Eye to eye with Irene

MM Hurricane Irene
NSSL's Mobile Mesonet is prepared to take weather measurements of Hurricane Irene as it makes landfall.

NOAA and University of Oklahoma researchers are in North Carolina to deploy two mobile radars and a state-of-the-art instrumented vehicle to intercept Hurricane Irene. They are joining research teams from across the United States to collect an unprecedented hurricane dataset to better understand these devastating storms and protect lives and property. The team includes researchers from the NOAA National Severe Storms Laboratory, the University of  Oklahoma (OU), and the NOAA Cooperative Institute for Mesoscale Meteorological Studies at OU.

Hurricanes are notorious producers of torrential rain. This combined with fierce winds, driving water and waves onshore, can cause devastating flooding even many miles inland.

Scientists will use the unique dataset from this storm to help improve techniques for estimating rainfall in extreme weather events, which will increase the accuracy of flood and flash flood forecasts and warnings. Researchers also want to understand severe turbulence and wind bursts in the hurricane near the ground to help set building code guidelines in hurricane prone areas.

Both mobile radars from the University of Oklahoma are equipped with dual-polarization technology that provides more accurate estimates of precipitation type and amount. This will be the first hurricane for the National Science Foundation-funded Rapid Scan X-band dual polarized radar (RaXPOL), which is sensitive enough to detect cloud particles. The storm intercept Shared Mobile Atmospheric Research and Teaching radar (SMART-R 2) uses a different frequency and detects precipitation.

Data from one of the mobile radars will be available online for public real-time viewing while it is gathering data: http://smartr.metr.ou.edu/smartr2/img.

Researchers plan to compare mobile radar data with the NOAA National Weather Service NEXRAD radar in Newport/Morehead City, N.C., recently upgraded with dual-polarization technology. It will be the first time three radars transmitting at three different frequencies will be operating simultaneously to scan a land-falling hurricane. Since each radar reveals different features of the storm, researchers will be looking for new clues in the rainfall characteristics of hurricanes.

In addition, a number of new weather instruments fixed to a vehicle will be tested during the deployment. Other teams will deploy a variety of sensitive weather instruments to measure clouds, size and speed of raindrops, infrared radiation, static electricity, turbulence, and wave surges.

For their own safety, the NOAA/University of Oklahoma team will choose a site designed to withstand Category-5 hurricane storm surge and will anchor their vehicles.

A SMART-R radar intercepted Tropical Storm Gabrielle in 2001, Hurricane Lilli in 2002, Hurricane Isabel in 2003 and Hurricane Frances in 2005. A mobile radar was also deployed during Hurricane Ike in 2008 and made the first dual-polarized scans of a hurricane eyewall.