Positioned as one of the biggest wild cards in determining the threat of hurricanes throughout the Florida Keys, rapid intensification is still a real concern as the island chain weighs new development decisions that could affect evacuation times from Key Largo to Key West.
But as National Weather Service warning coordination meteorologist Jon Rizzo told the Monroe County Commission on Nov. 20, modern advancements have helped to rein in potentially costly errors in forecasting for these storms.
Rizzo’s presentation was delivered during a special workshop session as the county moves toward a final Dec. 19 decision on whether to request more than 220 additional building rights for the island chain during the 2025 Florida state legislative session.
He examined 34 cases from 1852 to 2017 in which Category 2 or stronger storms – likely to trigger a resident evacuation if they occurred today – passed through an ellipse surrounding the Florida Keys.
Of the 34 storms, Rizzo said he found four (12%) that exhibited rapid intensification – defined as a wind speed increase of 35 mph or more in a 24-hour period – through their landfall in the Keys or “closest point of approach.” Eleven (32%) exhibited rapid intensification within 24 hours of landfall, and 12 showed the increase within 30 hours.
Acknowledging a margin of error in intensification forecasts, Rizzo said storms showed what he called “near-miss rapid intensification” increases of 29 mph or more in 14 of the 34 cases within the final 24 hours before landfall, while exactly half showed this near-miss increase within the final 36 hours.
“The strongest factor is Cuba,” Rizzo told the board. “If (storms) go over a part of the land mass, that halts the rapid intensification. But you’re now working within 12 hours of landfall, and that can weigh heavily on emergency management and their decisions. … To get a storm that strikes Cuba to rapidly intensify, it has to be moving much slower and end up in the straits (of Florida) and stall somewhere.”
Rizzo went on to review 15 cases of time-documented Monroe County evacuation orders, comparing the forecasted versus actual arrival times and intensities of tropical-storm-force winds or greater. In numerous instances, he said, evacuation orders erred on the side of caution, urging both tourists and residents to leave more than a day before strong winds arrived.
Making clear that his role is to provide forecasting information to emergency management officials, who subsequently make the appropriate evacuation decisions, Rizzo offered one final remark on rapid intensification:
“The best comment, that stays in my lane, is that we recommend planning for it,” he said.
Public commenters questioned whether Rizzo agreed with studies released by former NOAA hurricane forecaster and current Colorado State University researcher Mark DeMaria, claiming that current models would accurately predict rapid intensification only 32% of the time. Rizzo said that while he agreed with the general premise, recent advancements had narrowed the margin of error in rapidly-intensifying storms.
“When you go back 10 years ago, the greatest number of cases of missed intensity were rapid intensification cases, and that average was missing it by about 30 or 35 knots (wind speed),” he said. “What has changed over the last few years is that peak has shifted, so the errors are probably in the low 20s. … (Rapid intensification) will be missed, but not necessarily by 30 knots.”
Emergency Management Director Shannon Weiner reminded residents that Monroe is Florida’s only county to enjoy its own dedicated national weather service office.
Public commenters questioned Weiner about the risk of traffic bottlenecks on the mainland during a widespread evacuation, to which Weiner responded that her normal storm preparation protocols include calls at least once daily with officials in Miami-Dade, Broward and Palm Beach counties to share and coordinate each county’s expected protective actions.
“If I had to describe what you told us in 25 words or less, it’s that evacuation decisions are made by human beings, which means that we typically err on the side of caution,” said commissioner David Rice.
Options hinge on buildable parcels
The Wednesday workshop provided an update in ongoing efforts by county planning director Emily Schemper to identify vacant, buildable parcels within the county that could create liability for taxpayers through takings cases – triggered if the owner of a buildable lot is denied the opportunity to do so.
Schemper said her previous analysis has already excluded environmentally-sensitive parcels and those with density restrictions that would not allow for at least one home to be constructed, along with Rate of Growth Ordinance (ROGO)-exempt lots, properties to which ROGO permits were previously issued but allowed to expire, and other parcels zoned for alternative commercial uses.
