The first tropical depression in two months looks likely to form this week as an unusually calm Atlantic hurricane season shows signs of moving into high gear.
According to an update released at 2 p.m. Monday by the National Hurricane Center. A depression is the weakest form of tropical cyclone, a rotating low-pressure system classified as a depression, tropical storm, or hurricane depending on wind speed.
The system still lacks the well-defined center characteristic of tropical cyclones, according to the Hurricane Center. It is expected to move west, then west-northwest, at 5 –10 mph toward the islands of the northeastern Caribbean in the coming days, the hurricane center said. If it reaches tropical storm force, requiring wind speeds of at least 63 mph, it would be named Danielle.
The system is one of four low pressure areas being monitored for possible cyclone formation as the Atlantic settles into its traditional peak storm formation period. The most active part of the hurricane season is from mid-August to the end of October, with September 10 being the statistical peak of the season.
“It seems that September could really be the start of an active period in the tropics. A steady wave of energy rolling from Africa into the tropical Atlantic is expected to keep things active across the Atlantic basin for a while,” AccuWeather meteorologist Brandon Buckingham said.
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The increased activity is partly due to a decrease in atmospheric factors that had suppressed storm formation over the past month, according to a report from AccuWeather, the private forecasting service. These storm-suppressing factors include dry air and wind shear — the changes of wind direction with height that storms can tear apart.
“Conditions are changing in the tropical Atlantic,” according to the report by AccuWeather senior meteorologist Alex Sosnowski. “Over the past week, tropical disturbances, also known as tropical waves, moving westward from Africa have shown greater strength, and an area of brisk breezes, which forecasters cite as strong wind shear, has slowed development for much of the summer. prevented. staggered in part of the basin.
“Likewise, expanses of dry air above the heart of the basin are now littered with moisture pockets, which are a necessary ingredient for tropical systems to thrive.”
A second low-pressure trough could develop over the northwestern Caribbean this week, and some slow development is possible as the west-northwest moves across the northwestern Caribbean Sea and toward Mexico’s Yucatan Peninsula. As of Monday, the National Hurricane Center has given it a 10% chance of developing over the next five days.
A third outage about 600 miles east of Bermuda Monday has been given a 10% chance of developing in the five-day forecast. It is expected to disappear by the end of the week.
A fourth focus area is a tropical wave that is expected to hit the west coast of Africa on Tuesday and has been given a 30% chance of cyclone formation.
None of the systems pose a threat to Florida at this time.
This could well be the third August since 1961 that there has been no tropical storm in the Atlantic, according to AccuWeather.
There have been only three named storms so far this season — Alex, Bonnie, and Colin — and the last, Colin, dissipated on July 3, meaning this 57-day streak is the third longest in history. the Atlantic hurricane season has been without a named storm since 1995.
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The longest dry spell since 1995 has been 61 days, from June 18 to August 18 in 1999. However, that two-month period of inactivity was followed by a hectic conclusion to the hurricane season with five Category 4 storms (Bret, Cindy, Floyd, Gert and Lenny) and the soaking Category 2 Irene, who reached a rarity, with his eye going over Miami-Dade, Broward and Palm Beach counties in mid-October. There was also a 59-day streak during the 2007 season.
Forecasters say dry air, Saharan dust and wind shear are among the reasons why there have been no more storms this year.
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The last Atlantic hurricane was Sam, which became a hurricane on September 24 and maintained that status until October 5 when it carved a path between the United States and Bermuda.
Of the three storms mentioned so far this season, only Alex made his presence known in South Florida by dumping as much as a foot of rain in some areas.
The National Oceanic and Atmospheric Administration released its updated hurricane season forecasts earlier this month.
NOAA is forecasting 14 to 20 named storms and six to 10 hurricanes, with three to five being severe, meaning Category 3 or higher.
The hurricane season ends on November 30.