Hurricanes Helene and Milton Demonstrate How Each Storm is Different

Fri, Nov 01, 2024 at 8:00AM

Mike Silvers, CPRC, Owner, Silvers Systems Inc. and FRSA Technical Director

Dealing with hurricanes is a fact of life for Floridians. Our attention turns to weather reports starting as early as June and with increasing frequency into September (historically the most active month for Florida hurricanes) and well into October. For those of us in the roofing industry, it is imperative that we stay aware of the latest tropical storm developments. FRSA is committed to learning all we can from storms that hit Florida with near or above design wind speed
force. Determining where the storm will make landfall and the storm’s characteristics are important pieces of information that we use to determine how we respond.

Recently, I found myself, like so many of us, focusing on a tropical disturbance developing near the Yucatan Peninsula that was soon to become Hurricane Helene. Thanks to the incredible scientific resources that are available to us today, we have a good idea of the general track of storms and a good estimate of their expected intensity. Even with all this information available to us, a slight change in direction can significantly alter the storm’s path or an unexpected increase in intensity can add to the threat. This makes predicting the amount and the type of damage from a particular storm very difficult.

We’ve recently experienced several hurricanes that all caused significant damage but varied in ways that have a major impact on the type and amount of damage caused.

■ Hurricane Michael (October 2018) was the second strongest storm to hit Florida on record. As a Category 5 storm generating 160 mile per hour winds with a very high storm surge, it devastated areas in the Central Panhandle. Away from the coast, Michael continued to cause significant wind damage.

■ Hurricane Ian (September 2022) was only a slightly weaker Category 4 storm, with winds approaching 130 miles per hour. It sat over areas of Southwestern Florida for nearly 11 hours, moving very slowly while buffeting buildings with prolonged winds and drenching the region with flooding rains. It also caused an intense storm surge that nearly flattened Ft. Myers Beach, one of the most developed areas it impacted. It was the costliest and the deadliest hurricane to hit Florida in over 115 years.

■ Hurricane Helene (September 2024) was a very large storm. As it passed well off Florida’s west coast, its bands pummeled areas with rain along the east coast, 200 miles from the eye. Because of Helene’s massive size and the relatively shallow waters of the eastern Gulf of Mexico along Florida’s west coast, combined with the fast speed it was moving, a record-breaking storm surge was pushed forward as it moved northward.

Helene’s impacts were catastrophic along the central west coast’s barrier islands and surrounding areas that had been spared significant damage for decades. This area has never recorded water levels as high as those seen during Helene. As Helene closed in on Florida’s Big Bend region, the storm surge that was being produced from the backside of the storm’s rotation slammed into Florida’s coast near a relatively unpopulated area. The mass of water was trapped by the topography and had nowhere to go but inland. From Cedar Key to Horseshoe Beach to Steinhatchee to Keaton Beach around to St. Marks, the impacts were devastating. As the storm moved inland, its path crossed Perry and into North Florida with hurricane force winds. Even before it made landfall, the storm turned into an enormous rain maker. As it moved north into Georgia and beyond, it caused catastrophic flooding and unprecedented damage throughout much of the Southeastern United States.

The total number of deaths and the overall monetary costs related to Helene as of this writing are still unknown. Unfortunately, both have the potential to be extremely high. Human loss, physical injuries, the disruption caused to countless lives and the trauma that living through storms creates, is unimaginable. Problems arise from obtaining housing after storms and from the financial burden of paying for uninsured or underinsured losses, many from flood claims that require special coverages. It has been well documented that surviving these storms can have negative health impact and other effects that last for decades. Even if you are not directly exposed to these storms, you will be impacted at least financially when paying for the property insurance rate increases they cause. We must endeavor to learn all we can from these events to reduce losses and disruptions of all kinds in the future.

To help accomplish this, FRSA’s major focus during these events is how hurricane force winds affect Florida’s buildings and, particularly, the performance of roof systems. We often initiate and participate in hurricane mitigation assessment efforts by traveling to the impacted locations. Before we go, we need to determine if the type of storm and where it made landfall will yield enough information to make deployment worthwhile. Over the last 13 months, we have had three hurricanes (Idalia, Debby and Helene) that made landfall in the Big Bend region where development is relatively sparse where newer construction is rare and types of building construction are limited. So failures observed in this area may not correlate into the overall performance of the Florida Building Code’s (FBC) requirements, which are our primary purpose of deploying after a hurricane.

