Overall Green alert Tropical Cyclone for FLORENCE-18
in United States

Event Summary

Tropical Cyclone FLORENCE-18 can have a low humanitarian impact based on the maximum sustained wind speed,exposed population and vulnerability.

Updated: this report is based on advisory number 68: (06 Jul 2022 07:56).

From - To 31 Aug - 16 Sep
Exposed countries United States
Exposed population 1.5 million in Category 1 or higher
Maximum wind speed 241 km/h, Category 4
Maximum storm surge n.a.
Vulnerability Low (United States)

Weather forecast centres

Regional Specialized Meteorological Centres (RSMCs), Tropical Cyclone Warning Centres (TCWCs).

National Meteorological and Hydrological Services (NMHSs)

National Oceanic and Atmospheric Administration, National Weather Service of U.S.A.

Source: NOAA-GFS(Meteo); GDACS/NOAA (TcTrack )

Source: NOAA-GFS(Meteo); GDACS/NOAA (TcTrack )

Source: NOAA-GFS(Meteo); GDACS/NOAA (TcTrack )

Source: NOAA-GFS(Meteo); GDACS/NOAA (TcTrack )

Source: NOAA-GFS


Meteo Assessment +

Assessment and Weather Forecast over the Area of Interest

(13 Sep 2018 16:25)


  • PAST: TC FLORENCE moving west-northwest, strengthening on 30 August - 5 September (becoming Major Hurricane), weakening on 6-8 September (becoming again a Tropical Storm), regaining strength on 9-11 September, becoming again a Major Hurricane, and on 12 September has started slightly weakening again becoming a Category 2, while the size of the wind field has increased.
  • CURRENT: On 13 September at 09:00 UTC, its center was located approx. 325 km east-southeast of Wilmington (North Carolina, USA) and 405 km east-southeast of Myrtle Beach (South Carolina, USA), with maximum sustained winds of 175 km/h (Category 2 Hurricane).
  • FORECAST (as of 13 September, 09:00 UTC TC data): it is forecast to reach the coast of North Carolina or South Carolina (possible landfall area: near Wilmington, area of the border between the two states) on 14 September morning (UTC), as a Category 2 Hurricane (max. sustained winds of 160-170 km/h). After the landfall it could move slowly near or over the coast of South Carolina on 15 September, weakening into a Tropical Storm, and inland over eastern and western South Carolina on 16 September, weakening into a Tropical Depression.
  • UNCERTAINTY: It is forecast to reach North Carolina or South Carolina, probably the area of Wilmington, on 14 September morning (UTC), but there is still some uncertainty on the area of the landfall: some models provide a possible landfall in the southern areas of North Carolina, other in the northern areas of South Carolina, while most of the models agreed that it will be a strong Category 2 (close to Category 3) Hurricane when it reaches the coast, however small changes in strength might be expected before the center reaches the coast.