2020 Hurricane Season Brings Uncertainty, Sleepless Nights

MIAMI, FL — With Monday ushering in the official start of the 2020 Atlantic hurricane season there are a few things that are sure to give Michael Brennan sleepless nights between now and Nov. 30 as branch chief of the Hurricane Specialist Unit at the National Hurricane Center on the campus of Florida International University.

"Having a storm rapidly strengthen right before landfall beyond what we’ve been expecting — or beyond what emergency managers have prepared for, and ordered evacuations for — is sort of the worst case scenario," Brennan confided in an interview with Patch to mark the start of what is expected to be an above-average hurricane season.

"You’re always concerned about a hurricane hitting a major metropolitan area, where, even if you have a very high number of people get out — say you have 90 or 95 percent of the people who need to leave, leave — if you are in an area with a very high population, you can still have thousands or tens of thousands of people left behind in a very vulnerable position in a storm surge evacuation zone," said Brennan, who holds a PhD in atmospheric sciences. See also 2020 Atlantic Hurricane Season List Of Names and NOAA Predicts Strong 2020 Hurricane Season Amid Coronavirus

While there is a tendency for news reports to focus on the category of the storm — starting at Category 1 with minimum sustained winds of 74 mph and topping out at Category 5 with sustained winds of at least 157 mph or higher — most of the evacuation decisions are based on storm surge, which poses the greatest threat to people.

"There’s a lot of noise out there now in social media and elsewhere that can be very distracting from the actual hazards of the storm," Brennan said. "So, trying to craft a well honed message that can cut through that, and really help people focus on the dangers that the storm poses is probably one of the biggest challenges we have."

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This year the National Oceanic and Atmospheric Administration is forecasting with 70 percent certainty there will be 13 to 19 named storms with sustained winds of at least 39 mph (tropical storms). Of those, six to 10 are expected to become hurricanes with sustained winds of at least Category 1 strength, including three to six major hurricanes of Category 3 and higher with sustained winds of at least 111 mph.

"We really don’t have any ability to predict where individual storms are going to go until they actually form," Brennan shared. "We don’t know if we’re going to have a busy season where we have a lot of storms affecting land. Sometimes, we have a quiet season but all the storms are near land and it feels like a busy season to people. Other years, we have a lot of storms and they stay away from land and people don’t perceive it that way."

This year, the usual uncertainty that accompanies hurricane season is exacerbated amid concerns over the new coronavirus, which adds another element into hurricane planning.

"You really have to pay attention to what your local government and emergency management officials are saying about how evacuations will unfold in your community this year. There may be different locations. There may be different things you need to bring with you," Brennan said. "We’ve seen certainly discussions about how evacuations might be called for earlier in some locations. There may be requirements for you bringing masks or other PPE to a shelter."

This years's seasonal outlook forecast is also consistent with predictions by Colorado State University meteorologists, who said the 2020 hurricane season could bring 16 named storms — four more than the average.

Most people who watch the weather forecast on television have probably heard their local meteorologists refer to European and GFS forecast models. The European model is put out by the UK-based European Center for Immediate Range Weather forecasting while the National Weather Service is responsible for the GFS model.

"The model performance for each is not necessarily consistent from one storm or one year to another," Brennan acknowledged. "Some models do really well in some situations and not in others and the models are always changing."

Many people might be surprised to learn the National Hurricane Center takes a blended approach.

"We don’t really try to pick an individual model and go with that forecast," Brennan said. "We blend the best four or five models for forecasting a hurricane track together. By doing that, we’re able to make a forecast typically that’s better than what you would get from any one individual model."

Even so, sometimes forecasts can vary based on the people who interpret the data.

"It’s all science based but there’s often times when you have conflicting pieces of data — where you are forced to make a decision in the absence of concrete data or information about where the system is, or how strong it is," he said. "Thankfully, for storms that are affecting the United States, we typically have aircraft flying in them which gives us a lot more data, a lot more confidence in sort of the details of what the storm is doing now."

This year forecasters at the National Hurricane Center have gotten an upgrade in their computing power as well as a little extra help from the heavens.

Since May 26, a new fleet of six small satellites has been feeding more than 4,000 vertical sets of measurements of atmospheric temperature and humidity in the tropics and subtropics into daily forecast models. Measuring the moisture in and around tropical cyclones is considered key to forecasting hurricanes and other disturbances.

"If you have more resources, it allows you to run models in finer levels of detail," Brennan explained. "It allows you to run models with more sophisticated representations of the processes of the atmosphere and the ocean that are important to how a storm is going to evolve. So, as you acquire more computing resources it allows you to do more with numerical modeling and work to continually improve those models."

Two of the most important factors in determining whether a particular hurricane season is average or above average depend on the meteorological conditions known as El Nino and La Nina in the eastern Pacific.

"Right now we’re sort of in between El Nino and La Nina, but we may be trending toward a La Nina pattern by later in the season, which would sort of make the background conditions even more favorable for storms to form in the Atlantic," Brennan said. "If we’re going to realize sort of the high end of those ranges of the named storms — the hurricanes and major hurricanes — we’ll probably be trending toward a La Nina type pattern by the peak of the season."

We've already seen the first two named storms of the season — Arthur and Bertha. On Monday, forecasters were monitoring a disturbance over the Yucatan peninsula of Mexico that could move north into the Gulf of Mexico.

"It’s a reminder that hurricane season is here and we often can and do have systems that form in the Gulf of Mexico and can at times impact land areas within just a few days," Brennan said. "It’s a good reminder that we’re not going to always have a week or more to watch a system move all the way across the Atlantic and threaten land areas of the U.S."

Brennan advises people to listen to their local officials and heed warnings from the National Hurricane Center as threats arise.

"People just need to keep in mind that it's really the water that is the most dangerous aspect of most tropical storms and hurricanes," Brennan emphasized. "Increasingly, we’ve seen in this country rainfall flooding has taken a larger and larger percentage of lives, especially people driving automobiles into flooded areas, or around barricades into flooded roads."