Find us on Facebook

Diana Nyad’s 2013 Cuba-to-Florida Swim

“Finding the Right Weather Window for the Most Authentic Athlete of Our Time”
by Lee Chesneau

Diana Nyad, age 64, proved to herself and to the world what it means to follow through with fulfilling her lifelong dream in completing “The Swim”. She accomplished this phenomenal athletic feat not only with her own words, but also by her actions and deeds, unparalleled by anyone in my lifetime. After four previous attempts to be the first human being to swim from Cuba to Florida without a shark cage, Diana demonstrated not only that she has the right stuff, but the ability to put together a team of professionals that provided her the pathway and means of making a “Hollywood story’s dream come true”. Diana’s historic and epic achievement had more to do with the way she prepared for “The Swim”, the attention to detail in the preparation, learning and overcoming the challenges from previous attempts, superior physical and mental preparation, and most importantly, her impeccable integrity while congruently maintaining her own arduous training regimen.  Diana’s unselfish and unsolicited giving of her time, acknowledgment, and energy to others while focusing on the task at hand is also most commendable!

Advanced preparation and establishing protocol for communications and follow through was an ongoing and fluid process that began in the fall of 2012 and continued through the final successful Labor Day Weekend 2013 epic swim from Cuba to Florida. The members of her meteorological and oceanographic Xtreme Dream Team are beaming with pride and satisfaction for their contributing roles in Diana’s incredible “True Grit” performance!

My personal entrance to Diana’s team began when I was introduced by invaluable team member Vanessa Linsley (through her friend and team member Mary Ann DeGraw). I was asked to assist with Diana Nyad’s fifth attempt to be the first to swim from Cuba to Florida without the aid of a shark cage. It was the fall of 2012 and the window of opportunity, at least by the calendar, was closing. We were looking for light wind conditions (winds less than 10 knots) to present itself a week ahead of time. It appeared there was one that was surfacing, but was foiled by the emergence of a large area of disturbed weather (squally weather conditions) in the Northwest Caribbean Sea, which developed into a Tropical Depression (“TD”), climatologically normal for the area and time of the year. The “TD” eventually became “Super Storm Sandy”.  Water temperatures were already marginal and the rest was history as there were no possibilities left for Diana in 2012.

However, an important protocol was established with Vanessa. She ended up serving as my principal advisor as to how often to issue weather forecasts and its specific formatting (in simple laymen terms). The weather forecasts were issued to Diana at first, then later to other team members. Vanessa also introduced me to the “Hycom Oceanographic Model” and asked me to see if there were parallels to weather prediction conditions (mainly wind flow patterns) and the structure of water flow associated with the Gulf Stream, as predicted by the Hycom Oceanographic Model. Vanessa had minored in meteorology in college (as did famous Stan Honey, an icon in the recreational sailboat racing industry and present advisor to America’s Cup 2013). This is not an insignificant fact, as it was an ancillary benefit for me to communicate with a close team member directly involved with the boats involved with “The Swim”. The language of weather can be presented too complex or too simplified, but Vanessa helped make it easier for me to communicate to others not familiar with the language world of weather that only few lower licensing mariners possess (less than 1500 tons).

It is also VERY important to note that integrating any oceanographic forecast model did not change my approach to weather forecasting for the “The Swim”. The oceanographic model as a weather forecasting tool is not part of the process that I normally would use. The main source of weather information I routinely rely on, comes from several line offices of the National Weather Service (NWS).  These line offices include the Ocean Prediction Center (OPC), The National Hurricane Center (NHC), The Tropical Analysis and Forecast Branch (TAFB), and for “The Swim” of 2013m the National Weather Service Forecast Offices (NWSFOs) from Miami and Key West.

Critical to the forecast process I use, is for one to understand the cultural belief and methodology in validating previous forecasts with the most current analysis. This is critical in order to establish a level of trust and confidence in what I call “human intelligence forecasts”, especially those generated by professional meteorologists that are employed by the NWS. The NWS forecasters use a number of different raw weather model outputs (unfettered by human manipulation) as their source of weather input for their review during the forecast process. In other words, the review of various weather models and resulting forecasts become human interfaced!  So, rather than me starting from scratch, I review forecasts that have been initiated and vetted by the professional meteorologists that I used to interact with when I was employed by the NWS. Therefore, I know the level of effort that goes into a NWS forecast, and thus I have full confidence in the NWS forecaster process and their abilities once their products have been issued to the public domain. This maximizes my time and energy by accepting the vetted forecasts from these highly qualified NWS meteorologists. Does this mean I do not do some vetting and interfacing myself? When it comes to weather and the Gulf Stream, I most definitely go to work, and sometimes I over rule my former colleagues and tweak their forecast which then becomes my prediction! My experience with weather and the Gulf Stream is deep and personal having served on capital ships while in the US Navy! The use of and the comparison of the Hycom Oceanographic  Model with the weather forecasts is definitely intriguing, because as several weeks out (the middle of August, 2013 ), the   model predicted a favorable current Gulf Stream flow that ended up matching the weather window that  became the “fortuitous luck” that has always been needed for “The Swim”.

