How to: Predict a cold front
Fine art of forecasting good weather

We’re still waiting for our first official cold front …

But no reason to get worried quite yet.

This histogram shows the frequency that the first official cold front (i.e. two consecutive nightly lows below 60° F) arrives to Naples Florida, as based on the historical record from 1941 to present.

By “official” cold front, I’m going by Morton D. Winsberg’s definition in his seminal book Florida Weather. It’s a book that I’ve read over and over again. I call it a rereadable. Keep in mind Winsberg’s definition doesn’t count just drier air, an end to the summer rains or slightly cooler morning and evening temperatures. For the cold front to be “official” it needs to be a true blue slug of continental air that sends nighttime lows plunging under 60° F for two days in a row. Or in other words, it will inspire you to wear long sleeves, if not a scarf. And yes, if you’re a year-rounder who’s endured a full summer, it will have you celebrating, too.

As for when they arrive, it varies from year to year. Some years we get what I call an abnormally early teaser front (i.e. 2000) in early October, but most years (as shown by the distribution curve above) our first real dose of cold air doesn’t arrive until a week or two on either side of Halloween. Then there’s the year’s we have to wallow all the way to the end of November to get our official dose (i.e. 2013, 2020).

Thus my prediction: I’m going to be conservative and say by Thanksgiving it will have arrived (unless it’s another 1986 – see chart above).

Bar chart dynamics
How to read a monthly rain chart

South Florida has two distinct meteorologic seasons:

A 6-month wet season and a 6-month dry season.

How to read a rain chart

Things you should know: (1) The water year begins anew the start of May each year. But it’s not an exact science (i.e. precise point) when they start and end from one year to the next. For example, we classify October as a wet season month even though the afternoon rain showers usually end in early October. And the start of May is probably the swamp’s driest time, yet it’s also the same month, as it approaches June, that the summer rainfall pattern begins. (2) Most of my rainfall charts show background gray coding. That’s the historical statistics as counted from 1983 to present. Why 1983? It was a good year, and most of the SFWMD’s record by basin reaches back that far. Looking at the chart above, the dark gray band is the average range for each month (i.e. between the 25th and 75th %tile) and the light gray is the historic rang (i.e. between the max and min). The white bar in the middle is the normal or median monthly rain. (3) My charts are based on basin-wide rainfall, not local rainfall.

Newspapers calculated rainfall by calendar year. (They are wrong. How dare them!) They also calculate rainfall for an individual gage in Ft. Myers and Naples (The shame!).

In summary, numbers mean more if you can frame them against the expected values and ranges that came before. And its by water year, not calendar year, that we tally rainfall totals in south Florida.

How To: Fix a leak
Why dripping faucets bother me so much

How much water do I use per month?

My water bill read around 5,000 gallons.

Florida kitchen a hundred years ago

By “use” I don’t mean drinking it all. There’s the sprinklers, cooking, washing dishes and clothes, an occasional fill up of the pool, plus two bathrooms and showers.

Constant drip of water use


Still, doing the math, that works out to a hefty half tablespoon per second.

Talk about a leaky faucet!

How To: Ride the Water Cycle
The right and wrong way

Not to be mistaken …

With a giant bike in the sky.

Photo of bike taken at Oasis

The water cycle is more accurately represented …

By the water wheel below.

It receives water from the sky and sends it onto (and down into) the ground below (i.e. the aquifer).

Retired water wheel

Unlike the retired water wheel above,

The real hydrologic cycle is constantly in motion.

With no hope of retiring anytime soon.

How To: Survive a storm
Lessons learned from Hurricane Agnes

Early-season hurricanes are not the norm,

But they do happen from time to time.

If only they worked as good as they look

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!

We sheltered in the basement

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 – and so we found shelter in the basement until the storm passed.

How To: Revive a river

What’s America’s most iconic national park?

The Grand Canyon probably gets a healthy share of the votes.

Hydrograph of the Colorado River, before and after the Glen Canyon Dam

On that note …

I think it’s finally about time we let it’s river run free.

Yes it would be wild, and yes it would be unruly – but it would be a very American thing to do. Even if for just a year. I think one year could lead to two and then we’d seize the momentum from there. Somewhere Edward Abbey is nodding his head.