NOAA Seasonal Outlook Archives

NOAA Updates its Seasonal Outlook on November 21, 2024 – Still based on a weak La Nina starting very soon – Posted on November 22, 2024

By Sig Silber November 22, 2024weatherNo Comments

On the third Thursday of the month right on schedule NOAA issued their updated Seasonal Outlook which I describe as their Four-Season Outlook because it extends a bit more than one year into the future. The information released also included the Mid-Month Outlook for the following month plus the weather and drought outlook for the next three months. I present the information issued by NOAA and try to add context to it. It is quite a challenge for NOAA to address the subsequent month, the subsequent three-month period as well as the twelve successive three-month periods for a year or a bit more.

With respect to the long-term part of the Outlook which I call the Four-Season Outlook, the timing of the transition from Neutral to LaNina has been challenging to predict. We are still in ENSO Neutral. La Nina is the likely scenario soon, but the strength of the La Nina may be fairly weak.

From the NOAA discussion:

“Taken collectively, statistical and dynamical model forecast guidance of the Niño3.4 index favor the development of a weak and most likely short duration La Niña event. Some statistical model forecasts do favor a continuation of ENSO-neutral into and through winter 2024-2025. Dynamical model guidance predictions tend to support weak La Niña conditions to develop, including the majority of participant models from the NMME and C3S forecast suites. Most recent observations and the forecast guidance noted above favor La Niña to emerge during OND 2024 (57% chance) and it is expected to persist through JFM 2025. After JFM 2025, ENSO-neutral is the most likely category into the northern hemisphere summer of 2025.”

“Based on a weak La Nina and models overdoing trends, observed trends become more of the signal. Furthermore, higher frequency patterns (AO, MJO, and stratospheric variability) that result in increased uncertainty can also play a larger role. Those modes are largely not predictable on seasonal timescales,”

I personally would not have total confidence in this outlook given the uncertainty about there actually being a La Nina and its strength if it does happen. I forecasted the JAMSTEC three-season forecast last Saturday LINK. I do not have a lot of confidence that NOAA knows how to deal with a La Nina Modoki. The number of El Nino and La Nina events since 1950 is a fairly small number. When you further segment them by strength you end up with a very small number of events in each category (El Nino v La Nina and three or four categories of strength within each of perhaps 8 to 10 subcategories. This makes both statistical methods and dynamical models have a large error range. We are pretty confident now that we will have either a weak La Nina or Neutral with a La Nina bias meaning it will be in the Neutral Range but closer to a La Nina than an El Nino. This suggests that there is value in this forecast. The maps show the level of confidence that NOAA (really the NOAA Climate Prediction Center) has for the outlook shown when they show a part of the U.S. or Alaska differing from normal.

Let’s Take a Look at the (mid-month) Outlook for December.

It will be updated on the last day of November.

Then we look at a graphic that shows both the next month and the next three months.

The top row is what is now called the Mid-Month Outlook for next month which will be updated at the end of this month. There is a temperature map and a precipitation map. The second row is a three-month outlook that includes next month. I think the outlook maps are self-explanatory. What is important to remember is that they show deviations from the current definition of normal which is the period 1991 through 2020. So this is not a forecast of the absolute value of temperature or precipitation but the change from what is defined as normal or to use the technical term “climatology”.

Notice that the Outlook for next month and the three-month Outlook are fairly similar except in two places. This tells us that January and February will be substantially the same as December for most of CONUS and Alaska. Part of the explanation for this is that NOAA expects La Nina to impact all three months.

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The full NOAA Seasonal Outlook extends through December/January/February of 2026 (yes that is more than a year out). All of these maps are in the body of the article. Large maps are provided for December and the three-month period December/January/February Small maps are provided beyond that through December/January/February of 2026 with a link to get larger versions of these maps. NOAA provides a discussion to support the maps. It is included in the body of this article.

In some cases, one will need to click on “read more” to read the full article. For those on my email list where I have sent the url of the article, that will not be necessary.

NOAA Updates its Seasonal Outlook on July 18, 2024 – Substantially Different from the Outlook Issued last Month – Posted on July 19, 2024

By Sig Silber July 19, 2024weatherNo Comments

With respect to the long-term part of the Outlook which I call the Four-Season Outlook, the timing of the transition from Neutral to LaNina is challenging to predict. We are now in ENSO Neutral. La Nina is the likely scenario for this summer almost to the end of the forecast period.

First, Let’s Take a Look at the (mid-month) Outlook for August

It will be updated on the last day of July.

