Hurricane season is upon us. We would like to take a moment to clarify the AOP and Hurricane Deductibles. The hurricane deductible applies beginning at the time a Hurricane Watch or Warning is issued for any part of Florida by the National Hurricane Center, and ends 72 hours following the termination of the last hurricane watch or warning issued for any part of Florida.
If the storm is classified as a tropical disturbance, depression or storm, the AOP deductible is in effect.
What is the difference between a tropical disturbance, a tropical depression, or tropical storm?
A discrete tropical weather system of apparently organized convection – generally 200 to 600 km (100 to 300 nmi) in diameter – originating in the tropics or subtropics, having a nonfrontal migratory character, and maintaining its identity for 24 hours or more. It may or may not be associated with a detectable perturbation of the wind field. Disturbances associated with perturbations in the wind field and progressing through the tropics from east to west are also known as easterly waves .
A tropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1 minute average standard) ranges from 34 kt (39 mph,17.5 m/s) to 63 kt (73 mph, 32.5 m/s). The convection in tropical storms is usually more concentrated near the center with outer rainfall organizing into distinct bands.
When winds in a tropical cyclone equal or exceed 64 kt (74 mph, 33 m/s) it is called a hurricane (in the Atlantic and Eastern and Central Pacific Oceans). Hurricanes are further designated by categories on the Saffir-Simpson scale. Hurricanes in categories 3, 4, 5 are known as Major Hurricanes or Intense Hurricanes.
The wind speed mentioned here are for those measured or estimated as the top speed sustained for one minute at 10 meters above the surface. Peak gusts would be on the order of 10-25% higher.
What is a storm surge and how is it different from storm tide?
Storm Surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tide.
Storm Tide is the water level rise during a storm due to the combination of storm surge and the astronomical tide.
Storm surge inundation refers to the storm surge as height above ground level. For the SLOSH model, this is done by subtracting the average elevation of each grid cell from the water level computed by the model referenced to a vertical datum. This helps alleviate confusion inherent in past use of surge above an abstract geophysical reference level.
How are tropical cyclones different from tornadoes?
While both tropical cyclones and tornadoes are atmospheric vortices, they have little in common. Tornadoes have diameters on the scale of 100s of meters and are produced from a single convective storm (i.e. a thunderstorm or cumulonimbus). A tropical cyclone, however, has a diameter on the scale of 100s of *kilometers* and is comprised of several to dozens of convective storms. Additionally, while tornadoes require substantial vertical shear of the horizontal winds (i.e. change of wind speed and/or direction with height) to provide ideal conditions for tornado genesis, tropical cyclones require very low values (less than 10 m/s [20 kt, 23 mph]) of tropospheric vertical shear to form and grow. These vertical shear values are indicative of the horizontal temperature fields for each phenomenon: tornadoes are produced in regions of large temperature gradient, while tropical cyclones are generated in regions of near zero horizontal temperature gradient. Tornadoes are primarily an over-land phenomena as solar heating of the land surface usually contributes toward the development of the thunderstorm that spawns the vortex (though over-water tornadoes have occurred). In contrast, tropical cyclones are purely some oceanic phenomena – they die out over-land due to a loss of a moisture source. Lastly, tropical cyclones have a lifetime that is measured in days, while tornadoes typically last on the scale of minutes. For more information on tornadoes you can go to the Storm Prediction Center’s FAQ maintained by Roger Edwards.
An interesting side note is that tropical cyclones at landfall often provide the conditions necessary for tornado formation. As the tropical cyclone makes landfall and begins decaying, the winds at the surface die off quicker than the winds at, say, 850 mb. This sets up a strong vertical wind shear that allows for the development of tornadoes, especially on the tropical cyclones right side (with respect to the forward motion of the tropical cyclone). For the southern hemisphere, this would be a concern on the tropical cyclones left side – due to the reverse spin of southern hemisphere storms.
What about Florida? They get the most hurricane strikes; do they also get a lot of TC tornadoes?
Florida is no stranger to significant TC tornado activity. Among the larger outbreaks in recent Florida history are those produced by Agnes in 1972 (Hagemeyer 1997; Hagemeyer and Spratt 2002), Opal in 1995 (Sharp et al., 1997), and Charley, Frances and Ivan in 2004. Florida also gets many tornadoes from subtropical storms or TCs having hybrid characteristics, such as Josephine in 1996.
The Hurricane deductible is calculated anew in each calendar year. If the policy period does not coincide with the calendar year then a separate hurricane deductible will apply to loss that occurs during each calendar year in which the policy is in force. For example, if the policy period is from July 1st of calendar year 1 to June 30th of calendar year 2, a separate hurricane deductible applies to loss occurring from July 1st to December 31st of calendar year 1 and to loss occurring from January 1st to June 30th of calendar year 2. The Calendar Year Hurricane Deductible can be exhausted only once during each calendar year.
Single Hurricane Occurrence During Calendar Year Application: In the event of the first
windstorm loss to covered property caused by a single hurricane occurrence during a
calendar year, the dollar amount of the calendar year deductible is deducted from the
total of the loss for all coverages.
Multiple Hurricane Occurrences During Calendar Year: With respect to a windstorm loss
caused by the second, and each subsequent hurricane occurrence during the same
calendar year, Olympus will pay only that part of the total of all losses payable under
Section I-Property Coverages that exceeds the greater of:
a. The remaining dollar amount of the calendar year hurricane deductible; or,
b. The deductible that applies to fire that is in effect at the time of the loss.
The remaining dollar amount of the calendar year hurricane deductible is determined by
subtracting all previous windstorm losses caused by hurricanes during the calendar year
from the calendar year hurricane deductible.
Note: Hurricane deductible options may only be amended effective at the normal policy
This article is for informational purposes only and does not form a part of, replace, change or amend any terms, conditions, provisions or language within your Olympus Insurance policy. We encourage you to read your entire policy.