Three-Peat Archives - EconCurrents

NOAA Updates it’s ENSO Outlook on December 8, 2022

By Sig Silber December 9, 2022weatherNo Comments

Updated at 3:45 p.m. December 9, 2022 to complete certain edits that were not completed at the time this article was published. They add a little more clarity to the discussion.

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 again been adjusted slightly from the prior month. There is some disagreement on when this La Nina will end with the best guess being perhaps March. But some meteorological agencies believe it could be sooner than that.

But I have actually seen only a few signs of it starting to happen. But all the meteorologists agree that it will. Could they all be wrong? Probably not.

Will this La Nina transition quickly to the El Nino phase? That would be unusual but some of the models suggest this will happen.

NOAA Updates its ENSO Analysis on September 8, 2022 – La Nina will probably end soon.

By Sig Silber September 11, 2022weatherNo Comments

Nevertheless, that is what both NOAA and I think will happen. But it could happen a bit earlier or a bit later.

I provided a small sample of model runs by a number of different meteorological agencies that is presented by the Australian Bureau of Meteorology (BOM) and they suggest that maybe we will be in ENSO Neutral in January or February rather than March as NOAA seems to be thinking. NOAA is placing more weight on the statistical rather than dynamic models but statistics requires data and there have not been a lot of similar situations but what data there is suggests March is more likely than January or February. But perhaps this La Nina will continue beyond March. Maybe it will continue for a fourth year.

NOAA Updates its ENSO Analysis on July 14, 2022 – Increasing Chances of a Three-peat

By Sig Silber July 15, 2022weatherNo Comments

Of importance, the chances of a Triple Dip La Nina are still difficult to predict but seem to be higher than the estimate last month. I am not exactly sure how you define a Three-Peat. If it has to do with extending into early Winter the odds seem to be a bit higher. This is not likely to change the forecast for Winter but might change the forecast for next Spring. Finally, there is now less disagreement among meteorological agencies as to when this La Nina will end.

So I am referring to it as a Three-peat but it is not over until it is over. So it may not happen but it looks increasing as if it will.

NOAA Updates July Outlook – June 30, 2022 – Not Much Change – Some Ocean Indicators are Surprising

By Sig Silber July 1, 2022weatherNo Comments

Updated at 2:30 am EDT July 2, 2022 to incorporate the Week 3 – 4 Outlook which suggests that the second half of July will not be as cool in the Northwest but perhaps less warm elsewhere and the Monsoon may be less robust but some other areas will be less dry.

At the end of every month, NOAA updates their Mid-Month Outlook for the following month which in this case is July. They also issue a Drought Outlook for the following month and update the three-month Drought Outlook. We are reporting on that tonight. The updated Outlook is very similar to the Mid-Month Outlook. This is surprising since the Mid-Month Outlook was issued two weeks ago and there usually are more changes in that period of time.

For temperature, the shape and location of the large dry anomaly have changed a bit. The cool anomaly in the Northwest is now slightly larger. For precipitation, the area where an above-average Monsoon is forecasted is a little larger and shifted a bit to include more of New Mexico. there is a new small dry anomaly

We provide partial-month Outlooks for the first 22 days of July which allows us to somewhat assess if the Monthly Outlook is consistent with the partial-month Outlooks and it generally is. But we will not be able to answer that question definitively until the Week 3-4 Outlook is issued tomorrow. We will provide an update at that time.

We also provide enough information for readers to understand any changes from the Mid-Month Outlook and we try to figure out why these changes were made. Many of the changes are explained in the NOAA discussion which is included in the article. The partial-month forecasts that we have provided show how NOAA thinks this will play out as the weather pattern evolves during July.

There is also a discussion of the ENSO condition which is ever so slightly different than what NOAA used to develop the Mid-Month Outlook. But there is a fairly strong signal that this La Nina will end in late winter 2022/2023. The impacts on weather may not be noticed until Spring. But that is just the current forecast and can change.

We have also begun our tropical storm coverage. Yes, it is that time of the year. We are also providing special coverage of the Monsoon by providing the links to those daily updates.

NOAA Updates the ENSO Forecast on May 12, 2022- Chances of a La Nina Three-peat are 61%

By Sig Silber May 13, 2022weatherNo 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. 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.

NOAA Updates Their ENSO Forecast – La Nina Looks to Continue

By Sig Silber April 15, 2022weatherNo Comments

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.

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

By Sig Silber March 26, 2022ClimateNo 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.