The other meteorologist of Diana’s team was Dane Clark, a veteran of previous swim attempts by Diana. Dane and I just happen to literally grew up together in Miami, Florida, went to the same Junior High School (West Miami Jr. High), both of us served in the military to get initial forecasting experience, we both worked in the civil sector for NOAA, and now as private sector meteorologists, where at times compete against one another!

Dane has a completely different approach to the weather forecast process than I do. He does his own weather model comparisons from his sources of weather. For “The Swim, 2013, Dane came in late in the process (early August) and thus we had to establish our own protocol. With both of us working on behalf of Diana, Dane only wanted to be my principle weather advisor. Since I was already issuing 7- day weather forecasts to Diana when he came aboard,  he would advise me if the forecasts I generated he agreed with or otherwise. Most of the time he did. This should not have been surprising since we were dealing with the “Trade Wind Belt”, which by strict meteorological definition, means “steadiness in wind direction” throughout the year. For the intended swim track line for Diana’s swim, that would mean that direction was critical to its encounter with the Gulf Stream. The “Trades Winds” climatologically run counter  to the set and drift (direction and speed) the Gulf Stream 98 percent of the time. This means most of the time the winds are from an unfavorable Northeast, East, or Southeast direction (the latter deemed marginally tolerable by navigator John Bartlett), provided that the wind speed was light, which meant around 5 knots.

So, between Dane and I, we have over 80 years of experience between us and were able to put together our different career paths’ experience to find the right, but rare favorable weather window at least 7-days out to allow for Diana’s team of 35 to prepare to assemble in Key West, Florida, or Havana, Cuba and then further get ready for Diana’s swim from Cuba to Florida. There were many extensive discussions between us before any forecasts were issued to Diana and certain designated team members. As we entered the last half of August, I would sometimes phone Dane, especially when Diana was going through some anxiety with the end of summer approaching, and the elusive weather window seemed like it would never happen. I felt the same anxiety as I most certainly wanted to be right as to whether the window was there. Dane and I also needed to be on the same page, and up until the last week before “The Swim” we were!

Yet a forth but vitally important member of significant mention  was Dr. Walter (Frank) Bohlen PhD, renowned Oceanographer and Professor Emeritus of Oceanography in the Department of Marine Sciences at the University of Connecticut. For the past forty years he has been studying ocean and near shore currents and transport using a variety of field and laboratory techniques. He is currently part of the Long Island Sound observatory. Frank was instrumental in providing Diana’s navigator vital daily updates of the Gulf Streams altimetry data. This proved enormously helpful in plotting the pivotal pathway for Diana to make it to Key West from Havana, Cuba.

Dane and I got a hint of a possible window of favorable winds several weeks out for the end of August into the Labor Day Weekend, based on a favorable emerging weather pattern. This set in motion a level of excitement that was unparalleled over the long summer of relentless “Easterly Trades”, much too unfavorable for Diana to consider her fifth and final attempt. Then around the 22nd of August, 2013, the break-through we were looking for, dramatically presented itself as if all our prayers were answered. An upper level low was predicted to develop over south Florida, exactly what was needed to break down the relentless “Trade Winds”…beginning on the seventh  day at the end of my seven-day forecast that I issued routinely throughout the long drawn out summer.

As the window become more apparent 7-days out, in order to get her 35-member team on notice, Diana issued an “Amber Alert” which is a 48 hours’ notice for her team to pack their bags, get flight reservations made from as far away as Hawaii, and then inside 5 days out… she issues a “Red Alert” meaning the team members have 48 hours to get to Key West and Havana and then the next 24 hours, if the weather forecast is unchanged and within acceptable parameters, the swim is on!

