FORECAST and WARNING IMPROVEMENTS

 

Testbeds

Hazardous Weather Testbed/Experimental Warning Program (HWT/EWP)

The NSSL multi-sensor hail swath application display

The NSSL multi-sensor hail swath application shows the location of potentially large hail.

The Experimental Warning Program's mission is to improve the nation's hazardous weather warning services by bringing together forecasters, researchers, trainers, developers, and user groups to test and evaluate new techniques, applications, observing platforms, and technologies.

SHAVE

The Severe Hail Verification Experiment (SHAVE) was designed to take advantage of the ability to blend high-resolution radar data with geographic information.  The primary objective of the experiment was to collect high temporal and spatial resolution data that describe the distribution of hail sizes in hail swaths produced by severe thunderstorms.  These data enable several goals, including:

  1. to utilize the high-resolution verification data in the development of techniques for probabilistic warnings of severe thunderstorms,
  2. to evaluate the performance of a multi-sensor, multi-radar hail detection algorithm,
  3. to correlate changes in the hail size distribution with storm evolution,
  4. to enhance climatological information about hail in the United States.

The high spatial and temporal resolution of the dataset collected during the project facilitates the development of decision-making tools that improve forecasts and warnings of severe hail as well as improving the historical record of hail events.  The 2006 project began on May 15 and continued through August 12.  It utilized real-time hail swaths products from the WDSS-II system to enhance data collection via verification telephone calls to select data points along a storm's path immediately following storm passage.  Because the presence of hail is diagnosed via radar on the CONUS scale, it is possible to collect data from anywhere in the contiguous 48 states on a daily basis throughout the summer, which minimizes project "down days."  Data were collected by a team of University of Oklahoma meteorology students working closely with NSSL's warning applications scientists.

Geographic Information System Integration Into Warning Decision-Making and Severe Storm Verification

NSSL has begun utilizing Google Earth as a way to share experimental severe weather products with other researchers and operational meteorologists for evaluation and feedback. A variety of multi-sensor severe weather products are generated by NSSL and shared to Google Earth users via the internet at http://wdssii.nssl.noaa.gov. These products include spatially gridded fields of Vertically Integrated Liquid, Maximum Expected Hail Size, tracks of circulations derived from Doppler velocity data, composite reflectivity, and 30-to-60 minute forecast reflectivity fields, among others. These products, which have a spatial resolution of approximately 1 km by 1 km, are generated every one or two minutes within the Warning Decision Support System – Integrated Information (WDSS-II). The WDSS-II system provides the images in GeoTIFF format which may be imported into most Geographic Information Systems software including Google Earth.