Tropical Cyclone “Freddy” — The longest-lived and one-of-a-kind tropical cyclone in history

History is being made in the world of tropical cyclones, as Tropical Cyclone “Freddy” continues to make its mark. Born northwest of Australia on February 3, 2023, Freddy is now being called one-of-a-kind and the longest-lived cyclone ever documented.

• This storm is something never seen before and will undoubtedly go down in history as an exceptional tropical cyclone.
• Freddy traversed the entire 10 000 km (6 200 miles) wide Indian Ocean and became the first Category 5 storm of 2023, while also breaking the record for the most amount of cyclone energy ever recorded.
• The cyclone has made two landfalls to western Madagascar and Africa’s Mozambique, resulting in multiple fatalities. As of March 3, at least 14 people have been killed — 7 in Mozambique and 7 in Madagascar.
• Freddy could possibly make another landfall in Mozambique at the end of the week, but the forecast is still too uncertain to be able to precise timing and exposed areas.

Freddy originated from a weak area of low pressure that was embedded in a monsoon trough of low pressure stretching east-west across the Timor Sea between northern Australia and southern Indonesia. On February 6, 15 days before it would make its first landfall in Madagascar, both the Australian Bureau of Meteorology and the US Joint Typhoon Warning Center reported the formation of Tropical Cyclone “Freddy” about 676 km (420 miles) NW of the northwest coast of Australia.

In a rare but not unprecedented event, Freddy tracked across the entire Indian Ocean from east to west in almost a straight line with very little deviation in latitude. Along the way, Freddy underwent four separate rapid intensification cycles, the first southern hemisphere storm to do so. Freddy was also the first storm to reach the equivalent of Category 5 intensity on the Saffir-Simpson scale for 2023.

Most notably, Freddy has set the record for having the highest accumulated cyclone energy (ACE) of any southern hemisphere storm in history. ACE is an index used to measure the total amount of wind energy associated with a tropical cyclone over its lifetime.

Despite this, Freddy’s record-breaking streak is far from over. Forecast to crush the previous record set back in 1994 by Hurricane John’s 31-day streak across the Pacific, Freddy will retain tropical characteristics for at least another week.

This has resulted in a puzzling storm track that seems more like a pinball than a tropical cyclone, said meteorologist Rachel Modestino of The Weather Network.

Moving backward, Freddy is expected to double dip on Madagascar and Mozambique impacts. The storm aims to graze eastern Madagascar before heading back to Mozambique into the weekend, tallying its landfalls to at least three. This backtrack is abnormal as weather systems typically move from east to west in the Southern Hemisphere, but Freddy has moved the complete opposite for six days.

Upon its approach to eastern Madagascar, the storm is expected to strengthen into a Category 1 cyclone, grow vertically and interact with the prevailing westerlies. Freddy will travel northwest through the work week towards Mozambique, where its third landfall is forecast by Friday or Saturday, March 10 or 11.

At 06:00 am UTC on March 6, 2023, the center of Severe Tropical Storm “Freddy” was about 390 km (232 miles) SW of Antsirabe and 480 km (298 miles) SW of Fianaranstoa, Madagascar. The cyclone had a maximum 10-minute wind speed of approximately 92 km/h (57 mph) and was moving SW at a speed of 4 km/h (2.3 mph). Its minimum central pressure was 981 hPa, according to the La Reunion RSMC.

Freddy’s movement should slow down significantly today under the influence of contradictory steering flows, the center said.

A gradual turn towards the west and then the northwest should take place due to the strengthening of the subtropical ridge to the south and southwest of Freddy.

The trajectory should be established permanently towards the northwest from Tuesday, March 7. The dispersion between models remains strong for the rest of the week, concerning both the speed of movement and the direction of movement. However, according to the present forecast, Freddy could approach Mozambique at a mature stage at the end of the week.

In terms of intensity, Freddy is currently benefiting from rather favorable environmental conditions despite a small westerly shear stress which should cause its intensity to level off on Monday. Then, the intensification should remain slow at first because of the presence of mid shear, followed by the arrival in waters with less energetic potential.

From Thursday night to Friday, March 9 to 10, the improvement of the environment (the decrease of the mid shear, a good aloft divergence under the high troposphere ridge, and especially the arrival in a pocket of very warm waters), should allow the increase of the rate of intensification, to reach the stage of an intense tropical cyclone.

Impacts on inhabited lands during the next 72 hours

Madagascar

• Heavy rainfall in the next 24 to 48 hours over the coastal areas of South Menabe and Atsimo-Andrefana regions. Cumulative rainfall reaching 100 mm (4 inches), locally 200 mm (8 inches).
• Gale force winds over the Atsimo-Andrefana region, for the next 24h, mainly over the coastal areas, with the possibility of storm force winds in the immediate vicinity of the shore in the Toliara area on Monday morning. Gradually improving on Tuesday.
• Very rough sea from Cape Saint-Vincent to Cape Saint-Marie, gradually easing off from Monday night onwards.

Mozambique

• Freddy could possibly make landfall as a mature system at the end of the week, but the forecast is still too uncertain to be able to precise timing and exposed areas.

References:

¹ Freddy defies odds as the world’s longest-lived, invincible cyclone – The Weather Network – March 5, 2023

² Tropical Cyclone Freddy Brings Heavy Rain and Flooding to Madagascar and Mozambique – NASA/GPM – March 3, 2023

³ Severe Tropical Cyclone “Freddy” Advisory by RSMC La Reunion issued at 06:00 UTC on March 6, 2023

Featured image: Tropical Cyclone “Freddy” at 08:15 UTC on March 6, 2023. Credit: EUMETSAT/Meteosat-9, RAMMB/CIRA, The Watchers