NOAA Earth System Research Lab,
Physical Sciences Division
R/PSD 1, 325 Broadway
Boulder CO 80305-3328 USA
(303) 497-3060 fax -6949
Education:
B.S. 1985: Cornell
University (meteorology)
M.S. 1987: Pennsylvania State University (meteorology; NWP
concentration)
Ph.D. 1997: Cornell University (meteorology, applied math and
statistics minors)
Professional Experience:
1987 - 1991: United States Air Force. Officer-in-charge, Cloud Analysis Unit, Air Force Global Weather Central (now AFWA), Offutt AFB, NE. Responsible for research and development of improvements to the Air Force's cloud analysis and prediction models.
1991 - 1993: Senior Research Associate, Atmospheric and Environmental Research, Inc. , Cambridge, MA. Principal investigator on research projects for cloud nowcasting and use of profiler network data. Also performed research in cloud analysis and doppler radar data assimilation in mesoscale forecast models (using the CSU/RAMS model)
1993 - 1997: Ph. D. candidate in atmospheric sciences, Cornell University. Studying short-range ensemble forecasting using the Eta model (funded by the National Science Foundation). Minors in statistics and applied mathematics.
1997 - 2000: Postdoctoral fellow, National Center for Atmospheric Research, Boulder, CO.
2000 - 2005: Research Scientist, University of Colorado, CIRES (at the former NOAA/Climate Diagnostics Center), Boulder, CO.
2005 - current: Meteorologist, NOAA Earth System Research Lab, Physical Sciences Division, Boulder, CO.
Refereed Publications:
(1) Hamill, T. M., R. P. d'Entremont, and J. T. Bunting, 1992: A description of the Air Force real-time nephanalysis model. Wea. Forecasting, 7, 288-306.
(2) Hamill, T. M., and T. Nehrkorn, 1993: A short-term cloud forecast scheme using cross-correlations. Wea. Forecasting, 8, 401-411.
(3) Hamill, T. M., and D. S. Wilks, 1994: The difficulty in assessing short-range forecast uncertainty: demonstration with a probability-based contest. Wea. Forecasting, 10, 619-630.
(4) Wilks, D. S., and Hamill, T. M., 1995: Potential economic value of ensemble-based surface weather forecasts. Mon. Wea. Rev., 123, 3565-3575.
(5) Hamill, T. M., and S. J. Colucci, 1997: Verification of Eta/RSM Short-Range Ensemble Forecasts. Mon. Wea. Rev., 125, 1312-1327.
(6) Hamill, T. M., 1997: Reliability diagrams for multi-category probability forecasts. Wea. Forecasting., 12, 736-741
(7) Hamill, T. M., and S. J. Colucci, 1998: Evaluation of Eta/RSM Ensemble Probabilistic Precipitation Forecasts. Mon. Wea. Rev., 126, 711-724
(8) Hamill, T. M., 1998: Comments on "Short-Range Ensemble Forecasting of Explosive Australian East-Coast Cyclogenesis" Wea. Forecasting, 13,1205-1207.
(9) Hamill, T. M., 1999: Hypothesis tests for evaluating numerical precipitation forecasts. Wea. Forecasting, 14, 155-167.
(10) Hamill, T. M., C. Snyder, and R. E. Morss, 2000: A comparison of probabilistic forecasts from bred, singular vector, and perturbed observation ensembles. Mon. Wea. Rev., 128, 1835-1851.
(11) Hamill, T. M., and A. Church, 2000: Conditional tornado probabilities From RUC-2 forecasts, Wea. Forecasting, 15, 461-475.
(12) Hamill, T. M., and C. Snyder, 2000: A hybrid ensemble Kalman filter / 3D-variational analysis scheme. Mon. Wea. Rev., 128, 2905-2919. (nominated for NCAR's publication of the year award, 2000)
(13) Hamill, T. M., C. Snyder, D. P. Baumhefner, Z. Toth, and S. L. Mullen, 2000: Ensemble forecasting in the short to medium range: report from a workshop. Bull. Amer. Meteor. Soc., 81, 2653-2664.
(14) Hamill, T. M., 2001: Interpretation of rank histograms for verifying ensemble forecasts. Mon. Wea. Rev., 129, 550-560.
(15) Hamill, T. M., Whitaker, J. S., and C. Snyder, 2001: Distance-dependent filtering of background error covariance estimates in an ensemble Kalman filter. Mon. Wea. Rev., 129, 2776-2790.
