Night-time relief?

Does night bring relief from the Florida heat?

That’s a “yes” if you are counting on the Fahrenheit scale … about 15º worth. Night time lows dip into the 70s on most summer nights.



But don’t be fooled by those numbers:

The true metric is humidity. It increases into the 90 percent range – keeping the air “very warm” … and sticky.

That’s why if you listen outside in Florida on a quiet summer night, among other things, you’ll hear the low rumble of running air conditioners.


In that way, yes, night does bring relief from the Florida heat.

In search of monsoons

Does Florida have monsoons?

While I am not one to sit on the fence (as I am not a politician by nature, but rather a hydrologist): my research keeps leading me up on the same fence post – a semi-definitive and inconclusive “yes” and “no.”

It depending on how you look at it.



The evidence – or lack there of – is seemingly in favor of “no”:

The term “monsoon” is simply not part of Florida’s water lexicon, in both speech and written word. I can’t find it mentioned once anywhere in any of my book on my Florida book shelf.



But that raises my curiosity even more:

“Yes” it’s not mentioned, but “no” it’s not outright refuted either … that keeps me digging.

And after all, South Florida has a distinctly seasonal rainfall pattern.


Could this just be a case of regional nomenclature, as in American “TV” versus the British “Telly” … same thing, just different words?

Let’s take a look.



First a couple things about “monsoons.”

Monsoons aren’t defined by precipitation, but rather by a “shift in the winds."

Winter in India is dominated by a desiccating northerly wind blowing off the Himalayas and Siberian plateau. Come summer, the desert of western India (Rajasthan Desert) heats up and forms a low pressure.



That pulls in moisture laden air from all sides of the Indian peninsula.

Thus form the monsoonal – or seasonal – storms of the India. They account for roughly 80 percent of India’s rainfall.


Sounds familiar, right?

That’s the same pattern we have here in south Florida.


A big difference between Florida and India is geographic distribution:

India ranges from 15 to over 100 inches of annual rainfall, depending which part of the country you are in. Compare that to Florida fairly narrow range of between 40 and 60 inches of annual rain.


But that’s hardly proof one way or the other:

The American Southwest is famous for its “monsoons” – a firmly embedded term of the desert lexicon (I lived there) – despite a paltry 15 inch annual total.



As you can see, I’m still sitting on the fence … but also still digging.

Left behind

If you've ever been left behind,
then you can relate to this crab:

It got caught on the wrong side of the sand bar during low tide.

Face to a number

It’s one thing to look at hydrologic data,

But it’s quite another to see a water control structure up close in person.



As with many water ways of Florida, I got to know the data of the S-77 before I ever laid eyes on its “lock and dam.”

Its data sets are discrete, add together nicely on a spread sheet, fit neatly into a graph on a single sheet of paper … and above all – rolls in day after day (… after day after day), right to the doorstep of my computer.

It’s as tidy as hydrologic number crunching comes in south Florida.



Years passed until I finally had a chance to see the S-77 first hand, face to face.

It’s no small task: It took hours to drive to, an equal time to drive back from, plus the time we spend on the water. I was giddy with anticipation to see the structure – as, say, meeting a long lost relative – but upon seeing it, I was stupefied by the giant sprawling conglomerate of concrete, steel, earth, and electric my eyes looked out on.

It was nothing like I’d imagined.


I drove away a changed hydrologist: never would I look at the S-77 data quite the same way.

I am a man of water, but not “a man on the water” as often as I’d like. To be a hydrologist in the Everglades, it’s important to take that time …

Otherwise it’s just numbers.

String lily

Have you ever heard the expression:

“The rose isn’t beautiful because the rose is beautiful: the rose is beautiful for the time you spent with the rose?”


That’s from the “Little Prince,” but to be honest, I’m not sure the saying has anything to do with a “real" rose, let alone a whole field of them, as is the case with these string lilies (Crinum americanum) growing alongside Upper Wagon Wheel Road in Big Cypress Nat'l Preserve.


There were simply too many of them to spend much time with any single one:

I took the photo instead.

Middle waters

Isn't it the case in life that we focus too much on the end points?

Sometimes we forget about the places in the middle.



Case in point is along the Caloosahatchee.

Its headwater source is Lake Okeechobee and on the other end is its estuary, down along Ft Myers.

These days the story of the Caloosahatchee revolves around those two end points: how its getting too much water from the Lake, or not enough – and what impact that's having on the downstream estuary.



Between those two points the river passes quietly by LaBelle.

It's an Old Florida original.

I stopped by there a month ago, went up on the bridge, and watched the river flow. LaBelle is in the middle, but somehow removed. Standing there, between those extremes, I enjoyed a perfectly peaceful moment ... despite the traffic.

