1. Preliminary Consensus Forecast for the 2017 NE Monsoon Season
D. S. Pai
RCC, Pune

2. Verification of Last 2016 Forecast Outlook: OND 2016 & DJF 2016-17
Normal rainfall is most likely over most parts of south Asia during the 2016 Northeast monsoon season (October – December). However, below normal rainfall is likely over some areas of southeast peninsular India, Sri Lanka and Maldives. Below normal rainfall is also likely over some areas of north and eastern parts of the region. Above normal rainfall is likely over western and northwestern parts of Pakistan and some northeastern parts of the region.
During the season, normal to slightly above normal temperatures are likely, over most parts of the region.
Below normal precipitation is likely during the Winter Season (December 2016 to February 2017) over northern most parts of the south Asia, Maldives & neighboring Lakshadweep, and northeastern parts of South Asia including northeast India, east Nepal, Bhutan, and northern parts of Myanmar. Normal precipitation is likely over the remaining parts of the region.
During the season, normal to above normal temperatures are likely, over most parts of the region.

3. ENSO & IOD: Status and Forecast

4. ENSO Status : CPC
Equatorial SSTs were above average in the central Atlantic, the western Indian, and in the far western Pacific Oceans. SSTs were below average in the central and eastern Pacific

5. Latest Sub-Surface Temperature Departures in the Equatorial Pacific
In the last two months, negative subsurface temperature anomalies have expanded across the Pacific Ocean.
Most recent pentad analysis
Recently, the strongest negative anomalies lie between 170ºW-90ºW and extend to the surface.

7. MMCFS Forecast (Nino 3.4) Plume Forecast: SST anom PDF Corrected
Probability Forecast
The current ENSO neutral conditions over equatorial Pacific likely turn to cool neutral conditions during the OND season and then to weak La Nina conditions by early next year.

8. IRI/CPC Pacific Niño 3.4 SST Model Outlook
Although SSTs in the east-central tropical Pacific have cooled to the threshold for La Niña, the atmosphere continues to maintain largely ENSO-neutral patterns. The collection of latest ENSO prediction models indicates coolish ENSO-neutral or weak La Niña as two possible scenarios during Northern Hemisphere fall and winter.

9. Bureau Of Meteorology (POAMA & Other Models)
Published on 10th September 2017

10. IOD Condition

11. MMCFS Forecast (IOD) Probability Forecast
Plume Forecast: SST anom PDF Corrected
Probability Forecast
The current IOD neutral conditions over equatorial Pacific likely continue during the OND season and thereafter

12. IOD: Bureau Of Meteorology (POAMA & Other Models)

13. Summary of Status and Outlook of ENSO & IOD
Currently, ENSO neutral conditions are prevailing with Nino3.4 values close to normal values. Atmospheric conditions over the Pacific also indicate ENSO neutral conditions. The latest MMCFS forecast indicates high probability for cooling of SSTs over equatorial central and east Pacific leading to cool ENSO neutral conditions during the 2017 NE monsoon season and then turning to weak La Nina conditions in the early part of next year.
Currently, Indian Ocean Dipole (IOD) neutral conditions are prevailing. The latest forecast from the MMCFS indicates IOD neutral conditions to continue during the northeast monsoon season.

14. Forecasts from Country Representatives
Rainfall Forecast
Temp Forecast
AFGANISTAN
NORMAL
NORMAL TO ABOVE NORMAL
BANGLADESH
BHUTAN
INDIA (South Peninsula)
Normal
MALDIVES
MYNMAR
NORMAL TO SLIGTHTLY ABOVE NORMAL
OND: ABOVE NORMAL
JFM; ABOE NORMAL
NEPAL
NORMAL/ABOVE NORMAL
 NORMAL TO ABOVE NORMAL TEMPERATURES
PAKISTAN
SRILANKA
 NORMAL

15. MMCFS Precipitation Forecast: OND 2017
Normal to Above normal over southern and northeastern parts of India, southwest Srilanka and northern parts of Myanmar. Below normal in the remaining areas.

