Hurricane Research Division Milestones
Tropical cyclone wind radii estimation using an empirical inland
wind decay model
A method for estimating the maximum wind, and 34,50, and 64 kt wind radii of
landfalling tropical cyclones utilizing the operational NHC storm structure
and track forecasts and a revised version of the Kaplan/DeMaria decay model
was developed as part of the NOAA Joint Hurricane Testbed (JHT). This
technique was declared operational by the NHC for use in both the Atlantic
and East Pacific basins prior to the 2008 Hurricane Season.
A revised tropical cyclone rapid intensity index for the Atlantic and
East Pacific basins
A revised version of the original SHIPS rapid intensity index (RII) was
developed for the Atlantic and East Pacific basins as part of the NOAA Joint
Hurricane Testbed (JHT). The revised RII uses predictors from the Statistical
Hurricane Intensity Prediction Scheme (SHIPS) to estimate the probability of
rapid intensification (RI) for 3 different RI thresholds (25,30, and 35 kt)
utilizing linear discriminant analysis. The RII was declared operational by
the NHC prior to the 2008 Hurricane Season.
Validation of Hurricane Surface Winds Measured by the HRD SFMR
The HRD Stepped-Frequency Microwave Radiometer (SFMR) that is carried
aboard NOAA Hurricane Hunter aircraft has been determined to be
the most accurate and reliable remote sensing device available for
measuring hurricane force winds at the sea surface. Results of a
study show that surface winds measured by the SFMR are comparable
to the Global Positioning Systems (GPS) dropwindsonde measurements
that are the current standard. The benefit of the SFMR is that
winds are continuously measured during flights, allowing for more
complete mapping of hurricane surface wind structure.
Scientific paper available through
Eric Uhlhorn's webpage
Distributed Real-Time Hurricane Wind Analysis System
The H*Wind program integrates information from a variety of platforms in
and around a hurricane and creates a real-time wind field analyses,
for use by the hurricane specialists.
Designed a satellite-based modem method for transmitting
data from the NOAA WP-3 aircraft
Designed a system that allows satellite communication with the
computers onboard the NOAA WP-3 hurricane aircraft to fascilitate
the real-time transfer of data.
Rapid Intensification Index
A technique for estimating the probability of tropical cyclone
rapid intensification (RI) using the operational SHIPS model
output was developed for the Atlantic basin. This product was
provided to NHC hurricane forecasters in real-time in support of
Joint Hurricane Testbed (JHT).
Atlantic hurricane data (HURDAT) re-analysis project
This project has extended the Atlantic hurricane database back
35 additional years so that it now covers the period of 1851 to date.
It includes the estimated tracks and intensities for all tropical storms
and hurricanes every six hours, the "raw" observations from ships and
coastal stations from which the HURDAT was derived, specific U.S.
landfall data, basin-wide track maps of all tropical storms and
hurricanes, and comments from/replies to the OAR's
Best Track Change Committee.
First (only) real-time hurricane ensemble forecasting
A 41-member daily hurricane track ensemble forecasting system using
the VICBAR shallow water model has been run during the 1998 and 1999
hurricane seasons and will be run in realtime during the 2000
hurricane season. These forecasts will provide, for the first time,
estimates of the reliability of individual forecasts and probabilistic
landfall forecasts based on numerical guidance.
Improvements in track forecasts / targeting of
By finding locations in which the atmosphere is unstable to small
perturbations, and by sampling in and around these targets with
dropwindsondes, improvements of up to 35% can be achieved in forecasts
through four days.
Transmission of airborne surface wind speed and rainrate
The airborne Step Frequency Microwave Radiometer (SFMR) measures
microwave emissions from the ocean surface at six frequencies. These
are transformed with radiative transfer equations to obtain
measurements of surface wind speed and rain rate below the aircraft.
These data are transmitted in real time.
Ground-based hurricane wind fields from single Doppler
Doppler wind data from a single land-based radar can be used to deduce
the tropical cyclone windfield in much the same manner as data from a
single airborne Doppler Radar. These wind fields can provide
continuous monitoring of tropical cyclones as they approach landfall
along the U. S. coast for the first time.
Surface wave measurements from aircraft in tropical
An airborne scanning radar altimeter (SRA) generates a topographic map
of the sea surface in hurricanes over open ocean. Wave heights, their
variation around the tropical cyclone, and their direction of motion
are all measured, and can provide realtime estimates of wave height
and storm surge at landfall.
