postgraduate School

  • Ph.D. in 2020
  • Thesis: On Intensity Change and the Effects of Shortwave Radiation on Tropical Cyclone Rainbands
  • Current Affilation: Research Associate at Cooperative Institute for Research in the Atmosphere (CIRA)

  • Postdoc from 2017 to 2019
  • Current Affilation: ASP Postdoc at National Center for Atmospheric Research (NCAR)

  • Ph.D. in 2021
  • Thesis: Satellite-based Investigation of Convection and Precipitation in Tropical Cyclone Intensity Change
  • Current Affilation: Postdoc at Cooperative Institute for Research in the Atmosphere (CIRA)

  • Postdoc from 2014 to 2016
  • Current Affilation: Program Coordinator at NOAA/OAR/Off. of Weather and Air Quality

  • Annette Foerster  

  • Ph.D. in 2017
  • Thesis: Radar-derived Thermodynamic Structure of a Major Hurricane in Vertical Wind Shear
  • Current Affilation: ITGAIN Consulting Gesellschaft für IT-Beratung mbH

  • Jonathan Martinez  

  • Ph.D. in 2020
  • Thesis: Axisymmetric and Asymmetric Processes Contributing to Tropical Cyclone Intensification and Expansion
  • Current Affilation: ASP Postdoc Fellow at National Center for Atmospheric Research (NCAR)

  • M.S. in 2022
  • Thesis: Ensemble-Based Analyses of Liminal Extreme Rainfall Events Near Taiwan and Northern Colorado
  • Current Affilation: Atmospheric scientist at CPP Wind Engineering Consulate

  • Ph.D. in 2023
  • Thesis: Investigation of the dynamics of tropical cyclone precipitation structure using radar observations and numerical modeling
  • Current Affilation: NCAR ASP Postdoctoral Fellow

  • Andrew Frambach  

  • M.S. in 2015
  • Thesis: Dual-polarization Radar Characteristics of Convection in Hawaii during HERO
  • Current Affilation: Center for Severe Weather Research, Boulder, CO

  • Research Scientist I from Aug. 2018 to Oct. 2020
  • Current Affilation: Researcher at Geophysical Institude at University of Bergen, Norway

  • Chaehyeon Chelsea Nam  

  • Ph.D. in 2021
  • Thesis: Multi-scale Interactions Leading to Tropical Cyclogenesis in Sheared Environments
  • Current Affilation: Postdoc at the CSU tropical meteorology group

  • Research Associate from Jan. 2020 to Mar. 2021
  • Current Affilation: Senior Data Scientist at Nutrien Ag Solutions

  • Jhordanne Jones  

  • Ph.D. in 2021
  • Thesis: An Examination of the Large-Scale Drivers of North Atlantic Vertical Wind Shear and Seasonal Tropical Cylcone Variability
  • Current Affilation: Postdoc at Department of Earth, Atmospheric and Planetary Sciences of Purdue University

  • Research Associate from Jan. 2020 to May 2020
  • Current Affilation: Associate Scientist at National Center for Atmospheric Research (NCAR)