Triple Dip

On the second Thursday of every month, NOAA issues its analysis of the status of ENSO. This includes determining the Alert System Status. Although the current status remains the same i.e.  La Nina Advisory, the forecast has been adjusted somewhat from last month. The forecast calls for the La Nina to continue.  The timing is shown in the NOAA discussion and the IRI probability analysis. Of importance, the chances of a Triple Dip La Nina are still difficult to predict but seem to be slightly higher than the estimate last month. That would be a real disaster for the Southwest and the West Coast. The NOAA estimate for La Nina lasting into early Winter is 61%. This is a minority opinion in terms of other meteorological agencies almost all of which see La Nina ending sooner.

The impact of the NOAA forecast for the slow or non-existent transition from La Nina to ENSO Neutral will show up next Thursday when NOAA issues its Seasonal Outlook. The NOAA ENSO Status Update provides an advance indication of how the Outlook might change. There is a lag between the ENSO state and the impact on U.S. weather.  Thus the exact strength of the  La Nina may not be very important in terms of the actual impact on Summer weather including the North American Monsoon (NAM).  We may see some changes farther out in the NOAA Outlook that will be issued next Thursday in particular Fall and Winter. Although the chances that this will happen are slightly less this month, the possibility of a Triple Dip should be of considerable concern. It most likely will be reflected in the Outlook issued next Thursday but perhaps not. We will learn more about what NOAA thinks next Thursday.

This may read like a repeat of a prior article but it is not. It is simply that the situation has not really changed. On the second Thursday of every month, NOAA issues its analysis of the status of ENSO. This includes determining the Alert System Status. Although the current status remains the same i.e.  La Nina Advisory, the forecast has been adjusted somewhat from last month. The forecast calls for the La Nina to continue.  The timing is shown in the NOAA discussion and the IRI probability analysis. Of importance, the chances of a Triple Dip La Nina are not at all ruled out. That could be a real disaster for the Southwest and the West Coast.

The impact of the NOAA forecast for the slow or non-existent transition from La Nina to ENSO Neutral will show up next Thursday when NOAA issues its Seasonal Outlook. The NOAA ENSO Status Update provides an advance indication of how the Outlook might change. There is a lag between the ENSO state and the impact on U.S. weather.  Thus the exact date when La Nina meets the criteria for ENSO Neutral may not be very important in terms of the actual impact on Spring and Summer weather including the North American Monsoon (NAM).  We may see some changes farther out in the NOAA Outlook that will be issued next Thursday in particular Fall and Winter. But the possibility of a Triple Dip should be of considerable concern but it most likely will not be reflected in the Outlook issued next Thursday since it remains unlikely but possible. We will learn more about what NOAA thinks next Thursday.