(16) Hamill, T. M., and C. Snyder, 2002: Using improved background error covariances from an ensemble Kalman filter for adaptive observations. Mon. Wea. Rev., 130, 1552-1572.
(17) Hamill, T. M., 2002: Adaptive observations. Published in Encyclopedia of the Atmospheric Sciences, Elsevier Science, Ltd., 2537-2542.
(18) Whitaker, J. S., and T. M. Hamill, 2002: Ensemble data assimilation without perturbed observations. Mon. Wea. Rev., 130, 1913-1924.
(19) Hamill, T. M., C. Snyder, and R. E. Morss, 2002: Analysis-error statistics of a quasigeostrophic model using 3-dimensional variational assimilation. Mon. Wea. Rev., 130, 2777-2790.
(20) Snyder, C., and T. M. Hamill, 2003: Lyapunov stability of a turbulent baroclinic jet in a quasigeostrophic model. J. Atmos. Sci., 60683-688.
(21) Hamill, T. M., C. Snyder, and J. S. Whitaker, 2002: Ensemble forecasts and the properties of
flow-dependent analysis-error covariance singular vectors. Mon.
Wea. Rev., 131, 1741-1758.
(22) Snyder, C., T. M. Hamill, and S. J. Trier, 2003: Linear evolution of error covariances in a quasigeostrophic model. Mon. Wea. Rev., 131, 189-205.
(23) Hamill, T. M., 2003: Evaluating
forecasters'
rules of thumb: a study of D(Prog)/Dt Wea. Forecasting, 18,
933-937.
(24) Tippett, M., J. L. Anderson, C. H. Bishop, T. M. Hamill, and J. S. Whitaker, 2003: Ensemble square-root filters. Mon. Wea. Rev., 131,1485-1490.
(25) Whitaker, J. S., G. P. Compo, X. Wei, and T. M. Hamill, 2003:
Reanalysis without radiosondes using
ensemble data assimilation. Mon.
Wea. Rev. , 132, 1190-1200.
(26) Hamill, T. M., J. S. Whitaker, and X. Wei, 2004: Ensemble re-forecasting: improving medium-range forecast skill using retrospective forecasts Mon. Wea. Rev., 132, 1434-1447.
(27) Hamill, T. M., J. A. Hansen, S. L. Mullen, and C. Snyder, 2004: Meeting summary: workshop on ensemble forecasting in the short to medium range. Bull. Amer. Meteor. Soc. [after lengthy AMS delays, I decided not to publish].
(28) Hamill, T. M., R. S. Schneider, H. E. Brooks, G. S. Forbes, H. B. Bluestein, M. Steinberg, D. Melendez, and R. M. Dole, 2005: The May 2003 Extended Tornado Outbreak Bull. Amer. Meteor. Soc., 85, 531-542.
(28a) Hamill, T. M., R. S. Schneider, H. E. Brooks, G. S. Forbes, H. B. Bluestein, M. Steinberg, D. Melendez, and R. M. Dole, 2005: Supplement 1 to The May 2003 Extended Tornado Outbreak Bull. Amer. Meteor. Soc..
(28b) Hamill, T. M., R. S. Schneider, H. E. Brooks, G. S. Forbes, H. B. Bluestein, M. Steinberg, D. Melendez, and R. M. Dole, 2005: Supplement 2 to The May 2003 Extended Tornado Outbreak Bull. Amer. Meteor. Soc..
(29) Hamill, T. M., and J. S. Whitaker, 2005: Accounting for the error due to unresolved scales in ensemble data assimilation: a comparison of different approaches Mon. Wea. Rev., 133, 3132-3147.
(30) Hamill, T. M., J. S. Whitaker, and S. L. Mullen, 2006: Reforecasts, an important dataset for improving weather predictions Bull. Amer. Meteor. Soc., 87,33-46.
(31) Sutton, C. J., T. M. Hamill, and T. T. Warner, 2006: Will Perturbing Soil Moisture Improve Warm-Season Ensemble Forecasts? A Proof of Concept Mon. Wea. Rev., 134, 3174-3189.
(31a) Sutton, C. J., T. M. Hamill, and T. T. Warner, 2006: Appendix to "Will Perturbing Soil Moisture Improve Warm-Season Ensemble Forecasts? A Proof of Concept" Mon. Wea. Rev..
(32) Wang, X., T. M. Hamill, C. Snyder, and C. H. Bishop, 2006: A Comparison of Hybrid Ensemble Transform Kalman Filter-OI and Ensemble Square-Root filter Analysis Schemes. Mon. Wea. Rev., 135, 1055-1076.
