JACKSONVILLE, Fla. – This year the National Hurricane Center will debut a graphic that estimates the arrival of tropical storm or hurricane force winds.
A survey of Jacksonville residents shows people are split on the maps utility.
The product factors in storm uncertainties to predict the probability of wind arriving at locations in the storms path..
It is designed so people can finish storm preparation before 39 mph winds arrive which is generally considered a threshold too dangerous to be outside.
Emergency managers prefer longer lead times for basing evacuation decisions while many homeowners want to wait for more certainty on the forecast.
To accommodate both groups, two versions are available with different wind arrival probabilities.
The version providing more leeway for preparation is a map called, the earliest reasonable arrival time. It shows a 1 in 10 chance of winds reaching tropical storm force at a certain time.
What’s called the, most likely map, is based on 50% probability of winds occurring.
A survey looked at 4 regions in the country including Jacksonville to see how well people comprehended the wind maps.
Two out of three people correctly interpreted the new information.
In the the Northeast part of the country people were willing to take more risk preferring the 50% chance of arrival wind map.
TV weather broadcasters also preferred this version according to a survey of Chief Meteorologists.
Hawaii took a cautious approach looking for the greatest potential lead time available.
The survey found people in Jacksonville prefer both types of information nearly equally.
While the product was experimentally used last year, 2018 will be its first operational use and include speeds in mph along with knots.