VORTEX2

Severe convective weather, including tornadoes, other severe winds, hail, and lightning, impacts life and property throughout the world. In the United States, severe convective weather results in over a hundred deaths every year. NESL scientists study the processes by which thunderstorms produce severe weather with the goal of understanding and better predicting their occurrence.

NESL scientists have been collaborating with other scientists at NCAR, NOAA, universities, and private companies in the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX2). This field experiment in the US Great Plains is investigating tornadogenesis, near-ground winds in tornadoes, relationships between tornadic storms and their environments, and numerical weather prediction of supercells and tornadoes. NESL scientists have played key roles in the planning of VORTEX2, and they went to the field 10 May - 13 June 2009 for the first year of the field experiment.

In a fully mobile mode of operations, VORTEX2 fielded approximately 40 vehicles in 2009, with instruments that included mobile radars, mobile mesonets, a deployable surface observing network, sounding systems, tornado probes, photogrammetry cameras, and disdrometers. VORTEX2 intercepted supercell thunderstorms on 9 different days during 2009. The primary 2009 case for tornadogenesis studies is the 5 June 2009 Goshen County, Wyoming tornadic storm (Fig. 1). The Goshen County tornado lasted approximately 30 minutes and was rated EF2, with estimated near-ground wind speeds of 130 mph. Detailed VORTEX2 data collection began 20 minutes before the tornado formed and continued throughout the life cycle of the tornado.

NESL scientists will return to the field for the second year of the VORTEX2 field experiment 1 May - 15 June 2010. In the meantime, they are working with other VORTEX2 scientists to analyze data that were collected during the first year and to prepare for the field deployment in year two.

In addition to going to the field, NESL scientists are supporting VORTEX2 and participating in the NOAA Hazardous Weather Testbed Spring Experiment (described elsewhere in the Lab Annual Report) through real-time high-resolution WRF numerical weather prediction. NESL scientists produced WRF forecasts twice daily on a 3-km grid capable of producing convective storms explicitly. On many days of VORTEX2 operations, the explicit forecasts of supercell thunderstorms were accurate enough and had sufficient lead time to provide useful guidance to the mobile teams that were selecting target areas and planning instrument deployments.

VORTEX2 deployment around the Goshen County, Wyoming tornadic supercell thunderstorm, as viewed in real time on the Situational Awareness for Severe Storm Intercept display at 2209 UTC 5 June 2009. Instrument locations, city and town names, roads, and reflectivity from the KCYS radar (shading) are shown. (image provided by Rasmussen Systems and NCAR EOL).

 

Photo above (provided by David Dowell) shows the Goshen County, Wyoming tornado intercepted by VORTEX2 on 5 June 2009.