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.

winter

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.

holidays

It’s not the cold
Why daylight hours matter most

People go to great extremes …

To get an extra hour (or two) of sleep.

Comparison of the onset of sunset and sunrise in Naples, Florida (left) and Brussels, Belgium (right)

But what about trying to find extra hour or three of sunlight? Come winter time in northernmost latitudes of the Northeast United States (or in Belgium as shown on the chart above), the only escape from 16 hours of darkness (i.e. that’s 2/3rds of the day) is to travel south to a sunnier place like Naples, Florida. Not that it’s perpetual sunshine, but you will gain 2.5 hours of natural illumination. Compare that to the summer solstice where the opposite occurs: Only 7.5 hours hours separates sunset from sunrise compared to 10.3 hours on Florida’s southern tip.

There’s also a (tiny) bit of a temperature difference, but we won’t get into that. The moral of the story: South Florida is brighter, warmer and less dark than the icy northern climes of the continental US and Europe come winter time.

Or in other words, Happy Winter Solstice! And fear not: the downward trend in daylight hours is about to pivot. Just don’t expect it to happen fast.

animation switch short

Follow the rainbow
A pot of gold awaits

Sometimes in south Florida …

You simply have to ignore the month.

Looking north towards I-75 Alligator Alley

Technically speaking, we should be bearing down (and scarfing up) in preparation for a deep polar freeze (or two). Well, at least not yet. So far this December, the weather has been closer to the hot and humid summer pattern of pop-up showers and copious morning fog. How thick is that fog? Thick enough to make pea soup seem transparently thin. The commute ride into work, for those that have been doing it, has been a white knuckle ride with 300 ft visibility. On the good side, there’s the mid afternoon rainbow as seen above. At 1,000 feet above the ground, the air temperature is also delightfully cool.

temperature check

Sweltering December?
And why some call it perfect weather

December is touching up …

At record highs in Florida.

High, low and average air temperatures in Naples and Gainesville, Florida

The reason? Well, it’s south Florida of course. It never gets cold. Or not wintery cold like it does up on the continent. But even by Florida standards, the start of this December has been incredibly warm. Just how balmy has it been? Answer: Warm enough to convince me that we’re still on the summer shoulder season, i.e. mid October or late April. The only salvation: The temperature in my pool and in the gulf is cooler thanks to the thermal stability of water and its ability to hold on to the November temperature plunge. The evenings and morning have been delightfully pleasant, combined after a run with a plunge in the pool. And just to be clear: I’m not complaining, but for someone who grew up in the Northeast, the weather isn’t jiving with what I would normally expect on this calendar date.

But you know what they say about the weather: It’s sort of a corollary on the greenness of the grass, but with a twist: If you don’t like it just stay put, it’s sure to change in 15 minutes (plus or minus a week).

P.S. Deep polar cold front, wherever you are, I’m very unprepared but will welcome you with open arms when you arrive.

winter

Florida’s 70° Rule
For measuring summer and winter

People winter in Florida, as in the verb.

We call them snow birds.

Naples enjoys 3 weeks of winter to 20 weeks of summer

To them, without a doubt …

Winter the noun does not exist in south Florida.

Major caveat: To us “year rounders” the thermometer couldn’t be more clear. We go by the 70 degree rule. What is the 70 degree rule? You know it’s a cold day in Florida when the daytime high doesn’t rise above 70° F. We call those day “winter.” On the other side of the coin, you know its a hot day in Florida when the nighttime low doesn’t drop below 70° F. Going by the 70 degree rule, Naples averages 18 days of winter and 130 days of summer. As for the rest of the days, us “year rounders” call those spring and fall; or in the parlance of the northerners, “– that’s ridiculous, it’s all summer!” Well, not if you’re a Florida weather connoisseur.

tidal

Two Floridas
One's mild and the other is less mild

How much colder is …

Naples from Gainesville, Florida?

Comparison of high and low air temperatures in Gainesville and Naples, FL

Answer: In terms of daytime lows dropping below 50 degrees, Gainesville has already recorded 15 compared to zero in Naples. In fact, there’s only been six nights in Naples that even dropped below 60 degrees. That’s not including wind chill. Nor does it factor in that you are also wearing shorts.

Interestingly, Naples and Gainesville are in the same neighborhood when looking at daytime highs. It’s the nighttime lows that separate them. But that’s splitting hairs really. Everywhere in Florida has a mild winter compared to most of the rest of the United States.

Quandary of the double drop
When counting twice is okay

When does one rain drop …

Count as two?

Available on Apple Podcasts and Podbean

Maybe the better question to ask is when a rain drop only counts as half.  As good fortune would have it, the talking guitar from Firelight Radio podcast welcomes Bob from Go Hydrology into the house (and by “into the house” we me “at the campfire”) to discuss how hydrologists “deal with” rain drops that fall between the cracks of two seasons, with the million dollar question being this: Is it every appropriate (or scientifically accurate) to count a single rain drop twice. Find out the surprising answer in this illuminating episode of this “campfire-inspired and guitar-guaranteed” podcast.

dry season

Nothing lasts for ever
But November rains last a while

When the rain falls …

Is just as important as how much.

Holiday guide to the winter dry season

And there’s no better example than November rains. Last year it was Eta. This year it was the frontal storm that caught us by surprise. Or at least it caught me by surprise (as much as it was impossible to ignore as it slowly slogged through). Usually November is the gateway to the dry season: the start of the slow but steady descent into a state of less drenchedness (new word). In my book, November rains are as much wet season rains as they are dry season events for the reason that they have the effect of bumping the water table back up to a peak water state. November rains also have “staying power” because the regional evaporation machine is shutting down.

About the chart above. It’s plotted by replacing months into five major milestones (or inflection points) of winter dry season. They include (1) opening gate rains (Nov 1 – Nov 30), (2) cool season rains (Dec 1 – Feb 2), (3) green out rains (Feb 3 – Mar 22), (4) spring ebb rains (Mar 23 – May 15) and (5) start of wet season rains (May 16 – May 31).

Why those units and not months? Months are boring! And they also obscure the sub-seasons within the larger winter dry season whole. Dry season totals are not as important as when it falls. Last year’s Eta was the case in point. That November bounty (light blue bar) had staying power, but it didn’t save the swamp from descending into a spring drought. The taller green and yellow bars are the true drought-killing rains.