SPC outlook risk levels, explained
Each day the NOAA/NWS Storm Prediction Center (SPC) rates the severe-weather threat on a five-level categorical scale. The category tells you two things at a glance: how likely severe storms are, and how widespread and intense they could be.
The five categories, lowest to highest
- Marginal (1) — isolated severe storms possible; limited in coverage and generally not intense. Stay aware.
- Slight (2) — scattered severe storms; a few could be strong (some damaging wind, hail, or a brief tornado).
- Enhanced (3) — numerous severe storms expected, some intense. A day to have a plan and watch for warnings.
- Moderate (4) — widespread severe weather likely, including the potential for strong tornadoes or very damaging wind. Take it seriously.
- High (5) — a severe weather outbreak is expected; reserved for the most dangerous, high-confidence days. Rare, and a signal to be ready to act immediately.
Below Marginal, a day may be labeled General Thunderstorms— ordinary storms are possible but severe weather isn't expected.
Categories vs. probabilities
The colored categories are a summary of the SPC's underlying probabilistic outlooks — the chance of a tornado, damaging wind, or large hail within about 25 miles of a point. That's why two days can both be "Enhanced" but feel different: one might be driven by a wind-and-hail threat, another by a tornado threat. When it matters, look at the individual hazard probabilities, not just the headline category.
Where to see today's outlook
Atmostorm's daily severe weather outlook turns the current SPC Day 1 categorical outlook into plain language — the top risk level, the per-hazard read (tornado, wind, hail), and which states are most at risk — and updates through the day. To watch storms as they develop, open the live map with the outlook and radar layers together. Not sure what a watch or warning means? That's the companion guide.
Common questions
What are the SPC severe weather risk levels in order?⌄
From lowest to highest: General Thunderstorms, then Marginal (1), Slight (2), Enhanced (3), Moderate (4), and High (5). The number is the SPC's categorical risk on a 0–5 scale.
What does an Enhanced risk mean?⌄
An Enhanced risk (level 3 of 5) means numerous severe storms are expected, some of them intense. It's a step above Slight — a day to have a plan and stay alert to warnings, especially if you have outdoor activities.
Is a Moderate risk worse than an Enhanced risk?⌄
Yes. Moderate (level 4) is the second-highest category and signals the potential for widespread, long-lived, and intense severe storms — including strong tornadoes or very damaging wind. High (level 5) is reserved for the most dangerous, rare outbreaks.
Does a higher risk level guarantee severe weather where I live?⌄
No. The outlook describes the likelihood and coverage of severe storms across a broad area, not a certainty at any one spot. A High risk area may still have places that stay quiet — and a Marginal day can still produce an isolated damaging storm.
Educational summary, not official guidance. Always confirm current watches and warnings at weather.gov and follow your local NWS office and emergency officials.