Hurricane Dolly Slams Texas Coast

As the Gulf Coast starts to feel Hurricane Dollly's fury, the National Hurricane Center has a message it has repeatedly been sending the nation:

"Become familiar with what hurricanes can do, and when a hurricane threatens your area, increase your chances of survival by moving away from the water until the hurricane has passed! Unless this message is clearly understood by coastal residents through a thorough and continuing preparedness effort, disastrous loss of life is inevitable in the future."

Hurricane Dolly is headed for what Fox News calls "the heavily populated Rio Grande Valley" not far from Houston.

Citing census studies, the National Hurricane Center has an ever growing concern for vulnerable coastal areas of the U.S.. 50 million people have moved into these areas in the past 25 years and the experience gained from 7 major hurricanes during the past 3 years has not lessened their concern. What the National Weather Service's Hurricane Preparedness officials worry about the most is that people will think that no large loss of life will happen in a hurricane because of our advanced technology and forecasting abilities.

That bureau still emphasizes that catastrophic loss of life can occur in vulnerable areas if there are not proper preparedness plans formed, in place and well executed. In the case of Hurricane Dolly those concerns include heavy flooding, levees that may not hold, and evacuating thousands from threatened areas.

The National Hurricane Center keeps statistical information on deaths and damages occurred during hurricanes affecting the United States. The two most frequent inquires about hurricanes concern the death and damage they cause and their intensity. Hurricane Dolly will soon become a part of these statistics. In the Center's NOAA Technical Memorandum, NWS TPC-5, 2007 some very interesting reference points are available by which to judge Hurricane Dolly.

It hasn't been a busy year so far as hurricane seasons go. Hurricane Dolly is the first hurricane this season to make landfall. On average each hurricane season will produce 11 tropical storms, 6 of which will develop into hurricanes with 2 of those becoming major hurricanes. Hurricane Dolly won't be a major hurricane.

Each hurricane is judged individually, but generally speaking anything within 50 miles of where the center of a hurricane makes landfall is considered to have suffered a direct hit. Hurricane Dolly at this time is 56 miles east of the border town of Brownsville, Texas and moving in a NW direction according to VOA news
There is a difference between a hurricane hit and a hurricane strike. When a hurricane strikes the U.S. its center doesn't make it to land but hurricane force winds cause damage on land anyway. A hurricane hit refers to the center of the hurricane making landfall. Hurricane Dolly is a hurricane making landfall.

So far, with no reported deaths, Hurricane Dolly is not a deadly storm. A deadly hurricane is any hurricane causing 25 deaths or more. The 3 deadliest hurricanes were in Galveston, TX., in 1900, killing 8000 people, the lake Okeechobee, FL., Hurricane of 1928 which took 2500 lives and Hurricane Katrina in 2005 which killed 1500. The number in the Galveston Hurricane though could be as high as 12,000.

If Puerto Rico is counted, the fourth deadliest hurricane occurred there in 1899, killing 3369 people. 14 of the 15 deadliest hurricanes were category 3 hurricanes or greater. Large death tolls are primarily associated with a storm surge of 10 feet or more. A hurricane's storm surge is strongly dependent on the slope of the continental shelf . This can double the height of the storm surge for any given maximum wind. Hurricane Dolly's storm surge is expected to be 4-6 feet above normal high tide with winds of 100 m.p.h.

Hurricane Dolly is making landfall on the Texas Gulf Coast. That is in line with National Hurricane Center statistice that show pre-August hurricanes tend to primarily strike at the Texas to Northwest Florida coastline. The hurricane season is defined as June 1 - November 30. 40% of all hurricanes and major hurricanes hit Florida. 83% of all category 4 hurricanes or higher have hit either Florida or Texas, but both of these states have extensive coastlines which is reflected in the statistics. September, with 44 hurricanes since 1851, has about as many major hurricane hits as October (16)and August (30) combined. In October, most major hurricanes occur in Florida.

Houston, New York City, Tampa, Miami/Ft. Lauderdale and the Florida Keys are particularly vulnerable areas according to the Center. The Center predicts that because of coastal population growth and inflation almost every future major hurricane that makes landfall will replace one of the current most costly hurricanes. Miami, which statistically expects a major hurricane every nine years has experienced only one since 1950. Tampa has not experienced a major hurricane for 86 years. Brownsville, TX where Dolly is making landfall is a few hundred miles South of Houston, TX.

Right now nobody knows how much damage Hurricane Dolly will do. Hurricane Katrina with 81 billion dollars in damage was by far the costliest hurricane to ever hit the United States. 7 out of 13 of the costliest hurricanes to ever hit the U.S. occurred over the 2004 and 2005 hurricane seson. That statistic is after all hurricane damage was adjusted for inflation. Katrina did approximately twice the dollar damage as the next most damaging hurricane, Hurricane Andrew, a category 5 hurricane in 1992. On average a category 4 or greater hurricane strikes the U.S. every 7 years. Only 6 of the deadliest hurricanes since 1851 have occurred in the past 25 years whereas 60% of the most costly hurricanes have been during the past 25 years.

Intense hurricanes are also termed Major Hurricanes, and a Major Hurricane is a category 3, 4, or 5 hurricane on the Saffir/Simpson Hurricane Scale. A Major Hurricane is comparable to a Great Hurricane, a term used in older publications about hurricanes. For example, the Great Hurricane of 1900. Hurricane Dolly with 100 mile per hour winds is category 2 hurricane.

The National Hurricane Center compares hurricane intensity by comparing the central pressure at time of landfall of each hurricane. How intense is Hurricane Dolly? With a Central Pressure of 29.62 Hurricane Dolly would even be close to making the top 50 list of list of most intense hurricanes since 1851. By that measure, between 1851 and 2006, Hurricane Katrina was the third most intense hurricane to ever hit the U.S. with a central pressure of 27.17. Second most intense was the 1935 Florida Keys Hurricane (26.84), and the most intense was Hurricane Camille in 1969 (26.35). Camille and the Florida Keys Hurricane were both category 5 hurricanes. Katrina was a category 3. Hurricane Dolly appears to remain a category 2 hurricane of average intensity for a category 2 hurricane

Since 1851, 3 or 4 hurricanes have struck the U.S. in one year 37 times. Multiple major hurricanes striking in one year is more rare, occurring about once a decade since 1851.

Sociologists, according to the Center, estimate that people only remember the worst effects of a hurricane for about 7 years.