EWP: 2008 Spring Experiment Summary

Working Hypotheses

  1. Operational meteorologists can provide valuable feedback of experimental severe weather warning decision-making products and displays which are being designed and tested as candidates for operations.
  2. Operational meteorologists get exposed to the latest research and development ideas when immersed in a collaborative environment, and can carry that information back with them to share with their peers in the operational world.
  3. Researchers and technology specialists can gain a better understanding of the operational requirements of the severe weather warning forecaster if they work closely with them during real-time warning exercises in a testbed setting.

Specific Objectives

Research Perspective

  1. To work with NSSL scientists on the development of scanning strategies for the Phased-Array Radar (PAR).
  2. To work with NSSL, and Collaborative Adaptive Sensing of the Atmosphere (CASA) scientists on the development of algorithms and scanning strategies for low-cost gap-filling collaborative radar networks and how they affect decision making of NWS warring forecasters.
  3. To work with NSSL meteorologists and social scientists on a pioneering new project aiming to investigate innovative methods for communicating weather hazards, beyond NWS storm-based warnings.
  4. To work with Warning Decision Training Branch trainers on the development of best practices for the use of experimental research products designed for transition to operations.

Operational Perspective

  1. Evaluate operational utility of Phased Array Radar (PAR) technology, demonstrate and obtain forecaster feedback on basic adaptive electronic scanning of weather echoes and on storm-type optimized scanning strategies for surveillance of storm initiation and severe storms.
  2. Evaluate operational utility of Collaborative Adaptive Sensing of the Atmosphere (CASA) dense radar network data and low-level, real time wind products and forecasts derived from those data, for severe weather decision-making through real time warning situations and structured experiments with archived data.
  3. To identify best practices for using experimental products in nowcast and warning decision making and identifying appropriate display strategies within AWIPS.
  4. To evaluate the utility and effectiveness of gridded Probabilistic Hazard Information (PHI) to provide rapidly-updating high-resolution digital severe weather grids including probability information as a basis to create user-specific customizable severe weather warnings. The project scope included determining forecast team workload, discussions on warning uncertainty, and how they may be of benefit to users of severe convective weather hazard information.


  • NWS WFO: 19
  • NWS RHQ: 1
  • NWS WDTB: 8
  • International: 6 (Canada, Serbia)
  • Academia: 7

Preliminary Results

MRMS products

Probabilistic Hazard Information (PHI) hail grids (shaded rainbow colors), PHI hail and tornado warning polygons (mint green and red, respectively), and KTLX reflectivity (green and grey background grid) for 21 April 2008 in central Oklahoma. [+]

Probabilistic Hazard Information (PHI) hail grids (shaded rainbow colors), PHI hail and tornado warning polygons (mint green and red, respectively), and KTLX reflectivity (green and grey background grid) for 21 April 2008 in central Oklahoma.
  1. Very high temporal resolution data from PAR and CASA will radically change the concept of real-time radar data analysis (volume scans can be up to 10 times faster than the WSR-88D).
  2. Participants saw the potential usefulness of the Probabilistic Hazard Information concept, but it requires a stronger scientific and statistical baseline from which to derive probabilities than was available in this initial demonstration. Additionally, sociological research will be required to turn scientifically-based probabilistic hazard information into NWS products that a wide variety of end-users can understand and use.
  3. Data sets should be made available in AWIPS (and soon, AWIPS2) as it is the standard NWS software platform whose user interface is familiar with most visiting forecasters.
  4. The experimental WDSSII CONUS Multi-radar/sensor severe weather products, such as the gridded hail and “rotation tracks”, were very beneficial in providing warning decision guidance, and there was a strong consensus that they should become operational.


  1. EWP 2008 was the first major coordinated spring experiment for the Experimental Warning Program, and it set the stage for all future EWP spring experiments.
  2. First use of a blog to communicate happenings at NSSL. The live blog was also useful for external interests wanting to track operations in real-time.
  3. The PHI project led to the first specialized Weather And Society * Integrated Studies (WAS*IS) Workshop designed to address the future of severe weather warnings. This kicked off a major dialog between NWS, research meteorologists, and social scientists about the direction of hazardous weather communication that continues in full force today.

Related Publications

  • Heinselman, P. L., D. Priegnitz, T. Smith, D. Andra, R. Palmer, M. Biggerstaff, 2007: Spring 2007 National Weather Radar Testbed Demonstration. Preprints, 33rd Conference on Radar Meteorology, Cairns, Australia, AMS, CD-ROM, P5.7.
  • Heinselman, P. L., D. L. Priegnitz, K. L. Manross, T. M. Smith, R. W. Adams, 2008: Rapid sampling of severe storms by the National Weather Radar Testbed Phased Array Radar. Wea. Forecasting, 23, 808–824.
  • Heinselman, P. L., T. M. Smith, K. L. Ortega, K. Manross, 2009: Radar sampling of low-altitude circulations by phased array radar. Preprints, 25th Conference on International Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology, Phoenix, AZ, USA, Amer. Meteor. Soc., 9B.4.
  • Hondl, K. D., V. Lakshmanan, T. M. Smith, G. J. Stumpf, 2007: Warning Decision Support System - Integrated Information (WDSS-II) Progress and Plans. Preprints, 23rd Conference on Interactive Information Processing Systems, San Antonio, TX, USA, AMS, CD-ROM, 6.3.
  • Kuhlman, K. M., T. M. Smith, G. J. Stumpf, K. L. Ortega, K. L. Manross, 2008: Experimental probabilistic hazard information in practice: Results from the 2008 EWP Spring Program. Extended Abstracts, 24th Conference on Severe Local Storms, Savannah, GA, USA, American Meteorological Society, 8A.1.
  • Kuhlman, K. M., E. Gruntfest, K. A. Scharfenberg, G. J. Stumpf, 2009: Beyond Storm-Based Warnings: An Advanced WAS*IS Workshop to study communication of probabilistic hazardous weather information. Extended Abstracts, 4th Symp. on Policy and Socio-Economic Research, Phoenix, AZ, USA, Amer. Meteor. Soc., CD-ROM, 3.5.
  • Lakshmanan, V., T. M. Smith, G. J. Stumpf, K. D. Hondl, 2007: The Warning Decision Support System—Integrated Information. Wea. Forecasting, 22, 596-612, doi:10.1175/WAF1009.1.
  • Stumpf, G. J., S. B. Smith and K. E. Kelleher, 2005: Collaborative activities of the NWS MDL and NSSL to improve and develop new severe weather warning guidance applications. Preprints, 21st Intl. Conf. on Interactive Information Processing Sys., San Diego, CA, Amer. Meteor. Soc., P2.13.
  • Stumpf, G. J., T. M. Smith, D. L. Andra, D. W. Burgess, J. G. LaDue, L. R. Lemon, M. A. Magsig, K. Manross, D. J. Miller, S. Nelson, K. L. Ortega, K. Scharfenberg, D. W. Sharp, 2008: Experimental gridded warning guidance for severe convective weather threats. Extended Abstracts, 24th Conf. on IIPS, New Orleans, LA, USA, Amer. Meteor. Soc., P1.3.
  • Stumpf, G. J., T. M. Smith, K. Manross, D. L. Andra, 2008: The Experimental Warning Program 2008 Spring Experiment at the NOAA Hazardous Weather Testbed. Preprints, 24th Conference on Severe Local Storms, Savannah, GA, USA, American Meteorological Society, CD-ROM, 8A.1.