First (only) skillful realtime hurricane intensity
The Statistical Hurricane Intensity Prediction (SHIPS) model provides
the first and only consistently skillful guidance for tropical cyclone
Warm oceanic features and hurricane intensity change
Regular satellite-based oceanic topographic information provides
information on the underlying ocean structure, such as warm rings and
boundaries. Passage of hurricanes over such features affects their
intensity, allowing for improvements in intensity forecasting
especially in cases of rapid intensification.
First high-resolution measurements of vertical wind and
thermodynamic structure in hurricanes
Newly-developed dropwindsondes based upon Global Positioning System
technology can measure winds every half second during descent in the
eyewall of tropical cyclones. These measurements have become the
standard by which studies of the reduction of flight-level winds to
surface winds are made, and is now standard operational procedure on
all reconnaissance flights.
Empirical Hurricane Inland Intensity Model
An empirical model for predicting the winds in landfalling hurricanes
has been developed for the Gulf and east coasts of the U.S. This model
predicting the two-dimensional field of maximum surface winds (wind
swath) for storms after landfall. As of the 2000 hurricane season
this model is included in the operational SHIPS model, to make possible
over land predictions of intensity.
Shift to climatologically active Atlantic hurricane seasons
In the 70's and 80's, the overall hurricane activity in the Atlantic
basin was much lower than the previous several decades, especially the
stronger ("major") hurricanes. Several long-term climatic signals
have been found to have shifted, first in 1988, and again in 1995,
leading to the conclusion that the Atlantic had shifted back into a
more active and destructive phase that might last for at least the
next 10-20 years.
Cover article SCIENCE 20 July 2001
Vertically Scanning Doppler Radar
A Vertically Scanning Doppler Radar (VSDR) has been developed for use
on the NOAA aircraft. This instrument directly measures wind velocity
beneath the aircraft, and can provide wind profiles through the
Global Positioning System Dropwindsonde
The GPS dropwindsonde was developed for use with NOAA and Air Force
aircraft to take measurements in the environment and inner core of
hurricanes to improve their analysis and forecast.
Real-time hurricane surface wind analyses
A real-time system for objectively analyzing meteorological
observations in hurricanes using a common framework for wind exposure,
measurement height, and averaging time, has been developed. These
analyses are presented to NHC hurricane specialists as often as eight
times per day and have become the standard for assessing winds from
new remote sensing platforms. They are used to initialize numerical
forecast models, to provide forcing for storm surge models, and in
Transmission of airborne radar reflectivity images and
windfields from within the hurricane
Radar images of hurricanes, and analyses of windfields from Doppler
rada, previously only available from coastal radars when the hurricane
was near landfall, are now regularly available from the NOAA research
aircraft. This enables specialists to see convective features in
hurricanes generally obscured from satellites by high clouds and
windfield structure inside the storm. Features such as eyewall
replacement cycles and asymmetries that can help in forecasting of
intensity are now regularly seen before landfall.
National Hurricane Research Laboratory Achievements
National Hurricane Research Project Achievements
First hurricane flown throughout its life cycle.
NHRP follows a disturbance in the western Carribbean until it makes
landfall in Texas as Hurricane Carla 1961. They were able to fly
fourteen scientific missions into the growing storm over six days,
the first time a tropical cyclone had been followed from its formation
at sea to landfall as a major hurricane.
First successful deployment of a beacon balloon in
Air Force Hurricane Hunters deploy a constant pressure balloon-borne
radio beacon into the eye of Hurricane Helene 1958 in coordination
with the NHRP aircraft. Balloon remains in th eye's center of
circulation and is tracked remotely for two hours. Bob Simpson wins
a steak dinner from Herb Riehl in a bet over whether such a balloon
would stay in the eye or be carried out.
September 26, 1958
First three plane scientific mission into a hurricane
Both NHRP's dedicated Air Force B-50 aircraft fly a scientific
investigation into Hurricane Carrie 1957 in coordination with the
B-47 high altitude jet, the first such planned coordinated flights
between three planes.
September 15, 1957
First two plane scientific mission into a hurricane
One of NHRP's dedicated Air Force B-50 aircraft flies a scientific
investigation into Hurricane Greta 1956 in coordination with the
NHRP B-47 high altitude jet, the first such planned coordinated flights.
November 2, 1956
First flight into a hurricane where data is automatically
Noel LaSeur flies aboard one of NHRP's dedicated Air Force B-50 aircraft
into Hurricane Betsy 1956, the second flight of the Project's field program
and the first such flight where the automatic data recording system works.
The punch card deck of data is accidently dropped and scattered on the
tarmac. Several years of dedicated graduate student work is needed to
recover the information in proper order.
August 14, 1956