South Africa: First Update Regarding Triopical Storm 'Eloise'

Beira, in Sofala Province,Central Mozambique during a Category 4 Cyclone named Idai (file photo).
20 January 2021
South African Weather Service

The rain which Severe Tropical Storm "Chalane" brought to southern Africa during the Christmas and New Year period last year is still fresh in the minds of the general public. Now, a fresh tropical system named "Eloise" has developed and is currently positioned off the north-eastern quadrant of Madagascar. At the current time, "Eloise" is classified to be a Moderate Tropical Storm, with a central pressure slightly less than 1000 hPa (hectopascal) but nevertheless set to intensify in the coming days. "Eloise" is positioned at 14.2 degrees South and 56.7 degrees East, moving briskly at 14 knots (about 26km/h) in a west-south-westerly direction.

The most likely track "Eloise" will follow should take it close to the coast of Madagascar tomorrow, as it intensifies further to a Severe Tropical Storm, with sustained winds likely to exceed 100km/h. Hence as "Eloise" makes landfall on this coastline in the latter part of tomorrow, it is likely to cause considerable wind-related damage, as well as delivering torrential rain. Given the steep geographic terrain of eastern Madagascar, flooding and washaways are also a distinct possibility. Moreover, along the coast there will also be a risk of storm surge, especially on the southernmost leading quadrant of the storm system.

The good news is that, as "Eloise" moves across the landmass of northern Madagascar, it will be exposed to increased friction, as the winds interact with the rough land surface. Moreover, "Eloise" will be deprived of the latent heat energy which it would normally receive from a warm, tropical ocean. We can therefore confidently predict that "Eloise" will weaken significantly during this particular period. However, later in the lifecycle of "Eloise" it will without doubt begin to redevelop as it drifts back into the open ocean region of the Mozambique Channel this
Friday. It will be at this stage that "Eloise" will require close monitoring, as it has the potential to make landfall along the southern Mozambican coastline, between Beira and Vilanculos during the coming weekend.

Alternatively, "Eloise" could gradually begin to move on a more southerly parabolic path (often termed a "polewards-accelerating" trajectory), which could potentially take it further down the Mozambican coastline and (possibly) into the northeastern lowveld region of South Africa. At the current time, the speculative possibility of "Eloise" directly affecting South Africa is only one of a multitude of possible outcomes, given the long lead-time, and should be considered to be a "low probability / high uncertainty" worst-case scenario.

In light of the above, the South African Weather Service (SAWS) wish to strongly emphasise that, as with any and every tropical system worldwide, there is much uncertainty surrounding the prediction of future development and movement of "Eloise". Tropical systems are notoriously fickle and unpredictable, often exhibiting very erratic movement. Modern satellite remote sensing, as well as advanced ensemble numeric modelling techniques, do, however, mitigate much of this uncertainty, at least in the short-term. Notwithstanding the above, the general public can rest assured that SAWS will continue to be vigilant and to closely monitor the future evolution of "Eloise". Further timely updates in relation to "Eloise" will be issued as and when necessary.

Don't Miss

AllAfrica publishes around 800 reports a day from more than 130 news organizations and over 500 other institutions and individuals, representing a diversity of positions on every topic. We publish news and views ranging from vigorous opponents of governments to government publications and spokespersons. Publishers named above each report are responsible for their own content, which AllAfrica does not have the legal right to edit or correct.

Articles and commentaries that identify as the publisher are produced or commissioned by AllAfrica. To address comments or complaints, please Contact us.