Mangkhut and Florence are the names of two of the most powerful storms on the planet.
Mangkhut has now been classified as a super typhoon by the Hong Kong Observatory.
The United Nations Global Disaster Alerting Coordination system‚ GDACS‚ warns Mangkhut "is expected to have a high humanitarian impact based on the storm strength and the affected population in the past and the forecasted path.
"Up to 43.3 million people may be affected by wind speeds of cyclone strength or above."
Florence is a Category 4 hurricane labelled by the US National Hurricane Centre as "an extremely dangerous major hurricane"‚ packing 225km/h winds. It's predicted to make landfall most likely in North Carolina on the the US East coast some time early on Friday morning South African time.
The Washington Post reports "large and dangerous‚ Hurricane Florence is drawing ever closer to the coast of the Carolinas‚ where it threatens to become the most intense storm to strike the region in at least 25 years‚ since Hugo. The Category 4 storm is likely to produce 'catastrophic' flooding in the eastern Carolinas as well as destructive winds."