Getting a Handle on the World’s Wildest Weather
From Earth System Monitor,
By Susan Cobb, Meteorologist and Outreach
Content Specialist, National Severe Storms Laboratory
Read the complete issue of The Earth System Monitor,
a free quarterly bulletin that reports on NOAA environmental data and
information programs, projects, and activities. May
2008, Vol 16 No 4 (1.16 mb) 
The world’s wildest and most varied weather occurs in the United States. Hurricanes, blizzards, ice storms, thunderstorms, tornadoes, floods, and drought batter our country each year. In fact, no other nation endures the wide range of weather we see here. In this arena, the National Severe Storms Laboratory (NSSL) is doing its best to observe and predict the unpredictable and protect lives and property. Located in Norman, Oklahoma, the heart of tornado alley, NSSL is a leader in studying all aspects of severe weather. NSSL focuses on three main areas of research to improve severe weather forecasts and warnings.
Radar Research: Spies of the Sky
Radar is one of the most valuable tools in a forecaster’s arsenal; NSSL continues to use ingenuity and creativity to push radar technology to the edge. The National Weather Radar Testbed (NWRT) is a phased array radar and is available to the research community on a full-time basis. NSSL researchers have shown that phased array radar technology has the ability to rapidly scan severe weather on time scales of seconds instead of several minutes. This high temporal sampling provides an unprecedented opportunity to study rapidly evolving weather phenomena and explore the potential to extend warning lead times for severe weather. NSSL scientists also proved phased array radar can detect rotation, hail, microbursts, and gust fronts well ahead of other radars because of its rapid scan capability. Phased array technology will help forecasters provide longer lead times for tornado warnings—beyond the current average of 14 minutes—and other hazards. Using the NWRT, NSSL scientists are also exploring using phased array radar for aircraft tracking and wind profiling simultaneously with weather surveillance. This concept of a multifunction phased array radar has the potential to meet the Nation’s weather, aviation, and homeland security needs. NSSL continues to develop techniques with dual-polarized Doppler radar, providing significant improvements in rainfall estimation, precipitation classification (for example, rain, hail, snow, and sleet), and weather hazard detection. The entire National NEXRAD (WSR-88D) radar network will be upgraded in 2010-2011 with dual-polarization capability, improving echo classification, precipitation rate estimation, and data quality. NSSL scientists also use shared mobile radars to rapidly scan the atmosphere at low levels, below the beam of NEXRAD radars, to collect data on the structure of the storms. In areas where mountains block the beams of the regular radars, mobile radars provide extra rainfall data that help scientists determine the threat of flash floods and debris flows.
Hazardous Weather Research: Predicting the Unpredictable
NSSL researchers are exploring new ways to improve our understanding of severe weather causes and new ways to use that weather information more efficiently in forecasts and warnings. A cornerstone of this effort is the NOAA Hazardous Weather Testbed (HWT) facility, which is strategically located between operational forecast areas of the NOAA Storm Prediction Center and the NOAA National Weather Service (NWS) Norman Forecast Office. HWT allows forecasters and researchers to collaborate and share knowledge that will improve severe weather forecasts and vital forecasting tools. Every spring, NSSL scientists co-sponsor the annual Hazardous Weather Testbed Spring Experiment. During this focused collaboration period, researchers immerse themselves in the frontline operational and scientific challenges of forecasting hazardous this past winter. During the spring of 2009, NSSL researchers will undertake a major field study to continue their quest to understand how, when, and why tornadoes form; the structure of tornadoes; the relationship of tornadic winds to damage; and how to better forecast tornadoes. The VORTEX 2 project will use a large armada of mobile instruments to collect data on tornadic storms and provide clues into the tornado mystery.
Hydrometeorology Research: Forecasting Floods
By investigating the meteorological causes of flash flooding and working on flash flood and river flood warning decision-making tools, NSSL is working to save more lives and property. Researchers are discovering ways to blend data from multiple sensors, including radar, satellite, lightning, and rain gauges, to improve flash flood monitoring and prediction. These ideas are being tested in projects around the U.S., including California and North Carolina. NSSL also created a national testbed, the National Mosaic and Multi-Sensor Quantitative Precipitation Estimation system, to provide a real-time, aroundthe- clock, hydrologic applications development and testing environment. Results of this research will improve flood and flash flood watches and warnings. Severe weather research conducted at NSSL has led to valuable improvements in severe and hazardous weather forecasting, increasing warning lead times to the public. NSSL scientists are exploring new ways to improve our understanding of the causes of severe weather and ways to use weather information to assist NWS forecasters, emergency managers, and the public. ■
