11:50 AM (Wednesday) | *How cold was it? It was so cold in Florida this morning that iguanas were falling out of trees.*
Paul Dorian
Overview
Arctic air has chilled much of the eastern US over the past couple of days and this morning saw temperatures drop into the 30’s as far south as southern Florida. In fact, it was so cold across Florida this morning that cold-shocked iguanas were actually falling out of trees. These cold-blooded lizards usually survive a “cold-shock” like this when temperatures fall into the 30’s or 40’s and “wake up” as temperatures rise. The Arctic air that plunged into southern Florida took a north-to-south path over the Florida Peninsula from the northern US preventing any potential modification from the nearby relatively warm waters of the Atlantic Ocean or Gulf of Mexico.
Actual air temperatures in central Florida this morning were near or slightly below freezing and bottomed out in the upper 30’s across southern Florida…wind chill values were even lower. Map courtesy Weather Bell Analytics, NOAA
Details
The temperature this morning fell to 39.9 degrees (F) in Miami, FL as some of the coldest air in at least a couple of years plunged all the way down into southern Florida (and Cuba). A look at a “backward trajectory” plot shows that the air parcels now in southern Florida actually had their origin a few days ago in the northern Plains and this cold air mass took a path that avoided any potential warming effects from the nearby relatively warm waters of the Atlantic Ocean or Gulf of Mexico.
The air over south Florida this morning had its origins a few days ago in the Northern Plains; courtesy NOAA
In addition to the unusual cold, winds have been quite strong across Florida resulting in even lower wind chill values compared to the actual air temperatures. The pressure gradient over Florida has been quite strong between low pressure drifting over the Bahamas and strong high pressure now centered over the Mid-Atlantic region. This pattern has resulted in rather persistent and strong winds from the north-to-northwest across much of Florida gusting past 25 mph making it feel even colder than the actual air temperature.
According to preliminary reports, this is not a widespread record-breaking cold event; however, at least one low temperature record was broken earlier today in the Virginia Key section of Miami which bottomed out at 42.1 degrees (F). This record low smashed the previous record low for the date by 7.5 degrees and was the 11th coldest temperature observed at this location which is a barrier island in Miami.
With respect to the iguanas, these lizards are cold-blooded and slow down or become immobile when temperatures drop into the 40’s. They actually become lethargic at about 50 degrees and when temperatures reach around 40 degrees their blood doesn’t move around as quickly and they’ll often stiffen up as a result and fall out of trees in which they frequent. Once the temperatures rise, the iguanas will usually “wake up” and be on their merry way, but if the cold snap is for an extended period of time, they may not survive.
Iguanas aren’t dangerous or aggressive to humans, but they damage seawalls, sidewalks, landscape foliage and can dig lengthy tunnels. The males can grow to at least 5 feet long and weigh nearly 20 pounds. Female iguanas can lay nearly 80 eggs a year, and South Florida’s warm climate is perfect for the prehistoric-looking animals. Iguanas are native to Central America, tropical parts of South America and some Caribbean islands. Iguanas are allowed to be kept as pets in Florida, but are not protected by any law except anti-cruelty to animals. They’ve been in South Florida since the 1960’s, but their numbers have increased dramatically in recent years.
A two-week cold snap with temperatures below 40 degrees in 2010 actually killed off many iguanas, along with Burmese pythons and other invasive pests that thrive in South Florida’s subtropical climate. This week's cold snap, however, should be short-lived as temperatures are forecast to rebound into the mid-70’s for highs in Miami by Thursday afternoon.
One final note, there are signs that this may not be the only unusual cold air outbreak for the state of Florida this winter season. Some possibilities exist for a repeat performance (or two) between late January and the middle of February.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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