SIO: Issa - Post-Tropical

[Subtrop]

Moreover, a subtropical cyclogenesis is underway just off the east of South Africa, which has gale force winds within a quite symmetrical circulation, so much so that the RSMC starts monitoring Subtropical Depression "ISSA" (system number 11-20212022) this Tuesday at 12UTC.

Subtropical Depression ISSA

Position at 12UTC : 30.8oS / 31.6oE

Movement : South at 9 kt

Maximum winds averaged over 10min : 40 kt

Minimum central pressure : 997 hPa
For more information, please refer to warnings WTIO24 and WTIO30 issued this Tuesday at 12UTC (first warnings for this system).

[Nancy Smar]

92S INVEST 220412 1200 31.0S 31.0E SHEM 45 0

[Hurricanehink]

Floods in South Africa, which appear related to Issa, killed at least 45 people in the eastern portion of the country.

So Issa isn't that unusual for forming near South Africa. There were subtropical storms in the same area in April 2000, April 2001, April 2003, and April 2007. There were likely more earlier than that, but Meteo-France didn't classify storms south of 30º until 2003. For comparison, northern Florida is around 30ºN. Although the basins are different in terms of the water circulations and landmasses, the storms aren't that different, so I think it's good that the MFR is classifying storms like this. Some storms have affected South Africa after hitting Mozambique, but it's rare (according to the best track) for storms to form so close to the coast.

[doomhaMwx]

What an interesting little system! This is classified as a subtropical storm by MFR but it certainly appears to have transitioned to a tropical system overnight (JTWC has also issued a TCFA).

[Hurricanehink]

Damn, a tragedy is unfolding in South Africa. With a death toll of 259, Issa is apparently now the deadliest natural disaster on record. https://amp.theguardian.com/world/2022/apr/13/south-africa-floods-deadliest-storm-on-record-kills-over-250-people

[Hurricanehink]

Damn, a tragedy is unfolding in South Africa. With a death toll of 259, Issa is now one the country’s deadliest natural disasters. The deadliest were floods in 1987 that killed 506 people. https://amp.theguardian.com/world/2022/apr/13/south-africa-floods-deadliest-storm-on-record-kills-over-250-people
https://lwes.co.za/2021/03/25/greatest-south-african-natural-disasters/