Tropical Storm Philippe brings heavy rain and flooding to Caribbean Islands

Tropical Storm Philippe, a weather system that was swirling in the Atlantic Ocean, started causing flooding and dropped heavy rain across the northern Windward Islands and the Leeward Islands early Tuesday, forecasters said.

Here are three things to know about Tropical Storm Philippe:

• The center of Philippe was forecast to continue passing near the northern Leeward Islands on Tuesday morning, producing heavy rain. While the storm will move north later in the day, the strongest winds and heaviest rains will likely happen in the islands to the south of the center, forecasters said.
• Tropical storm warnings were in effect for Anguilla and Antigua and Barbuda, the National Hurricane Center said. Up to 8 inches of rain was predicted in Barbuda by early Wednesday, forecasters said, warning that the rain may cause isolated flash floods. The rest of the Leeward Islands and northern Windward Islands may see up to 5 inches of rain.
• Philippe could intensify more significantly around the middle of the week.

We’re over halfway through the Atlantic hurricane season.

The Atlantic hurricane season started June 1, and runs through Nov. 30.

In late May, the National Oceanic and Atmospheric Administration predicted that there would be 12 to 17 named storms this year, a “near-normal” amount. On Aug. 10, NOAA officials revised their estimate upward, to 14 to 21 named storms.

There were 14 named storms last year, after two extremely busy Atlantic hurricane seasons in which forecasters ran out of names and had to resort to backup lists. (A record 30 named storms took place in 2020.)

This year features an El Niño pattern, which started in June. The intermittent climate phenomenon can have wide-ranging effects on weather around the world, and it typically impedes the number of Atlantic hurricanes.

In the Atlantic, El Niño increases the amount of wind shear, or the change in wind speed and direction from the ocean or land surface into the atmosphere. Hurricanes need a calm environment to form, and the instability caused by increased wind shear makes those conditions less likely.

At the same time, this year’s higher sea surface temperatures pose a number of threats, including the ability to supercharge storms. That unusual confluence of factors has made it more difficult to predict storms.

There is consensus among scientists that hurricanes are becoming more powerful because of climate change. Although there might not be more named storms overall, the likelihood of major hurricanes is increasing.

Climate change is also affecting the amount of rain that storms can produce.

In a warming world, the air can hold more moisture, which means a named storm can hold and produce more rainfall, like Hurricane Harvey did in Texas in 2017, when some areas received more than 40 inches of rain in less than 48 hours.

Researchers have also found that over the past few decades storms have slowed down, sitting over areas for longer.

When a storm slows down over water, it can absorb more moisture. When the storm slows over land, it can release more rain over a single location. In 2019, for example, Hurricane Dorian slowed to a crawl over the northwestern Bahamas, resulting in a total rainfall of 22.84 inches in Hope Town during the storm.

This article originally appeared in The New York Times.