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Understanding NOAA's Storm Prediction Center Intensity Levels: A Comprehensive Guide

June 17, 2026 · The Clime Team
Understanding NOAA's Storm Prediction Center Intensity Levels: A Comprehensive Guide

The National Oceanic and Atmospheric Administration's (NOAA) Storm Prediction Center (SPC) has introduced a refined approach to communicating severe weather threats across the United States. This enhancement, known as Conditional Intensity Groups (CIGs), aims to provide clearer insights into the potential severity of storms, enabling better preparedness and response.

What Are Conditional Intensity Groups (CIGs)?

Conditional Intensity Groups, or CIGs, are a set of three intensity levels—Level 1, Level 2, and Level 3—integrated into the SPC's severe weather outlooks. These levels specifically address the potential intensity of significant severe hazards, such as tornadoes, wind gusts, and hail, should severe weather occur. The introduction of CIGs supplements the existing five-level risk categories (Marginal, Slight, Enhanced, Moderate, and High) by focusing on the expected strength of the most severe storms within a given area. (origin-west-www-spc.woc.noaa.gov)

How Do CIGs Enhance Severe Weather Communication?

Prior to the implementation of CIGs, the SPC utilized a "hatched area" on outlooks to denote regions where particularly severe hazards were anticipated. This method, while informative, did not specify the expected intensity of these hazards. With the addition of CIGs, the SPC now provides a more nuanced forecast by indicating not only the likelihood of severe weather but also the potential severity of the most intense storms. This dual-layered approach allows for a more comprehensive understanding of the threat landscape. (foxweather.com)

Breakdown of Intensity Levels

Each hazard—tornadoes, wind, and hail—has its own set of intensity levels:

  • Tornadoes:

  • Level 1: Potential for EF2-type tornadoes.

  • Level 2: Potential for EF3-type tornadoes.

  • Level 3: Potential for EF4-type tornadoes.

  • Wind:

  • Level 1: Potential for hurricane-force winds (74+ mph).

  • Level 2: Potential for organized bow echoes or derecho-type wind events.

  • Level 3: Potential for major derecho-style events with widespread severe damage.

  • Hail:

  • Level 1: Potential for hail 2 inches or larger.

  • Level 2: Potential for hail 3.5 inches or larger.

These classifications help the public and emergency managers understand not just the likelihood of severe weather but also the potential severity of the most intense storms that could develop. (iweathernet.com)

Practical Implications for Preparedness

The integration of CIGs into SPC outlooks offers several practical benefits:

  • Enhanced Decision-Making: By understanding both the probability and potential intensity of severe weather, individuals and organizations can make more informed decisions regarding safety measures and resource allocation.

  • Improved Public Communication: The clear delineation of intensity levels aids in conveying the severity of threats to the public, reducing confusion and promoting timely responses.

  • Targeted Resource Deployment: Emergency managers can prioritize areas with higher intensity levels, ensuring that resources are directed where they are most needed.

How Clime Supports Severe Weather Preparedness

Clime offers a comprehensive suite of tools designed to enhance severe weather preparedness and response:

  • Real-Time Weather Monitoring: Clime provides up-to-date weather information, including severe weather alerts, to keep users informed of current conditions.

  • Interactive Forecasts: Users can access detailed forecasts that incorporate SPC outlooks and intensity levels, aiding in understanding potential severe weather threats.

  • Personalized Alerts: Clime allows users to set customized alerts for specific weather conditions, ensuring timely notifications for severe weather events.

  • Educational Resources: Clime offers educational content to help users understand weather patterns, SPC outlooks, and best practices for severe weather preparedness.

By leveraging Clime's resources, individuals and organizations can enhance their preparedness for severe weather events, aligning with the SPC's efforts to provide clearer and more actionable weather information.

Conclusion

The introduction of Conditional Intensity Groups by NOAA's Storm Prediction Center marks a significant advancement in severe weather communication. By providing both the likelihood and potential intensity of severe weather events, CIGs enable more effective preparedness and response strategies. Tools like Clime further support these efforts by offering real-time information and educational resources, empowering users to make informed decisions in the face of severe weather threats.

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