UCAR Tip Sheet: Hurricanes

Contact: David Hosansky UCAR Communications Telephone: (303) 497-8611 E-mail: hosansky@ucar.edu Cheryl Dybas National Science Foundation 703-292-7734 E-mail: cdybas@nsf.gov

BOULDER—Forecasters are calling for another busy Atlantic hurricane season, in line with the record number set over the last eight years. This tip sheet includes news briefs, hurricane experts, and hurricane-related Web sites. The experts are drawn from the National Center for Atmospheric Research (NCAR) and from member institutions of the University Corporation for Atmospheric Research (UCAR). NCAR, whose primary sponsor is the National Science Foundation (NSF), is managed by UCAR, a consortium of 66 universities offering Ph.D.s in atmospheric and related sciences.

News briefs

Mobile radars head for hurricanes

Three truck-mounted Doppler on Wheels radars will look for landfalling U.S. hurricanes this year. The latest DOW debuted this spring as the first mobile Doppler to operate in rapid-scan mode. It bombards storms with six simultaneous beams to collect a three-dimensional picture of the atmosphere every 10 to 15 seconds. The new NSF-funded radar was built by an NCAR team working with DOW founder and NCAR affiliate scientist Joshua Wurman (Center for Severe Weather Research). Earlier DOW units have gathered data from the eyes of five hurricanes.

The new rapid-scan Doppler on Wheels unit tracks a storm. high resolution image: dow3.tif (18 MB, 3072 x 2048)

Also this year, NCAR and Colorado State University will evaluate another mobile Doppler radar designed at Florida State University. Once complete, the unit will scan in two different wavelengths, gathering key data on cloud particles in hurricanes and other weather systems..

Looking down through a hurricane: A new view

These striking images show a unique dual look at a hurricane in progress. During the 2001 CAMEX project (see Web site below), NCAR scientists Andrew Heymsfield and Aaron Bansemer collected data from NASA's DC-8 aircraft as it flew through Hurricane Humberto. They have now combined data from the DC-8's airborne Doppler radar (operated by the Jet Propulsion Laboratory) and from a separate sensor that estimates the number and size of cloud particles. Next to the hurricane's eye (gap on right-hand side of lower image), intense rain bands (red strips) feature a high percentage of ice crystals (top image). The presence of so many large ice crystals swirling through the top of Humberto surprised the research team. They are now preparing a journal article summarizing the results. high resolution image: heymsfield.jpg (305 KB, 1200 x 1629)

The challenge of forecasting hurricane rains

Residents of Houston knew where Tropical Storm Allison was headed in June 2001, but the city was broadsided by up to 36 inches of rain—well above the amount called for in flood warnings. More than 40 people died as Allison tracked from Houston to Philadelphia, leaving more than $4 billion in damage. Despite progress in forecasting the tracks of hurricanes and tropical storms, computer models are still poor at estimating their rainfall, according to William Bua, a project scientist in UCAR's Cooperative Program for Operational Meteorology, Education and Training (COMET). Bua used Allison to develop three online case studies to train forecasters on the potential shortcomings of high-resolution computer models in predicting flooding from tropical storms (http://meted.ucar.edu/topics_hurricane.php). Among his findings: "A good storm track does not necessarily produce a good precipitation forecast." His study shows that a fourfold increase in one model's horizontal resolution could have actually degraded the rainfall forecast for Houston.

Rainfall from Tropical Storm Allison spread death and damage from Texas to Pennsylvania. (Photo courtesy FEMA.)

About High-Resolution Images and Video: If your browser cannot open/download the images on this page, try our FTP site. Find the filename (e.g., cloud.tif) in the FTP directory and either drag its icon to your desktop, click on the filename (Mac), or right-click on the filename (PC).