The top row is what is now called the Mid-Month Outlook for next month which will be updated at the end of this month. There is a temperature map and a precipitation map. The second row is a three-month outlook that includes next month. I think the outlook maps are self-explanatory. What is important to remember is that they show deviations from the current definition of normal which is the period 1991 through 2020. So this is not a forecast of the absolute value of temperature or precipitation but the change from what is defined as normal or to use the technical term “climatology”.

Notice that the Outlook for next month and the three-month Outlook are fairly similar. This tells us that September and October will be fairly similar to August.

The expansion of the area impacted by drought development is extensive but different than what was predicted last month. There is also a large area of drought improvement.

The full NOAA Seasonal Outlook extends through August/September/October of 2025 (yes that is more than a year out). All of these maps are in the body of the article. Large maps are provided for August and the three-month period August/September/October. Small maps are provided beyond that through August/September/October of 2025 with a link to get larger versions of these maps.

NOAA provides a discussion to support the maps. It is included in the body of this article. In some cases, one will need to click on “read more” to read the full article. For those on my email list where I have sent the url of the article, that will not be necessary.

NOAA Updates its Seasonal Outlook on May 16, 2024 – La Nina is Coming: Published May 17, 2024

By Sig Silber May 17, 2024weatherNo Comments

With respect to the long-term part of the Outlook which I call the Four-Season Outlook, there is a rapid transition from El Nino to ENSO Neutral to LaNina. So getting the timing right is challenging. We are for all practical purposes now in ENSO Neutral. La Nina is the likely scenario for this summer almost to the end of the forecast period. The Outlook beyond June has not been significantly changed from what was issued last month. This suggests increasing confidence in the outlook. The forecast is a canonical La Nina plus trends.

First, Let’s Take a Look at the (mid-month) Outlook for June

It will be updated on the last day of May.

The top row is what is now called the Mid-Month Outlook for next month which will be updated at the end of this month. There is a temperature map and a precipitation map. The second row is a three-month outlook that includes next month. I think the outlook maps are self-explanatory. What is important to remember is that they show deviations from the current definition of normal which is the period 1991 through 2020. So this is not a forecast of the absolute value of temperature or precipitation but the change from what is defined as normal or to use the technical term “climatology”.

Notice that the Outlook for next month and the three-month Outlook are somewhat different, especially about precipitation. This tells us that July and August will be different than June to some extent.

The full NOAA Seasonal Outlook extends through June/July/August of 2025 (yes that is more than a year out). All of these maps are in the body of the article. Large maps are provided for June and the three-month period June/July/August. Small maps are provided beyond that through June/July/August of 2025 with a link to get larger versions of these maps.

NOAA provides a discussion to support the maps. It is included in the body of this article. In some cases, one will need to click on “read more” to read the full article. For those on my email list where I have sent the url of the article, that will not be necessary.

NOAA Updates its Seasonal Outlook on April 18, 2024 – La Nina is Coming: Published April 19, 2024

By Sig Silber April 19, 2024weatherNo Comments

With respect to the long-term part of the Outlook which I call the Four-Season Outlook, there is a rapid transition from El Nino to ENSO Neutral to LaNina. So getting the timing right is challenging. La Nina is now the likely scenario for this summer almost to the end of the forecast period. The Outlook beyond May has not been significantly changed from what was issued last month. This suggests increasing confidence in the outlook. I may write another article on the implications of this forecast for agriculture and perhaps energy usage.

First, Let’s Take a Look at the (mid-month) Outlook for May

It will be updated on the last day of April.

The top row is what is now called the Mid-Month Outlook for next month which will be updated at the end of this month. There is a temperature map and a precipitation map. The second row is a three-month outlook that includes next month. I think the outlook maps are self-explanatory. What is important to remember is that they show deviations from the current definition of normal which is the period 1991 through 2020. So this is not a forecast of the absolute value of temperature or precipitation but the change from what is defined as normal or to use the technical term “climatology”.

Notice that the Outlook for next month and the three-month Outlook are somewhat different, especially with regard to temperature. This tells us that June and July will be different than May to some extent.

The full NOAA Seasonal Outlook extends through May/June/July of 2025 (yes that is more than a year out). All of these maps are in the body of the article. Large maps are provided for May and the three-month period May/June/July. Small maps are provided beyond that through May/June/July of 2025 with a link to get larger versions of these maps.

NOAA provides an excellent discussion to support the maps. It is included in the body of this article. In some cases, one will need to click on “read more” to read the full article. For those on my email list where I have sent the url of the article, that will not be necessary.

