The High Plains Regional Climate Center has an experienced team of climatologists, IT professionals, graduate students, and undergraduate interns that are all committed to serving the region. On this page you can learn more about the background of each person on the Center's team.

Rezaul Mahmood, Ph.D.


Phone: (402) 472-6166
Fax: (402) 472-2946
Contact Rezaul

B.Sc. University of Dhaka
M.Sc. University of Dhaka
M.A. State University of New York, Albany, NY
Ph.D. University of Oklahoma

Dr. Rezaul Mahmood is a Professor in the School of Natural Resources and specializes in climate and weather. He is also the Director of the High Plains Regional Climate Center (HPRCC). Rezaul has received his Ph.D. from the University of Oklahoma and joined UNL in 2018. He has published nearly 80 peer-reviewed papers in highly respected journals. Rezaul’s research focuses on meso-scale meteorology, climatology and observations, regional climate, modeling atmospheric impacts of land use land cover change, modeling impacts of soil moisture on weather and climate, and air quality meteorology. Before joining HPRCC and UNL he was a professor at Western Kentucky University (2001-2018) and provided leadership in development of the Kentucky Mesonet, WKU’s High Performance Computing Center, and Meteorology Program. His research has been funded by the NSF, NOAA, USDA-ARS, and others. Since 2009, Rezaul has been the Editor-in-Chief of the journal ‘Earth Interactions’, jointly published by the American Meteorological Society (AMS), American Geophysical Union (AGU), and American Association of Geographers (AAG). Rezaul was a member of the National Climate Assessment and Development Committee (NCADAC) during 2011-2014 and guided completion of the 3rd National Climate Assessment Report. Right after finishing his PhD., Rezaul was a postdoctoral research scientist at the HPRCC between 1999 and 2001.

Climatology Staff

Natalie Umphlett, Ph.D.

Regional Climatologist

Phone: (402) 472-6764
Fax: (402) 472-2946
Contact Natalie

B.S. University of Nebraska-Lincoln
M.S. University of Nebraska-Lincoln
Ph.D. University of Nebraska-Lincoln

Dr. Natalie Umphlett is a Regional Climatologist and Assistant Geoscientist at the High Plains Regional Climate Center. In this position, she serves as the climate services manager and public liaison for the Center, working closely with stakeholders and partners on climate monitoring for enhanced decision making. She has been with the Center since 2008 and her current research focuses on understanding ways in which climate data and information can be incorporated into municipal planning processes.

Crystal Stiles, Ph.D.

Applied Climatologist / Assistant Geoscientist

Phone: (402) 202-3320
Fax: (402) 472-2946
Contact Crystal

B.S. Western Kentucky University
M.S. Western Kentucky University
Ph.D. University of Nebraska-Lincoln

Dr. Crystal Stiles directs the HPRCC's stakeholder engagement and tribal engagement programs. She coordinates with regional climate partners, evaluates climate data and information needs for stakeholders in the region, and identifies and exercises opportunities to grow awareness and use of the Center’s climate data and information. Crystal is also a drought specialist, providing expertise and assistance on activities and projects led by the National Drought Mitigation Center at UNL and NOAA’s National Integrated Drought Information System (NIDIS).

Technical Staff

Shellie Hanneman

Data Quality Technician

Phone: (402) 472-6706
Fax: (402) 472-2946
Contact Shellie

Shellie is responsible for quality control monitoring of incoming hourly and daily data from the Automated Weather Data Network (AWDN), involving the states of Nebraska; Colorado; Kansas; Iowa; South Dakota; North Dakota and Wyoming. She also assists in the preparation of data requests, data entry, and the retrieval of climate data. Shelllie looks for any significant weather impacts in the region for the monthly newsletter, and provides notary services when a certified document is required.

Jamie Lahowetz

AWDN Manager

Phone: (402) 472-6786
Fax: (402) 472-2946
Contact Jamie

B.S. University of Nebraska-Lincoln

Jamie is responsible for the management and development of the Automated Weather Data Network. Many of his tasks include addition and removal of new stations, maintenance of storage and retrieval system, and corrections to current data archive. Mr. Lahowetz stays in contact with state mesonets in order to keep data and specifics of stations up-to-date.

Warren Pettee

Applications Programmer

Phone: (402) 472-8885
Fax: (402) 472-2946
Contact Warren

B.S. University of North Carolina at Charlotte
M.S. University of North Carolina at Charlotte

Warren develops new products for end-users in both the web front-end and through server-side software solutions. He works with HPRCC staff to turn research and stakeholder needs into modern tools for end-users. Warren is responsible for on-going development of the ACIS Climate Summary Maps, GIS products, and HPRCC's online tools.

William Sorensen

Senior Applications/Systems Programmer

Phone: (402) 472-8767
Fax: (402) 472-2946
Contact Bill

B.S. University of Nebraska-Lincoln

Bill is responsible for development and maintenance of software for acquiring, storing, managing, and distributing climate data. He provides scientific programming skills in support of applied climate research and product development efforts. He is also involved in development of climate applications and is the HPRCC's representative on the software development team for the Applied Climate Information System project.


Interns are responsible for aiding technical and research staff members in various projects. This includes applied climate research, data processing, and web development. They are also responsible for the preparation of data requests and the retrieval of climate information.

Grace Campbell

Carmelo Lattuca

Gannon Rush

Graduate Students

Kierstin Blomberg

PhD. Student

Kierstin is a doctoral student in the School of Natural Resources, pursuing a Ph.D. in Natural Resource Sciences with a specialization in Climate Assessment and Impacts. Under the direction of our Director Rezaul Mahmood, Kierstin's research focuses on the land-atmosphere interactions and land use land cover change and their impacts on weather and climate. Specifically for her dissertation, she is using modeling to study the impacts of irrigation on precipitation in Nebraska and surrounding areas.

Daniel Whitesel

M.S. Student

Daniel Whitesel is a masters student for the School of Natural Resources and is working toward an M.S. in Natural Resource Sciences with a specialization in Climate Assessment and Impacts, under the advisement of HPRCC Director RezaulMahmood. His research focuses on the use of modeling to determine the effects of opposite boundaries on convective precipitation. He hopes to later applied what can be learned from current research to determine the impacts of land use/land cover changes on derechos