Sun sun sun sun RAIN!

Most days you can see the rain coming ...

But sometimes it starts raining right out of the blue.




Not a big deal in this case since I was already wet up to my knees nor was there any lightning. Not that it still wasn't surprising:

It was brilliant blue sky and sun until I felt the first drop!

Swift River Below!

As seen looking downstream
from a closed bridge

Shelter from the storm

When it rains in the forest ...

Leaves catch the drops before they hit the ground.

East Branch of the Swift River in Massachusetts
is running high for the fall
September 2011

Then mushrooms grow in the moist leaf litter below.

Not a bad shelter for forest gnome

It's been a rainy fall in New England.

Florida-wide rain chart

This June was unusually dry
relative to the 30-year record.

Florida's rainiest month?

Is September Florida's wettest month?

Pond apple are still at their peak ...
But waters could start subsiding soon.

It is the last pure month of the summer "wet season." Hurricanes can still strike the peninsula in October or November, but baring an El Niño in the air, those months tend to lump in the dry season.

Most water bodies "peak" in September as a result.

While tabulating rainfall "statewide" may seem like a stretch ...
This data record is quite long:

It goes back to 1895.

But to answer the question:

Scanning through the historical record, i.e., the black dots in the calendar graph above, September does lay claim to two of Florida's three rainiest months on record:

September 1979 and September 2004.


Both months had two hurricane-strength storms make landfall in Florida: 

Hurricane David and Frederic in the case of September 1979 and Frances and Jeanne in September 2004.

View from Shark Valley Tram after Fay

The other Big Rain Month Goliath, i.e. the third black dot, is August 2008.

Tropical Storm Fay wasn't hurricane strength, but what it lacked in high-wind gusts it made up for in turtle-slow speed: it crawled across almost every part of Florida (except Tampa) in a five-day slow motion parade.


The result was a fully flooded Everglades into the fall as shown above.

Lake Okeechobee's Port Myakka

As seen in March 2008
(at  below 10.1 ft above sea level)

Good news first!

First the good news:

Lake Okeechobee has risen above 11 ft!

Here's the two-year hydrograph,
(20 year statistics color-coded in back.)

Lake Okeechobee is only partly lake.

The interior portion of its levee also contains wetlands, but so long as Lake stage stays below 11 ft they stay dry.  As shown on the hydrograph above, i.e., the orange band, waters have now risen into the green "littoral zone" for the first time since the end of April. That put this year's dry spell streak at 150 days compared to 511 days for the lake stayed below the 11 ft line just a few years back in 2007-2008 (see extended hydrograph below.)

Here's the fifteen-year hydrograph.

High water was the problem from 2002-2006,
but in recent years it's been drought.

Now for the bad news:

That still puts the lake stage at 4.5 feet below the twenty-five year median for late September and -- gasp! -- the wet season is about two weeks from drawing to a close.

Not counting Tropical weather.

The upcoming dry season could be a doozy!

Indian Summer never lasts!

Boston area leaves were mostly green,
but showing signs of beginning to turn:

Cold weather can't be far behind!

Indian Summer invades north

Naples Summer may be long ...

But at least we can count on it!

The warming trend allowed us, unbelievably, to swim

Let me explain:

Day after day, at least temperature wise, daytime highs and nighttime lows are predictably pretty much the same -- highs in the low nineties and lows in the seventies.


Compare that to way up north on the continent.

Not only is it a shorter summer, it's more variable as well.

Hard to believe mosquitoes were so thick so late in Fall ...
Blame it on the spell of warm and wet weather!

Then there's the curious case of the unexpected warming following after what, at first, appears to be the predictable post Labor Day cold-weather descent into fall.

I was up in Boston this past weekend to witness one first hand.


Was it Indian Summer?

Nobody seemed to know for sure, let alone what the exact definition of Indian Summer might be. The one thing everyone could agree on was thanking me, sarcastically, for bringing up the "warm and humid" weather from Florida.

This pond freezes over for ice hockey and skating in the winter ...
but it was warm enough to swim in the pool at the top of the hill instead.

I'm good, but not that good:

If only I could have reversed it on my return trip and brought down the cold soon-to-be arriving New England air to south Florida instead!

Up in the air

Air plants capture their own water
straight from the sky

Too much of a good thing?

Resurrection fern welcomes rain storms …

Except in the cases of exceptionally strong winds.

Here's a curious case of a floating air plant!

