PSD Staff List  »  Tom Hamill
Tom Hamill – Meteorologist
Image of Tom Hamill
Forecast and Modeling Development Team
Affiliation: NOAA
Phone: (303) 497-3060
Mailing Address:
NOAA/ESRL Physical Sciences Division
325 Broadway
Boulder, CO 80305

Fax: (303) 497-7013


I perform, coordinate, and lead R&D to improve NOAA's probabilistic weather forecasts on time scales of days to several weeks. The probabilistic forecasts are based on ensembles of weather simulations using different initial conditions and methods for simulating imperfections in the forecast model. I also am involved in the "post-processing" of ensembles of forecasts, making corrections to the real-time forecasts based on discrepancies noted between past forecasts and observations or analyses. My team and I develop these research methods, demonstrate their suitability for operational use, and then work with colleagues in the National Weather Service to adapt them for daily use by forecasters and the public. We document our work in the form of peer-reviewed journal articles, presentations, white papers, book chapters, and so forth.

I have several additional roles. I am co-chairperson of the World Meteorological Organization's (WMO's) Data Assimilation and Observing Systems committee. I am on the management board of the NOAA-NCAR Developmental Test Center, and I am on Cornell University's Department of Earth and Atmospheric Sciences review board. I have previously been an editor of the American Meteorological Society's journal "Monthly Weather Review" and served for many years on the WMO's Working Group for Numerical Experimentation. Recently I contributed to the NWS Service Assessment in the wake of the severe flooding in Boulder (Sep 2013).

My CV and list of my journal articles can be found at Many of our experimental forecast products based on our global ensemble reforecast data set can be found at

Research Interests

  • Ensemble prediction methods
  • Ensemble-based data assimilation
  • Statistical post-processing
  • Forecast verification


  • Ph.D., Atmospheric Science, Cornell University, 1997
  • M.S., Atmospheric Science, Penn State University, 1987
  • B.S., Atmospheric Science, Cornell University, 1985

Professional Activities

  • Co-Chair, World Meteorological Organization Data Assimilation and Observing Systems Working Group
  • Team lead, NWS Next-generation Global Prediction Systems Project, Ensemble Development Team
  • Member, University Corporation for Atmospheric Research Modeling Advisory Committee (UCACN MAC)
  • Member, NOAA-NCAR Developmental Test Center Management Board
  • Member, Cornell University Department of Earth and Atmospheric Sciences review board

Professional Memberships

  • American Meteorological Society

Honors and Awards

  • 2017 : American Meteorological Society fellow
  • 2001 : Presidential Early-Career Award for Scientists and Engineers
  • 2002 : American Meteorological Society Editor's Award for Monthly Weather Review.
  • 2008 : NOAA outstanding scientific paper award for 2006 BAMS article on reforecasting
  • 2013 : Department of Commerce Bronze Medal (with Jeff Whitaker) for development of ensemble Kalman filters.

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