With the favorable forecast trend continuing from the end of the initial 7-day forecast and now 5 days out prior to Diana’s “Red Alert” issuance, Dane and I were not in complete agreement with the emerging weather window (in terms of direction and speed). We were however, able to discuss our different approaches and find common ground as to whether or not there would ever be a perfect window (3 to 5 days of calm conditions or very light winds). We both came to the conclusion that September is more problematic in finding any remotely favorable window and agreed to the Labor Day Weekend swim attempt. It was Diana’s most likely opportunity to attempt her 5th and final go at it. In other words both of us agreed that the winds would be a bit better than just marginal compared to unacceptable as they had been over most of the summer. It would still not” swim perfect” (doldrum conditions or no wind at all). My initial call was for variable less than 10 knots at the time of the decision of Diana’s Red Alert. In a phone conversation, Diana asked me if I had to pick a direction what direction would the wind be?  I said South-Southeast (but since it would be under 10 knots, still would qualify as light and variable)!

I telephoned navigator John Bartlett, and discussed the expected forecast for winds and weather. I made sure that he knew that winds would not be “swim perfect” but I expected them to be from South to Southeast winds over open waters and would be less than 10 knots. John was interested in what the prospects for thunderstorms would be and I indicated high, because of the upper level low that would impact the track line. I was also concerned about a day time start because of the land–sea interface with the north coast of Cuba and the onshore sea-breeze (North or Northeast) effect which would be against Diana at the start of “The Swim”. Both Dane and I were in agreement on that prospect, thus we recommended a night time start to get away as far as possible for the Cuban coast and the wind against a possible north setting current (Hycom oceanographic model). John indicated they needed to be about 20 nautical miles offshore from his experience operating in the Florida Straits and from a prior swim attempt by Diana. John figured they should be there by 11 AM before the onshore sea breeze would kick in (assuming a Friday night start).

When the final critical window (3 to 5 days of no wind or light winds of less than 10 knots from a direction different from North, NE, and E) that was necessary for consideration to attempt the swim from Cuba to Florida, Diana assembled her team that was to travel to Cuba and held a meeting on Thursday night and decided against a Friday night start in favor of a Saturday morning one. There were obvious other over-riding consideration other than weather that went into the decision as to when “The Swim” would commence.

The long awaited swim attempt began on a Labor Day weekend Saturday morning near 9:00AM and then on Labor Day Monday afternoon (52 hours, 54 minutes, and 18 seconds later) culminated in a successful lifelong dream Diana had to swim from Cuba to Florida: 110.86 statute miles! The weather was not “swim” perfect but the weather forecasts also indicated that the weather would not be “swim” perfect. The two meteorologists on Diana’s Xtreme Dream Team were instrumental in not only predicting the weather window but ensuring the team knew ahead of time what to expect. Coupled with Frank Bohlen’s critical Gulf Stream altimetry data, this was a true team effort that made it possible for Diana (who obviously did the heavy lifting) to complete the swim and fulfill her dream.

Once again, it is important for me to acknowledge the valuable input the “professional skippers and sailors” provided as organized by Vanessa Linsley, who tirelessly tracked Diana’s progress while monitoring actual local weather conditions, ocean current movement, and ocean temperature from the accompanied running vessels. The weather observations validated the forecasts for both wind and weather (thunderstorm and squalls) as it impacted Diana’s progress.

Dane Clark is the consummate professional!! It is truly rare for two meteorologists to agree consistently on weather forecasts as we did. The concerns that Dane had within days leading up to “The Swim” that I did not completely share with, was more than compensated for when he alerted me on the surge of thunderstorm activity that impacted the boat flotilla during the second night of “The Swim”

I would also like to acknowledge Diana, of course, for her role in the final call and decision to take advantage of the less than “swim perfect” window of opportunity. From a pure weather point of view (both Dane and recommended a Friday night start), Diana was resolute and did not waiver from her decision to make a go of it. Once “The Swim” started, should I mention again the 52 hours, 54 minutes, and 18 seconds later herculean effort that culminated in a successful lifelong dream Diana had to swim from Cuba to Florida: 110.86 statute miles?…YES!!!

See the links below to get a sample of Diana’s epic accomplishment:

Diana Nyad on Facebook

Diana Nyad on Twitter

Below are the typical forecasts that were issued earlier in the summer and those just before and during “The Swim”. It should be noted that Dane was consulted with continuously.


