Strong positive readings have dominated since the summer. Such values are indicative of a La Nina circulation featuring blocked weather patterns and enhanced North Atlantic and West Pacific tropical activity. Here in NC and VA we can thank the circulation for summer's endless heat.
Recently there was a nosedive in the index which also was part of the rise in global AAM and burst of equatorial westerly winds noted earlier this week. The dip and steep rise indicates the likelihood that the surge of momentum will come to a screeching halt near the SE around Oct 28. This kind of pattern usually is a great warning of an extreme or unusual weather event. My suspicion is that a strong cold front and possibly interaction with a storm system will complete the destruction of summer.
|Data Source: The Long Paddock|