Just because this area is lightly inhabited doesn’t make these losses any less traumatic for those who experience them, particularly for the third time in just over a year. These three storms hit a 50-mile section of the state’s more than 8,400 miles of coastline. Our hearts go out to those who have had to endure this.

Even though we may not visit the area, we can still gather useful information from these events. One very useful tool we use is provided by the National Oceanic and Atmospheric Administration (NOAA). Within a few days, they begin posting aerial images of impacted areas. You can find these at www.floridaroof.com/noaa_helene.

When you open the map, you’ll see dark strips along the coast. Zoom in on any of these and you will eventually see relatively good images of the area and the buildings. Notice dark brown swimming pools and all sorts of displaced items – boats, docks, cars and in some cases, even buildings. You can make out roof covering types and, in some cases, the damage that exists. These images are used when we deploy to find locations with damage we can learn from. They also provide information about the type of damage experienced. These images, when reviewed consistently, can be very revealing. Previous storms that approached hurricane speeds over the past decades left building after building with exposed sheathing or decks with the roof coverings hanging off structures or completely displaced. More recently, we don’t see nearly as much of this type of damage until the winds approach or exceed design wind speeds or the damaged roof coverings are already in questionable condition. This is no small accomplishment and has only been achieved due to the persistent dedication and hard work from industry professionals who understand how important it is to produce and install more resilient roof systems. Improvements made through building code changes and material improvements are clearly making a big difference. Our industry should take great pride in the
work that has been done but stronger storms will continue to reveal areas that can be improved upon. FRSA and our industry partners are committed to learning all we can post-hurricane, not only from our observations but from first-hand accounts from our members. Our membership puts us in a unique position to obtain information that very few would have access to. If you have observed unusual or interesting damage or failures, please share them with us.

UPDATE: Hurricane Milton Makes Landfall on Florida’s West Coast Less Than Two Weeks After Helene Causes Historic
Damage

I completed the Helene portion of this article Friday before a new disturbance near the Yucatan Peninsula caught my interest. In a matter of a few days, it became Hurricane Milton, which grew to a Category 5 storm packing over 156 mph winds. It was accurately forecasted to impact the west central coast of Florida somewhere near the Tampa Bay region. This appeared to be the type of event that many of us have dreaded. A major storm hitting a densely populated coastal region. I watched closely, not only for my professional interest but also for personal reasons due to the track's anticipated landfall. It was to hit very close to where I live in Manatee County, located on the south
end of Tampa Bay. As it turned out, at least from a storm surge perspective, Tampa Bay had figuratively dodged a bullet. A high pressure front weakened Milton to a Category 3 storm just before landfall. It reportedly made landfall at Siesta Key near Sarasota, keeping the worst storm surge out of Tampa Bay. Interestingly, the highest recorded wind speed was near Anna Maria Island on the northern tip of Manatee County, near the southern opening to the bay. The contour map shown here had the strongest wind near Ft. DeSoto State Park and Tierra Verde, in Pinellas County’s southern tip on the northern opening.

The same wind contour map below shows why this hurricane will always be different, not only because of confounding information of where the highest winds were measured far from landfall but also personally for me (and my family). The actual path ended approximately 12 miles south of my home. It’s shown as a red star also on the contour map. The eye passed over us and I had the chance to stand in the calm of the eyewall. I’ve heard doing so described as eerie and I would agree. Having witnessed the high winds Milton produced will help me better understand the trauma that some folks experienced. The impact of Milton so close on the heels of Helene’s devastating storm-surge is, as they say, adding salt to the wound. Thankfully, Milton did not reach design wind speeds but we will still try to learn all we can from this still very strong storm. I will not have to deploy to some far-off part of the state but can start
very close to home.

It took a little longer to start assessing the roof damage caused by Milton (normally done three days after landfall) due to the need to deal personally with the aftermath. About a week after the storm made landfall, I began conducting
observations. On the following pages are some of the photos of damage I captured of asphalt shingle, clay and concrete tile, metal panels and low slope systems.

Click on the link below to see the photos and the ending to the article. Photos start on page 16. 

Click here to see Photos


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