NOAA Adds “Conditional Intensity” to Convective Outlooks to Flag Potential for More Violent Severe Storms

A long-running forecast tool gets a new layer of meaning

Convective Outlooks issued by NOAA’s Storm Prediction Center (SPC) have long served as an early signal that severe thunderstorms may be possible. These outlooks provide advance notice that hazards such as damaging winds, hail, and tornadoes could occur, offering critical lead time for emergency managers and other decision makers who need to prepare resources, staffing, and public messaging.

For decades, that lead time has been a core strength of the outlooks. However, one limitation has remained: while the outlooks quantify the likelihood of severe weather, they have not provided a clear way to distinguish between days when severe storms are expected to be more routine versus days when the atmosphere may support especially violent or extreme outcomes.

That is set to change with the addition of hazard severity information called Conditional Intensity. Beginning in early March 2026, SPC plans to incorporate this new element into its official Convective Outlook products, allowing forecasters to highlight areas where storms may be more intense—even if the overall coverage of severe weather is expected to be limited.

Why “Conditional Intensity” matters for risk communication

Severe weather risk is not only about how many storms occur, but also about what any individual storm could do. According to SPC, the new Conditional Intensity information is designed to help communicate that distinction more directly.

“High-end severe weather like intense and violent tornadoes cause by far the greatest loss of life and property, and this improvement allows us to highlight days when these specific threats are more likely," said Evan Bentley, Warning Coordination Meteorologist for NOAA’s Storm Prediction Center. “Now, even when the probability of a severe hazard is low but the intensity is high, we can convey that threat.”

In practical terms, Conditional Intensity is meant to complement the existing probability-based structure of Convective Outlooks. The traditional approach has focused on quantifying the threat in terms of expected occurrences—how many tornadoes, large hail events, or severe wind reports might happen within a given area. The new approach adds a second dimension: the potential for the most extreme versions of those hazards.

From “how many” to “how intense”

SPC describes Convective Outlooks as a way to quantify the threat for severe weather—essentially estimating the number of severe weather instances in a given region. This has been valuable guidance for planning and situational awareness, especially when outlooks provide multiple days of lead time.

Conditional Intensity adds another layer by emphasizing where more extreme events are more likely. In SPC’s description, that includes scenarios such as violent tornadoes, as well as other high-end hazards related to destructive winds and large hail.

The distinction is important because severe weather setups can vary widely in how they pose danger. Some events may produce numerous reports across a broad area, while others may produce fewer storms overall but with greater potential for severe impacts where storms do occur.

How the new guidance can change interpretation of a forecast

SPC provides an example of how Conditional Intensity can help clarify what a forecast “means” in real-world terms.

• High coverage, lower intensity: A wind event may be anticipated to generate many reports, but relatively few significant severe reports. In that case, the outlook could show higher coverage probabilities while the Conditional Intensity forecast is lower.
• Low coverage, higher intensity: Another setup might suggest only one or two high-end storms are likely to occur. That could correspond to lower coverage probabilities, but a higher Conditional Intensity forecast—signaling that any storms that do form could produce more extreme impacts.

This is the kind of nuance that can be difficult to communicate with probability information alone. Conditional Intensity is intended to make that nuance more visible, helping users recognize when the primary concern is not necessarily the number of storms, but the potential consequences of the storms that do develop.

SPC notes that this differentiation is vital guidance when positioning resources and preparing citizens. In other words, it can support decisions about readiness and response by clarifying whether a severe weather day is more likely to be broadly disruptive, intensely destructive in isolated areas, or somewhere in between.

Development began in a testbed setting

The concept behind Conditional Intensity was first explored during the 2019 Spring Experiment in the NOAA Hazardous Weather Testbed in Norman, Oklahoma. That experiment provided an environment for forecasters and partners to evaluate new approaches to forecasting and communication before they become part of official products.

During that Spring Experiment, the Severe Hazards Desk issued conditional intensity forecasts for tornadoes, destructive winds, and large hail. The forecasts used areas corresponding to whether significant severe weather was considered unlikely, possible, or expected.

SPC credits participants in the experiment with laying the groundwork for the eventual development of Conditional Intensity as a formal addition to Convective Outlooks. The goal was to identify and highlight areas of greatest concern for violent weather and a higher potential for societal impacts.

From experimental forecasts to official outlook information

After the initial exploration in 2019, SPC continued refining the concept in subsequent years. Since late 2021, SPC forecasters have been producing Conditional Intensity forecasts experimentally, using multiple severe weather events as opportunities to improve the intensity guidance.

SPC describes this as an internal experiment lasting more than four years. Over that period, forecasters worked to evaluate and improve how well the experimental forecasts could discriminate between different levels of conditional intensity across various severe weather hazards.

According to SPC, forecasters have demonstrated skill in the ability to discriminate between the conditional intensities of different severe weather hazards. Based on that progress, the center indicated it is ready to share this information officially through the Convective Outlook.

When the change is scheduled to appear

The Conditional Intensity addition is scheduled to appear in the Day 1 Convective Outlook on March 3, 2026. SPC also notes a practical consideration for the rollout: if a substantial severe weather threat exists on March 3, the implementation will be shifted to another day that same week.

This scheduling detail reflects the operational reality that major forecast product updates are ideally introduced when forecasters can focus on implementation without the added pressure of an unusually high-impact weather day.

What users can take from the update

For many users of Convective Outlooks—especially emergency managers and other decision makers—the value of the product has always been its early warning function. It helps identify when severe storms are possible days in advance, supporting planning and preparedness.

Conditional Intensity is intended to strengthen that role by making it easier to recognize when the most dangerous outcomes are more plausible, even if the overall probability of severe weather is not especially high. In effect, it can help answer a question that often arises during severe weather season: not only whether storms could occur, but whether the environment may favor particularly intense, violent storms.

The update also reflects a broader emphasis on communicating risk in ways that better match how people make decisions. A forecast that indicates a limited number of storms may still require significant readiness if those storms have a higher chance of producing extreme impacts. Conditional Intensity is designed to help convey that kind of scenario more clearly within the structure of the Convective Outlook.

Key points at a glance

• Convective Outlooks provide advance notice that severe storms with damaging winds, hail, and tornadoes are possible.
• Emergency managers and decision makers have relied on these outlooks for decades for critical lead time.
• Until now, the outlooks did not differentiate days when especially violent or extreme weather is expected.
• Conditional Intensity adds hazard severity information, allowing SPC to highlight areas at risk for more intense, violent storms.
• The concept was explored in 2019 during the Spring Experiment in the NOAA Hazardous Weather Testbed in Norman, Oklahoma.
• SPC has produced Conditional Intensity forecasts experimentally since late 2021 and plans to add them officially after more than four years of internal testing.
• The addition is scheduled for the Day 1 Convective Outlook on March 3, 2026, with flexibility to shift within that week if a substantial severe weather threat exists that day.

As the change takes effect, the Day 1 Convective Outlook will continue to serve its established purpose—quantifying the threat for severe weather—while also offering a clearer signal about when the most extreme forms of severe hazards may be more likely. For communities and agencies that use outlooks to guide readiness, the added Conditional Intensity information is designed to support more informed preparation for the full range of severe storm possibilities.