20 May 2016

Hurricane Preparedness Week: Local Edition

The week of May 15-21 is Hurricane Preparedness Week, so what better time to send out some relevant information!  I have been a resident of Biscayne Park and Miami-Dade County since February 2012, but have a long history of tropical cyclone work.  I have some background information on my website at

Seasonal climatology

The Atlantic hurricane season spans June 1 through November 30, and by design, the vast majority of activity is typically confined to those dates (not necessarily all of it).  Within the season, about half of the activity (climatologically) falls between August 20 and September 20th.

Although the climatological peak of the season is in early September, the month with the most hurricane impacts in south Florida is October.  June, July, and November have typically been relatively quiet here, while August and September are when the strongest storms have hit.  Also note that about half of our storms come from the east (generally Jun-Sep) and half come from the west (generally Oct-Nov).

A long lucky streak

Florida has not been hit or affected by a hurricane since October 24, 2005 when Wilma passed across the peninsula.  That span, or "hurricane drought", is unprecedented in known history by a huge margin.  The previous record was about six years, and the average return period is roughly 1.4 years.  There is no obvious physical reason for this, as there have been plenty of hurricanes since then, and other states (and countries) have gotten hit by hurricanes multiple times.  One of these years, our luck will run out.

Zooming in to Miami-Dade County, the hurricane "drought" is not a record yet, but it's long.  The county has only been affected 4 times in the past 50 years, including 1 major hurricane (defined to be Category 3+).  Compare that to the previous 50 years, when the county was hit 17 times, 11 of which were major hurricanes!  The chart below shows a timeline of hurricane impacts with major hurricanes marked in red, and overlaid in the orange line is the county's blossoming population.

The influx of new residents together with a lack of hurricanes results in a dangerous combination of inexperience and complacency.

Trees and Debris

While having a long break from hurricanes is nice, it has also allowed a unique situation to arise: we now have over 10 years of untested tree growth.  Trees can get full, top-heavy, rotten, etc, and strong gusty winds are really good at finding those weak points.  Since October 2005, trees around here have not experienced any serious wind-related threat, so we can expect the next hurricane to create an abnormally large mess (downed power lines, roof and house damage).

This is the perfect time to look around your property to see what you can to minimize damage before a storm threatens.  That includes random unused outdoor items, and especially trees.  Having your trees properly pruned, thinned, and/or topped (or removed if they're dead or rotten) now can save you and your neighbors damage and power loss during a storm.  If the tree is growing into or over power lines, it's best to report it to FPL and they'll take care of it (it saves them time to do preventative work rather than repair work).


305-442-8770 (options 1-1-5... request tree trimming service)

Evacuation zone and Plan

In the event of an intense hurricane approaching, storm surge becomes a concern.  Storm surge is the rise of water levels due to strong onshore winds "bulldozing" the ocean onto land, and is the #1 killer during hurricanes in the U.S. by far.  Storm surge also does not correlate perfectly with a storm's category... it also depends on the size of the storm, coastal topography, offshore bathymetry, and more.  A large slow-moving Category 1 hurricane could generate a larger storm surge than a small Category 3 hurricane, for example.  "There's more to the story than the category!"

In Miami-Dade County, our evacuation zones are defined by storm surge risk (not wind risk), and the zones are not limited to the immediate coast.  The surge of water can travel up canals and rivers if the wind is aligned just right.  The zones are crude in shape, and the entire county would never experience the peak surge or evacuation orders.  But knowing your zone letter gives you a general sense of your potential risk from storm surge... here is a map centered on my local area:

and here is the interactive website if you want to peruse more on your own:

If you ever do decide to evacuate, it is a good idea to have a place and plan in mind before the stress of an approaching storm sets in.  And always let friends and neighbors know where you're going and how to contact you.


Review your policies and coverage, and make sure you know a number to call after a storm if you need to file a claim.  Keep important documents (including insurance policies) in a safe and dry place.  A quick call to your agent is easy and can give you peace of mind that you have the coverage you thought you had.

This summary is just intended to provide some background and general information, but in the event of a storm, listen to official forecasts (National Hurricane Center) and local authorities.

I have been writing updates/blogs on Atlantic tropical cyclones since 1996, and if you wish to be added to my email list so you can be notified of new posts, please let me know (brian[dot]mcnoldy[at]gmail[dot]com).  And if you have any questions regarding anything in this post, don't hesitate to contact me.

Hoping for another safe season,

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