Rains have been elusive so far; they may be more unpredictable this year, says a perplexed weather office.
The La Nina conditions, which usually help fetch more rains, have weakened over the country and ENSO-neutral conditions which continue during the current monsoon season would lead to increased uncertainty in the monsoon forecasts, says central weather office during its revised second stage monsoon forecast. The revised forecast notes that the monsoon is expected to remain below normal for the country, while normal for central India which includes Gujarat. Dr. Kamaljit Ray, director, India Meteorological Department, Ahmedabad, said, “The chances of unfavourable seasonal variations become more dominant during the ENSO-neutral conditions. Hence predicting the rain pattern at times leads to increased uncertainty during such a seasonal phase.”
The Central weather office’s Long Range Forecast Update for 2011 Southwest Monsoon Rainfall over the country notes that the moderate to strong La Nina conditions that prevailed in the equatorial Pacific during mid-August 2010 to early February 2011 have completely weakened during subsequent months and have dissipated to neutral conditions around mid-May 2011. The latest forecasts from a majority of the dynamical and statistical models indicate strong probability for the present ENSO-neutral conditions to continue during the current monsoon season and the remaining part of 2011. “It is important to note that in addition to El Niño and La Niña events, other factors such as the Indian Ocean Sea surface temperatures (SSTs) have also significant influence on India monsoon. However, the latest forecasts do not suggest development of either a positive or a negative Indian Ocean Dipole event during the 2011 monsoon season. In the absence of strong monsoon forcing from both Pacific and Indian Oceans, intra-seasonal variation may become more crucial during this southwest monsoon season and lead to increased uncertainty in the monsoon forecasts,” it notes.
And the element of uncertainty indeed seems dominant as, the weather office notes that the northern limit of monsoon (NLM) passes through 22.0°N/60.0°E, Porbandar, Ahmedabad, Udaipur, Ajmer, Jaipur, Dholpur, Shahjahanpur, Pantnagar, Patiala and Jammu. And the conditions are favourable for further advance of southwest monsoon over these parts. The central office has clearly indicated monsoon onset during June 13 to June 25 for Gujarat, however, the state office has not been able to announce the onset yet due to elusive absence of rains.