(33) Wang, X., T. M. Hamill, and C. Snyder, 2006: On the theoretical equivalence of differently proposed ensemble/3D-Var hybrid analysis schemes Mon. Wea. Rev., 135, 222-227.
(34) Hamill, T. M., and J. S. Whitaker, 2006: Probabilistic quantitative precipitation forecasts based on reforecast analogs: theory and application Mon. Wea. Rev.,134, 3209-3229.
(35) Hamill, T. M., and J. Juras, 2006:
Measuring forecast skill: is it
real skill or is it the varying climatology?
Quart. J. Royal Meteor. Soc., 132, 2905-2923.
(36) Hamill, T. M., 2006: Ensemble-based atmospheric data assimilation Chapter 6 of Predictability of Weather and Climate, Cambridge Press, 124-156.
(37) Wilks, D. S., and T. M. Hamill, 2007: Comparison of ensemble-MOS methods using GFS reforecasts. Mon. Wea. Rev., 135, 2379-2390.
(38) Hamill, T. M., 2007: Comments on "Calibrated Surface Temperature forecasts from the Canadian ensemble prediction system using Bayesian Model Averaging. Mon. Wea. Rev., in press.
(39) Schaake, J. C., T. M. Hamill, R. Buizza, and M. Clark, 2007: HEPEX, the Hydrological Ensemble Prediction Experiment. Bull. Amer. Meteor. Soc., 88, 1541-1547.
(40) Hamill, T. M., and J. S. Whitaker, 2006: Ensemble calibration of 500 hPa geopotential height and 850 hPa and 2-meter temperatures using reforecasts. Mon. Wea. Rev., 135, 3273-3280
(41) Hamill, T. M., 2007: Making
the AMS carbon neutral: offsetting the impacts of flying to
conferences. Bull. Amer. Meteor. Soc., Nov. issue.
(42) Hagedorn, R, T. M. Hamill, and J. S. Whitaker, 2007: Probabilistic
forecast calibration using ECMWF and GFS ensemble forecasts. Part I:
2-meter temperature. Mon.
Wea. Rev., 136,
2608-2619.
(43) Hamill, T. M., R. Hagedorn, and J. S. Whitaker, 2007: Probabilistic
forecast calibration using ECMWF and GFS ensemble forecasts. Part
II: precipitation. Mon.
Wea. Rev., 136,
2620-2632.
(44) Wang, X., D. M. Barker, C. Snyder, and T. M. Hamill,
2007: A
hybrid ETKF-3DVAR data assimilation scheme for the WRF model. Part I:
observing system simulation experiments. Mon. Wea. Rev.,
accepted.
(45) Wang, X., D. M. Barker, C. Snyder, and T. M. Hamill, 2007: A hybrid ETKF-3DVAR data assimilation scheme for the WRF model. Part I: real observation experiments. Mon. Wea. Rev., accepted.
Conference Papers:
1) Hamill, T. M., and T. Nehrkorn, 1993: A short-term cloud forecast scheme using cross correlations. Preprints, Ninth International conference on Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology, American Meteorological Society, Boston, MA, 96-101.
2) Hamill, T. M., and T. Nehrkorn, 1993: Sensitivity tests of a coupled single doppler temperature retrieval / data assimilation system. Preprints, 26th International Conference on Radar Meteorology, American Meteorological Society, Boston, MA, 427-429.
3) Grassotti, C., T. Hamill, R. Isaacs, G. Gustafson, D. Johnson, and V. Jakabhazy, 1994: Analysis Integration with SERCAA: Optimizing the analysis of multiplatform/multisensor satellite-derived cloud parameters. Preprints, Seventh Conference on Satellite Meteorology and Oceanography, American Meteorological Society, Boston, MA.
4) Wilks, D. S., and T. M. Hamill, 1995: On the economic value of forecasting forecast skill. Preprints, 14th Conference on Weather Analysis and Forecasting, American Meteorological Society, Boston, MA, J5(7)-J5(12).
5) Hamill, T. M., and S. Colucci, 1995: Random and systematic error in NMC's short-range Eta ensembles. Preprints, 13th Conference on Probability and Statistics in the Atmospheric Sciences, Boston, MA. 51-56.
6) Hamill, T. M., and S. Colucci, 1996: Eta/RSM Ensemble Usefulness for Short-Range Forecasting. Preprints, 11th Conference on Numerical Weather Prediction, American Meteorological Society, Boston, MA, j43-j45.