Unincorporated Monroe County has about 1,618 viable lots remaining, she said, added to 452 developable lots from Marathon and 219 from Islamorada.
In October, the BOCC elected to move forward with a request for at least 220 additional building rights from the state – the maximum number that could be added to the county while preserving the legally-required 24-hour evacuation for permanent residents, according to current models.
Any additional request will require modification of the statutes governing the Florida Keys as an Area of Critical State Concern. That decision will be made in a special Dec. 19 meeting of the BOCC in Marathon, following formal suggestions from Key West, Marathon and Islamorada that will eventually inform a countywide request to the state.
Sample options for additional unit requests presented by Schemper at Wednesday’s session ranged from 100 additional units for the county – already secured as Monroe County’s portion of the 220 units requested in October – up to an additional 2,294 units representing a blend of market rate, affordable and multifamily affordable housing units.
Options posed in Schemper’s presentation hinged on a number of variables that may influence the landscape of future takings cases, including whether or not the buildable lots were purchased prior to the adoption of ROGO restrictions in 1992, after the state’s last award of building allocations to the Keys in 2011, or after the Keys’ adoption of a tier system providing an advantage during the permit application process for less environmentally-sensitive parcels. Other variables include whether parcels are waterfront or dry lots and whether their zoning would allow for alternative commercial uses or larger multifamily affordable housing developments.
Following community feedback that heavily favored incentivizing homeownership for full-time Keys residents, the board quickly gave Schemper its blessing to pursue formulating a definition for a new classification of housing units, given the working title of “workforce market-rate housing” in Wednesday’s session.
The newly-defined pool could reserve units to be occupied exclusively by those who earn 70% of their incomes as a member of the Keys’ workforce, but could remove the income restrictions and financial implications of deed restricting a property as a traditional workforce or affordable unit, Schemper said. A grant program could potentially provide first-time home builders with funding in exchange for agreeing to one day sell their home exclusively to other qualifying members of the Keys’ workforce.
“This is the type of housing unit I’ve been pushing for all along,” said commissioner Michelle Lincoln. “What it does is satisfies the need of our community to keep our families and workforce here with the ability to aspire for homeownership and protect these units from becoming a vacation rental unit. And it does it in a way that doesn’t tweak our vacation rental law, so we’re not getting into any trouble with the state.”
Fifth survey results
Assistant planning director Cheryl Cioffari presented results from the fifth and final survey in an online series presented by the county to gauge resident input on requests for additional building rights.
A strong majority of 76.5% of survey respondents said they would support a slower rate of distribution of building rights than is currently used, citing primary concerns of day-to-day traffic, environmental degradation and a loss of small-town feel if additional units are accepted.
Respondents listed government land acquisition and allowing non-residential uses of parcels previously designated for residential development as their preferred mechanisms to reduce takings cases.
Asked what percentage of additional units given by the state should be reserved for affordable or workforce units, a majority of respondents recommended to reserve more than 50% for either category.
A large majority of survey takers spoke against additional development, with 46.28% requesting zero additional units and 38.09% recommending the 220 units or fewer.
The next steps:
- Tuesday, Dec. 3, Marathon City Hall: The Marathon City Council will hold a workshop for resident input on Marathon’s request for units. A formal request will be finalized via resolution at the council’s regular session on Tuesday, Dec. 10.
- Tuesday, Dec. 10, Founders Park Community Center: The Islamorada Village Council will finalize a request for units at its regular December meeting.
- Wednesday, Dec. 11, Murray Nelson Government Center: At its regular December meeting, the BOCC will receive a presentation on a county infrastructure study to determine infrastructure needs with additional building allocations.
- Thursday, Dec. 12: The Key West City Commission will finalize a request for units at its regular December meeting.
- Thursday, Dec. 19, Marathon Government Center: The BOCC will meet in a special session to finalize a request for ROGO allocations from the State of Florida.
