Overall Green alert Tropical Cyclone for FOUR-21
in India
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Impact Single TC
Impact all weather systems in the area

Impact

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

Meteorological source GDACS
Exposed countries India
Exposed population No people in Category 1 or higher
Maximum wind speed 65 km/h
Maximum storm surge n.a.
Vulnerability High (India)
Landfall between
11 Nov 2021 06:00 - 11 Nov 2021 12:00

in India

GDACS Score

GDACS alert score for Tropical Cyclones is 0.5 (GREEN Alert), 1.5 (ORANGE Alert), 2.5 (RED Alert)
For more info on GDACS alert score click here.
  Wind Storm surge Rainfall GDACS score
Current 56 km/h n.a. n.a. 0.5
Overall 65 km/h 0.0 m n.a. 0.5

Maximum winds, storm surge, rainfall (Current: over the next 72 h, Overall: entire TC track) based on GDACS impact

Wind

56 km/h Current Max.

Up to 12.7 million people in Tropical Storm strength or higher (see SSHS)

Impact Timeline

Alert Date (UTC) Max Winds (km/h) Population in
Tropical Storm or higher
Population in
Cat 1. or higher
Countries
Green 1 11 Nov 2021 06:00 65 13.6 million No people India
Green 2 11 Nov 2021 12:00 56 12.7 million No people India

Bulletin Timeline

Alert Date (UTC) Category Max winds
(km/h)
Population in
Tropical Storm
Population in
Cat.1 or higher
Location (lat, lon) Countries
GREEN
1 11 Nov 2021 06:00 Tropical storm 65 no people no people 13, 80.9
GREEN
2 11 Nov 2021 12:00 Tropical depression 56 no people no people 13.1, 80 India
GREEN
2 12 Nov 2021 00:00 Tropical depression 46 no people no people 13.3, 79.2 India
GREEN
2 12 Nov 2021 12:00 Tropical depression 37 no people no people 13.5, 78.6 India
Actual track of the current bulletin
The alert for forecast greater than 3 days is limited to Orange level.
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Exposed population - AoIs

Exposed population in the potential affected countries, provinces and populated places

Countries

Country
India

Provinces

Region Province Country Population
Tamil Nadu India 58.9 million people
Andhra Pradesh India 70.2 million people

Populated places

Name Region Province Country City class Population
Avadi Tamil Nadu India City 240000 people
Poonamallee Tamil Nadu India City -
Ambattur Tamil Nadu India City 340000 people
Sriperumbudur Pallavaram Tamil Nadu India City -
Tambaram Tamil Nadu India City 130000 people
Chennai Tamil Nadu India Major city 4.3 million people
Takkolam Tamil Nadu India City -
Arkonam Tamil Nadu India City -
Kanchipuram Tamil Nadu India City 150000 people
Tirukkalukkunram Tamil Nadu India City -

Critical infrastructure

Airports, ports, nuclear plants and hydrodams at risk, if affected, are listed below.

Airports

Name IATA Code Elevation (m) Usage Runway type IFR Runway Length (ft)
Madras Chennai MAA 15 Civ. Paved Yes 12000
Tambaram 27 Mil. Paved No 5900
Arkonam 84 Mil. Paved Yes 11000

Ports

Name LOCODE Country
Madras INMAA India

Nuclear plants

Name Country Reactors
KALPAKKAM INDIA 2

Rainfall

Rainfall accumulation of the past 24h, as detected by the Global Precipitation Measurement mission of NASA. For more information, see https://www.nasa.gov/mission_pages/GPM/main/index.html.

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StormSurge

The JRC has developed an experimental global storm surge model. The calculations are published about 20 minutes after a new advisory is detected by GDACS. The calculations identify the populated places affected by storm surge up to three days in advance, using the forecasted track. When forecasts change, the associated storm surge changes too and alert levels may go up or down. All links, data, statistics and maps refer to the latest available calculation. If the calculation for the last advisory is not completed, the latest available calculation is shown.