7) Cohen, A.S., Hamill, T. M., and Colucci, S. J., 1996: Evaluating Eta/RSM Ensemble Forecasts and Display Methods During Selected Heavy Precipitation Events of 1995-1996. Preprints, 15th Conference on Weather Analysis and Forecasting, American Meteorological Society, Boston, MA., j75-j78.
8) Hamill, T. M., and Colucci, S. J., 1997: Perturbations to the Land Surface Condition in Short-Range Ensemble Forecasts. Preprints, 12th Conference on Numerical Weather Prediction, (Phoenix) American Meteorological Society, 273-276.
9) Hamill, T. M., 1997: Hypothesis Tests for Precipitation Threat Scores Through Resampling. Preprints, 13th Conference on Probability and Statistics in the Atmospheric Sciences, (Phoenix), American Meteorological Society, Boston, MA, 51-56.
10)Mullen, S. L., M. Poulton, H. E. Brooks, and T. M. Hamill, 1998: Post-processing of ETA/RSM ensemble precipitation forecasts by a neural network. Preprints, First Conf. on Artificial Intelligence , Phoenix, AZ, Amer. Meteor. Soc., J31-J33.
11)Hamill, T. M., J. S. Whitaker, and C. Snyder, 2001: Distance-dependent filtering of background error covariance estimates in an ensemble Kalman filter. Preprints, 14th Conf. Numerical Weather Prediction (Ft Lauderdale), American Meteorological Society, Boston, MA
12)Hamill, T. M., and C. Snyder, 2001: Using improved background error covariance estimates from an ensemble Kalman filter for targeted observations. Preprints, 9th Conf. Mesoscale Processes (Ft Lauderdale), American Meteorological Society, Boston, MA.
13)Hamill, T. M., 2002: An overview of ensemble forecasting and data assimilation. Preprints, 14th Conf. Numerical Weather Prediction (Ft Lauderdale), American Meteorological Society, Boston, MA
14)Hamill, T. M., J. S. Whitaker, and C. Snyder, 2001: Generating initial conditions for ensemble forecasts: Monte-Carlo vs. dynamic methods. Preprints, AMS Symposium on observations, data assimilation, and probabilistic prediction. (Orlando), American Meteorological Society, Boston, MA, j1-j6.
15)Hamill, T. M., and J. S. Whitaker, 2004: Model errors in ensemble forecasts: the structure of errors from unrepresented scalesPreprints, 16th NWP/20th W&F Conference, Seattle, American Meteorological Society.
16)Hamill, T. M., J. S. Whitaker, and X. Wei, 2004: Ensemble re-forecasting: improving medium-range forecast skill using retrospective forecasts.Preprints, 17th Probability and Statistics Conference, Seattle, American Meteorological Society.
17) Sutton, C. J., T. M., Hamill, and T. T. Warner, 2004: Impacts of perturbed soil moisture conditions on short-range ensemble variability Preprints, 16th NWP/20th W&F Conference, Seattle, American Meteorological Society.
18) Whitaker, J. S., and T. M. Hamill, 2005: Ensemble data assimilation in the NCEP GFS. THORPEX meeting, Montreal, Canada, Dec. 2004.
Technical Reports:
1) Hamill, T. M., 1992: Prediction of thunderstorm initiation through 4-dimensional data assimilation of Doppler radar data. PL-TR-92-2029, Phillips Laboratory, Bedford, MA, 84 pp.
2) Hamill, T. M., and T. Nehrkorn, 1993: Sensitivity testing of a single-Doppler temperature retrieval and forecast system. PL-TR-93-2071, Phillips Laboratory, Bedford, MA, 86 pp.
3) Hamill, T. M., and R. N. Hoffman, 1993: SERCAA cloud analysis integration: design concepts and interaction with cloud forecast models. PL-TR-93-2100, Phillips Laboratory, Bedford, MA, 54 pp.
4) Nehrkorn, T., T. M. Hamill, and L. W. Knowlton, 1993: Nowcasting methods for satellite imagery. PL-TR-93-2021, Phillips Laboratory, Bedford, MA, 113 pp.
5) Hamill, T. M., T. Nehrkorn, and L. W. Knowlton, 1994: Use of wind profiler data in short-range forecasting. PL-TR-94-2009, Phillips Laboratory, Bedford, MA, 125 pp.
6) Gustafson, G. B., (many others), and T. M. Hamill, 1994: Support for Environmental Requirements for Cloud Analysis and Archive (SERCAA): Algorithm Descriptions. PL-TR-94-2114, Phillips Laboratory, Bedford, MA, 100 pp.
