Category Archives: Tropical Cyclones

A large circulation sproducing heavy rainfall, very strong winds and storm surges

Tropical Cyclone Fantalia Indian Ocean April 12 2016

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A tropical storm is rapidly transitioning into a potentially strong tropical cyclone across a remote area of the Indian Ocean. While there have been a few tropical cyclones this season across the Indian Ocean, they have either been weak or have had short life spans and have had no impact on any land masses.

However, this storm appears to be different because it is headed towards the west according to models prepared by CIMSS. The latest model suggests the storm passing to the north of Mauritius but there would be concern if the storm continued to track further west as it could potentially impact the north east coast of Madagascar.

What makes this storm different from other Indian Ocean storms this season is that this one is transitioning rapidly from a tropical storm into a tropical cyclone over waters of 31C between latitudes 13.3 degrees south and 69.7 degrees east and 13.4 degrees south and 68.1 degrees east. Wind speeds have rapidly increased near the centre from 35 knots to 60 knots (65 km/h to 111 km/h) within a space of a few hours. Within 12 hours, this storm is expected to be above the threshold of a tropical cyclone with wind speeds of 75 knots (Approximately 139 km/h) close to the centre.

The late season storm could potentially reach Category 4 on the Saffir Simpson Scale with winds of 120 knots (Approximately 222 km/h) within 3 days.

The NASA Worldview satellite photo of the storm of the 11/4/16 shows its development and convection is visible. More up to date satellite photos shows a storm that is in an advanced state of transitioning into a strong storm.

Generally it has been a quiet season for such storms across the Indian Ocean. However this is one storm that does have potential to strike a landmass especially if it follows its current course.


1 - CIMSS (Satellite photos and forecast plots of Tropical Cyclone Fantalia) 12/4/2016.
2 - NASA Worldview (With overlays) 11/4/2016.

Tropical cyclone Zena gives Fiji a glancing blow April 6 2016

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The islands of Fiji are still recovering from the aftermath of Tropical Cyclone Winston which reached Category 5 on the Saffir Simpson Scale at peak intensity. This storm impacted Fiji around February 20 2016 with estimated sustained winds of 180 miles per hour (Approximately 289 km/h) and became the strongest storm to hit the islands.

During Wednesday 6 April 2016 and with the islands still in recovery phase from that storm, another tropical cyclone has given the Fiji Islands a glancing blow although in this case, the storm was much weaker. Unlike the first tropical cyclone, much of the activity passed just to the south and west of the main islands and was out to sea.

The storm was named Tropical Cyclone Zena.

The storm formed to the west north west of the Fiji Islands and tracked east south east. The storm had a short life span and it dissipated over waters south of the islands. At peak strength, the storm reached Category 2 on the Saffir Simpson Scale with peak wind gusts of approximately 170 km/h but its peak strength occurred mainly across open ocean.

The storm weakened as it approached the islands and passed to the south. Notwithstanding this, some damage occurred although the main impacts were flooding from passing storms and or rain bands.

With no eye visible and with the storm becoming disorganised, the storm weakened.

The Fiji islands had been affected by bursts of heavy rain and flooding from storms between Sunday and Wednesday and with Tropical Cyclone Zena impacting the area, a rain gauge at Nandi collected 474.5 mm of rain within 4 days (Source Accuweather rainfall data for Nandi 8/4/2016). The latest storm has added to the overall disaster affecting the islands.

On April 6, the NASA satellite image of the storm showed Zena a fully fledged storm west of Fiji and with a small visible eye.

As seen on the CIMSS plots of late Wednesday 6 April, tropical Cyclone Zena had reached a peak intensity of Category 2 but the storm was going into decline as it brushed the islands. The storm was becoming disorganised and at 7.30 pm 6/4/16, an eye was no longer visible on the satellite photos. The storm continued its decline and by the 7/4/2016, the storm was downgraded to a tropical storm and the storm soon broke apart.


1 - ACCUWEATHER - Rainfall data for Nandi Airport dated 3 to 6 April 2016.
2 - CIMSS (Images and plots of Tropical Cycloen Zena) dated 6/4/2016.
3 - NASA MODIS Worldview – Image of Tropical Cyclone Zena dated 6/4/2016.