NOAA Issues Four-Season Outlook on July 21, 2022

By Sig Silber July 22, 2022weatherNo Comments

Preparing to Say Goodbye to La Nina, but Not Quite Yet

The three-month period Jan/Feb/Mar next year seems to be when the overall precipitation situation improves but for some reason the temperature situation does not and may be worse for several months along parts of the Southern Tier. You can take La Nina out of the forecast, but the warming trend continues. For many parts of CONUS, 2023 will be better than 2022. At least that is what NOAA is predicting right now.

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 June 9, 2022- Maybe Yes, Maybe No on La Nina Ending in 2022

By Sig Silber June 10, 2022weatherNo Comments

Of importance, the chances of a Triple Dip La Nina are still difficult to predict but seem to be slightly lower 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 lower. This is not likely to change the forecast for Winter but might change the forecast for next Spring. Finally, there is now more disagreement among meteorological agencies as to when this La Nina will end.

NOAA Updates its June Outlook May 31, 2022 – Quite a Big Change in Twelve Days

By Sig Silber June 1, 2022weatherNo Comments

There has been a large change in the weather outlook for June from NOAA.

At the end of every month, NOAA updates their Early Outlook for the following month which in this case is June. 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 quite different from the Early Outlook which NOAA now calls the Mid-Month Outlook. For temperature, the above-normal area is smaller than the Mid-Month Outlook and a large intrusion of colder air is expected along much of the Northern Tier. The drier than normal area is significantly reduced from the Mid-Month Outlook and shifted a bit and there are two additional areas of wetter than normal in the Outlook.

We provide partial-month outlooks for the first 24 days of June which allows us to somewhat assess if the Monthly Outlook is consistent with the partial month forecasts and it generally is. But we will not be able to answer that question definitively until the Week 3-4 Outlook is issued on Friday.

There is also a discussion of the ENSO condition which is slightly different than what NOAA used to develop the Mid-Month Outlook. The Negative Arctic Oscillation (AO) expected in the first half of June is a major factor.

We have also begun our tropical storm coverage. Yes, it is that time of the year.

NOAA Issues their Four-Season Outlook on May 19, 2022

By Sig Silber May 21, 2022weatherNo Comments

Change Appears to be Coming

Today is the third Thursday of the month so right on schedule NOAA has issued what I describe as their Four-Season Outlook. The information released also includes the Early Outlook for the single month of June plus the drought outlook for the next three months. I summarize the information issued and provide links to additional maps. Additionally, I have included quite a bit in this article. I want to remind everyone that last Thursday NOAA issued their ENSO outlook and that has a lot of influence on their Seasonal Outlook. The Seasonal Outlook generally reflects La Nina conditions initially with no clear indication of when this La Nina will end. There could be a triple-dip La Nina. That is not the most likely scenario but certainly can not be discounted. There is fairly good news with respect to the North American Monsoon (NAM).

The exact location of the Drought seems to be shifting a bit especially after this Summer. See the set of twelve overlapping three-month maps and my comments for details.

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 Outlook for May, 2022 – It is an improvement

By Sig Silber May 1, 2022weather2 Comments

At the end of every month, NOAA updates their Early Outlook for the following month which in this case is May. They also issue a drought outlook for the following month. We are reporting on that tonight. The updated Outlook is quite different from the Early Outlook which NOAA now calls the Mid-Month Outlook. It is overall less warm and less dry than the Mid-Month Outlook.

We provide partial-month outlooks for the first 27 days of May which allows us to validate if the Monthly Outlook is consistent with the partial month forecasts and it is. 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. Most of the changes are explained in the NOAA discussion which is included in the article. The NOAA discussion describes the changes but does not provide a lot of insight into the reasons for the changes other than a change in the wave pattern that they describe as more troughing in the western Northern Tier. The partial-month forecasts that we have provided show how NOAA thinks this will play out as the weather pattern changes during May.

There is also a short discussion of the ENSO condition and it is looking less likely that there will be a Three-peat of the La Nina but that a near La Nina may be the more likely situation for Fall and Winter. Those forecasts can change but it looks like a marginally better situation with the focus on the words marginally better.

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.