Home
Weather London
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Career
    Home / Weather News /

    Tropical storms merge in East Pacific

09:00
7 August 2024

Double Fujiwhara effect
Tropical storms merge in East Pacific

In the East Pacific, two sets of tropical systems are currently undergoing a fascinating and rare process; the Fujiwhara effect.

Multiple tropical systems are currently churning away in the East Pacific, with two interactions of the Fujiwhara effect expected to happen simultaneously to two pairs; Emilia and Fabio, alongside Carlotta and Daniel.

For Carlotta and Daniel, Daniel has since dissipated into a tropical depression, and Carlotta is weakening. Emilia and Fabio continue to mesh as they undergo Fujiwhara.

Where does the name Fujiwhara come from?

In the 1920s, Japanese meteorologist Sakuhei Fujiwhara was the first to describe the effect of the merging of two tropical cyclones.

What is the Fujiwhara effect?

When two cyclones get close enough to each other, their circulations can interact, allowing them to rotate around one common point, rather than two separate ones. Tropical cyclones can influence each other's circulation up to 1400 km apart.

While it is rare for this weather phenomenon to take place, it's even more significant that it is happening simultaneously to two pairs of cyclones at the same time.

While Carlotta and Daniel in the top left are weakening, Tropical Storms Emilia and Fabio can be seen very close together on the WeatherRadar too.

This is also the first time since August 1974 that four named storms have occurred simultaneously in the eastern North Pacific.

In the Fujiwhara effect, if one cyclone is stronger than the other, the smaller cyclone will orbit the larger one, eventually getting absorbed.

In more unusual cases, the effect can be amplified when the cyclones come together. From the two smaller cyclones, one larger and stronger cyclone may form.

In other instances, both can continue dancing around their mutual centre of rotation, before eventually separating on altered trajectories.

Meanwhile Debby, in the Atlanticread more
More on the topic
Equinox marks the start of autumn. Days start to get shorter. . . Wednesday, 23 September 2026
Split image showing Stonehenge in warm sunlight beside a tree-lined park glowing with vivid orange, red, and golden autumn leaves.
Wednesday, 23 September 2026

Days start to get shorter

Equinox marks the start of autumn
Severe weather rolls on in Europe. Heavy rain and hail. . . Thursday, 17 September 2026
Weather radar showing severe thunderstorms and frequent lightning over northern Italy.
Thursday, 17 September 2026

Heavy rain and hail

Severe weather rolls on in Europe
Hurricane POLO remains dangerous. Many storms in the Pacific. . . Thursday, 24 September 2026
Thursday, 24 September 2026

Many storms in the Pacific

Hurricane POLO remains dangerous
All weather news
This might also interest you
Historic Storm Éowyn arrives. On this day.... . . Saturday, 24 January 2026
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday, 24 January 2026

On this day...

Historic Storm Éowyn arrives
Long-term trends need a pinch of salt. 40 °C in July?. . . Tuesday, 30 June 2026
Temperature radar of 2022 heatwave where the all-time temperature record in the UK was set. Warning symbol overlain.
Tuesday, 30 June 2026

40 °C in July?

Long-term trends need a pinch of salt
Super Typhoon Bavi threatens Taiwan. Up to 1,000 mm of rain. . . Wednesday, 8 July 2026
The image shows an intense tropical cyclone over the western Pacific, east of Taiwan and the Philippines. The centre of the system is depicted as a light purple and white vortex with a clearly visible eye, surrounded by a ring of red and orange areas indicating the strongest wind speeds. A white arrow marks the typhoon’s predicted track towards the north-west, in the direction of Taiwan. To the west of the storm lie the Philippines, with the cities of Manila and Cebu; to the north of these lies Taiwan, with Taipei. Further west, the Chinese coast, including Hong Kong, and parts of Vietnam can be seen. The coloured wind map shows predominantly green areas outside the storm’s core, indicating significantly weaker winds. White streamlines illustrate the typhoon’s anti-clockwise circulation in the Northern Hemisphere. The highest wind speeds are concentrated around the eye of the cyclone.
Wednesday, 8 July 2026

Up to 1,000 mm of rain

Super Typhoon Bavi threatens Taiwan
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwittertikToklinkList