Brownsville has become the answer to a trivia question: What is the last The National Weather Service branch to have its radar updated to dual-polarization technology?
The south Texas branch was among 122 NWS radar sites to receive the upgrades, which began nearly two years ago. The updated technology is helping federal weather forecasters more accurately track, assess and warn the public of approaching high-impact weather.
The Wichita branch was among the first in the nation to receive the upgrade, with the installation occurring in July 2011.
Dual-polarization is the most significant enhancement made to the nation’s federal weather radar system since Doppler technology was first installed in the early 1990s, officials for the National Oceanic and Atmospheric Administration said.
Dual-pol radar sends and receives both horizontal and vertical pulses, which produces a much more detailed picture of the size and shape of the objects in the sky. This provides meteorologists the ability to distinguish between rain, snow, hail and non-weather items such as wildfire smoke plumes, birds and insects. Conventional Doppler radar only has a one-dimensional view, making it difficult to tell the type of precipitation or object in the sky.
The new radars have been able to detect debris balls created by tornadoes, offering further confirmation of a damaging twister.
“This achievement is the result of years of research, development and continued investment that’s helping us become a more weather-ready nation,” said Dr. Louis Uccellini, director of NOAA’s National Weather Service, in a prepared statement. “It is amazing what we can see with dual-pol technology. This game-changing technology has already helped forecasters issue more accurate and timely warnings to the public and has saved lives.”
Dual-pol is credited with providing improved detection of heavy rainfall, which can increase warning time for flash floods. During winter storms, forecasters use dual-pol information to monitor a transition from snow to sleet and freezing rain, which allows for a more accurate forecast. Dual-pol can also spot airborne debris giving forecasters the ability to confirm a tornado on the ground, even in the dark or when hidden by heavy rain. The new technology has also been used to help detect hazards to aircraft, such as volcanic ash plumes, icing conditions and birds.
The National Weather Service has used dual-pol to develop 14 new radar products that have improved the speed, understanding, and accuracy of the information it provides about extreme weather. Forecasters now have more confidence to accurately assess weather events and be more descriptive in weather warnings, which helps improve public response to the warnings.
NOAA officials touted a few “success stories” attributed to the new radar technology:
On Feb. 10, 2013, NWS weather forecasters in Jackson, Miss., used the new radar technology to confirm a powerful tornado (EF-4) was moving across Southern Mississippi’s Lamar County toward the populated city of Hattiesburg. Forecasters warned the public using detailed, descriptive language about the tornado’s size and path, resulting in no fatalities. On the same day, dual-pol information helped the Jackson forecasters recognize thunderstorms with particularly heavy rainfall rates, enabling them to issue flash flood warnings more than an hour before flash flooding started.
On Nov. 7-8, 2012, NWS meteorologists at the Boston forecast office relied on dual-pol radar information to help locate the rain/snow line as a nor’easter traversed the area. During the afternoon and evening, a storm formed across Rhode Island and eastern Massachusetts. Snow fell to the west of the boundary where temperatures dipped into the 30s, while rain fell to the east where temperatures held in the 40s. Using dual-pol information, forecasters were able to accurately track the slow progress of the rain-snow line and provide short term forecasts which helped department of transportation officials focus their snow removal assets and for the media to highlight the hazardous routes to the traveling public.
In addition to the 122 NWS-owned radars, the full nationwide radar network includes another 37 radar sites owned by the FAA and Defense Department, which will be completely upgraded to dual-pol technology this summer. NOAA’s NEXRAD radar program is a tri-agency effort with NOAA, the Federal Aviation Administration, and the United States Air Force.