Warn on Forecast

News Archive

New System Automatically Detects Supercell Thunderstorms

Posted May 23, 2011

NWS forecasters will be evaluating a new weather-adaptive three-dimensional variational data assimilation (3DVAR) system from NSSL/CIMMS that automatically detects and analyzes supercell thunderstorms during the 2011 Experimental Warning Program in the Hazardous Weather Testbed. The program runs from May 9-June 10, 2011.

Early identification of supercell thunderstorms is critical to the public severe weather warning process since 90% of supercell thunderstorms produce tornadoes, large hail and damaging winds.

The 3DVAR system uses data from the national WSR-88D radar network and NCEP's North American Mesoscale model product to automatically locate regions of thunderstorm activity. It is able to identify deep rotating updrafts that indicate a supercell thunderstorm at 1 km resolution every five minutes in these regions.

The 3DVAR analyses contain full three-dimensional wind field and precipitation fields, and can provide estimates of storm dynamics such as the strength of the updraft. In addition, by combining observations from multiple radars, the 3DVAR system provides a single information source that can reduce the observational data flow that challenges forecasters every day.

During the 5-week project, 3DVAR products will be available to participating NWS forecasters in near real-time to determine if these high-resolution analyses can improve their awareness of the hazardous weather threat.

The system performed well during the spring of 2010, detecting and analyzing significant severe weather events including tornado outbreaks in Mississippi, Arkansas, Kansas and Oklahoma. More recently, the significant tornadoes in Greensburg, Pa. and Mapleton, IA in early April were also well identified and analyzed.

hail storm

Supercell updrafts (left) and rotation are tracked with 3D-VAR.

View a preliminary display of the product »

Warn-on-Forecast Workshop Held, Feb. 23, 2011

Posted Feb. 28, 2011

The first annual workshop for the Warn-on-Forecast project was held on 23 February 2011 in Norman, Oklahoma, on the University of Oklahoma campus. The workshop brought together over 60 participants from across the United States to listen to progress reports from all the groups participating in the project. These reports indicated that the project is moving forward with research that will lead to improvements in lead time for severe weather warnings. However, the project has the potential to benefit a number of different weather information user communities, including surface transportation, aviation, and renewable energy, as well as applications to help improve warnings of tornadoes, hail, damaging winds and flash floods in order to help develop a Weather Ready nation.

Presentations from the 2011 Warn-on-Forecast Workshop

Warn-on-Forecast Workshop Held, Feb. 18, 2010

Posted May 14, 2010

The initial kickoff workshop for the Warn-on-Forecast project was held on 18 February 2010 in Norman, Oklahoma. The workshop brought together researchers from all the organizations involved in the project to discuss project goals, define responsibilities, and determine how to manage this project that involves multiple organizations in two US states. One outcome of the workshop was approval of the Warn-on-Forecast Project Plan. Another outcome is that the researchers involved in the project were able to meet each other and discuss the challenges ahead. Workshops are planned for every year of the project.

Presentations from the 2010 Warn-on-Forecast Workshop

Warn on Forecast workshop attendees

2010 Warn on Forecast Workshop attendees.