Weird summer weather these days includes something called a …
There’s yet another weather phenomenon beachgoers have to watch for in on the Gulf of Mexico. It’s the meteotsunami, a water wave seen June 21 on Clearwater Beach.
The storm is another bit of off-kilter weather that seems to be hitting the Gulf of Mexico this summer, where oddities include record heat, scarce afternoon rains, bathtub-hot beach water and an upgraded hurricane forecast. All of this is not even a year after Hurricane Ian.
According to Stephen Mullens, assistant instructional professor of meteorology at the University of Florida, of all the summer weather, the meteotsunami weather phenomenon is rare and was caused by a “squall line” summer storm.
“This squall line in particular had a bow echo look,” said Mullens, in describing the phenomenon. The squall line looks on a map like a bow from a bow and arrow. But they are uncommon in the summer in Florida.
In general, a squall line is associated with very high winds. The strength of the winds is what caused the squall line to look like a bow on the map. A squall line with strong winds can cause tornadoes and hail, though most often in winter.
The recent meteotsunami occurred on Clearwater Beach on June 21, but they are known to hit up and down the Gulf of Mexico coast. A recent wave hit Sanibel Island’s Castaways Beach and Bay Cottages on Dec. 20, 2018. At the time, the temperature dropped 10 degrees, and the wave came up five feet.
Another meteotsunami hit Naples on Jan. 17, 2016. One of the worst reported on record was in 1910 on Lake Michigan. In that incident, ten reportedly good swimmers on Grand Haven beach were washed out to sea. The deadly wave came while 45,000 people on the beach watched in horror.
While the name and the use of the word tsunami makes the phenomenon sound extremely dangerous, these rare occurrences are defined as “large waves caused by storms,” according to the National Ocean Service of the National Oceanic and Atmospheric Administration. The meteotsunami is not a storm surge, however.
Breezy Summer Storms
The good news is that unlike a traditional tsunami caused by an earthquake, the “meteo” version can only be caused by actual storms, which are well predicted and can be seen on radar, or if you happen to be lollygagging on the beach.
Most of the storms seen in Florida in the summer, other than hurricanes, are Florida’s eagerly anticipated afternoon “sea breeze” storms that bring rain and evening cooling. These storms are not the cause of meteotsunamis. “They can’t happen from our normal summertime storms,” said Mullens.
“They cause some lightning and rain,” Mullens continued. “That’s about all they are really going to do. Storms need to be over a hundred miles across to push enough water to create a meteotsunami.”
During the summer season, the extreme heat on land collides with cooler water along our beach shores, traditionally bringing breezes and a quick rain. The effect is pronounced on any shoreline, but it is particularly unique to Florida, which is surrounded by water, yet has a dry, flat interior.
This year, however, the sea breeze storms have been scarcer. Gasparilla Island, Cape Haze and neighboring coastal communities have missed some of regular summer afternoon rains found inland. Historically, rains have begun in June. The 1990 weather classic Florida Weather by the Prof. Dr. Morton D. Winsberg of Florida State reported that each July, there are typically 10 to12 days of rain of at least a tenth of an inch in our area.
Storms in mid-June brought some relief and hope, but the coast has gone back to dryness, confirmed with rain data Mullens pulled from the Community Collaborative Rain, Hail and Snow Network, or CoCoRaHS. The crowdsourcing weather site shows data from thousands of volunteer weather watchers worldwide.
While there are no CoCoRaHS watchers on Boca Grande, there are dozens in Charlotte and Lee counties. For instance in the dry period from May 28 to June 10, data Mullens pulled from the site showed that there was not even an inch of rain in the Cape Haze area, but respondents reported from two to seven inches inland from North Port down to Cape Coral. From June 25 to July 6, there was less than an inch of coastal rain, but two to five inches inland.
Hot Water Temps
Worldwide, this June was the hottest June on record, according to the European Center for Medium-Range Weather Forecasts.
WFLA Chief Meteorolgist Jeff Berardelli tweeted in a thread that this was the “first time since I can remember in Tampa that we’ve had mainly westerly flow since late May, so like a month plus. Very few, if any, days dominated by SE/Trade wind.”
The water has been hot, as well.
A hot Gulf is not a new thing, even if it is certainly warmer than in previous years.
Even in Jules Verne’s 1870 science-fiction novel Twenty Thousand Leagues Under the Sea, narrator Pierre Aronnax talked about the warmth of the Gulf to Capt. Nemo. “ “That comes,” I told him, “from the water temperature of the Gulf Stream, which, as it leaves the Gulf of Mexico, is barely different from your blood temperature.”
While the water wasn’t quite 98.6 degrees, this week NOAA has reported Fort Myers water temps over 90 degrees.
These high temperatures of the Gulf of Mexico create the possibility for more hurricanes, but do not cause them.
“It’s not like the water was cold last year,” said Mullen, who reminded us that Everglades National Park water temps have approached 95 degrees this week.
For the hurricane season, which began June 1 and ends Nov. 30, current predictions were just moved upward by forecasters from Colorado State University, from 15 named storms predicted, to now 18. The forecast came with the caveat that uncertainty with the outlook was larger than usual.
“We can have a lot or a little,” said Mullens. In normal years, a Pacific El Niño is expected to cause fewer hurricanes, but this is a unique year. The hot Atlantic ocean is expected to cause more hurricanes. These don’t occur at the same time very often.
Among the population, there is always the unfounded hunch that because we had such a bad one last year, we are somehow exempt this time.
“The last year doesn’t affect the number of storms this year,” said Mullens.