NOAA Updates its Seasonal Outlook on January 18, 2024 – Winners and Losers. Rapid Changes in ENSO Phases

By Sig Silber January 19, 2024weatherNo Comments

Lightly Edited at 7:38 pm EST January 20, 2024

On the third Thursday of the month right on schedule NOAA issued their updated Seasonal Outlook which I describe as their Four-Season Outlook because it extends a bit more than one year into the future. The information released also included the Mid-Month Outlook for the following month plus the weather and drought outlook for the next three months. I present the information issued by NOAA and try to add context to it. It is quite a challenge for NOAA to address the subsequent month, the subsequent three-month period as well as the twelve successive three-month periods for a year or a bit more.

With respect to the long-term part of the Outlook which I call the Four-Season Outlook, there is a fairly rapid transition from El Nino to ENSO Neutral to LaNina. Thus there are some changes from what was issued last month.

First, Let’s Take a Look at the (mid-month) Outlook for February.

It will be updated on the last day of January.

The top row is what is now called the Mid-Month Outlook for next month which will be updated at the end of this month. There is a temperature map and a precipitation map. The second row is a three-month outlook that includes next month. I think the outlook maps are self-explanatory. What is important to remember is that they show deviations from the current definition of normal which is the period 1991 through 2020. So this is not a forecast of the absolute value of temperature or precipitation but the change from what is defined as normal or to use the technical term “climatology”.

Notice that the outlook for next month and the three-month outlooks are somewhat different, particularly with respect to precipitation. This tells us that March and April will be different than February to some extent.

The full NOAA Seasonal Outlook extends through February/March/April of 2025. All of these maps are in the body of the article. Large maps are provided for February and the three-month period Feb/Mar/Apr. Small maps are provided beyond that through April of 2025 with a link to get larger versions of these maps.

NOAA provides an excellent discussion to support the maps. It is included in the body of this article. In some cases, one will need to click on “read more” to read the full article. For those on my email list where I have sent the url of the article, that will not be necessary.

Taking Another Look at the NOAA Seasonal Outlook – What about this Coming Winter? Published on August 19, 2023

By Sig Silber August 19, 2023weatherNo Comments

Usually, we pay the most attention to the Mid-Month forecast for the next month which is September, the three-month Outlook for September through November and the Seasonal Drought Outlook.

Tonight I want to focus on the months beyond September through November 2023 In particular I want to focus on the winter months.

NOAA is showing a warmer than normal Northern Tier and equal chances for the rest of CONUS other than Florida

NOAA is showing a dry extreme Northern Tier and a mostly wet Southern Tier and the Southeast. But what about the Colorado River Basin? Pretty much a normal year? What about New Mexico? If the Jet Stream is so far south that there will only be normal precipitation for Northern New Mexico and Colorado? That is not a good scenario for New Mexico.

NOAA Updates its Four Season Outlook on August 17, 2023

By Sig Silber August 18, 2023weatherNo Comments

Take a look at September and the three-month period that includes September. The first row in this graphic is the Mid-Month forecast for September. The bottom row shows the outlook for the next three months including September.

The full NOAA Seasonal Outlook extends through August/September/October of 2024. All the maps are in the body of the article.

NOAA provides an excellent discussion to support the maps and the changes (which are minimal) from what was issued a month ago. It is best to read the full discussion but here are some of the highlights:

Re ENSO:

The median North American Multi-Model Ensemble (NMME) consolidation forecast exceeds +1.5 degrees C at its peak in late autumn and early winter before decreasing at longer leads with greater uncertainty.
The CPC consensus ENSO outlook indicates greater than a 90 percent chance that El Niño will continue through winter, with greater than a 60 percent chance that the strength of the Niño 3.4 anomaly will exceed +1.5 degrees C at its peak.

[Editor’s Note: How do we define the strength of El Nino? It is very informal but over 1.0 is considered moderate versus weak, over 1.5 is considered strong and over 2.0 is considered very strong.) It is a logical approach since the warmer the temperature anomaly the more we expect the Walker Circulation to be impacted. But it does not work out that way in all cases for all areas and some think the rate of change of the Nino 3.4 reading is also very important]

For September:

Above normal temperatures are favored for most of the western CONUS, consistent with anomalous ridging.
The strongest probabilities (greater than 50 percent) of above-normal temperatures are indicated near the Four Corners region.
However, probabilities of warmer than normal conditions are tempered across much of the northwestern CONUS for the weeks 3-4 period, which includes most of the first half of September. [Editors’ Note: Remember this Outlook was issued on August 17 so three to four weeks from then is early September]
Farther to the south and east, enhanced above-normal temperature probabilities are indicated across the Southern Plains, Lower Mississippi Valley, and parts of the Southeast.
Equal chances (EC) of above, near, and below normal temperatures are indicated for the remainder of the eastern CONUS.
Above-normal temperatures are favored for southern, eastern, and northern Alaska.
Above-normal precipitation is favored across the Southeast northward to the Mid-Atlantic and westward to parts of the Tennessee and Ohio Valleys
Conversely, below-normal precipitation is favored farther to the north and west for the western Great Lakes and Upper Mississippi Valley
Latest weeks 3-4 guidance from the ECMWF and GEFS depict a wet signal across the Baja Peninsula and the Gulf of California, suggestive of potential tropical cyclone (TC) activity. This potential TC activity leads to a slight tilt toward above-normal precipitation for parts of the southwestern CONUS.
Farther to the north, above-normal precipitation is favored for western Alaska
A weak tilt toward below-normal precipitation is indicated for Southeast Alaska due to weeks 3-4 guidance

For SON 2023

Above-normal temperatures are favored across Alaska and the western CONUS in the SON and OND 2024 temperature outlooks.
The greatest probabilities exceed 50 percent for northern Alaska and parts of the Southwest, due to decadal trends.
Above-normal temperatures are also favored eastward across the southern Contiguous United States (CONUS) into the Southeast and northward through the eastern CONUS into the eastern Great Lakes region, consistent with the consolidation of tools.
Decadal trends lead to higher probabilities of above-normal temperatures over the Northeast.
Potential El Niño impacts for the SON and OND seasons include cooler temperatures over much of the central CONUS, leading to weaker probabilities for above-normal temperatures
During SON 2023, above-normal precipitation is favored for western and northern Alaska and the southeastern CONUS,
Below-normal precipitation is favored for the Pacific Northwest, a small area of the Southwest, and the western Great Lakes region.
Enhanced probabilities of above-normal precipitation for parts of Alaska are supported by dynamical and statistical tools.
Below-normal precipitation for the Pacific Northwest and Great Lakes and above-normal precipitation for the Southeast are consistent with El Niño impacts, and largely persist through the next several leads.
Below-normal precipitation for parts of the Southwest in the SON season is consistent with the persistence of a weaker-than-normal Southwest monsoon, while the outlook for the month of September favors above-normal precipitation in areas of southern California, Nevada and Arizona to the west due to shorter-term moisture flow from the East Pacific.

Beyond SON 2023:

From the NDJ 2023-24 to the FMA 2024 seasons, as the leads extend through autumn into winter, increasing probabilities of above-normal temperatures are forecast from the Pacific Northwest across the northern tier of the CONUS into the Midwest and Northeast, consistent with increasing impacts of a strengthening El Niño.
Equal chances of above, near, and below normal temperatures (EC) is forecast across the southern tier of the CONUS with a tendency towards cooler temperatures arising from El Niño impacts.
For MAM 2024 and longer leads through SON 2024, the outlooks relied heavily on the ENSO-OCN tool, and decadal trends provide most of the available climate signals.
The seasonal temperature outlooks evolve toward a similar pattern at the longest leads (MAM 2024 through SON 2024), and the forecasts generally depict a u-shaped pattern of enhanced probabilities of above-normal temperatures over the CONUS, and EC in the northern central CONUS into the central Mississippi valley.
Below-normal precipitation is forecast across much of the northern tier of the CONUS from parts of the Pacific Northwest to the Great Lakes region from NDJ 2023-24 to FMA 2024, due to the expected strengthening El Niño.
The enhanced probabilities of above-normal precipitation for the Southeast increase and extend westward incrementally across the Southern Plains into the Southwest for these leads, also consistent with a strengthening El Niño.
For the MAM 2024 season and longer leads, areas of above- and below-normal precipitation coincide with signals due to decadal trends, including enhanced probabilities for below-normal precipitation in areas of the northwestern CONUS and enhanced probabilities for above-normal precipitation in the lower Mississippi Valley and Mid-Atlantic region.

NOAA Updates their Seasonal Outlook – El Nino coming but not here yet – May 27, 2023

By Sig Silber May 27, 2023weatherNo Comments

Lightly edited at 5:54 p.m. EDT Saturday, May 27, 2023 mostly to compare the new to the prior Seasonal Outlook. They are very similar.

On the third Thursday of the month right on schedule NOAA issued what I describe as their Four-Season Outlook. The information released also included the Mid-Month Outlook for the single month of June plus the weather and drought outlook for the next three months. I present (apologies for the delay) the information issued and try to add context to it. It is quite a challenge for NOAA to address the subsequent month, the subsequent three-month period as well as successive three-month periods for a year or a bit more.