Lee Chesneau
Aug 7

to John Bartlett, Diana Nyad, Walter Bohlen, John Berry, Dane Clark, Vanessa Linsley

Days 1-3 WX Synopsis Lower Keys, FL Straits & North Coast of Western Cuba
North Atlantic high pressure system is producing a light to moderate East to SE winds from the western Bahamas, the Lower Keys, the FL Straits, and western Cuba (North Coast) Tonight into Friday night.. Miami and Key West weather radar indicates no significant shower or TSTM activity over the lower keys and the FL Straits next several hours

WX Forecast Tonight
Winds SE to 10 knots. Seas 1 to 2 ft 2 feet GS).
Isolated showers & TSTMS most likely GS late night and early morning hours (winds to 35 knots/choppy seas vicinity TSTMS)
THUR Through FRI night
Winds East to SE 10 to 15 knots Seas 2 to 3 feet (4 ft. GS).
Isolated showers and TSTMS  (winds to 35 knots/choppy seas more likely GS late night and early morning hours)

4-7 Day WX Outlook Lower Keys, FL Straits & North Coast of Western Cuba

4-7 WX Synopsis Lower Keys, FL Straits & North Coast of Western Cuba (Sat-Wed)
High pressure continues to dominate the weather pattern over the western Atlantic, Bahamas through the FL Straits, and western Cuba Sat through Wed. Moderate Easterly wind flow also is expected to continue from a more pronounced Easterly direction and drooping off a bit only on Mon…before picking up again Tue- WED.

WX Forecast Sat & Sun
Winds East to SE 10 to 15 knots Seas 2 to 3 feet (4 ft GS).
Isolated showers and TSTMS  (winds to 35 knots/choppy seas more likely GS late night and early morning hours)

WX Forecast Mon
East to SE Winds 8 to 12 knots or less. Seas 1 to 2 feet.(up to 3 feet GS).
Isolated showers and TSTMS (winds to 35 knots/choppy seas more likely GS late night and early morning hours)

WX Forecast Tue & Wed
Winds East to SE increasing 8 to 16 knots. Seas 2 to 3 feet (4 feet GS).
Isolated showers and TSTMS (winds to 35 knots/choppy seas more likely GS late night and early morning hours).

Onward Diana!


Dane Clark
Aug 7

to Lee

Lee,  good job, and I agree it  looks like no window for at least a week….Dane


Lee Chesneau
Aug 12

to Diana, Walter, John, Dane, Vanessa

Good afternoon Diana from sunny Seattle!

It takes discipline to conquer just about every challenge known to the human race. Discipline (and lets throw in some patience) allows you to pursue your dreams and make them reality. You are doing just that!

The weather, an important component at this critical stage, is not yet cooperating. However, we (your met team) know what to look for and is in daily contact with one another one way or another!

Both upper levels weather conditions and the reflective surface weather pattern are forecast to continue its unfavorable East to Southeast sustained winds to 15 knot for the next 7 days, through Monday Aug 18th  (with some shorter periods of winds less than or even more). Expect the typical summertime pattern of day time land based thunderstorms and nighttime and early morning showers (squalls) and thunderstorms over exposed waters between Cuba and the lower keys.

Winds and TSTM activity (especially nighttime and early morning hours) over the GS will be a bit more enhanced.

The tropics are also becoming a bit more active with Tropical Waves moving westward from the tropical north Atlantic into the Caribbean Sea and intro central America during the next 7-days. The National Hurricane Center (NHC) is watching one now over the SE Caribbean Sea which is expected to move into the Yucatan Peninsula and southern GOM during this time frame with less than 20 percent chance for development into a full fledged tropical storm. However, this is as of today, and when it comes to tropical cyclones every area of disturbed weather needs close monitoring for possible development which we will do and update as necessary.

Onward Diana & Team!!


Lee Chesneau
Aug 21

to John, Diana, Dane, Walter, Bonnie, Vanessa

Today 12Z forecast review pushes back the beginning of a favorable wind condition for the area of Diana’s swim we were teased with yesterday. By favorable…we are looking for light winds less than 10 knots from a direction from SOUTHEAST through WEST. .

Yesterday’s (Tuesday, August 27th forecast) promise of light and variable winds less than 10 knots is now expected to be from the East to SE 10 to 12 knots and that now will extend into Wednesday August 28th. Before then the near sustained winds to 15 knots also from the East to SE are forecast. This is a consensus forecast between your two professional meteorologists!
As we approach Labor Day weekend, fall is beginning to show up over the north Pacific Ocean as is the north Atlantic Oceans. A change in the weather pattern is also inevitable elsewhere near or shortly after the same time frame, as both Dane and I both agree we are on the cusp of seeing, and therefore will result in a likely opening of a window of light and favorable winds over the geographic area of  Diana’s swim…based on a change in the weather pattern.

