Ophelia was upgraded by the National Hurricane Center (NHC) to a Category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale on the most recent advisory issued today at 11 a.m. EDT.

Ophelia becomes this year's third major hurricane in the Atlantic. The NHC always gives the reasoning behind its track and intensity forecast as well as the basis for the initial center position and initial intensity. In this case, NHC did not have aircraft reconnaissance information to help determine the initial intensity. Satellite estimates alone were used to determine the major hurricane status. The satellite technique, known as the Dvorak Technique, is objective once an eye is visible. The intensity estimate is basically determined in infrared satellite imagery by the warm eye temperature and how embedded that eye is within the cold surrounding central dense overcast. 

The most recent satellite intensity estimate received at the NHC was from the University of Wisconsin's Cooperative Institute for Meteorological Satellite Studies and estimated Ophelia to be a solid 100-knot (115-mph) hurricane.

The NHC forecasters would much prefer to base the intensity on the more accurate aircraft reconnaissance data. But we can't afford to keep an airplane flying into a tropical cyclone 24 hours per day throughout the life of the cyclone. The satellite is actually the primary observing system in the tropics and the Dvorak technique is in use in the various tropical cyclone forecasting centers around the world. The technique has proven its usefulness for nearly 40 years.

To date the Atlantic has seen 16 named storms, including four hurricanes. And we have two months to go before the end of the season.