Lost water

Not only was this May our earliest start to the “wet season,” as I tabulate the data, it’s also the quickest start ever to the start of a new "water year."

Yes, that’s right, May (not January … and not October) marks the beginning of the water new year in south Florida.


Why not January?

That is indeed the cookie cutter approach, and one you still see used in the newspapers, is to lump rainfall in alignment with the calendar year (from January to December). But that doesn’t work south of Okeechobee (or at least work well): January falls dead center in the middle of the winter-spring “dry season.”


Why not October?

It’s the standard up north on the continent. But that’s because it tends to coincide with the low water ebb of its mountain-fed river systems.


May marks our low water mark,

And also – mid month – the start of the summer-fall wet season.

That makes it the obvious spot to start the meteorological new year.



It sounds obvious enough … as all things do, in hindsight.

But it took me a good three years when I first moved down here to break free from my old “continental” mindset. The standard, too, up north too was to look at rainfall relative to the four seasons. South Florida has only two seasons (as defined meteorologically), but to divide the year only by them oversimplifies the math.

Thus I developed my Pippi Longstocking graph: “cool colors” indicate wet season months, “warm colors” shows the dry season – but it also goes the additional step of highlighting individual months as well.



That’s helpful for when trying to dissect the anatomy of a single year.

Take 1995 for instance.

It stands out like a giant sequoia among all other years. Yes, it stands the tallest, almost 20 inches of rain greater than the bars that surround it, but that’s only half the story. The true beginning of the record 1995 wet season starts with the record-wet “dry season” that preceded it (as indicated by the “warm colors” on the top of the bar to the left).
That gave the 1995 wet season a “high base” to start from.


Compare that to this May’s deep drop of the water table. That started this wet season off from a “very low” base.

So yes, the water year starts anew each May, but not all “starting lines” are equal:

This year had to make up for lots of “lost ground” from the deep “dry season” hole it started from …


Otherwise known as “lost water.”

Heat wave (as normal)

Florida is in the grips of a heat wave.

I know what you’re thinking – “it’s summer, in Florida … of course it’s a heat wave!”



But the past few days have been hot even by Florida standards:

Miami teetered in the high nineties, unusual for a city where – like clockwork – summer highs stay in the low 90s.

Tallahassee broke above the 100º F mark.


To the uninitiated, that may seem reversed. Shouldn’t Miami be hottest since it’s farther south?

Add another to the list of Florida's "seemingly strange (but explainable)" weather peculiarities.


Florida isn’t as homogenous as the “out of staters” would lead you to believe.

Although, yes, in summertime, it’s always hot in Florida.

We don’t need a heat wave to tell us that!

Tall order to re-fill

The swamp has rebounded, but it still has a ways to climb:

The pinelands – our highest country – are still dry.



Last year the pinelands stayed wet for 4 months.

Compare that to the wet prairies which stayed wet for 7 months, cypress for 8, and swamp forest for 9 months.

Usually those "deeper wetlands" stay wetter for longer: but this year’s spring drought quickened the pace of the water table decline.


Swamp stage is currently “normal” for mid June.

That’s a bit of a surprise considering the chart-topping rains we had in May.



Does that mean that June rains have been unusually low?

Not really:

The month isn’t over, but – at least over the Big Cypress – we’ve had our normal wet season pattern of rains.


This hydrologic mystery is better explained by the swamp water exemption to the meteorological rule (actually, it’s more of a wise tale) that “all droughts end in floods.”

When the water table bottoms out as low as it did this spring, the swamp turns into a giant “dried out” sponge.


May rains always have to “re-soak the sponge” before they can “re-fill the swamp,”

Only this year, the sponge was especially thick.

That made it a tall order to "re-fill."

Floating islands

Florida has lots of islands, and lots of water surrounding them, on top of which are many things that float:

Turns out it also has “floating islands!”


When big rains follow an extended drought, the rapid (and deep) submergence of oxygen filled peat, plus some wave action, can cause the peat to become buoyant – and then “pop up” from the bottom or simply dislodge from the lake shore:

Thus a floating island, or tussock, is born.



Where it goes from there is the whimsy of the wind … and water levels. Sometimes they get deposited up on higher terrain. Other times they drift ashore to the dismay of property owners. Other times they won’t go way.

In the Everglades many “tree islands” formed from the same process.


The photograph was taken by Matt Hasty on one such island in Lake Jesup (Seminole County) during the multi-day “no name” storm of mid May. Those rains popped lake levels up 4 feet and, in the process, also brought some new floating islands to life.

Excellent photo Matt!

Not New Jersey

You may have caught the news:

Scientists are predicting a record-setting “dead zone” in the Gulf of Mexico this summer.



How big you may ask?

