Current Science

Open Access Open Access  Restricted Access Subscription Access

Active Northeast Monsoon over India during 2015 - An Assessment of Real-Time Extended Range Forecast


Affiliations
1 Director General of Meteorology, India Meteorological Department, New Delhi 110 003, India
 

Associated with strong El Nino, the southwest monsoon rainfall over India during June to September 2015 was deficit, while the northeast monsoon (NEM) during October to December 2015 over the southern peninsula was very active, particularly during November and early December. Associated with the active phases of NEM, southeast India, especially Tamil Nadu (TN) and Puducherry experienced unprecedented rainfall activity leading to devastating floods over TN, with the megacity of Chennai being the worst affected. The present study discusses the performance of operational extended range forecast (ERF) up to three weeks of this unprecedented NEM rainfall activity over the southern peninsula and TN using the bi-model average (BMA) ERF based on outputs from the Japan Meteorological Agency Ensemble Prediction System and National Centre for Environmental Prediction's (NCEP's) latest version of Climate Forecast System (CFSv.2) coupled model. The BMA forecast captured the likely delay in the onset of NEM over meteorological (met) subdivision TN and associated weak phase of monsoon during October 2015. Similarly, the BMA forecasts also captured the active phases of NEM during November and early December 2015. Although it is difficult to capture the actual magnitude of observed high-rainfall departure over a smaller domain of met-subdivision scale, the BMA-based ERF could capture the active phase of NEM over southern peninsular India, including the metsubdivision TN with a lead time of 1-2 weeks. Quantitatively, the excess NEM rainfall spells during 2015 and particularly that during 5-11 November and 12-18 November 2015 are reasonably well captured in the BMA forecast, although forecast rainfall departure was lower than the actual departure.

Keywords

Bi-Model Average, Climate Forecast System, Extended Range Forecast, Floods, Northeast Monsoon.
User
Notifications
Font Size

  • India Meteorological Department (IMD), Northeast Monsoon, FMU Report No. IV-18.4, 1973.

  • Rao, Y. P., Southwest monsoon: synoptic meteorology, IMD Met. Monograph No. 1/1976, India Meteorological Department, 1976, pp. 1–367.

  • Sridharan, S. and Muthuchami, A., Northeast monsoon rainfall in relation to El Niño, QBO and Atlantic hurricane frequency, Vayumandal, 1990, 20(3–4), 1.08–1.11.

  • De, U. S. and Mukhopadhyay, R. K., The effect of ENSO/anti ENSO on northeast monsoon rainfall, Mausam, 1999, 50, 343–354.

  • Jayanthi, N. and Govindachari, S., El Niño and northeast monsoon rainfall over Tamil Nadu. Mausam, 1999, 50(2), 217–218.

  • Khole, M. and De, U. S., A study on northeast monsoon rainfall over India. Mausam, 2003, 54(2), 419–426.

  • Raj, Y. E. A. and Geetha, B., Relation between Southern Oscillation Index and Indian northeast monsoon as revealed in antecedent and concurrent modes. Mausam, 2008, 59, 15–34.

  • Geetha, B. and Raj, Y. E. A., Indian northeast monsoon as a component of Asian winter monsoon and its relationship with large scale global and regional circulation features. Ph D thesis, University of Madras, 2011.

  • Kripalani, R. H. and Kumar, P., Northeast monsoon rainfall variability over south peninsular India vis-à-vis the Indian Ocean dipole mode. Int. J. Climatol., 2004, 24, 1267–1282.

  • Pattanaik, D. R., Meteorological subdivisional-level extended range forecast over India during southwest monsoon 2012. Meteorol. Atmos. Phys., 2014, 124, 167–182.

  • Abhilash, S. et al., Prediction and Monitoring of Monsoon Intraseasonal Oscillations over Indian monsoon region in an Ensemble Prediction System using CFSv2. Clim. Dyn., 2014, 42, 2801–2815.

  • Pattanaik, D. R., Rathore, L. S. and Kumar, A., Observed and forecasted intraseasonal activity of southwest monsoon rainfall over India during 2010, 2011 and 2012. Pure Appl. Geophys., 2013, 170, 2305–2328.

  • Tyagi, A. and Pattanaik, D. R., Real time extended range forecast activities in IMD – Performance Assessments and future prospects. IMD Met. Monograph, 2012, No. ERF 01/2012, pp. 1–132.

  • Suranjana, S. et al., The NCEP climate forecast system. J. Climate, 2006, 19, 3483–3517.

  • Suranjana, S. et al., The NCEP Climate Forecast System Version 2. J. Climate, 2014, 27, 2185–2208.

  • Ishii, M., Shouji, A., Sugimoto, S. and Matsumoto, T., Objective analyses of sea-surface temperature and marine meteorological variables for the 20th century using ICOADS and the KOBE collection. Int. J. Climatol., 2005, 25, 865–879.

  • IMD, Climate Diagnostic Bulletin of India, Post-monsoon Season from October to December 2015, India Meteorological Department, Special Issue No. 79, pp. 1–22.

  • Pattanaik, D. R., Pai, D. S. and Mukhopadhyay, B., Rapid northward progress of monsoon over India and associated heavy rainfall over Uttarakhand: a diagnostic study and real time extended range forecast. Mausam, 2015, 66, 551–568.


Abstract Views: 284

PDF Views: 99




  • Active Northeast Monsoon over India during 2015 - An Assessment of Real-Time Extended Range Forecast

Abstract Views: 284  |  PDF Views: 99

Authors

D. R. Pattanaik
Director General of Meteorology, India Meteorological Department, New Delhi 110 003, India
M. Mohapatra
Director General of Meteorology, India Meteorological Department, New Delhi 110 003, India

Abstract


Associated with strong El Nino, the southwest monsoon rainfall over India during June to September 2015 was deficit, while the northeast monsoon (NEM) during October to December 2015 over the southern peninsula was very active, particularly during November and early December. Associated with the active phases of NEM, southeast India, especially Tamil Nadu (TN) and Puducherry experienced unprecedented rainfall activity leading to devastating floods over TN, with the megacity of Chennai being the worst affected. The present study discusses the performance of operational extended range forecast (ERF) up to three weeks of this unprecedented NEM rainfall activity over the southern peninsula and TN using the bi-model average (BMA) ERF based on outputs from the Japan Meteorological Agency Ensemble Prediction System and National Centre for Environmental Prediction's (NCEP's) latest version of Climate Forecast System (CFSv.2) coupled model. The BMA forecast captured the likely delay in the onset of NEM over meteorological (met) subdivision TN and associated weak phase of monsoon during October 2015. Similarly, the BMA forecasts also captured the active phases of NEM during November and early December 2015. Although it is difficult to capture the actual magnitude of observed high-rainfall departure over a smaller domain of met-subdivision scale, the BMA-based ERF could capture the active phase of NEM over southern peninsular India, including the metsubdivision TN with a lead time of 1-2 weeks. Quantitatively, the excess NEM rainfall spells during 2015 and particularly that during 5-11 November and 12-18 November 2015 are reasonably well captured in the BMA forecast, although forecast rainfall departure was lower than the actual departure.

Keywords


Bi-Model Average, Climate Forecast System, Extended Range Forecast, Floods, Northeast Monsoon.

References





DOI: https://doi.org/10.18520/cs%2Fv112%2Fi11%2F2253-2262