In the early years of hurricane research, meteorologists tried to alter these violent monsters through Project STORMFURY, a program that focused on storm modification. The idea was to modify the structure of the hurricane to create a weaker storm. However, after 20 years of study and experimentation, scientists determined that storm modification was ineffective. It was decided that the best way to protect American citizens from hurricanes was to study them from every possible aspect to increase the accuracy of forecasts and warnings.
The Science of Hurricanes
The National Hurricane Research Project now exists as the Hurricane Research Division within the Atlantic Oceanographic and Meteorological Laboratory, a NOAA research lab based on Virginia Key in Miami, Fla. Today, NOAA boasts the only organization in the world that routinely designs and executes scientific research flights into hurricanes. Its mission is to advance our basic physical understanding of hurricanes. This understanding, in turn, leads to better forecasts of hurricane motion, intensity, wind structure, and rainfall, as well as human impacts.
While the data collected during hurricane season add to the knowledge base, this information must be analyzed and compared to both developing theories and forecast models. NOAA's research meteorologists constantly strive to understand and predict what we can expect from both individual storms and trends in hurricane activity based on the recorded knowledge of all previous hurricanes, a concept known as climatology.
Improved Understanding and Ability to Monitor
Historically, hurricane landfalls on the U.S. East Coast were common during the 1940s through the mid-1960s. In the 1970s and 1980s, landfalls were few. Activity now appears to have returned to the high level that characterized the immediate post-World War II period. These fluctuations in activity are most pronounced for major hurricanes. They also correlate with changes in observed sea-surface temperatures in the North Atlantic, known as the Multi-Decadal Mode—a North Atlantic and Caribbean sea surface temperature shift between warm and cool phases that lasts 25 to 40 years each. If the hurricane climatology and the Multi-Decadal Mode prove to be reliable guides, we may expect the first decade or two of the 21st Century to produce more of the most damaging major hurricanes—Categories 3,4, and 5 on the Saffir-Simpson scale.
A serious concern is the phenomena known as "rapid intensification" that can transform a hurricane from a Category 1 or 2 to a Category 4 or 5 in less than a day. The transformation is dangerous because it is the only process that creates "major hurricanes" - with winds blowing faster than 115 mph. Major hurricanes account for 80 percent of the damage, although they represent only 20 percent of (total hurricane) occurrence. As Hurricane Opal in 1995 illustrates, rapid intensification is nearly impossible to forecast. Opal intensified from a Category 3 to a Category 4 storm during the night of October 3rd. Only the equally abrupt, and equally un-forecast, weakening just offshore prevented the possibility of an unprecedented disaster for the U.S. Gulf Coast.
The Statistical Hurricane Intensity Prediction (SHIPS) model developed at AOML provides the first and only consistently skillful guidance for tropical cyclone intensity prediction. Although this model is available in real time and has had some success, there is still much to learn before accurate intensity forecasts become routine. Satellite-based oceanic information and airborne probes provide information on the underlying ocean structure, such as deep eddies of warm water. Monitoring the passage of hurricanes over such features and the resulting effects on their intensity, allows for improvements in intensity forecasting, especially in cases of rapid intensification.
The Stepped Frequency Microwave Radiometer (SMRF) is a promising tool for direct measurement of surface winds. This instrument has flown aboard research aircraft for more than 20 years and has finally matured enough to transition to operations. It works by sensing the break up of bubbles in the foam created by wind passing over the churning ocean surface. This technology allows NOAA's "Hurricane Hunters" to accurately measure wind speed at the ocean surface, the area where it will have the most direct impact on coastal structures and communities.
During the 2001 hurricane season, AOML's hurricane researchers combined with a massive research team—including university and NASA partners—to capture a complete top-to-bottom snapshot of a hurricane over a two-day period. As a result, Hurricane Humberto became the most completely and well-documented hurricane in the history of meteorology, with researchers amassing four times more data than acquired in previous storms.
AOML has helped set the stage for a new generation of higher resolution hurricane models that are now being developed. These models will provide more accurate forecasts needed to protect lives and property with a minimum of false alarms. For more information about AOML's Hurricane Research Division, please visit their Web site. The site features frequently asked questions about hurricanes, a listing of HRD's major accomplishments over the past 10 years and information about the 10th anniversary of Hurricane Andrew, which hit the Florida coast in August 1992.
Relevant Web Sites
NOAA's National Hurricane Research Project
NOAA's Hurricane Research Division
NOAA's Atlantic Oceanographic and Meteorological Laboratory
NOAA's Aircraft Operations Center
Hurricane forecasts
Frequently Asked Questions about Hurricanes
Media Contact:
June 3, 2002 — The U.S. Navy and Air Force began flying reconnaissance missions into tropical cyclones in 1944 to warn civilians and military personnel of approaching typhoons and hurricanes. It wasn't until 1954, however, when Hurricanes Carol, Edna, and Hazel swept up the eastern coast of the United States (Hazel went directly over Washington, D.C.), that policy makers decided to finance research. In 1955, Congress authorized funding to create the National Hurricane Research Project, whose mission was to conduct hurricane research in hopes of improving not only our scientific understanding, but improve hurricane forecasting as well.
NOAA's Aircraft Operations Center flies two WP-3D turboprop airplanes (See image to the right) that represent a unique scientific resource and are the mainstay of HRD's annual campaign of airborne hurricane observations. Tropical cyclones are ideal subjects for study from instrumented aircraft. The eye of a hurricane is relatively small—only a few kilometers across. An airplane can traverse its center 5-10 times in the course of a flight lasting 6-8 hours. Expendable probes can report atmospheric and oceanic conditions as they drop from flight level, while aircraft radars have the ability to observe storms in detail. In 1997, a third aircraft, a Gulf Stream IV-SP jet, entered the inventory. This airplane is dedicated to observations in the environment around hurricanes to improve operational hurricane track forecasts.
AOML research has produced accurate, timely maps of surface winds in hurricanes (such as the graphic to the right, which depicts maximum sustained wind speeds when Hurricane Andrew made landfall near Miami, Fla., on August 24, 1992. Click image for a larger view). These maps, which are based upon aircraft and other observations, are invaluable for preparation of forecasts before landfall and for damage assessment after landfall. The maps are prepared routinely whenever a hurricane threatens land. A particularly important application of these products is the speedy identification of the most severely devastated areas, that enables disaster response teams to respond quickly where they are most needed.
NOAA's Hurricanes Page
Jana Goldman, NOAA Research, (301) 713-2483