It's going to be cold and getting even colder. It doesn't happen very often that temperatures in South Florida get near the 30-degree mark.
Over the last decade-plus, one can count on one hand how many days the mercury has hit 32 degrees. What many new arrivals are not aware of, and some old-timers may not remember, is freezes and frosts used to be much more common.
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Is the ice box door open?
National Weather Service forecasters have been warning all week of a bomb cyclone and nor'easter rolling through the northeastern U.S. Meteorologists on Wednesday were saying the "feels like" temperatures in Florida were expected to bottom out around:
18 degrees in Jacksonville
19 degrees in Tallahassee
22 degrees in Orlando
25 degrees in Tampa, Vero Beach
28 degrees in West Palm Beach
30 degrees in Naples.
Disclaimer: Actual temperatures may vary. Why? Mainly because weather forecasters often miss the mark. Also, these numbers are calculated by including the wind speeds, which will be in the 15-20 mph range.
Basically, after this cold front moves through, there will be an "Arctic door" left open that sweeps cold, dry air all the way from Northern Canada down to the Florida Keys and Bahamas. It's been a while since folks in the lower third of Florida felt these kind of temperatures.
But this next cold front could push low temperatures lower.
How low can we go?
I've lived through more than a half-century of Florida winters. I remember several days when I was stunned by how cold it got, and what the impacts were:
Jan. 19, 1977: The day it snowed in Miami. In Jensen Beach, where I grew up, Mom excitedly woke my brother and I up out of bed. It was cool being 10 years old and watching tiny snowflakes land on my tongue. The snow didn't exactly pile up, just pretty much melted when it hit the ground. I do remember being angry we didn't get a "snow day" off from school.
Jan. 28, 1986: Temperatures were in the low 20s at Cape Canaveral's Launch Pad 39B and icicles hung from rigging when Space Shuttle Challenger prepared for its liftoff. I was digging soil samples in an orange grove at the Indian River Research and Education Center in Fort Pierce about 100 miles south of the cape. It was still in the 30s when the shuttle's engines fired up. My work colleague saw the cloud high above the Florida horizon 73 seconds into the fateful flight. When I looked up, I knew immediately all seven astronauts were lost. Sad, cold day.
Christmas Eve 1987 & 1989: Hard freezes gripped Florida. Pipes in Tampa burst. Citrus trees in Central Florida were killed. Fortunately, the freezing temperatures didn't stay too low for too long.
Jan. 1-12, 2010: Temperatures never climbed over 50 degrees for much of Florida. It really changed the landscape by freezing back tropical species.
Set aside the whining on social media and the funny memes about cold temperatures in South Florida and let's take another look at it. Is there a silver lining with a dip below the freezing mark?
Believe it or not, good things can come from chilling down the warmest spot in the nation once a year or once every other year. Here are some ways it helps:
There are over 500 non-native invasive species of fish, invertebrates, reptiles, amphibians, birds and plants in Florida, according to the Florida Fish and Wildlife Conservation Commission. Many are from tropical climates and everything, including people, discover the Sunshine State is an ideal place to thrive and multiply.
Warm winters without freezes have enabled critters to swim and slither their way north along the peninsula. Iguanas, red-headed agama lizards, pythons, cichlids, armored catfish and Brazilian pepper trees are pushing north a little further every year, becoming entrenched and outcompeting native species.
A good sharp freeze can kill these species and stop their migration in its tracks.
Control spread of tropical natives
Not all things spreading north are invasive. When a tropical plant or fish moves into new territory, it can also become a problem for the new ecosystem it has decided to inhabit.
Snook have been moving into Cedar Key and are being caught in the Suwanee River. They are potentially displacing and feeding in nursery waters for redfish, black drum, sheepshead and grouper, which have had those waters to themselves.
Red mangrove trees are moving into the Halifax River and Tomoka Basin coastal estuaries, where spartina grass is the native vegetation along tidal waters. Mangroves can change the chemical composition of the soil and water around them, competing and pushing out other plants.
Neither snook nor mangroves are freeze-tolerant.
There is a delicate balance between cold weather and how it affects open-field agriculture in Florida. Cold temperatures for limited lengths of time can cause sugars to build up in some fruits and vegetables, making them taste sweeter after harvest.
Strawberries that ripen into season during the winter months and are largely grown in Hillsborough, Polk and Manatee counties will enjoy cold temperatures as long as there isn't a hard freeze below 32 degrees for longer than a couple of hours. It's similar with citrus where Central Florida growers still have thousands of acres of oranges grown for juice like Valencia, Hamlin and Ambersweet varieties.
Here are some ways it doesn't help:
Manatees & sea turtles
Cold stress can be deadly for manatees and sea turtles in coastal waters. Annually, about 50 manatees a year are deemed to die from exposure to cold temperatures. Sea turtles are also susceptible, and there is a multi-organizational coordinated effort to help prevent too many turtles from winding up dead from the cold.
Cold damage to produce
If it's below freezing for too long, fruit on citrus trees will get burned, and drop off. Strawberry plants can die. Tomatoes, bell peppers, beans, corn, lettuce and cabbage will all be wiped out by temperatures below freezing for over eight hours or so.
No one wants to see a repeat of 2010, when temperatures remained below 50 degrees for 10 days all the way to the Keys. The number of snook killed by cold weather was incalculable. It caused a moratorium on harvest for the next couple of years.
So let's enjoy the cold spell. Then, let's hope it warms up quickly again.
Ed Killer is TCPalm's outdoors writer. Sign up for his and other weekly newsletters at profile.tcpalm.com/newsletters/manage. Friend Ed on Facebook at Ed Killer, follow him on Twitter @tcpalmekiller or email him at email@example.com.
This article originally appeared on Treasure Coast Newspapers: Cold weather: Florida environment benefits, suffers from freezing temps