A storm system in the Atlantic has been upgraded and called Tropical Storm Philippe, becoming the 16th named storm of the hurricane season, as it inches toward the U.S.
Philippe was named on Saturday night as it increased in strength on its journey westward across the central Atlantic Ocean, as shown by National Oceanic and Atmospheric Administration (NOAA) models. As of 5 a.m. AST on Monday, it had maximum sustained wind speeds of 50 mph.
At 500 AM AST (0900 UTC), the center of Tropical Storm Philippe was located near latitude 17.4 North, longitude 43.9 West. Philippe is moving toward the west-northwest near 10 mph (17 km/h), the National Hurricane Center said in a Monday morning advisory.
“This general motion is expected for the next day or two, with a gradual turn to the northwest by mid-week. Maximum sustained winds remain near 50 mph (85 km/h) with higher gusts.
Little change in strength is forecast during the next few days. Tropical-storm-force winds extend outward up to 115 miles from the center.”
No coastal watches or warnings are in effect yet, as the storm is still a long way off the U.S. east coast.
Philippe comes days after Storm Ophelia, which caused widespread flooding as it made landfall in North Carolina, and only around a week after Hurricane Lee slammed into New England.
Storms are named alphabetically in order of occurrence every year: 2023’s storms were named Arlene, Bret, Cindy, Don, Emily, Franklin, Gert, Harold, Idalia, Jose, Katia, Lee, Margot, Nigel, Ophelia, Philippe, Rina, Sean, Tammy, Vince, and Whitney.
“Atlantic tropical cyclones can develop in a variety of ways. During August and September, the many systems have their origins as tropical waves that emerge off the coast of west Africa,” Nicholas S. Grondin, an assistant professor of meteorology and physical geography at the University of Tampa, told Newsweek.
“These waves are typically associated with troughs of low pressure and therefore cloud coverage and precipitation.
As the system moves west, assuming the conditions are ideal for tropical cyclone development, such as warm sea surface temperatures, low amounts of vertical wind shear, and instability, the trough can organize into a closed low-pressure system.
“If its sustained winds are less than 34 knots, or 39 mph, it is considered a tropical depression and assigned a number by the National Hurricane Center in Miami.
A storm gets a name from a pre-determined list if its winds reach tropical storm intensity, at least 34 knots or 39 mph.”
Once wind speeds reach 74 mph, a storm is reclassified as a hurricane. Category 1 hurricanes are between 74 and 95 mph, Category 2 between 96 and 110mph, Category 3 between 111 and 129mph, Category 4 between 130 mph and 156mph, while Category 5 hurricanes are 157mph and over.
“There are many environmental factors that control how a storm intensifies or weakens,” Haiyan Jiang, a professor of Earth and environment at Florida International University, told Newsweek.
“Among them, the most important ones are warm sea surface temperatures and ocean heat content, low vertical wind shear, and high atmospheric moisture.”
The NHC currently forecasts Philippe is moving northwest toward the U.S. East Coast, but this may change in the coming days as several other environmental factors come into play.
“The National Hurricane Center uses a variety of observations and suite of numerical weather prediction guidance to build tropical cyclone track, intensity, and storm surge forecasts,” Grondin said.
“Observations for storms far from land, such as Tropical Storm Phillippe, are frequently derived from satellites and aircraft measurements from the NOAA and Air Force Hurricane Hunters.
Closer to land, ground-based observations from surface stations and radar are useful tools for forecasters to use. Numerical weather prediction or computer models are used during all stages of forecasting storm tracks and intensity.
“One common tool is to use ensemble forecasts, which are multiple runs of the same computer model with slightly different initial conditions.
In general, National Hurricane Center forecasts are very good and continue to improve with time, especially track forecasts. For example, the National Hurricane Center 72-hour track forecast error has improved from over 200 nautical miles in 2000 to about 75 nautical miles in 2022.”
