Monday, May 25, 2015

Experimental Climate Monitoring and Prediction for Maldives – May 2015

HIGHLIGHTS

In April 2015 less than average monthly rainfall was observed throughout the Maldives. Usually the rainfall is high in April and the relatively high rainfall in the first two weeks in northern and southern islands was not sufficient to put this above the long-term average. The first week of May saw more than 100 mm rainfall in northern and southern islands and low rainfall in the central islands. The cumulative deficit of rainfall for the past year shows about 25% below normal for the northern islands and close to normal for the southern and central islands. The NOAA CFS models predict up to 50 mm in the next few from 20-25th May. A clean El Nino has onset in the Maldives and this coupled with the warmer Indian Ocean shall lead to warmer months in the next six months. The Central and Northern Islands are likely to have a dry tendency for the next four months followed by a wet tendency from October to December.


Below average rainfall observed in the entire country in March 2015

 Printable Version of the Full Report (PDF)


---------------------------Inside this Issue------------------------

  1. Monthly Climatology
  2. Rainfall Monitoring
    1. Daily Satellite derived Rainfall Estimates
    2. Monthly Rainfall derived from Satellite Rainfall Estimate
    3. Monthly and Seasonal Monitoring
  3. Ocean Surface Monitoring
  4. Rainfall Predictions
    1. Weekly Predictions from NOAA/NCEP
    2. Seasonal Predictions from IRI

SUMMARY

Climatology

Monthly Climatology:

Usually the average precipitation in May normally is about 200 mm throughout the country. High precipitation is usually observed closer to south-western coast of India in June and gradually decreases from north to south of Maldives (about 400 mm in northern island and about 200 mm in southern islands). In July the rainfall decreases down to about 150 mm in northern islands and about 200 mm in central and southern islands. Wind direction is usually south-westerly in March and in April northern islands receive south-easterly wind while southern islands receive easterly wind. Strong easterly wind is usually observed in May and in June only northern islands get strong easterly wind. In July the entire country usually do not receive strong wind.


Climatology



Monitoring

On the 12th of May up to 30 mm rain was observed in northern and southern islands. Then on the 13th rainfall ceased in northern islands while up to 100 mm heavy rain was observed in southern islands. No rainfall was observed on the 14th and 15th and low rainfall was observed on the 16th, 17th and 18th in southern and northern islands.


Monthly and Seasonal Monitoring:

Less than average rainfall was observed throughout Maldives in April 2015 with less than 100 mm total monthly rainfall observed in the entire country. Rainfall increased until mid-April up to 40 mm in northern islands and about 60 mm in southern Maldives. Thereafter during the next two weeks a decreasing trend in rainfall was observed. In early-May a sudden increase in rainfall was observed in southern and central islands where more than 100 mm rainfall was observed.


Ocean State Monitoring:

Pacific Seas State May 14, 2015:

During late April through mid-May 2015 the SST was at a weak to moderate Niño level. The atmospheric variables also indicate an El Niño pattern, including weakened trade winds, low Southern Oscillation Index and excess rainfall in the central tropical Pacific. The consensus of ENSO prediction models indicate weak to moderate El Niño conditions during the May-July 2015 season in progress, likely strengthening during summer and lasting through 2015.

Indian Ocean Monitoring May 21, 2015: 

0.5 C0 Warmer than usual Sea surface temperature was observed around Maldives and across the equatorial Indian Ocean




Predictions

Weekly Rainfall Forecast:

According to NOAA models, up to 50 mm rainfall is expected in northern and central islands during 20th- 25th May 2015 while only light rainfall expected in southern islands. No unusually heavy rainfall events are expected during this period.



Seasonal Rainfall and Temperature Prediction:

As per IRI Multi Model Probability Forecast for May to July, the total 3 month precipitation shall be climatological. The 3 month average temperature has a 50-60% likelihood for northern islands and about 60% likelihood for southern-most islands of being in the above-normal tercile during this period.



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