They won’t know for sure until July, but probably somewhere in the neighborhood of 8,000 square miles, or – as has been touted in the electronic media outlets – “roughly the size of New Jersey.”



That bothers me!

Actually two things do: First is the “dead zone” – our Gulf Stream waters should be getting cleaner (not worse) – that’s a given; But second, why drag New Jersey into the mess?

Not only is it not a Gulf Coast state, nor is it even in the Mississippi watershed, it’s not even a water body!


Lake Erie is the shoe that "almost fits."

At 9,940 square miles it is a tad bigger than the projected area of low oxygen, but isn’t it appropriate in this case to buy a shoe that leaves a little room for growing?


The real culprit of course has nothing to do with New Jersey, or Mississippi for that matter (as in “the state”) … and not even with the river, but rather the watershed:

It feeds the river (with high flows and nutrients), which spills into the gulf, which fuel the algal blooms, which steal away the oxygen.


I say that we “Gulf Coast and Mississippi Valley” citizens take the matter into our own hands.

Let’s start by comparing the “dead zone” to something on our own turf, such as our locally-available “Okeechobee” measuring cup.

By my calculations this year’s hypoxic waters will span an area 12 times the area of Lake Okeechobee.


How big is the Mississippi?

The river crested at 1,000,000 cfs earlier this June, or in “Lake Okeechobee” terms, enough to fill the lake from bottom to top in 2.5 days.


That’s one big river, but I was thinking of the watershed … which is where the problem lies:

Not New Jersey.

Low tide

I’m a big “low tide” enthusiast:

Tidal pools … sandbars … the angled beach front … the foaming surge of incoming waves: it’s a hydrological wonderland in miniature.

It’s an ephemeral one as well – which perhaps makes it all the sweeter (as is a kid lost in a candy store). It makes me think about how the same processes, at a bigger scale and over geologic time, shaped the peninsula and its water bodies.



The first photo brought to mind the Everglades.

The elevated sandbar could be the Atlantic Coastal Ridge (Miami) and the tidal pool behind it the shallowly inundated river of grass.


Beach terraces mark tidal turning points.

That makes me think of the inland terraces left behind by the high sea level stands of antiquity which, combined with the modern day ascent of the seas, probably means this sand castle is built too close to the water line.


Low tide seeps are fun to watch.

The tiny rivulets of saltwater pick up and carry away grains of sand. That makes them deepen and lengthen over time. You can see the same process at work at a larger scale (and with fresh ground) up on the panhandle, forming Florida’s unique steep head stream valleys.


This walled pit of sand was my modest attempt to improve water flow.

While I can assure you I had only the best intentions in mind, the whole enterprise quickly unraveled – seepage became rampant, stability nonexistent and channel sedimentation unstoppable.



As I stepped back to take in the full glory of my creation, I was dismayed by the eye sore I had created instead. From an aesthetic standpoint justice would have been better served by leaving well enough alone.


But I walked away with my head held high:

There would be more low tides to get it right … or wrong:

The incoming tide would erase it either way.

"Fake" shutters

Does the early May 11th start to the wet season mean an increased chance of a June hurricane?

Probably not,

But it does provide an opportunity to look back on June surprises of hurricane seasons past.



Agnes (June 1972) sticks out in my mind.

It goes in the record books as my first hydrologic memory, not as a Floridian – where it made landfall, but as a native Marylander where I was born, and where the storm passed through on its way up the Atlantic Coast.



I was only 3 years old at the time.

My mother and father judiciously had us take cover under ground, not for the reason we didn’t have shutters on our windows – we did, but because those shutters were fake!

The so called "ornamental shutters" were made of flimsy plastic, manufactured too narrow to cover the full width of glass, and – the final insult – drilled permanently into the wall siding.

They looked great on a sunny day, but that was about the good of them!



But Marylanders are nothing if not innovative: we found safety in the basement … and after the storm passed, also found a thin sheen of water on the slab floor.

(That discovery marked the beginning of my father’s futile attempts to battle a chronic moisture problem in our basement, predictably ending each time with him admitting defeat (tinged with a sense of awe) to the subterranean river that coursed beneath our house.)



The good news is that I would grow up to become a hydrologist.

The bad news is it took 25 years.

But it’s better late than never in hydrology ... unless, of course, it comes to June hurricanes which, in any season, are always early.


Speaking of early surprises -- "Happy Father's Day, Dad!" We have a letter in the mail and I'll give you a call on Sunday (... and/or Saturday).

Bouncing thermometer

Here’s a “bouncing" graph showing the daily “high and low temperature” bands for Naples Florida and Fargo Minnesota.


Why is it bouncing?

Hint: it has nothing to do with basketball,

Rather, its bouncing because Fargo is so cold ... Or is it because Naples is so warm? Probably a little of both!