It is very useful to read the excellent discussion that NOAA issues with this Seasonal Outlook. In general, the overall level of confidence in the Seasonal Outlook is lower than usual for many reasons that are addressed in the NOAA discussion. It is best to read the full discussion but here are some of the highlights:

Equatorial SSTs are near-to-above average across most of the Pacific Ocean and atmospheric conditions reflect ENSO-neutral conditions [Editor’s Note: The Atmosphere has not yet responded to the warming in the Eastern Pacific which is marginally at El Nino levels].
At least a weak El Niño is likely given high levels of above-average oceanic heat content, but the range of possibilities include an 80 percent chance of at least a moderate El Niño and a 55 percent chance of a strong El Niño by the end of the year.
This likely warm start to June along with monthly dynamical and statistical tools support increased probabilities for above-normal temperatures from the Pacific Northwest east to the Northern Great Plains.
The NMME along with an increased potential for an early season TC [tropical cyclone] to emerge from the western Caribbean Sea favors above-normal precipitation [in June] for parts of the Southeast.
The JJA 2023 temperature outlook favors above-normal temperatures over the western CONUS, the Southwest, the Gulf States, along the eastern seaboard, and for much of the state of Alaska.
The JJA 2023 precipitation outlook depicts below-normal precipitation probabilities over the Pacific Northwest and parts of the Northern Rockies, the Southwest, and south coast of Alaska. NMME and C3S are in good agreement on below normal precipitation over the southwest and wet soil moisture over the Four Corners region may provide a sluggish start to the Monsoon this summer. Above normal precipitation probabilities are indicated over parts of the Middle and Lower Mississippi Valleys, the Ohio and Tennessee Valleys, the Southeast, and mid-Atlantic. Parts of the Central Plains tend to be anti-correlated with the monsoon region, and as such a weak tilt toward above normal precipitation is indicated.
Confidence decreases in September-November (SON) 2023 and following seasons as lead time increases and dynamical models become more uncertain, however, El Niño is expected to become more dominant in the forecast(s), and the pattern begins to reflect El Niño conditions during fall and winter seasons.
Decadal [Temperature] trends become the dominant player in spring and summer 2024, with below normal trends over the Pacific Northwest and above-normal trends over the Mid-Atlantic.

NOAA Updates its Four Season Outlook on January 19, 2023 – Rapid Transition to ENSO Neutral and then possibly to El Nino

By Sig Silber January 21, 2023weatherNo Comments

On the third Thursday of the month right on schedule NOAA issued what I describe as their Four-Season Outlook. The information released also included the MId-Month Outlook for the single month of February plus the weather and drought outlook for the next three months. I present the information issued and try to add context to it. It is quite a challenge for NOAA to address the subsequent month, the subsequent three-month period as well as successive three-month periods for a year or a bit more.

We will begin to see the impacts of the end of La Nina for precipitation in May/June/July of 2023. And the outlook for the Southwest Monsoon has changed from above normal to normal.

We may see the impacts of El Nino Conditions on the temperature in Dec/Jan/Feb 2023-2024 and on precipitation in Sept/Oct/Nov 2023 but the impacts will be small and strangely impacting the Eastern half of CONUS more than the West. The Outlook is not for a wetter-than-normal West but for some relief from the heat.

The maps show a series of changes which I have highlighted in my comments. Next winter will be very different than this winter.

It is very useful to read the excellent discussion that NOAA issues with this Seasonal Outlook.

Looking Ahead 28 Days from December 16, 2022; Plus Weekend Report; Plus Excerpts from NOAA Four-Season Outlook

By Sig Silber December 17, 2022weatherNo Comments

Updated at 6:32 p.m. EST Monday, December 19, 2022 (Our regular evening report will be published tonight).

Once a week we show many of the actual forecast maps not just provide the links to these maps. This makes it easier for the reader. Our report provides a separate forecast for Days 1 and 2, Days 1-5, Days 6 -10, Days 8 – 14, and weeks 3 and 4. We also include a next-day and 10-Day Global Average Temperature and Cumulative Precipitation Forecast. This provides information that is useful to readers in terms of planning their activities for the weekend and the next 28 days. Over the weekend and into Monday there will be frequent updates of the short-term forecast.

Looking out 28 days, what we see is:

For Temperature: The previous colder-than-normal air mass that entered the Northwest is moving east and being replaced by warmer-than-normal air from west to east.
For Precipitation: The evolution of the predicted Southern Tier drought for the first part of 2023.

We have also included the January 2023 and the JFM 2023 Outlook from the NOAA Seasonal Outlook issued on December 15, 2023.