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Hurricane Charley: 5 Lessons Learned From Storm That Slammed Florida A Decade Ago | The Weather Channel
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Hurricane Safety and Preparedness

Hurricane Charley: 5 Lessons Learned From Storm That Slammed Florida A Decade Ago

  

Hurricane Charley roared ashore in southwest Florida as a Category 4 hurricane on Aug. 13, 2004, packing maximum sustained winds of 150 mph.

In just under seven hours, Charley carved a multi-billion dollar swath of destruction across the Florida Peninsula, one of the ten costliest U.S. hurricanes at the time and the strongest hurricane to have hit the U.S. since Hurricane Andrew 12 years earlier.

Charley was a unique hurricane and provided experience for what would be a pair of awful hurricane seasons in 2004 and 2005.  Here are some of the most important lessons learned from a weather forecast and communications perspective.

1) Don't fixate on the center track.

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Forecast cone for what was then Tropical Storm Charley on Aug. 10, 2004 at 5 p.m. EDT. (NOAA/NHC)

The projected path graphic, sometimes referred to as a forecast cone, shows an area where a tropical cyclone's track is expected to remain 60 to 70 percent of the time, according to the National Hurricane Center (NHC).

In other words, there's inherent uncertainty in the future path, which increases in time, hence the cone shape. For example, the average track error of an Atlantic named storm three days away is just shy of 145 miles.

One challenge Hurricane Charley posed was its forecast track roughly parallel to the western coast of Florida, implicating millions along this densely populated stretch from the Florida Keys to north of Tampa/St. Petersburg. 

The graphic above shows the NHC forecast cone from 5 p.m. EDT on Aug. 10, roughly three days before landfall. Note the white area of the cone covered all of southwest and west-central Florida.

However, if you went simply by the skinny black line, showing the most likely forecast path at that time, you might conclude that despite being a hurricane at that point, the center might stay to the west of the area eventually hit hardest. This is far too precise a forecast to put all your chips on so far out in time.

For this reason, we have not and will not draw a center line in our forecast cones on The Weather Channel and weather.com. If you are in the forecast cone, there is a threat the center may pass over you, placing you in the threat of most intense winds and coastal storm surge. 

Of course, tropical cyclones are not points, so their impacts extend some distance from the center, depending on the size of the circulation.

Even in the majority of instances the center stays within the forecast cone, that doesn't mean all the impacts are confined within the cone as well. "You do not want people to pay attention to the cone. You want them to pay attention to warnings," says Bryan Norcross, senior hurricane specialist at The Weather Channel.

2) Pay attention to forecast changes.

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Animation of NHC forecasts for Hurricane Charley from August 11, 2004 at 5 p.m. ET through August 13, 2004 at 2 p.m. ET. (NOAA/NHC)

The animation above takes you through the NHC forecasts from the time the first hurricane watch was issued for southwest Florida north of the Florida Keys to near the time of landfall of Hurricane Charley.

The center of the forecast cone (the "thin black line"), targeted the Tampa/St. Petersburg metro for a time on August 12. The largest evacuation in Pinellas County history resulted. In all, about 1.9 million Floridians were urged to evacuate. The narrative had been written in the media for a Tampa/St. Pete. landfall. 

In the last three hours before landfall, the center of Charley took a subtle, but crucial bend to the east, making landfall just north of Captiva Island, then tracking over Punta Gorda and Port Charlotte, sparing the Tampa/St. Pete. metro from the worst. We'll address the last-minute rapid intensification of Charley a bit later.

Note that throughout the animation, Port Charlotte, the Tampa/St. Pete. metro and Orlando remained within the forecast cone. Hurricane watches were posted about 36 hours ahead of landfall in the hardest hit areas, and warnings were hoisted about 23 hours prior to landfall.

Despite that, due to the focus on Tampa/St. Pete., some Charlotte County residents felt they didn't have adequate warning, according to the official service assessment released by NOAA in January 2006.

According to the NHC's final report on Charley, the track forecast error within 24 hours of landfall was on the order of 45 miles, less than the five-year average of 60 miles. "No one near the landfall location should have been surprised by the arrival of this hurricane," concluded the report. 

"A big factor in the Charley surprise was that the national media was concentrated in Tampa," said Bryan Norcross, senior hurricane specialist at The Weather Channel. "Even the Florida governor went to Tampa. All of this took the focus off the rest of the coastline causing an artificial sense of safety in southwest Florida."

Wobbles in forecast tracks of hurricanes are common, and in this case of such a small hurricane, this subtle bend to the east made all the difference between destructive wind damage in Tampa/St. Pete. or Port Charlotte and Punta Gorda. 

As with winter storms, severe weather outbreaks, even a chance of rain, forecasts can and do change as you near the event. This is particularly true with hurricanes.

Do not take one initial forecast well before any hurricane as set in stone. Check back frequently for any changes in the forecast leading up to the event. 
 

