The first dual-polarized Doppler radar data of a landfalling hurricane eyewall was collected as Hurricane Ike came ashore in Texas last weekend. The data was collected by a new mobile dual-polarized X-band radar (called NO-XP) built and operated by NOAA NSSL and the University of Oklahoma. Radars with dual-polarization capabilities — radio waves that are sent out both horizontally and vertically — can more accurately determine precipitation types and amounts.
The radar was positioned near League City, TX and collected data on Hurricane Ike from about 5 PM CDT through about 7 AM CDT. NO-XP was on the edge of the western portion of the eyewall, and the maximum wind gust at this location was 84 MPH. From its position, the NO-XP combined with the Houston, TX WSR-88D (HGX) radar created a dual-doppler region that encompassed most of the western half of Ike’s eye. The Doppler on Wheels, operated by the Center for Severe Weather Research was in the vicinity and also provided dual-doppler coveragel. Another mobile radar operated by the University of Alabama-Huntsville was on the north side of Houston and was able to collect data on the eastern half of Ike’s eye. Dual-polarization data was collected during the entire period.
NSSL’s field command vehicle and a mobile mesonet were also in Texas providing support.
The NO-XP is a new mobile radar built to study precipitation processes as well as severe weather and became operational in April 2008. Research data provided by the NO-XP will help improve the quality and accuracy of forecasts and warnings of hazardous weather.
The NO-XP’s predecessors, two SMART-Rs, or Shared Mobile Atmospheric Research and Teaching Radars, have collected data on similar storms. In September 2001, the mobile C-band radar jointly owned by NSSL, OU, Texas A&M and Texas Tech, intercepted a land-falling tropical cyclone, T.S. Gabrielle, in Florida. The SMART-Rs also captured data from Hurricane Lili in 2003 and Hurricane Isabel in 2005.
More information: http://www.nssl.noaa.gov/smartradars/