Lack of rain causes them to shrivel and dry on the vine. But all it takes is for a few sprinkles of rain to green them up into a lush display which grows and turns greener by the storm until, waterlogged and heavy a haphazard burst of blustery wind knocks it down into the water of the knee-deep swamp below.

In layman’s language we call that …

Too much of a good thing.

Naples Pier

As seen in September between 5 and 6 o'clock
(Come December, at the same time, the sun will be setting!)

Pier of many people

There's always something to do ...

Or see at Naples Pier.



Probably funnest of all is people watching!

Grasshopper finds dry perch

There aren't as many as earlier in the summer ...
But there are still some around.

Power in numbers

Can you see the dry ground in this photo?

Hint: Think small.

As much as I admire ants ...

These ants found a way to stay high and dry where, left untouched, the natural order of things is low and wet.  Of course when it rains their nest probably gets soaking wet ...

If not totally dissolved.

I try to avoid their bite.

Not that ants are afraid of rebuilding if it does.

Rare pond apple!

Fallen pond apple eludes swamp

Seasons of the swamp?

Northerners think of Florida as a land of eternal summer.

But our swamps have seasons, too!



You just have to know where to look.

Upstream and down

Left is upstream and right is down ...
Straight ahead is a hundred miles to Miami!

Return of Turner River!

On Tamiami Trail
looking downstream Turner River
August 2011

Nine miles to Chokoloskee!

In Turner River
looking upstream at Tamiami Trail
June 2011

Of course having water in the channel helps!

Traditional stream channels are rare in The Big Cypress and Everglades.

Turner River is among the widest (100 ft) and longest (9 miles.)

Ridge and slough

The Everglades is mostly ridge (green) and slough (white)

Islands in the stream

The Everglades is mostly ridge and slough …

As far as the eye can see.

Can you see the tree island?
Can you see the direction of flow?

Tree islands are down there, too.

They dot the shallow freshwater sea as tear-dropped shaped mounds of dry and rarer still – shaded! – archipelagos oriented in the direction of regional flow …

Better known as the River of Grass.

Tree island below!

As seen in Northeast Water Conservation Area 3,
looking upstream (north.)

Tree islands next door

Slash pine marks the high ground of Big Cypress Swamp.

What’s the equivalent next door in the Everglades?

Water-animated diagram of major habitats of the Everglades

That would be the tree islands.

As shown in the diagram below, the tree islands of The Glades and the slash pine of The Big Cypress are perched at approximately the same height relative to the natural rise and fall of the water table. Neither sees water within their realm, if at all, until the very peak of the summer-fall wet season.

The glades isn't so much deeper ...
as in total percentage it has more deep area

Tree islands are different in other ways:

For one, they comprise a much smaller percentage of the total landscape (less than five percent) in comparison to the approximate twenty percent of the Big Cypress Swamp which is comprised of pinelands.


Two, tree islands are also surrounded by deeper water.

The vast majority of the Everglades is slough and ridge. Stepping off a tree island will land you in a knee deep slough whereas as similar step from the slash pines islands of The Big Cypress will put you in shin deep (or even dry) marl prairie instead.

September stage in Shark Slough is down compared to last year

Caveat:

At least that’s usually the case.


Water levels are running low this summer in Everglades Nat’l Park. This is usually the time of year when waters are encroaching at the perimeters of the tree islands. Instead – thanks to a deficit of rain and the closed gates upstream, water stage is a good half foot below that level.

Compare that to the Big Cypress Swamp where the wetting front rose into the pines a good month ago.

Here's the full hydrologic history going back to the 1950s.

Do you see how this fall's peak is down
relative to the period from 1995 to 2005?

Why?

For one, it’s been rainier … plus we don’t rely on gates.


Big Cypress Nat’l Preserve is largely a rain-driven watershed.

Late morning clouds

Mornings are usually sunny in the swamp,
but you can see them building up, too.

Did tropics confuse continent?

The Continent and Floridian Peninsular as hydrologic opposites.

Spring is a time of roaring rivers and swollen lakes on the continent while down south on the peninsula water turns scarce and wildfires take spark.

Continental streams usually reach their ebb in fall

And vice versa in fall:

The swamp is at flood stage while continental rivers are at the bottom of their summer baseflow recession.


At least that’s usually the case.

This year in New England rivers are cresting at record levels … in fall! Don’t forget where all that water came from – The Tropics – in the form of Hurricanes Irene and Lee.

Except when they get two consecutive tropical storms!