16. NCEP CFS Forecast
Normal to Above normal rainfall over southern part and some areas of northeastern part of the region.

17. Met Office Glosea5 PRECIPITATION probability Forecast
OND Forecast
OND Skill
OND: Above normal over eastern & Southern most parts (Maldives).
Climatological probability over remaining areas.

18. Met Office UK (Dr. Colman)
Most skilful combination is 50% calibrated.
Above average favoured in NE India, Bangladesh, N Myanmar, Sri Lanka, Maldives; Below average favoured over parts of NW India. Near normal or no signal elsewhere.
Input: CMC1 precipitation, CMC2 and CFS SST

19. JMA: Precipitation Probability Forecast over South Asia: OND 2017: Initial date: 8 September 2017
[mm/day]
Anomaly (shaded)
Precipitation is most likely to be near or above normal over South Asia.

20. ECMWF Precipitation Anomaly Forecast
OND: Above normal over some areas northern and east parts of the region.
Climatological probability for remaining areas.

21. IRI Precipitation Probability Forecast
Above Normal precipitation is likely over some areas of northwestern, southeastern and eastern parts of the region. northwest and eastern parts of the region. Climatological probability in the remaining parts of the region.

22. WMO_LC_LRFMME: Precipitation for OND 2017
Wet condition over India and Myanmar in PMME continues for DJF 2015/16.
Climatological probability over most parts of the region

23. Temperature Forecast

24. MMCFS T2mForecast: OND 2017

25. NCEP CFS2 T2m Forecast
Below normal to normal temperatures along the Himalayas and over southeast Peninsular India and eastern part of Sri Lanka. Above normal temperatures over the remaining areas of the region

26. UKMO: Glosea5: T2m Forecast
OND Skill
OND Forecast
Normal to above normal temperatures over most parts of the region

27. ECMWF T2m Anomaly Forecast
Normal to above normal temp. are likely over most parts of the region.

28. IRI T2m Anomaly Forecast
Above Normal temp. are likely over north, northwest and eastern parts of the region. Climatological probability in the remaining parts of the region.

29. JMA: T2m Forecast over South Asia for OND 2017: Initial date: 8 September 2017
[mm/day]
Anomaly (shaded)
Temperatures are most likely to be above normal over most parts of South Asia. Below normal to normal rainfall over some northwestern parts of the region

30. WMO_LC_LRFMME: 2mT for OND 2017
Wet condition over India and Myanmar in PMME continues for DJF 2015/16.
Above Normal Temperatures over most parts

31. Draft Consensus Forecast Map
OND Precipitation
OND Temperature
Temperature over most of the region is likely to be normal to slightly above normal

32. Summary
Below normal rainfall is most likely over some parts of SE Peninsular India, north Sri Lanka and some areas of northeastern part of the region. Above normal is most likely over southeastern part of the region and along the coastal areas of region around the north Bay of Bengal. Other areas of the region that includes the northwest and central areas of the region which generally receive very little rain during the season are likely to receive normal rainfall.
During the season, normal to slightly above normal temperatures are likely, over most parts of the region.

33. This consensus forecast outlook for the 2017 northeast monsoon season rainfall and temperature over South Asia have been developed through an expert assessment of the prevailing global climate conditions and forecasts from different climate models from around the world. Currently cool neutral ENSO conditions prevail in the Pacific Ocean and these conditions are likely to continue and turn to border line/ weak La Nina conditions in the early next year. It is also recognized that this year, in the absence of SST forcings from Pacific and Indian oceans, other regional and global factors as well as the strong intra seasonal features of the region will have larger influence on the climate anomaly patterns over the region leading to increased uncertainty in the prediction of this year’s rainfall and temperature patterns over the region.
For more information and further updates on the northeast monsoon outlook on national scale, the respective National Meteorological and Hydrological Services (NMHSs) may be consulted.
A separate consensus statement for winter season (December 2017 to February 2018) will be issued in November 2017.

34. Thank you
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