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

A long-standing forecast tool gets a new layer of detail

Convective Outlooks issued by NOAA’s Storm Prediction Center (SPC) have long served as an early, high-level signal that severe thunderstorms may be possible. These outlooks are widely used because they provide advance notice that storms capable of damaging winds, hail, and tornadoes could develop. Emergency managers and other decision makers have relied on them for decades as a way to gain critical lead time—often measured in days—to prepare for severe weather.

Until now, however, there has been a key gap in what those outlooks could communicate. While the outlooks have been effective at describing the likelihood of severe hazards, there has not been an official way within the product to differentiate between days when severe weather might be more routine versus days when the potential exists for especially violent or extreme impacts.

That is changing with the introduction of a new hazard severity element called Conditional Intensity. Added in February 2026, Conditional Intensity is intended to help forecasters highlight areas where storms that do occur may be more intense or violent, even if the overall probability of storms is not particularly high.

Why intensity matters as much as coverage

Severe weather forecasting often involves balancing two related but distinct questions: how likely severe storms are to occur, and how intense those storms could be if they do occur. Traditional Convective Outlooks have been a way for SPC forecasters to quantify the threat for severe weather in terms of the expected number of events—such as tornadoes, large hail, or severe wind reports—within a given area.

Conditional Intensity adds another layer to that approach. Rather than focusing only on how many severe events might happen, it is designed to highlight where the storms that form could be more extreme. This includes the potential for violent tornadoes and other high-end hazards that can drive the greatest impacts.

As Evan Bentley, Warning Coordination Meteorologist for NOAA’s Storm Prediction Center, explained, the most intense forms of severe weather account for a disproportionate share of losses. “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,” Bentley said. He added that the new information can be valuable even when probabilities are low: “Now, even when the probability of a severe hazard is low but the intensity is high, we can convey that threat.”

How Conditional Intensity complements existing outlook probabilities

In practice, Conditional Intensity is meant to help users distinguish between different kinds of severe weather setups that might otherwise look similar at a glance. An outlook area may indicate a meaningful chance of severe weather, but the nature of what is expected can vary widely—from many storms producing mostly lower-end severe reports, to a small number of storms that could be unusually destructive.

The concept can be illustrated by comparing two different scenarios described by SPC:

• High coverage, lower intensity: A wind event anticipated to generate many reports but few significant severe reports could be forecast with higher coverage probabilities but a lower conditional intensity.
• Low coverage, higher intensity: An event where only one or two high-end storms are anticipated could have lower coverage probabilities but a higher conditional intensity forecast, signaling that any storms that do form could bring more extreme impacts.

This distinction is not merely academic. The ability to separate “more storms” from “more destructive storms” can shape how communities prepare. SPC notes that this kind of guidance is vital when positioning resources and preparing citizens, because it helps differentiate between more and less destructive severe weather setups.

From research and testing to an operational product

The Conditional Intensity concept did not appear overnight. The level of detail it provides was first explored during the 2019 Spring Experiment held in the NOAA Hazardous Weather Testbed in Norman, Oklahoma. During that experiment, the Severe Hazards Desk issued conditional intensity forecasts for several hazards—tornadoes, destructive winds, and large hail.

In those experimental forecasts, areas corresponded to whether significant severe weather was considered unlikely, possible, or expected. Participants in the Spring Experiment helped lay the groundwork for what would become Conditional Intensity, with the goal of highlighting areas of greatest concern for violent weather and an elevated potential for societal impacts.

Testing continued beyond the initial experiment. Since late 2021, SPC forecasters have been producing Conditional Intensity forecasts on an experimental basis, using multiple severe weather events as opportunities to refine how intensity is assessed and communicated.

After more than four years of internal experimentation, SPC forecasters concluded they had demonstrated skill in their ability to discriminate between conditional intensities of different severe weather hazards. With that confidence, the center is now moving to share this information officially through the Convective Outlook product.

What changes for users of Day 1 Convective Outlooks

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

For many users—especially emergency managers, public safety officials, and others who make time-sensitive decisions—the Day 1 outlook is a key planning tool. It is often used to support staffing decisions, resource placement, and public communication ahead of an expected severe weather day. With Conditional Intensity added, the outlook is expected to better convey when the main concern is not just the chance of severe storms, but the possibility that any storms that do occur could be particularly intense.

Why the new information can improve preparedness decisions

SPC’s explanation of Conditional Intensity emphasizes a practical problem faced by decision makers: severe weather risk is not one-dimensional. Two days may both carry a risk of severe storms, but the expected impacts could differ dramatically depending on storm mode, intensity potential, and how concentrated the threat is.

By adding a severity-focused element, SPC aims to provide guidance that can be used alongside existing probability-based outlooks. The goal is to help users interpret risk in a more nuanced way—especially when the expected number of storms is low, but the potential intensity is high.

That nuance can matter when planning for worst-case outcomes. A day featuring widespread storms with mostly lower-end severe reports may require broad situational awareness and routine readiness. A day with fewer storms but a higher potential for violent outcomes may call for a different posture, including heightened focus on the areas most likely to experience the highest-end impacts.

A clearer signal for high-end hazards

SPC’s messaging around Conditional Intensity repeatedly returns to a central point: the most violent or extreme severe weather events can drive the greatest societal consequences. The new layer is designed to make it easier to highlight those days and those areas where the potential for intense hazards is elevated.

Importantly, this does not replace the existing Convective Outlook framework. Instead, it builds on it—retaining the long-standing approach of quantifying hazard probabilities while adding a complementary view of hazard severity. In doing so, SPC is seeking to communicate a fuller picture: not only where severe storms might occur, but where the storms that do occur could be especially dangerous.

Key points at a glance

• Convective Outlooks provide early notice that severe storms capable of damaging winds, hail, and tornadoes are possible.
• Emergency managers and decision makers have used these outlooks for decades to gain days of lead time.
• Conditional Intensity adds hazard severity information to help highlight areas at risk for more intense or violent storms.
• The new layer can help distinguish between widespread, lower-end severe setups and lower-coverage events that could produce extreme impacts.
• The concept was explored in the 2019 Spring Experiment and tested experimentally by SPC since late 2021.
• Conditional Intensity is scheduled to appear in the Day 1 Convective Outlook on March 3, 2026, with flexibility to shift implementation within that week if needed.

With Conditional Intensity, SPC is formalizing a way to communicate something forecasters and emergency managers have long needed: a clearer signal not just that severe weather is possible, but that the most intense forms of it may be on the table—even when the overall number of storms is expected to be limited.