Powerful front
Wind, lightning, rain and cooler air

During the winter in south Florida,

It doesn’t rain, but when it does it pours.

Winter fronts are major weather events in south Florida

And often it also brings along lots of wind at the frontal boundary, plus a squall line of thunderstorms that can dole out as much rain as they do lightning strikes, or maybe a combination of the two. Usually they pass through fast, leaving behind a wake of downed palm fronds and a return of blue sky above. The blue is usually a little deeper and clearer and quite a bit cooler and crisper. Fronts in Florida are most remembered for what they leave behind: a momentary reversal of the water cycle, new puddles of rain water, and a day or three (and sometimes a week) of continental air with daytime highs in the 70s.

Everglades Restoration at Sunset
As seen at the S-356 and S-334

Water is famously said to have …

A mind of its own.

Short narrated video at the Everglades S-356

Or in other words, it’s going to flow where it wants to flow. Except in the Everglades at spots like this where with pumps and gates we tell the water when and where it can and cannot flow and by how much. As primordial a landscape as the Everglades appears to be (with its ancient alligators and horizon-to-horizon flooded expanse, don’t mistaken that with being completely wild and free. Concrete structures and pumps guard its perimeter and dole out its water in a system that’s so complex that even a well seasoned hydrologist like me is sometimes left scratching his head. Not that I won’t eventually figure it out, and usually just in time for another mystery to unfold.

Pump-filled canal
S-356 and S-334

Unlike a hydrologist …

Water never sleeps at night.

Everglades Restoration in action at the S-356 and S-334

Take for example the S-356 (foreground) and S-334 (background) control point that I drove by at twilight the other day. The S-356 was busy back-pumping water from the Miami side of the levee back into the Everglades. It’s destination: To one of the three new bridges. There was a side of me that wanted to launch a canoe and follow the water to its final flow path. But I had places to be and people to meet, and so except for taking this photo I was on my way east and south towards the Keys.

Looking west towards the bridges that feed NE Shark River Slough

Seasons of the swamp
And where we're at now

Meteorologically the swamp has two seasons …

The wet season (May to mid October) and the dry season (November into May.)

Not your typical four seasons, but four nonetheless

But terrestrially the swamp sees four seasons on the ground.

1.Soaking in season. The early part of May is usually the crunchiest time of the year to walk through the swamp: water is absent except in the deepest pools. By month’s end the wet season will have started, followed by June – the rainiest month of the year; yet only rarely do waters peak this early. Late May through June is usually a “soaking in” season for the preserve.

2. Sheetflow season. The onset of summer, lasting into early fall, coincides with an extensive but ephemeral sheet of shallow flowing water in the swamp. Its flowing aspect is achieved when waters rise to the base of the hydric pinelands (i.e., a depth of 20 inches in the pond apple swamps) and higher. The depth, spatial extent and flow rate of sheetflow typically peak between late August and early October.

3. Hydrologic Interregnum. Starting with the demise of sheetflow in mid fall and lasting through winter is the hydrologic interregnum. This is an approximate five month period in which “wet season” water is still present on the ground, but atmospherically the “dry season” has set in, thus initiating the slow demise of the swamp’s expansive sheet of surface water. The duration of surface water in any one spot is largely habitat dependant, but may also be sustained by winter rains, particularly during El Niño years. Pinelands go dry first, followed by marl prairies which eventually leads to a retreat of waters into the tall cypress and pond apple swamp.

4. Spring drought. The swamp ebbs to its low water mark in April and May due to the cumulative effect of months with little rain and increasing rates of evapotranspiration (rising temperatures, expanding hours of daylight, and plant transpiration). During this period, surface water is practically absent from the swamp other than smallish (typically less than an acre) and isolated pools called dry season refugia.

The above chart shows the relation of south Florida’s two meteorologic seasons, i.e. wet and dry, with the landscape hydrology of the swamp.  The typical duration of flooding in major swamp habitats is also shown.

What season are we currently in?

Answer: Winter dry season (meteorologically) but still high up in “hydrologic interregnum” season (terrestrially).

The “spring drydown” season will be delayed and most likely short, if at all — but I wouldn’t rule out one yet.

Watersheds of south Florida

Behind the song

Behind every great song …

Is the story behind the song.

Bobby Angel discusses his song about the Gunpowder River

In this exclusive interview, singer/songwriter Bobby Angel provides cryptic clues and other nuggets about the making of the song. Topics include why he chose the Gunpowder River over the Mighty Susquehanna River right next door, why the song shares similarities to a parking lot at a trailhead, and why the Gunpowder River is more complicated and has a richer history than at first glance.

Backstory: The song took about a week to write from the start to finish. The opening line came to me while hiking the river trail on the Little Gunpowder with my brother a few days after Christmas. I abandoned an early “simpler” version of the song a day later in favor of a more complicated tale between the “old mill” run of the river and its upstream modern-day reservoir. But it wasn’t until a week later in Florida that I tied the song together with a few tweaks and the final two lines of the last stanza.

But a song is never complete for a “nature folk” troubadour as myself until sit down for the “interview after the song.” I’ll also have to sing it a couple dozen times to really seer it into my memory. And even then, songs have to be played over and over again to really meld the vocals with the guitar and bring the true meaning and feeling of the song out.

Read the lyrics

Listen to the song

Mighty Susquehanna
And the dam that (tries to) control it

The upstream dam …

turns on and off throughout the day.

Looking upstream through the fog and snow to the Conowingo Dam

But it’s never enough to completely shut the river off. The Susquehanna Flats are wide. About a mile to be exact. This photo is taken about 2 miles downstream of the Conowingo Dam that was completed in 1928, coincidently the same year as the Tamiami Trai. So who would have ever thought: a thousand miles apart, the headwaters to Chesapeake Bay and the Everglades got cut off on the exact same year.