Hurricane Experts

Robert Gall	303-497-8160	gall@ucar.edu
NCAR Mesoscale and Microscale Meteorology Division/U.S. Weather Research Program Specialty: Analysis of tropical systems, including the wind structure in and near hurricane rainbands and the analysis of hurricane winds through radar-based techniques. Gall is also lead scientist of the U.S. Weather Research Program, a multiagency project to examine high-impact weather phenomena, such as hurricane landfalls, and improve forecasting. .
Rol Madden	303-497-1360	ram@ucar.edu
NCAR Mesoscale and Microscale Meteorology Division/U.S. Weather Research Program Specialty: Regional effects of the Madden-Julian Oscillation. Researchers have linked clusters of Pacific thunderstorms to the formation of Atlantic hurricanes, including those in the Gulf of Mexico. The source of these eastward-moving clusters is the Madden-Julian Oscillation, a 30- to 60-day atmospheric cycle co-discovered in the 1970s by Madden. As an upper-level wave generated by an MJO cluster approaches South America, the risk of hurricanes and tropical storms in the Gulf of Mexico and western Caribbean Sea increases severalfold, according to work by Eric Maloney (Oregon State University) and colleagues. Madden and NCAR's Julie Caron are now working to devise a forecast tool that might give two to three weeks' notice of enhanced Atlantic hurricane risk as an MJO approaches.
Terry Hock	303-497-8767	hock@ucar.edu
NCAR Atmospheric Technology Division Specialty: Measurement of winds through Global Positioning System (GPS) dropsondes. Hock led NCAR's development of this revolutionary device. Thousands of these GPS dropsondes have been deployed since 1996 from hurricane-hunting aircraft. They report winds between flight level and the sea surface at 16-foot intervals. The dropsondes have gathered the first high-resolution wind data from the eyewall, which swirls around the calm eye of a hurricane.
Chris Davis	303-497-8990	cdavis@ucar.edu
NCAR Mesoscale and Microscale Meteorology Division Specialty: Evolution of hurricanes and other intense cyclones. Davis and colleagues have used the NCAR/Penn State Mesoscale Model, version 5 (MM5) to reproduce the fine-scale structure that drives the birth and strengthening of tropical cyclones. Davis has also studied rapid intensification of nontropical coastal storms and the effects of mountains on midlatitude storm systems.
Roger Pielke Jr.	303-735-3940	pielke@cires.colorado.edu
University of Colorado, Center for Science and Technology Policy Research Specialty: Hurricane impacts and related societal factors. A political scientist, Pielke has written extensively on weather prediction and societal vulnerability. He and colleague Christopher Landsea (NOAA Hurricane Research Division) have outlined the relationship of El Niño and La Niña to U.S. hurricane damage and examined trends in population and wealth to reevaluate the costs of historic U.S. hurricanes. Pielke is the co-author of Hurricanes: Their Nature and Impacts on Society (Wiley, 1997) and Prediction: Decision-Making and the Future of Nature (Island Press, 2000). He is also the creator of the Extreme Weather Sourcebook.
Jay Baker	850-893-8993	jbaker@coss.fsu.edu
Florida State University, Department of Geography Specialty: Human response to hurricanes, including evacuations. Through on-site visits and interviews after hurricanes, Baker has examined how people respond to warnings and evacuation orders, including their use of information sources and perceptions of vulnerability to hurricane damage. He also has studied how emergency managers use forecasts and other information to implement evacuation plans.

Related sites on the World Wide Web

Hurricane Strike! Hurricane Science and Safety for Students
This multimedia package, aimed at middle schoolers, conveys basic concepts of atmospheric science, climate, and geography, as well as key safety and preparedness skills. The learner is a virtual houseguest of the Castillo family in Fort Walton Beach, Florida. Photos, sound, animations, and reports from expert Steve Lyons (The Weather Channel) take the learner through the course of a seven-day hurricane threat. The package was developed by UCAR's Cooperative Program for Operational Meteorology Education and Training (COMET), in collaboration with the Federal Emergency Management Agency, the National Weather Service, and the American Red Cross.

Extreme Weather Sourcebook
Hosted by the University of Colorado, this multiagency site offers yearly totals and state-by-state comparisons for hurricane damages for the 20th century, normalized to account for trends in population and wealth. Florida, Texas, and North Carolina are the leaders for hurricane damage, with Florida averaging over $2 billion per year.

CAMEX-4
The Fourth Convection and Moisture EXperiment (CAMEX-4), conducted in 2001, used NASA-funded aircraft and surface-based remote sensors to study the development, tracking, intensification, and landfall impacts of tropical storms and hurricanes.

CSU Tropical Meteorology Project
This site, from Colorado State University, includes seasonal hurricane outlooks from CSU professor William Gray and colleagues and a comprehensive set of answers to frequently asked questions about hurricanes and other tropical cyclones. Compiled by Christopher Landsea (NOAA).

NOAA Tropical Prediction Center (TPC)
This site includes official outlooks, climatology, and statistics on hurricanes, tropical storms, and tropical depressions. TPC includes the National Hurricane Center, which issues hurricane watches and warnings and calculates official projections of storm tracks. NHC now issues long-range hurricane outlooks similar to those created at CSU.

NOAA Hurricane Research Division (HRD)
This site includes frequently asked questions about hurricanes and extensive background on the hurricane research conducted by HRD and collaborators, both national and international. A catalog of the hurricane-hunting flights conducted by HRD since 1994 is also included.

The University Corporation for Atmospheric Research manages NCAR under primary sponsorship by the National Science Foundation.