7) Nehrkorn, T., J. Hegarty, and T. M. Hamill, 1994: Real-data tests of a single-Doppler radar data assimilation system. PL-TR-94-2199, Phillips Laboratory, Bedford, MA, 49 pp.
Professional Service
1997 - current : Proposal reviewer for National Science Foundation
1999 - 2003 : Associate Editor, Monthly
Weather Review
1999 : Coordinator, NCAR Workshop on Ensemble Forecasting
2003 : Coordinator,
Workshop on Ensemble Forecasting
2005 : Coordinator, HEPEX Workshop on
Hydrologic Ensemble Prediction.
2005-current : Member, THORPEX TIGGE International Steering Committee
2005 : Member, HEPEX International Steering Committee
2006-2007: Associate Editor, Weather
and Forecasting
2006-current: Member, American Meteorological Society Committee
on Probability and Statistics
2007: Coordinator, AMS Short Course on Ensemble Prediction Methods
2007-current: Editor, Monthly
Weather Review
2007-current: Member,
NOAA/NWS Forecast Uncertainty Steering Team
2007-current: Member, American Meteorological Society Ad-Hoc Committee
on Uncertainty in Forecasts (co-chair, Working Group III, "Solutions")
2008: Member, drafting committee for AMS statement on probabilistic
forecasting.
Awards
1997 : National Center for Atmospheric Research Advanced Studies
post-doctoral fellowship
2001 : Presidential
Early-Career Award for Scientists and Engineers
2002 : American Meteorological Society's Editor's Award for Monthly
Weather Review.
Funded Proposals
1991: "Nowcasting Methods Testing" $144,917 by U.S. Air Force, PRDA PL/LY 91-05 Developed new ways to use satellite and doppler profiler data for nowcasting.
1995: "Short-range ensemble prediction..." $86,003 by National Science Foundation. Grant funded my dissertation research (submitted under my advisor's name).
2001: Diversifying Ensemble Forecasts with Stochastic Convection (co-PI; Brian Mapes, PI). National Science Foundation. $343,000.
2002: Incorporating the Uncertainty of Atmosphere-Land Surface Interactions into Ensemble Forecasts. National Science Foundation, $320,000.
2002: Collaborative Research: ITR/Ensemble-based state estimation for a next-generation weather forecasting model, $220,706.
2004: THORPEX, An Intercomparison of Bred, Perturbed Observation, and Ensemble Transform Kalman Filter Methods for Initializing Ensemble Forecasts (co-PI, Jeff Whitaker). NOAA-B8R2WRP, $210,373.
Invited Lectures
National Centers for Environmental Prediction (1995, 1996, 1997,
2000, 2006) ; NOAA Techniques Development Lab (1996) ; European Centre
for
Medium-Range Weather Forecasts (1998) ; National Weather Service
COMET Numerical Weather Prediction Faculty Course (1999) ; National
Severe Storms Lab (1999) ; University of Oklahoma (1999) ; University
of
Arizona (2000) ; University at Albany/State University of New York
(2000); NASA/Goddard (2000) ; Canadian Meteorological Centre (2001) ;
Colorado State University (2001, 2003); Cornell University (2001, 2003)
; Massachusetts Institute of Technology (2001); AER, Inc. (2001) ;
National Weather Service COMET Climate Variability
Course (2002, 2006, 2007) ; NCAR (2000, 2002, 2004, 2005, 2007) ECMWF
Seminar
on
Predictability (2002);
University of Colorado (2002); ECMWF (2004, 2005, 2006, 2007);
University of
L'Aquila, Italy (2004); UK Met Office (2004);
NOAA/FSL (2004); University of Washington (2004, 2007); NOAA
Headquarters
(2004);
NOAA/MDL (2004); University of Maryland (2004); UK Met Office (2004) ;
National Academy of Sciences (2005); Canadian Meteorological Centre
(2006); National Weather Service
COMET Climate Variability Course (2006); NCAR Terrestrial
Hydrometeorology Workshop (2006); NCAR Verification Workshop (2007);
IUGG, Perugia, Italy (2007); University of Oklahoma (2007); NCAR
COMET Hydrological Forecast Course (2007), Southwest
Hydrometeorological Workshop, Tucson (2007); University of Washington
Climate Impacts Group (2007); ECMWF
Workshop on Ensemble Prediction (2007); Mediterranean
School of Mesoscale Meteorology, Sardinia, Italy (2008).