Virginia Quay is located just southeast of downtown Miami, on the doorstep of Florida and firmly within the strike zone of Hurricane Alley. Hurricane Alley is a warm zone ideal for hurricane formation that extends eastward across the Atlantic to Africa. Since the mid-19th century, more than 250 hurricanes have struck the continental United States, often with devastating consequences. Virginia Keys is also home to the National Oceanic and Atmospheric Administration’s Marine Meteorological Laboratory, where scientists work hard to constantly improve hurricane predictions. One of their most pernicious problems over the years is the difficulty of predicting when relatively small-looking storms will suddenly explode in strength and intensity. This phenomenon often surprises victims.
“We go to bed and the storm looks very violent on the satellite, and then we wake up the next morning and all of a sudden it’s getting stronger,” says Rosen University of Miami, also at Virginia Keys. Sharanya Majumudar, a hurricane researcher at the Steele School of Ocean, Atmosphere and Earth Sciences, said: “So we all ask, ‘Why did that happen?'”
The answer isn’t always clear, making it very difficult to predict a rapid intensification—defined by meteorologists as a hurricane’s maximum sustained wind speed spike of 35 miles per hour or more over a 24-hour period. However, accurate prediction of hurricane intensity is especially important because storm power increases exponentially with wind speed. When the wind speed doubles, the force on houses, power lines and other infrastructure quadruples. And as the climate warms, research suggests that more storms will intensify rapidly and at a faster rate.
Now that the new model, which took more than three years to develop, can provide early warnings of rapid intensification, NOAA scientists believe it will be able to more accurately predict impacts such as rainfall and storm surges. I’m here. Forecasters at the National Hurricane Center will begin using a new model this summer called the Hurricane Analysis and Forecasting System (HAFS). “In my opinion, we cannot improve forecasts fast enough to overcome four times the number of people living in this region. [coastal] says Frank Marks, director of hurricane research at the NOAA Atlantic Ocean Meteorological Institute.
One of the most alarming examples of rapidly intensifying storms was 2004’s Hurricane Charlie. Warnings were issued along Florida’s southwest coast well before the storm. About 24 hours before Charlie’s onslaught, it was forecast to intensify into a Category 2 to Category 3 storm. However, within just five hours of August 13, and less than six hours before landfall, the storm’s winds rose to 34 mph. By the time it hit Captiva Island, Florida, winds were 150 mph, just a few miles short of Category 5. It was the strongest storm to hit Florida since Category 5 Hurricane Andrew devastated Homestead in 1992. Charlie caused more than $15 billion in property damage, but only its small size and relatively fast forward speed prevented it from doing more damage. “Whenever a storm intensifies near land, but especially when the intensity is ill-predicted or not anticipated at all, the public is at far greater risk because of ill-preparedness. “It will be,” says Kristen Corbociello, a hurricane researcher and modeling expert at the university. Albany. “Therefore, the potential loss of life and damage to infrastructure would increase significantly.”
Certain key factors determine whether tropical cyclones (a broad term for tropical cyclones or hurricanes) form, how strong they are, and how quickly they grow. The engine that drives all tropical cyclones is convection. A huge amount of moist rising air creates a vacuum at the surface, sucking in the surrounding air as a spiraling wind. This convection is facilitated by warm ocean waters and high humidity, but dry air cools the storm through evaporation and impedes convection. Calm skies must also be a priority, as crossing winds, called shear, can puncture the eddies of hurricanes that have just formed. So having information about the environmental conditions of a storm is “very important, but not enough to say with certainty whether a rapid intensification will occur,” says NOAA research meteorologist John Kaplan. .
The internal physics of storms are also important to this process. For example, if a thunderstorm near the center is very symmetrical, the pressure will “drop like a rock,” and the lower the pressure in the center, the higher the wind swirling around the center, says Marks. says Mr. Corbocielo, who was not involved in the HAFS study, explains that such symmetry traps the heat emitted by developing clouds in the storm’s eye wall. This will further promote convection. The hurricane cylindrical eye wall should also not be tilted and should remain straight up and down. When tilted, the heating spreads over a wider area and the pressure drop is less dramatic, Corbociello said.
Due to the limitations of modeling these internal processes, as of the early 2010s, only 12% of rapidly intensifying tropical cyclones were predicted. Over the next decade, scientists used additional funding from Congress to send drones and manned “Hurricane Hunter” aircraft to gather more data on wind speed, humidity and temperature directly from the storm’s eye wall. I was able to. This more detailed data will allow computer models to more accurately describe and predict storm behavior, helping meteorologists improve their forecasts. According to Marc DeMaria, a former NOAA hurricane forecaster and now a senior researcher at Colorado State University, the current model correctly predicts rapid intensification 32 percent of the time. “The inherent predictability of rapid intensification may be low,” says Demaria. This is because small, unobservable changes in the way eddies develop can have a large impact on the timing of the phenomenon.
HAFS-equipped forecasters hope to improve their records by catching at least half of the rapidly intensifying storms. HAFS provides a more detailed representation of the storm’s internal dynamics and more data that can be manipulated. It can also ingest data from them faster than the current model, allowing forecasts to be updated more frequently. Another key innovation involved ‘nesting’ his HAFS model within a larger Global Forecast System (GFS) model, which has higher resolution than previous hurricane models. Scan the ocean like a magnifying glass. This nesting allows forecasters to tackle another major challenge: calculating how atmospheric features such as cold fronts and high pressure zones affect the interior physics of hurricanes. “There is a cold front somewhere in another region of the globe that can affect the path and strength of a hurricane,” said Sundararaman “Gopal” Gopalakrishna, NOAA Senior Meteorologist and HAFS Principal Designer. says Ng.
HAFS will officially go live on July 1st. That means forecasters at the National Hurricane Center may use his HAFS, along with other models, as a guide when making forecasts this summer. Gopalakrishnan said he is excited to see how HAFS performs and expects HAFS to perform much better than the model it replaces. “We’re going to look at it with a hawk’s eye,” says Marks.
