Tropical storm Debby brings significant flooding to Florida

Tropical storm Debby has proved to be a tricky storm to forecast accurately and continues the unusual start to the 2012 Atlantic tropical storm season. Debby became the fourth named tropical storm on Sunday and as we wrote at the time there was a divergence of opinion in forecast models but the consensus was that Debby would meander westwards, intensify and likely strike Texas after possibly attaining hurricane status. Well the forecast changed and instead tropical storm Debby has taken the other route towards Florida.

It was unusual enough for the fourth named storm of the season to form in June, that hasn’t happened for many years and we’re told this year will be a ‘below average’ Atlantic storm season. It’s even more unusual for forecasts to change so dramatically during the life of a storm and in Debby’s case the storm chose the opposite route to the National Hurricane Center advisories.

So tropical storm Debby, which remains a very large storm, moved slowly north and eastward and has just made landfall on the Florida Gulf coastline. Debby still has maximum sustained winds of around 40-45mph. Tropical storm Debby has storm force winds extending as much as 175 miles from the center of the storm and is bringing a lot of rain with her. You can see Debby’s latest location and forecast path below.

Tropical storm Debby forecast path

Florida has already had a soaking thanks to the size of Debby as she approached and now the NHC are forecasting that as tropical storm Debby crosses the state she could drop isolated amounts of rainfall as high as 25 inches in some northern Florida areas. More widely rainfall totals of 6 to 8 inches are expected. That will cause some significant flood events as the ground across much of northern Florida is already saturated from the last few days of rainfall.

Risk modeler RMS said of the current situation; “The National Weather Service has flash flood warnings in place across this area. It is estimated that over 35,000 properties are without power as a result of damage to poles and power lines. A state of emergency has been declared in Florida in association with Debby.”

Tropical storm Debby is forecast to cross Florida slowly and will likely weaken to depression status again before emerging off the east coast into the Atlantic where the storm will likely intensify back to tropical storm status. After that the forecast models again cannot agree, with the majority predicting Debby will strengthen a little and accelerate to the north and east away from land, but some say Debby could even make a second landfall on the U.S. east coast.

It’s a very difficult storm to predict and so worth keeping an eye on our Atlantic hurricane season page for the latest information.

At the moment it’s expected that tropical storm Debby will cause some amount of insured losses due to the flooding damage and inundation from storm surge along the Gulf Coast. How large an insurance event tropical storm Debby will be is hard to say at this time, but given the extent of flooding it could be significant enough to trouble some reinsurance programs by the time the storm crosses Florida. That’s unlikely to trouble any catastrophe bonds, but with the resurgence of indemnity triggered hurricane cat bonds there is a greater risk posed by this type of tropical storm which brings significant rainfall than there was when parametric triggers were all the rage.