BTSSSIS (SISR)
About
Level 1 – Weak / Marginal Storm [ALPHA] [POPCORN]
Intensity: Minimal organization, low energy.
Potential Threats: Brief heavy rain, isolated lightning, weak wind gusts.
Likelihood of Severe Weather: Very low (<10%).
Spotter Action: Routine monitoring; no immediate concern.
Level 2 – Moderate / Developing Storm [BRAVO] [BRUISER]
Intensity: Some organization, moderate energy.
Potential Threats: Stronger wind gusts (40-50 mph), small hail (<1"), frequent lightning.
Likelihood of Severe Weather: Low to moderate (10-30%).
Spotter Action: Watch for strengthening; report if conditions worsen.
Level 3 – Strong / Organized Storm [CHARLIE] [CHARGER]
Intensity: Well-structured, high energy, capable of severe weather.
Potential Threats: Damaging winds (50-70 mph), large hail (1-2"), possible weak tornado (EF0-EF1).
Likelihood of Severe Weather: Moderate to high (30-60%).
Spotter Action: Active spotting; relay critical updates.
Level 4 – Intense / Severe Storm [DELTA] [DOMINATOR]
Intensity: Highly organized, very high energy, significant severe risk.
Potential Threats: Destructive winds (70+ mph), very large hail (2"+), strong tornadoes (EF2-EF3), flash flooding.
Likelihood of Severe Weather: High (60-90%).
Spotter Action: Urgent reporting; seek safe positioning.
Level 5 – Extreme / High-End Storm [ECHO] [ENDER]
Intensity: Exceptionally organized, extreme energy, potentially life-threatening.
Potential Threats: Catastrophic winds (90+ mph), giant hail (3"+), violent tornadoes (EF4-EF5), extreme flooding.
Likelihood of Severe Weather: Very high (>90%).
Spotter Action: Extreme caution; prioritize safety; relay critical info immediately.
Tags:
PDS - Particularly Dangerous Situation: From Wikipedia: In weather forecasting in the United States, "particularly dangerous situation" (PDS) is the wording used by the National Weather Service and the Storm Prediction Center to convey special urgency in watch or warning messages for unusually extreme and life-threatening severe weather. It is used in the format "This is a particularly dangerous situation..." at the discretion of the issuing forecaster. A watch or warning bearing the phrase is referred to as a PDS watch or PDS warning. Its first usage in the SISR scale was on March 10, 2026 during that day's severe weather outbreak.
Emergency - From Wikipedia: A tornado emergency is an enhanced version of a tornado warning, which is used by the National Weather Service (NWS) in the United States during imminent, significant tornado occurrences. Although it is not a new warning type from the NWS, issued instead within a severe weather statement or in the initial tornado warning, a tornado emergency generally means that catastrophic, widespread damage is expected to occur and a high likelihood of numerous fatalities is expected with a large, strong to violent tornado.
When used by the SISR System, Emergency is used as a general conveyance of potentially record breaking weather phenomena which could cause damage of extreme magnitudes, and potentially mass casualty incidents. Emergency is a level above PDS in the SISR scale, and Emergency is the highest intensity rating level that can be given to any outbreak using the SISR. There has never been a Level 5 Emergency declaration which resulted in Level 5 Emergency damage. The first issuance was on March 16, 2026, however, thankfully, that outbreak underperformed significantly.
Information
SISR – BT Studio Storm Intensity and Severity Rating
SISR is an in-house weather intensity prediction system currently in Early Alpha. It is designed to provide preliminary assessments of severe weather events, focusing on squall lines, supercells, and other classic severe convective systems typically observed in the Midwest during spring and summer.
Limitations:
SISR is not yet capable of accurately assessing threats from weather phenomena outside its current scope. This includes, but is not limited to:
Winter weather events such as snowstorms, blizzards, or ice storms
Tropical weather systems and hurricanes
Localized flash flooding unrelated to organized convective storms
Rare or atypical severe events outside the standard spring/summer severe weather pattern
Because of these limitations, SISR should not be relied upon as the sole source of critical safety information. For the most accurate and official severe weather predictions, warnings, and guidance, please consult the National Weather Service (NWS) at weather.gov.
Future Development:
SISR is actively being developed and will be upgraded to include:
Winter weather tracking (snow, ice, mixed precipitation)
Broader severe weather phenomena across diverse regions and seasons
Enhanced predictive capabilities for atypical storms and evolving weather patterns
Improved integration of radar, satellite, and model data for more refined intensity assessments
SISR is intended as a supplemental tool for storm enthusiasts, hobbyists, and preliminary forecasting, offering an early look at storm intensity trends. As the system matures, it will provide more comprehensive coverage and higher predictive confidence across a wider range of meteorological phenomena.