3) Every hurricane or tropical storm is unique

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Visible satellite loop of Hurricane Charley making landfall near North Captiva Island, Florida on August 13, 2004. (NOAA/NWS)

Charley did rapidly intensify into a Category 4 hurricane at landfall. However, a hurricane's wind speeds are only one factor of its overall impacts.

Charley's diminuitive size, with peak winds confined to roughly seven miles from the center, as well as fast forward speed kept storm surge relatively low for this strong a hurricane. Visual evidence at Sanibel Island suggests a peak storm surge of 6-7 feet above ground.

Compare that to the devastating storm surge from Hurricane Katrina of 27.8 feet above ground level in Pass Christian, Mississippi. Katrina was a Category 3 hurricane at landfall.

(MORE: Size Matters For Hurricane Storm Surge)

What Charley lacked in surge was made up for in wind damage. In the path of the eyewall, damage was extensive and devastating and what you would expect of a Category 4 hurricane.

Future giant hurricanes such as Katrina (New Orleans | Mississippi), Rita, Wilma, Ike and Superstorm Sandy drove home the point to respect a hurricane's size as much as its intensity.

(MORE: Does the Saffir-Simpson Scale Need an Improvement?)
 

4) Hurricanes aren't just a coastal thing

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Area of significant damage (yellow) and secondary damage with isolated tornadoes (red) from Hurricane Charley in central Florida on August 13, 2004. (NWS-Melbourne, Florida)
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Hurricane Charley's damage, as with nearly all tropical cyclones, wasn't limited to its landfall location. Charley tore like a buzzsaw across the Florida Peninsula on Aug. 13, 2004. Some meteorologists described the damage swath as similar to a "very wide tornado."

A 1995 paper by John Kaplan and Mark DeMaria from NOAA found a hurricane's forward speed exerts a critical influence on the extent of inland wind damage. A faster-moving hurricane is able to penetrate farther inland before weakening.

(MORE: The Inland Wind Threat)

Moving at a forward speed of up to 25 mph, Charley tracked from Punta Gorda to near Daytona Beach, roughly 180 miles, in less than seven hours that afternoon and evening.

The National Weather Service in Melbourne, Florida, lacking a specific warning to cover an inland hurricane eyewall, issued a one hour-long tornado warning emphasizing destructive winds over 100 mph and possible tornadoes. NWS-Melbourne then followed-up with severe weather statements every 20 minutes warning those in the path of Charley's eyewall. 

Orlando, about 125 miles from where Charley first made landfall, measured sustained hurricane-force winds (79 mph) with a peak gust of 105 mph. 

In all, 2 million Florida customers lost power, some for weeks.

Hurricane Ike four years later would provide an even more spectacular example of the inland wind threat with hurricanes, with wind damage from the western Gulf Coast to Upstate New York.

You may live a couple hundred miles from the coast, but beware of landfalling hurricanes speeding up as they move inland. You may have downed trees, power outages, or even structural damage to deal with.
 

5) Intensity forecasts remain a challenge


 

One of the more unnerving facets of tropical cyclones is rapid intensification, or RI for short.

This is the sudden growth in intensity of a tropical storm or hurricane of at least 35 mph in maximum sustained wind in a 24-hour period or less.

When RI happens in the open ocean, it's notable. When it happens near landfall, it's a scenario every forecaster, emergency manager and coastal residents fears. Imagine going to sleep expecting a tropical storm, then waking up the next morning to a Category 2 or stronger hurricane knocking on your doorstep.

Official forecasts from the National Hurricane Center did call for Hurricane Charley to strengthen from a Category 2 to a Category 3 hurricane 24 hours before landfall. 

Charley underwent RI from Category 2 to Category 4 status in just five hours the morning of its landfall. Charley made landfall at its peak intensity that afternoon near Cayo Costa, Florida, packing maximum sustained winds of 150 mph. 

Today, a stepped-frequency microwave radiometer, or SFMR, is available on reconnaissance aircraft to help estimate peak surface wind speeds in a tropical cyclone by, simply put, measuring the brightness of spray from the ocean.

No SFMR instrumentation was aboard either the NOAA P3 or Hurricane Hunter reconnaissance missions before Charley's landfall, a valuable tool that could have detected rapid intensification ahead of landfall, according to the NOAA service assessment.

While forecast track error for Atlantic tropical cyclones has diminished since 1990, forecast intensity error over that same period has remained relatively flat.

"It's extremely difficult for models to resolve the small-scale features that can often be tied to intensification cycles of tropical cyclones," says Dr. Michael Ventrice, operational scientist at WSI. 

Meteorologists and scientists at the National Hurricane Center and Hurricane Research Division continue to develop new statistical models and techniques to alert forecasters of the potential of a tropical cyclone to rapidly intensify. This is one of the most active areas of research in tropical meteorology.

The ultimate goal is to forecast another Charley-like RI event several days before it happens, providing additional precious lead time for preparation and/or evacuation.

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