Or in other words,

That’s Florida-style rain spiking those New England hydrographs!

Monarch butterfly

Looking south from Tamiami Trail

Birders exclusive!

Can you see the green heron?

Unlike the snowy-white egrets and ibis,
this bird blends in!

Inside looking out

It's shaded and deep in the cypress dome,
compared to out in the bright sun of the shallow prairie.

House of water

Sometimes when I step into a cypress dome ...

I feel like I'm going inside a house.



Not that I'd ever want that much water on my floor!

Jetport below!

Landing strip is two miles long,
towering cloud is seven miles high.

Water cycle of the Tortoise and the Hare

South Florida’s water cycle ...
resembles the Tale of the Tortoise and the Hare.

Rainfall is fast and evaporation is slow ...
over a year they usually balance out.

Rainfall is the Hare.

Summer rains are drenching and drainage of the swamp’s flat landscape poor. That causes water to rise rapidly and stay there through the summer and into early fall.


But come mid October the wet season ends.

That’s when the Hare falls asleep and the dry season begins.

The Hare sprints ahead from late May into early fall

Enter the Tortoise:

Evapotranspiration is slow and steady worker – some would say inexorable. As dry season weeks turn into months and the Tortoise marches on, by some point in the winter and definitely by spring pretty much all the water in the swamp is gone.

Or in other words, drought.


Even worse:

Wildfires!

The Tortoise is slow and steady all year long

But not so fast.

The Hare wakes up in May and a new wet season begins.


The water cycle has no beginning or end.

Rain chart aficionados only!

Click on map to view your local rain chart

Summer drought of the big rains?

Where have all the Big Rain Days (BRDs) gone?

We’ve only had two so far this year (we average six per year) … and have yet to have one since the start of the wet season in May.

Florida has a hyperactive water cycle:
Rains are as big as the sun, i.e., evaporation, is intense.

What exactly is a Big Rain Day?

The calendar graph below shows a full history of south Florida’s Big Rain Days from 1992 to present. BRDs are shown on the chart as the blue dots. The larger the dot the bigger the BRD. Among the biggest were Fay in August 2008 and Mitch in November 1998. But even the smaller blue dots are regionally significant days of rain.


BRDs are formally defined in Webster’s Dictionary* as any day in which 1 inch or more of rain was recorded across all of south Florida. It’s one thing to record multiple inches of rain at a single gage, or a cluster of gages in one basin, but it takes the arrival of a huge weather system to spread a full inch (or more) of rain across all of south Florida from the Kissimmee headwaters on down.

These are overnight hydrologic game changers.

This could be one of the few wet seasons
that misses out on at Big Rain Day:

Do you see the other? 

When do Big Rain Days occur?

The natural assumption would be the summer wet season, and to a point that is correct. Over the past two decades, sixty percent of the Big Rain Days have fallen in the wet season months of May through October. Surprisingly, July – smack dab in the middle of our rainy period – is the single most least frequent month. The biggest month is June: It accounts for one of every five BRDs.


Also big are September and October –

Combined, they account for one of every four BRD.

Continental fronts, not tropical weather, bring us our dry season BRDs.

So I wouldn’t count this year out just yet.


And by the way, I just double checked:

Big Rain Days are not included in Webster’s Dictionary just yet, nor in any of my meteorology text books, although – for the record – I think it definitely should be. The term was coined by meteorologists with the South Florida Water Management District in West Palm Beach.

A half year earlier

March 2011

Cypress are shin deep

Here are three of my favorite cypress knees
(Not to be mistaken with knee deep.)

Lots to see high and low

In the background you can see a pond apple forest.
That's where it's really knee deep.

As for at the knees its only up to the shins.

Suspended in motion

This tree has been falling slowly for a couple years now

Florida's sentinel chicken?

Is Tallahassee Florida's sentinel chicken?

When it comes to the arrival of cool weather -- yes.

Do you see the recent plunge
in Tallahassee's nighttime low?

While Naples is mired in the dog days of its never ending summer, Tallahasee got its first dose of "cooler" air last week. Can you see in the animated graph above the dive in Tallahasee's nighttime low temperature -- Brrrr! -- into the fifties.  In comparison, nighttime lows a few hundred miles south in Naples are hovering in the high seventies.

The good news is that the sentinel chicken just tested positive for a mild strain of the fall.


For those of you from our state's capitol, my apologies for this analogy.

Light at top shining down

Sweetwater
August 2011