• Gerrit Hiemstra, MSc

    Co-founder and Chief Executive Officer

    Gerrit is a meteorologist with in-depth experience in the meteorological field. He graduated in 1986 at Wageningen University as Agricultural Engineer, with a specialisation in Agricultural Meteorology, followed by a 9-year period as operational weather forecaster in a commercial weather company.

    After a brief period as head of the operational weather service at Schiphol Airport he founded the successful commercial weather company WeerOnline, which was sold in 2009.

    Gerrit is also the well-known weather presenter of NOS, the national news organisation of the Netherlands, since 1998.

    At Weather Impact Gerrit is responsible for project acquisition and contract management.

  • Arnold Lobbrecht, PhD

    Co-founder and Chief Technology Officer

    Arnold graduated in 1986 from Delft University of Technology as Civil Engineer. He gained experience in hydrology, water management and informatics during a 12-years period at a multinational consultancy firm.

    After 4 years of research he obtained in 1997 his PhD in operational water management. After that he became part-time professor of hydroinformatics at UNESCO-IHE in Delft, guiding a group of PhD researchers. In 2000 he established HydroLogic, a hydroinformatics company, working on water & ICT projects.

    His experience is in decision support systems with focus on flood forecasting, water availability and droughts.

  • Saskia van Pelt, PhD

    General Manager

    Dr. Saskia van Pelt works at Weather Impact as General Manager.

    She graduated in 2009 at the Earth System Science and Climate Change Group of Wageningen University. She subsequently started a PhD research into the analysis of uncertainty in the projections of climate change.

    She has been employed at Weather Impact since it was founded in 2014. She has experience as project leader in different countries in Africa and knows the many challenges of working with farmers and other stakeholders in the agricultural value chain on the African continent. As business developer she has a large network with scientific institutes, NGO’s, governmental organisations and corporations both in Africa and the Netherlands.

  • Fiona van der Burgt, MSc

    Project leader and consultant

    Fiona van der Burgt MSc. works at Weather Impact as project leader and consultant.

    She has a background in physics, climate change and meteorology and graduated as climate physicist at the Utrecht University in 2014.

    At Weather Impact she makes extensive analysis of local climates. She has a broad experience in providing operational services in developing countries and big data analytics. Her research work focuses on the impacts of climate change on agriculture and risk analysis of extreme weather for individual farmers. She combines her analytic capabilities with creativity and good communication skills to develop solutions for our clients. As project leader she has a large network with scientific institutes, NGO’s, governmental organisations and corporations in South-East Asia, Africa and the Netherlands.


  • Stefan Ligtenberg, PhD

    Project leader and consultant

    Dr. Stefan Ligtenberg works at Weather Impact as project leader and consultant.

    Stefan graduated in 2009 at Wageningen University in Meteorology and Air Quality. He finished his PhD in 2014 on the field of polar meteorology at Utrecht University. Subsequently he started two postdoctoral positions at Utrecht University, for the last he received an NWO VENI scholarship.

    At Weather Impact, Stefan works as consultant and project leader. He has experience with weather forecasting in Southeast Asia and East Africa. He is an expert in translating meteorological weather parameters in messages that fit the local context of a farmer.

  • Bob Ammerlaan, MSc


    Bob Ammerlaan MSc. works at Weather Impact as consultant.

    Bob has a background in Physics and Meteorology and graduated in 2018 at Utrecht University in Meteorology, Physical Oceanography and Climate.

    At Weather Impact, Bob works as consultant meteorology and climate change. He is responsible for the operational services at Weather Impact. He has experience with weather forecasting in Southeast Asia and East Africa and is an expert in using agricultural and meteorological information to give the best advice to local farmers.

  • Tamara Lancel

    Management Assistant

    Tamara Lancel works at Weather Impact as Management Assistant.

    She graduated in Hotel & Hospitalitymanagement in 2007 and has a background in the hospitality industry, organizing congresses and events. In her last job she worked as a training coordinator and arranged technical IT trainings for the Benelux and Africa region. Tamara is very strong in planning, coordinating and organizing, and has experience in broad administrative and logistic work. At Weather Impact she supports the team in marketing, HR, administration, acquisition and other organizational tasks, to share our expertise about smart weather solutions.