Be patient, steady, and resolute going forward from here everyone, as there still a lot of calendar in front of us…Onward!

Lee Chesneau
Aug 26

to John, Diana, Walter, Bonnie, Vanessa

To All:
After reviewing the weather pattern over this  past weekend, it is important for me to note that there have been a consistent forecast trend toward lighter wind conditions (less than 10 knots) setting up beginning this next weekend starting Friday Aug 30th into Sunday and early Monday (Sept 2nd).  The key question I need to answer for you is from what direction other then the persistent East or SE direction that has been in play for some time now. I will evaluate the 12Z forecast cycle and update the forecast for this afternoon later today.
I am prepared to put all on the line (call it guts ball). As we enter the peak of the hurricane season, Tropical Cyclones are a distinct probability, but forecasting them beyond 3 to 5 days is NOT realistic. As of this e-mail,(southern GOM Fernand aside) there are no prospects in the western tropical or subtropical Atlantic Ocean and Caribbean Sea on the horizon!.



Lee Chesneau
Aug 26

to John, Dane, Diana, John, Walter, Vanessa

To All:

The weather pattern from this afternoon 12Z forecast favor East to SE winds 10 to 15 knots through Thursday, Aug 29th…with lighter wind conditions setting up with a clear disruption from the East to SE 10 to 15 knot just noted above…to 4 to 8 knots from SE to SSE beginning late Friday into Monday (Aug 30th through September 2nd). Dane and  I have discussed this.
Tonight’s 00Z forecast package will take us into early Tuesday (Sept 3rd). If this trend continues with light wind conditions as noted above  and with no hint of  tropical cyclone activity indicated over the Labor Day weekend to contend with …we will then have a window of opportunity that should be strongly  considered. Human interfaced forecasts are not calling  for ENE to NE 4 to 11 knots noted by your e-mail below!!

Let discuss results of the human interfaced forecast from the 00Z forecast package tomorrow AM



Dane Clark
Aug 26

to Lee


New model runs this afternoon don’t look that good now this weekend!! Let’s see what the 00Z run brings.



Lee Chesneau
Aug 27

to Dane

TKS Dane for this…I did l NOT have a good nights sleep over this. We will chat in the AM your time!


Lee Chesneau
Aug 30

to John, Diana, Bonnie, Walter, John, Vanessa

The upper level low centered near the southern tip of SW FL that Dane referred to earlier today remains in place this afternoon and will continue through Sat but will track to the West of the area by Sun The numerous TSTMS  East and NE of  where Diana’s swim will take place have diminished today. Expect light winds over the weekend from SE and at times from the East from 5 to 10 knots. Sea states will be less than 2 feet.
Will continue forecast updates once daily, and if possible please send your weather reports as well.
Fair Winds,


Lee Chesneau
Sep 1

to Alex, John, Diana, Walter, Dane, Vanessa

24-Hour Synopsis
The weak upper level low and trough influencing the area over the past several days has shifted west to near the NW tip of the Yucatan peninsula. An upper level ridge over the NE Bahamas has its periphery now extending through eastern portion of the FL Straits. Its influence on the surface is a well defined but light (less than 10 knots) SE to SSE wind flow. This will continue for the next 12 hours then we will see the wind direction back some to a more of a East to SE direction during the next 12 to 24 hours. Strong build up of TSTM activity over western Cuba is moving northward over the coastal waters and if the complex holds together it could  over run Diana track line later tonight and since over Diana is currently over GS…may also have numerous embedded lightning strikes before abating during daytime hours on Monday.

24-Hour Forecast
Expect winds to be SSE to SE 5 to 9 knots. Wind ,wave heights one (1) foot. Swell Waves 2 to 3 Feet. Late night and early morning TSTMS/frequent lightning strikes possible, especially over the GS (wind gusts to 35 knots and wind waves increasing   to 4 to 7 ft. Vicinity TSTMS).
Monday Daytime Hours

Expect winds to back to East to SE 6 to 9 knots. Wind wave heights one(1) foot. Swell waves 2 to 3 feet. Isolated TSTMS/lightning strikes. Note…wind gusts to 35 knots and wind waves increasing to 4 to 7 ft Vicinity TSTMS.
Next scheduled forecast update near 8 AM.
Real time WX Observations strongly encouraged.
Fair Winds.