UCAR Tip Sheet
|| FOR IMMEDIATE RELEASE: July 15, 2003
UCAR Tip Sheet: Hurricanes
Telephone: (303) 497-8611
National Science Foundation
BOULDERForecasters 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.
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:
(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:
(305 KB, 1200 x 1629)
The challenge of forecasting
|Residents of Houston knew where Tropical Storm Allison was headed
in June 2001, but the city was broadsided by up to 36 inches of rainwell
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
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.)
Images and Video:
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NCAR Mesoscale and Microscale Meteorology Division/U.S. Weather
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.
|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.
|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.
|NCAR Mesoscale and Microscale Meteorology
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.
|University of Colorado, Center for Science and Technology
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
|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
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.
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.
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
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
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.