Height of Atlantic Hurricane Season Yields Research Advances

Compiled by Barry Reichenbaugh
Office of Oceanic and Atmospheric Research

Recent heightened hurricane activity in the Atlantic has provided NOAA researchers with opportunities to test new observing technologies and advance forecasting and techniques that could contribute to improvements in the accuracy of hurricane landfall predictions and hurricane intensity predictions.
 

 

Global Drifter Program
Hurricane Gustav passed directly over 12 ocean buoys deployed by NOAA’s Global Drifter Program and the Air Force Reserve 53rd Reconnaissance Squadron "Hurricane Hunters."  OAR’s Atlantic Oceanographic & Meteorological Laboratory (AOML) participated in a WP-3D flight directly over the drifters.  Researchers are hopeful that the data from the drifters and flights will increase NOAA’s ability to understand and predict intensity change in hurricanes, one of the goals of the Hurricane Forecast Improvement Project (HFIP), a multi-agency effort to improve the accuracy and reliability of predicting rapidly intensifying storms and extend the certainty of hurricane prediction lead times. 
 
Tail Doppler Radar
WP-3D missions were flown into Gustav and Ike in collaboration with the NESDIS Ocean Winds project to validate data from the NASA QuikSCAT satellite.  Other WP-3D missions gathered Tail Doppler Radar data to test initialization in hurricane models.  A total of 16 radar analyses were sent in real-time for use by the National Weather Service’s Environmental Modeling and National Hurricane Centers. 

Some flights also were used to validate Stepped Frequency Microwave Radiometer (SFMR) data in shallow water near landfall to help researchers determine how to best use SFMR in these shallow conditions, where storms have the greatest impact.  The Federal Emergency Management Agency (FEMA) used AOML’s H-Wind surface wind analysis in preparation for Gustav to help decide parameters for HAZUS, FEMA’s software program for estimating potential losses from disasters.

New Mobile Radar Captures Dual-Pol Data on Hurricane Ike
The first dual-polarized Doppler radar data of a landfalling hurricane eyewall was collected as Hurricane Ike came ashore in Texas Sept. 13. The data was collected by a new mobile dual-polarized X-band radar (called NO-XP) built and operated by OAR’s National Severe Storms Laboratory (NSSL) and the University of Oklahoma. Radars with dual-polarization capabilities — radio waves that are sent out both horizontally and vertically — can more accurately determine precipitation types and amounts.

The radar was positioned near Lake Jackson, Texas, and collected data on Hurricane Ike from about 5 p.m. (CDT) through about 7 a.m. (CDT).   The NO-XP was on the edge of the western portion of the eyewall, and the maximum wind gust at their location was 84 miles per hour. From its position, the NO-XP combined with the Houston, Texas, NEXRAD Radar created a dual-doppler region that encompassed most of the western half of Ike’s eye. Another mobile radar operated by the University of Alabama-Huntsville was on the north side of Houston and was able to collect data on the eastern half of Ike’s eye. Dual-polarization data was collected during the entire period.

NSSL’s field command vehicle and a mobile mesonet were also in Texas providing support.

Hurricane Visualizations from NOAA's Environmental Visualization Program
Hurricane Hanna	Hurricane Gustav	Hurricane Ike

Tests of New Flooding Observation System Successful During Hanna
Tropical Storm Hanna’s track along the southeast U.S. coastline took the storm into an area where a flood observation and warning project has been under development for several years.  The North Carolina and South Carolina Sea Grant Programs and NOAA’s multi-agency CI-FLOW (Coastal and Inland Flooding Observation and Warning) project is intended to demonstrate improved forecasts of inland and coastal floods and flash floods in the Tar-Pamlico and Neuse River basins.  That area suffered devastating human and economic losses from Hurricanes Floyd and Dennis in North Carolina in 1999.
 
Rainfall and storm surge from Hanna provided critical data for ongoing preliminary testing of CI-FLOW.  Post-event verification, available on the Q2 home page, indicated a high level of correlation between the CI-FLOW model component estimates and traditionally measured rainfall and storm surge recordings.  The CI-FLOW research team will continue to investigate and use all the data sets gathered in Tropical Storm Hanna to demonstrate how linking inland streamflow models to coastal/ocean models can improve the accuracy of NOAA’s hydrologic information for citizens located in coastal watersheds.

Hurricane Model Performance
OAR’s Geophysical Fluid Dynamics Laboratory hurricane forecast system has performed very well this season, including the important storms Gustav, Hanna and Ike. This has made a significant contribution to the remarkable performance by the National Hurricane Center, whose official error at five days for these important storms was near 200 nautical miles.
 
The availability of a large computer (the Texas Area Computer Center) also allowed NOAA researchers to run a pair of high-resolution models for Gustav, Hanna and Ike.  The Flow-following Icosahedral Model (FIM) was run globally at 15 km resolution, and the Weather Research and Forecast ARW model at 2.5 km resolution was run over the hurricane domains.  According to scientists close to the subject, initial results of the model runs look promising.

NOAA Regional Collaboration Yields Gulf Web Portal for Tropical Storm Hazards
A direct result of the NOAA regional collaboration effort (and enthusiastic volunteers) is a new Gulf-wide web portal for assisting the public in planning for and recovering from tropical storm hazards. The site was developed for Gustav, but it will have much broader applications.  Spearheaded by Mississippi/Alabama Sea Grant, the site was compiled in a week’s time through the efforts of several NOAA entities. 

Flight into Ike by Head of NOAA Research Provides Exceptional View of Storm’s Rapid Intensification Richard W. Spinrad, NOAA Assistant Administrator for Oceanic and Atmospheric Research, participated in a research flight into Hurricane Ike Sept. 10, 2008, while the huge storm was still in the Gulf of Mexico.  The data-gathering flight aboard the NOAA WP-3D hurricane research aircraft tail number N42RF (affectionately known as Kermit the Frog) took Spinrad, other researchers and crew on eight penetrations into the eye of Hurricane Ike.  Spinrad said he was “very impressed” with the professionalism of both the crew and scientists aboard the aircraft.  “I was able to experience firsthand the dramatic intensification of this storm,” said Spinrad.  “It’s given me an even better appreciation for all we're trying to do in the Hurricane Forecast Improvement Project (HFIP).”