Seasonal Climate Forecast

MAURITIUS METEOROLOGICAL SERVICES

Winter 2017 Outlook

for the

Republic of Mauritius

 

 

1.0 Introduction

 

The Winter 2017 Seasonal Outlook prepared by the Mauritius Meteorological Services, gives an insight of the expected evolution of the climate during the winter months in the Republic of Mauritius. The contents of this outlook are meant to be used as general guidelines for planning  purposes by stakeholders in various socio-economic sectors.  Winter starts around mid-May and ends in October.

 

2.0 Background

 

Weather during Winter is often characterised by persistent trade winds emanating from anticyclones in the South Indian Ocean. Temperatures are cooler, especially during the months of June to September. May and October are usually known as transition months with alternate relatively warm and cold episodes.

 

The behaviour of various meteorological parameters in analogue (similar) years as well as El Nino Southern Oscillation (ENSO) and sea surface temperature in the Indian Ocean are analysed to generate objective scenarios for the winter months. Global, regional and local predictors are analysed during the preparation of this outlook.

 

3.0 Extreme weather Events

 

In line with the findings of Intergovernmental Panel for Climate Change (IPCC) fifth Assessment Report (AR5) in April 2014, extreme weather events are likely to occur occasionally during winter over the Republic of Mauritius.  These include high intensity rainfall with occasional thunderstorm, cold spells and windy conditions lingering for days and rather active cold fronts leading to squally weather.

 

4.0 Conclusions

 

This section applies to the islands of the Republic of Mauritius

 

Based on the above indicators, the most likely outcome for Winter 2017 is as follows:

 

(i) Cumulative rainfall over Mauritius will be above normal during the first part of winter and close to normal during the second part. On average, rainfall will be slightly above normal over Mauritius with a mean of about 850 mm. The rainy periods will be mainly concentrated over the Central Plateau, to the East and the South.

Normal rainfall is expected over Rodrigues with a mean of 350 mm over the island.

Normal rainfall is also expected at St Brandon with a mean of 270 mm.

Slightly below normal rainfall is expected at Agalega with a mean of 390 mm.

 

(ii) On average day temperature will be close to the seasonal mean, both at Mauritius and Rodrigues. However, temperatures may be slightly below the normal during the second half of July and the remaining months of winter. Night temperature will be slightly above normal during the first three (3) months of winter and near normal during the remaining months.

Furthermore, on some occasions it is most likely that minimum temperature at Mauritius may drop to near 12 degrees Celsius especially during July and August and occasionally in September and October.

At Rodrigues, minimum temperature may drop to near 14 degrees Celsius over the high grounds.

 

Table 1 below shows the forecast monthly average maximum and minimum temperatures in degrees Celsius for the different region of Mauritius as well as for Rodrigues (Pointe Canon).

 

 

Table 1: Expected monthly average maximum and minimum temperatures over Mauritius.

	May		Jun		Jul		Aug		Sept		Oct
	Max	Min	Max	Min	Max	Min	Max	Min	Max	Min	Max	Min
EAST	27	20	25	19	24	17	24	17	24	17	25	18
WEST	29	20	27	19	26	17	26	17	27	17	28	18
NORTH	29	19	27	17	25	16	26	17	26	16	28	17
SOUTH	27	21	26	20	24	18	24	18	25	18	26	19
CENTRE	25	19	23	17	22	16	22	15	22	15	24	16

 

Table 2: Expected monthly average maximum and minimum temperatures over Rodrigues.

	May		Jun		Jul		Aug		Sept		Oct
	Max	Min	Max	Min	Max	Min	Max	Min	Max	Min	Max	Min
Pte-Canon	28	22	27	21	26	19	25	19	26	19	27	20
Plaine Corail	28	22	27	21	26	19	25	19	25	19	26	20

 

 

 

 

 

 

 

 

(iii) Trade winds, mainly from the East South East, will blow at an average speed of 25 to 35 km/h. Occasionally, particularly during the peak winter months of July and August, with the passage of strong anticyclones to the south of the Mascarenes, wind gusts are likely to reach 80-90 km/h in some exposed areas.

 

(iv) On some occasions, seas will become very rough with heavy swells generated by the combined effect of deep travelling lows and strong anticyclones to the south of the Mascarenes. These swells are likely to reach the shores of Mauritius, Rodrigues and St Brandon causing ‘raz-de-maree’ on some occasion, especially in the southern and western sectors.

 

This report will be updated at the end of July 2017.

 

Rajan Mungra

Director

Meteorological Services

 

12 May 2017