One thing is for sure: it’s been an unusually cold start of the summer for Minnesotans (… not that they can’t handle it):

Meteorologist Daryl Ritchison reports in his Storm Tracker blog that Fargo recently spent 5 consecutive days below the 60º F mark – a first for June. Even more telling has been the absence of tornadoes. All that cold air has pushed the traffic along tornado alley further south.


The tell-tale line for me is the 70º F mark.

That line is shown by the light orange band on the “bouncing" graph.


Here in Naples we’re in our 5-month stretch where not even nightly temperatures drop below the mark. Come winter, day-time temperatures usually find a way above 70, even if night-time lows drop into the 50s and 60s.


Compare that to the Fargo.

Daytime highs only manage to break the 70º F mark for 3 short months (plus an Indian summer) … after that’s it’s a steep plunge back into the Canadian freeze.


But Minnesotans are to cold and snow what Floridians are to heat and humidity ...

Even if they do relish the warm weeks of a fleeting summer the same as we do our ephemeral blasts of winter.

Slough stages comeback

Shark River Slough bottomed out in May at a new 15-year low water mark.

Water stage has rebounded almost 2 feet since then, pushing the wetting front up into the ridge habitat of the famed "River of Grass."



Current stage is almost identical to mid June of last year ... but that’s where the similarity between the two years ends.

Our most recent year (June 2008-June 2009) year saw both high and low water extremes: The Park’s primary source of upstream water, the S-12s, were opened to full capacity in October, followed up a half year later with an unusual "complete dry down" of the slough.



Compare that to the year before (June 2007-June 2008).

Slough stage was consistently repressed all year long (setting the 15-year low water mark for 8 consecutive months); but unlike this May, the low-lying sloughs stayed wet all year round.


What difference does the difference make?

Ecologically, in the short term, it’s hard to say. Duration of water in the wetlands is an important shaper of the landscape and its biota, but there are other factors too.


The long-term prognosis is clear, and generally agreed upon: the park needs more water … less through the S12s and more from its northeast source.

That’s a work in progress.

Summer holidays

The south Florida water year is traditionally divided into wet and dry halves, but the wet season also has a life cycle of its own.

I tend to think of it in terms of major holidays.



The wet season comes to life in the week or two running up to Memorial Day.

Dry skies of the spring give way to afternoon rise of cumulonimbus clouds. These storms are “convectional” … and tend to be spotty. This May was unusually wet as shown on the graph



Memorial Day to the July 4th generally marks the wet season’s rainiest period. Convectional showers become the norm, and are often enhanced by remnant upper atmospheric instability left over from the spring.


Independence day ushers in a lull in the wet season.

The upper atmosphere instability that stokes the rains of June (our rainiest month) is replaced by the more homogenous (and stable) winds of the easterlies blowing off the Bermuda High.

As the weeks progress, this momentary lull is offset by (1) a rising wave of tropical activity and (2) full maturation of the day-time sea breeze funneling in from the coast. These inland breezes collide mid peninsula to form mammoth front lines (that slowly drift west), better known as our “convergence” storms.




These are the apocalyptic storms that blot out the sun, and – for the old timers – serve as the sign that the wet season has finally arrived. You can set your watch to them … so the local folklore goes.



Next up is Labor Day.

Up on the continent, it signals the “end of summer.”

But here in south Florida it marks wet season’s final crescendo:

Water levels are peaking, tropical storms are threatening, and – if and where they fall (September and October account for a full 50 percent of hurricanes making landfall in Florida) – waters rise up to (and over) the brim.





A psychological component factors in as well:

The long humid summer creates a Florida equivalent of “cabin fever”. That, combined with rising anxiety of tropical storm tracking (and everything that goes with it – shuttering windows, stocking supplies, evacuation planning, 24-hour news coverage) rises the wet season to a feverish pitch.


Then comes Columbus Day.

The “convectional” and “convergence” storms shut down first, early in October. By Columbus Day – at long last – night time cooling arrives.

The nail in the coffin is also our first taste of the winter to come: a cold front.

Keep in mind that the tropics remain in play through November (Wilma hit Naples on October 24th), but storm intensity tends to weaken as the official season nears its close on November 30th.


In a nutshell, that’s our wet season by the summer holidays.

Rhododendrons

Gardeners are fanatical about plants in general – but some are more special than others, and more often than not, they are of the flowering variety.

Rhododendrons are the perfect example:

Aficionados eagerly await their bloom each spring, and are rarely disappointed.



Photos were taken in early June at Concord Square in Massachusetts (not Florida), just down the road from Walden Pond.


North Florida is home to the Florida Flame Azalea (Rhododendron austrinum) which blooms in late March and April.