The Mauritius Meteorological Services-Regulations (Warning)

THE MAURITIUS METEOROLOGICAL SERVICES ACT 2019
Regulations made by the Minister under sections 5 and 11 of the Mauritius Meteorological Services Act 2019
1. These regulations may be cited as the Mauritius Meteorological Services (Warnings) Regulations 2023.
2. In these regulations –
“Act” means the Mauritius Meteorological Services Act 2019;
“gust” means the instantaneous peak value of surface wind
speed recorded or expected;
“heavy rain” means rainfall resulting in a minimum of 25 millimetres of rain in 30 minutes;
“heavy rain watch” means a communique issued not less than 12 hours, nor more than 24 hours, before heavy rain;
“intense tropical cyclone” means a tropical low system in which the average wind speed is estimated to be not less than 166, nor more than 212, kilometres per hour;“moderate tropical storm” means a tropical low system in which the average wind speed is estimated to be not less than 63, nor more than 88, kilometres per hour;

“National Crisis Committee” has the same meaning as in the National Disaster Risk Reduction and Management Act;

“sea state” means the general condition of the sea, which may be –
(a) calm, with wave height of 0 to 0.1 metre;
(b) smooth, with wave height of 0.1 to 1.25 metres;
(c) moderate, with wave height of 1.25 to 2.5 metres;
(d) rough, with wave height of 2.5 to 4.0 metres;
(e) very rough, with wave height of 4.0 to 6.0 metres;
(f) high, with wave height of 6.0 to 9.0 metres;
(g) very high, with wave height of 9.0 to 14.0 metres; or
(h) phenomenal, with wave height of above 14 metres;

“severe tropical storm” means a tropical low system in which the average wind seed is estimated to be not less than 89, nor more than 117, kilometres per hour;
“storm surge” means the difference between the actual water level caused by a meteorological disturbance and the water level which would have been attained in the absence of the meteorological disturbance;
“strong wind” means wind speed of not less than 40 kilometres per hour and gusts of not less than 90 kilometres per hour;
“swell wave” means an ocean wave system raised at a distance over the ocean due to winds blowing over that area;
“torrential rain” means weather conditions resulting in a minimum of 100 millimetres of widespread rains and which are likely to continue for several hours;
“tropical cyclone” means a tropical low system in which the average wind speed is estimated to be not less than 118, noir more than 165, kilometres per hour; “tropical depression” means a tropical low system, in which the
average wind speed is estimated to be not less than 51, nor more than 62, kilometres per hour;
“very intense tropical cyclone” means a tropical low system in which the average wind speed is estimated to exceed 212 kilometres per hour.

3. For the purpose of section 5 of the Act, the Mauritius Meteorological Services shall, in accordance with regulation 4, issue
warnings for –
(a) the Island of Mauritius or Rodrigues in the event of a tropical depression, a moderate tropical storm, a severe
tropical storm, a tropical cyclone, an intense tropical cyclone, a very intense tropical cyclone, heavy rain, a
heavy swell, a storm surge or strong wind;
(b) Agaléga or St Brandon in the event of a heavy swell, a storm surge or strong wind.

4. The Mauritius Meteorological Services shall –
(a) (i) in the event that a tropical depression, a moderate tropical storm, a severe tropical storm, a tropical cyclone, an intense tropical cyclone or a very intense tropical cyclone is likely to affect the Island of Mauritius or Rodrigues, issue a –
(A) cyclone warning class I not less than 36 hours, nor more than 48 hours, before the occurrence of gusts of 120 kilometres per hour;
(B) cyclone warning class II so as to allow, as far as practicable, 12 hours of daylight before the occurrence of gusts of 120 kilometres per hour;
(C) cyclone warning class III so as to allow, as far as practicable, 6 hours of daylight before the occurrence of gusts of 120 kilometres per hour;
(D) cyclone warning class IV when gusts of 120 kilometres per hour are recorded in some places and are expected to continue;

(ii) following the issue of a cyclone warning class III or a cyclone warning class IV and subsequent observations indicating that the risk of cyclonic gusts of 120 kilometres per hour has abated and the cyclone is moving away, issue a safety bulletin for the purpose of –
(A) lifting the cyclone warning class III or cyclone warning class IV, as the case may be; and
(B) informing the public of the existence of any severe weather conditions associated with the cyclone and other environment risk, depending on the nature and extent of the damage occurred during the passage of the cyclone;

(iii) following the issue of a cyclone warning class I, a cyclone warning class II or a safety bulletin, as the case may be, issue a termination bulletin after consultation with, and following advice from, the National Crisis Committee to the effect that outdoor risks have considerably decreased;

(b) in the event of heavy rain, issue a –
(i) heavy rain watch;
(ii) heavy rain warning, as far as practicable, not less than 30 minutes, nor more than 6 hours, before the occurrence of heavy rain;
(iii) torrential rain warning, following observations indicating that accumulated rainfall has reached 100 millimetres in a given region or is likely to reach 100 millimetres in a given region in the ensuing hour, and the rain is expected to continue;
(c) in the event of a heavy swell, issue a heavy swell warning, as far as practicable, about 12 hours in advance before
swell waves of 4.0 metres or above are likely to affect the sea state in the vicinity of the Island of Mauritius,
Rodrigues, Agaléga or St Brandon;
(d) in the event of a storm surge, issue a storm surge warning, which may be included in a cyclone warning referred to in paragraph (a), when a tropical depression, a moderate tropical storm, a severe tropical storm, a tropical cyclone, an intense tropical cyclone or a very intense tropical cyclone is evolving close to the Island of Mauritius, Rodrigues, Agaléga or St Brandon;
(e) in the event of a strong wind, issue a strong wind warning, as far as practicable, about 12 hours in advance before wind speed of not less than 40 kilometres per hour, with gusts of 90 kilometres per hour, is likely to affect the Island of Mauritius, Rodrigues, Agaléga or St Brandon.

5. The regulations shall come into operation on 14 January 2023.
Made by the Minister on 13 January 2023.