International H2O Project

Drylines and fronts will be a key focus of the largest-ever weather field experiment in North America--the International H2O Project (IHOP_2002). Scientists from Canada, France, Germany and the U.S. will study weather over the Southern Great Plains from May 13 to June 25, 2002. They hope to enhance their understanding of the process of convection initiation and boundary evolution, and learn what types of data are needed to make forecasts of thunderstorms and rainfall amounts more specific.

NSSL scientist Conrad Ziegler, in collaboration with CIMMS scientist Erik Rasmussen and Penn State scientist Paul Markowski, will lead NSSL's contribution to IHOP through the ground-based mobile data collection effort. NSSL will provide a SMART radar, nine mobile mesonet vehicles, one mobile sounding system, a photography vehicle, and the field coordination vehicle. This contribution has received significant external support from the National Science Foundation (NSF), the NOAA United States Weather Research Program (USWRP), the NOAA High Performance Computing and Communications (HPCC) program, and the NSSL Director's Discretionary Fund.

The number of mobile facilities involved in IHOP and the coordination of their movement is unprecedented. To investigate the atmosphere, IHOP will use up to six research aircraft carrying in-situ and remote sensors, including an array of airborne Doppler and water-vapor sensing lidars. A large groundbased array of mobile mesonet vehicles, mobile sounding systems, profilers, and radiometers will nest within the aircraft sampling areas. Four mobile radars, never before used in concert with each other, will spend many hours scanning the atmosphere. A field coordination (FC) vehicle will be located in the center of the target area and serve as the hub of the mobile digital network. Weather data from remote probes will be transmitted to the FC by radio frequencies, and for the first time, the FC will be able to communicate with the Norman Operations Center by satellite broadband Internet and satellite phone.

Predicting rainfall amounts continues to be a mystery -- flash floods caused by heavy thunderstorm rainfall are responsible for more deaths than hurricanes, tornadoes, windstorms or lightning. Annual property damage from flash floods alone exceeds $5 billion. Data gathered from IHOP will detail the thunderstorm initiation process and provide the groundwork for new forecast rules in the prediction of heavy rainfall.