NOAA has changed its outlook for a La Nina from "watch" to "advisory", basically going from it might happen to they’re quite sure it will.
Right now, temperatures in the Pacific are where they are supposed to be, or what NOAA calls neutral. But, SST anomalies across the tropical
have cooled during August, when compared to those for July. First 10 days of september are maintaining the trend, though weakly. This has increased the chance of La Niña returning during the last quarter of 2011.
Current ENSO indicators are approaching values typically associated with La Niña events. NOAA scientists don’t think temperatures will stay there much after the last quarter of 2011. After that, temperatures in the Pacific should drop below normal again, kicking off what forecasters say could be another La Nina.
However, some models predict only modest cooling resulting in a borderline-La Niña event, but others predict stronger cooling. Vagaries presumes there is an expectation that the trend towards La Niña will continue, and if a La Niña does form, it will be weaker than the strong 2010-11 event.
The official monthly SOI for August was +2.1.During September, the SOI, has increased marginally. Further cooling of the central
coupled with persistent positive SOI values in the next few months would further increase the chance of a La Niña event at the end of 2011.
has precipitated heavy rains in Orissa, with Balasore receiving 123 mms in 9 hrs on Wednesday. Kolkata too had good rains today with Alipore measuring 33 mms in the day.
received had a severe thunderstorm today, and received 75 mms of rain in a short spell of time in the afternoon.
An upper air W.D. is likely to cause medium scale precipitation and snow in the higher reaches of H.P. and
areas will also benefit from this system.