Overall Green alert Tropical Cyclone for DIANMU-21
in Viet Nam, Laos

Event summary

Tropical Cyclone DIANMU-21 can have a low humanitarian impact based on the maximum sustained wind speed, exposed population and vulnerability.

GDACS ID TC 1000832
Name DIANMU-21
From - To 22 Sep - 23 Sep
Exposed countries Viet Nam, Laos
Exposed population No people in Category 1 or higher
Maximum wind speed 65 km/h Tropical storm
Maximum storm surge 0.3 m (23 Sep 11:00 UTC)
Vulnerability High (Vietnam)


For more info on GDACS alert score click here.
Wind Storm surge Rainfall GDACS score
GDACS 65 km/h 0.3 m n.a. 0.5
Single TC: maximum expected impact (wind, storm surge, rainfall)
HWRF 94 km/h 0.5 m 846 mm 0.5
GFS 119 km/h 0.4 m 432 mm 0.5
ECMWF 61 km/h 0.5 m 445 mm 0.5
Beta Version - All weather systems in the area: maximum expected impact (wind, storm surge, rainfall)
Maximum expected impact (wind, storm surge and rainfall) using different data sources.
Virtual OSOCC
Meteo assessment
Satellite products
Analytical products
Vietnam, Cambodia, Laos, Thailand - Tropical cyclone TWENTYONE (ECHO 23 Sep 2021)Thu, 23 Sep 2021 10:57

  • Tropical Cyclone TWENTYONE formed over the western South China Sea and is moving northwest towards central-eastern Vietnam.  On 23 September at 0.00 UTC, its centre was located approximately 215 km east of Quy Nhon City (Bình Dinh Province) with maximum sustained winds of 56 km/h (tropical depression).
  • TWENTYONE is forecast to continue northwest, and it will make landfall over southern Quang Ngai Province on the late morning of 23 September as a tropical storm. After that, it will cross central Vietnam and reach southern Laos and eastern Thailand weakening.
  • On 23-24 September, heavy rain and strong winds are forecast over the Provinces of central and eastern Vietnam and heavy rain is expected over southern Laos, eastern Thailand and northeastern Cambodia.
Detailed event map. European Union, 2021. Map produced by EC-JRC.
The boundaries and the names shown on this map do not imply official endorsement or acceptance by the European Union.

Updates on volcanic activity (Smithsonian)

Latest media headlines

Articles: 5 | About casualties: 0 | Last hour: 0

Umbrellas out, more monsoonal rain in the wake of ‘Dianmu’2021-09-26T04:31+0200.

With tropical depression Dianmu now well into the Bay of Bengal and continuing to weaken, another low depression sits over Thailand’s lower north, continuing to drop rain in most parts of the country. The region is also coming to the end of
More rain seen as deficit shrinks to two per cent2021-09-25T09:22+0200.

The Bay of Bengal has suddenly woken up to extreme weather activity with the India Meteorological Department (IMD) declaring a cyclone watch after an innocuous remnant from a tropical storm in the South China Sea drifted in and started to c
Le typhon Dianmu sème la désolation dans plusieurs provinces2021-09-24T18:15+0200.

Le typhon a balayé les provinces de Hoà Binh, Phu Tho, Quang Tri, Dà Nang, Quang Ngai, Binh Dinh, Binh Thuân et Kon Tum avant de s’affaiblir en dépression tropicale, provoquant d’importants dégâts, a-t-il indiqué. Dianmu a également inondé
Le typhon Dianmu sème la désolation dans plusieurs provinces2021-09-24T17:47+0200.

Hanoi (VNA) – Au moins deux pêcheurs sont portés disparus, 39 maisons et deux écoles ont été endommagées lors du passage du typhon Dianmu, le sixième de la saison au Vietnam, a fait savoir vendredi 24 septembre le Comité national de pilotag

Estimated casualties (PAGER)

USGS estimates the number of casualties for each earthquake for the Prompt Assessment of Global Earthquakes for Response (PAGER) product.
The graph shows the current fatalities estimate.

Exposed population

Data, images, links, services and documents

For this events, GDACS has links to information from the following sources: EC-JRC (38), (1), DesInventar (1), WMO (1), INFORM (2),