Three-Peat or Triple-Dip is not a Cause for Celebration

March 26, 2022Posted inClimateNo Comments

We have discussed this before but the fact that there is a possibility of a third La Nina Winter is a good reason to discuss it again. I would say that is is not real likely. But if it happens, it would be very serious. So that is why it is worth discussing. We have not previously discussed how Global Warming makes any drought more dangerous but that should be obvious. We know that the negative phase of the Pacific Decadal Oscillation (PDO) results in a higher ratio of La Nina to El Nino Events. But we have not discussed how Global Warming might impact the PDO. So we are not addressing the broader question of whether or not Global Warming is increasing the chance of a third year of La Nina but simply looking at the evidence that a third year is a possibility. It seems that NOAA may be more concerned about the possibility than some other weather forecasting agencies in other part of the world, but we will attempt to show that their concern is not unreasonable.

ENSO Update March 10, 2022: La Nina Remains and if Anything is Stronger

March 12, 2022Posted inweatherNo Comments

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 to fade perhaps but right now it is stronger.  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 ruled out. That could be a real disaster for the Southwest and the West Coast.

The impact of the NOAA forecast for the 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 forecast might change. There is a lag between the ENSO state and the impact on U.S. weather.  Thus the exact date when a fading 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).  But the possibility of a Triple Dip should be of considerable concern. We will learn what NOAA thinks next Thursday.

NOAA Updates the Status of ENSO February 10, 2022

February 11, 2022Posted inweatherNo Comments

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 to fade.  The timing is shown in the NOAA discussion and the IRI probability analysis. The Australian Meteorological Service thinks this will happen sooner and I agree. I present some information that suggests that NOAA has the timing wrong and that the transition to ENSO Neutral will occur fairly soon.

The impact of the NOAA forecast for the 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 forecast might change. To repeat, I expect the demise of La Nina to occur somewhat sooner than predicted by NOAA.  It is not a significant difference. There is a lag between the ENSO state and the impact on U.S. weather.  Thus the exact date when a fading 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 will learn what NOAA thinks next Thursday.

NOAA Updates the Status of ENSO

January 14, 2022Posted inweather2 Comments

Updated on January 14, 2022 by adding a graphic. 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 as La Nina Advisory, the forecast has been adjusted somewhat from last month.  The earlier forecast was that we would transition to ENSO Neutral Status very soon. Now it looks like the La Nina will extend into Spring. The impact of that will show up next Thursday when NOAA issues their Seasonal Outlook. The NOAA ENSO Status Update provides an advance indication of how the forecast might change.