End of road?
Or just a momentary reprieve

There’s a saying that …

The darkest hour is just before the dawn.

Firelight Radio is available on Apple Podcasts and Podbean

Well, sometimes you don’t even have to wait that long. That’s where campfires come in. There have been a lot of major inventions over the eons. The toaster. The comb. Just as seen on TV products. The list goes on. But has there ever been as good an invention as the campfire? Maybe the wheel. But that’s splitting hairs. The truth is that the there’s really no other antidote out there for what ails the soul than spending some quality time around a campfire. At least for my money. And campfire’s are usually free. That’s the best part.

Find out more about the campfire talks at Campfire Park at https://campfirepark.org.

water table

Two months of drop
And four more to go

Water levels in the swamp …

Have been steadily dropping for two months.

Hydrograph of water depth in Big Cypress Nat’l Preserve
Historic calendar of water depth in Big Cypress Nat’l Preserve

The reason? That’s what it always does. It is a bit surprising that the pop-up storms of December didn’t do more to steady or reverse the recession. And that’s not to say we don’t have a big water-cycle reversing storm in the dry season cards yet. What we can say is that water levels are a foot lower than this time last year and an inch or two below the long-term average for early January. The long-term forecast is this: We have four more months of dry season until the summer rains start up.

In the meanwhile, if you get out into a dome or a strand, you’ll still find plenty of water, and a good amount of moisture in the marl prairies, too. It isn’t until March, April and May that the swamp dives down into deep drought.


Balmy winter (so far)
Unless you go a few hours north

It’s not often that you get …

Summer storm clouds in December.

High and low temperatures in Naples and Gainesville, FL

But for much of December, morning fog gave way to puffy white cumulus clouds that by mid afternoon were showing vertical growth. More than just growth, they were giving us spot showers and then blowing west and causing more rain in Naples at night. Hey, I’m all up for a rain shower — but I like my dry season, too. Here’s to hoping that January has some solid and lasting cold fronts in store. I’m ready with my scarf and hat so bring it on!

Caveat: I’m not saying “Gainesville Cold.” That might be a little too frigid for my taste, although I have a fleece, too, that I can pull out if need be. (See chart above)

temperature check

Ode to the sun
And how just a little bit matters

It wasn’t so much the cold …

As it was the lack of sun.

Comparison of day and night temperatures up and down the east coast

While I enjoyed every minute of my winter solstice stay up in Maryland, and the Piedmont Plateau country to be more specific, it was the lack of sun more than the cold that wore me down. On several hikes, despite it being mid day and not rainy, I simply couldn’t find the sun. The clouds and the fog were that dense. Then came the brisker days when sun was out but it didn’t give much warmth. Or more correctly stated, it gave no warmth at all so long as I was walking away from it, leaving me to wonder why I didn’t wear another layer of clothes. Then came the surprise: On the return trip, the shining sun on my face made all the difference. I actually had to strip down a layer.

I know how it all is: It rises, it falls, it rises again. At some point we take the sun for granted. Don’t! The tiniest of sliver made all the difference up north. We most value the things we lack. Living in the land of Florida sunshine I forgot that. Traveling reminds us of the smallest things.

bobby angel

Ode to a river
Pretty Boy and the Gunpowder music video

To be honest I was miffed:

How could cartographers leave the Gunpowder out?

Words and music by Bobby Angel

My response was to right this song. Yes, the Susquehanna River is the Chesapeake Bay’s largest tributary, and the Potomac River is bigger too and also drains the Shenandoah Valley. But to look at a map of the drainages of the Chesapeake Bay and to leave the Gunpowder out downright irked me on too many levels to count. But what is a hydrologist to do? And who do I complain to? My philosophy: Never complain and never explain, and rather get down to the business at hand. And specifically, that means telling the story of a pretty special river that sadly people don’t know exists, or sorely misunderstand. The opening line to the song came to me while hiking the river trail just above Jerusalem Mills. I refined the lyrics in the following days in the loft overlooking a brook that feeds the river. But it wasn’t until returning to Florida that I finally put the final touches on the song, and in particularly the last two lines.

Where does this song rank in the Maryland song canon? Behind the Star Spangled Banner and Maryland My Maryland, I’m having trouble coming up with a third. That being the case, I’ll rank it 2nd since Maryland My Maryland is a knock off of Oh Tanenbaum.

New Year Reprieve
Resolutions officially on hold

This just in:

The new year is officially canceled.

Animation comparing water and calendar years

Well, actually — canceled is a bad way to phrase it. What I mean is that 2022 is already 8 months old. And when I say 2022, I’m talking the water year, not the calendar year. Most people (so I am told — and this truly horrified me) go by the calendar year. I’m not here to tell you that’s a completely flawed approach, but if you’re a hydrologist or trying to get in touch with the water cycle, May 1st not January 1st marks the start of the new year. The reason? May 1st marks the start of south Florida’s 6-month wet season (May-Oct) followed by its 6-month dry season from November through April. January 1st is pretty insignificant in comparison other than being the start of the third month of the dry season.

Or in other words, forget your resolutions and live it up. South Florida’s true new year is still 4 months away.


Happy new year!

Usually when I see “fireworks,”

I think Fourth of July.

But that’s because I hail from The Continent.

Down here on the south Peninsula, New Year’s Eve is the big night. For one it gets dark earlier, but the bigger reason is the cool (yet warm by Northern standards) weather plus the low chance of rain, i.e. it’s our meteorologic dry season.

Have a happy, healthy and hydrologic 2022!