The Great Galveston Hurricane of 1900 is the deadliest natural disaster to ever strike the U.S. Eight-thousand lives, probably more, were lost. Without accurate forecasting and radio to spread the news, hurricanes struck with little or no warning. Prior to 1900, forecasts were based on barometric change or cloud cover change and news was relayed via telegraph. Warning time was limited.
Hurricane forecasting today is far more sophisticated. The early radio pioneer Heinrich Hertz once said “I do not think that the radio waves I have discovered will have any practical application.” Nevertheless, together radio and digital computing are currently the backbone of hurricane forecasting. One of the more important forecasting tools is radiosonde transmitters dropped from aircraft that measure conditions at all elevations as they fall through the atmosphere. That data is continuously radioed back to receiving stations. Military aircraft flying through the eye of the hurricane, drones flying in the hurricane, and surface water buoys also radio data to forecast centers.
Likewise, at the dawn of the space age, skeptics questioned the usefulness of satellites. Today satellites are another critical element in hurricane forecasting. The first weather satellite, TIROS-I, launched in 1960. Today, the U.S. alone operates over a dozen weather satellites. Imagery at multiple spectrums (colors) is provided by the GEOS series of satellites. A dozen other countries operate weather satellites.
Large-scale synoptic flow, a technical term for the large high and low-pressure regions commonly seen on weather maps, is the primary predictor for the future track of a hurricane. Their presence in relation to the current position of a hurricane pull and push the hurricane. Data on these high and low-pressure systems is also gathered by satellites.
The data from all of these sources is gathered and used in complex computer models by numerous organizations.
The National Hurricane Center (NHC) within the National Oceanic and Atmospheric Administration (NOAA) assembles and distributes forecasts. The NHC is the primary source of information on the track, intensity, and impact of hurricanes in the Western Hemisphere.
Forecasting the intensity of hurricanes can be more difficult than forecasting the track. Dorian has proven to be particularly vexing to forecasters. As is typically the case with hurricanes, Dorian was being watched before it became a tropical storm and five days before it became a hurricane. But after it passed northeast of Puerto Rico, it intensified more than predicted. On Sunday, September 1, a radiosonde near the Bahamas recorded surface winds sustained at 180 mph and gusts to 203 mph.
The devastation in the Bahamas was unimaginable, but forecasting undoubtedly saved lives. Fortunately, Dorian weakened somewhat before impacting the Southeastern coast.