METEOROLOGY – EVERE WEATHER & TORM CALCULATOR
Total Totals Index
A precise tool.
What is the Total Totals Index & How does it work?
The Total Totals Index (TTI) is a meteorological index used to assess the potential severity of thunderstorms. It combines temperature, moisture, and wind shear parameters to provide an estimate of the likelihood of severe weather events such as tornadoes, large hail, and damaging winds.
The TTI is calculated using the formula: [TTI = 10left(frac{T_{850} – T_{500}}{T_{850}}right) + 20left(frac{q_{v,850} – q_{v,500}}{q_{v,850}}right) + 30left(frac{w_{s,850} – w_{s,500}}{w_{s,850}}right)]
The TTI is calculated using the formula: [TTI = 10left(frac{T_{850} – T_{500}}{T_{850}}right) + 20left(frac{q_{v,850} – q_{v,500}}{q_{v,850}}right) + 30left(frac{w_{s,850} – w_{s,500}}{w_{s,850}}right)]
TTI = 10left(frac{T_{850} – T_{500}}{T_{850}}right) + 20left(frac{q_{v,850} – q_{v,500}}{q_{v,850}}right) + 30left(frac{w_{s,850} – w_{s,500}}{w_{s,850}}right)
T = Temperature (K)
q_v = Specific Humidity (g/kg)
w_s = Wind Shear (m/s)
q_v = Specific Humidity (g/kg)
w_s = Wind Shear (m/s)
Parameters
Result
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Frequently Asked Questions
What is the Total Totals Index (TTI)?
The TTI is a meteorological index that combines temperature, moisture, and wind shear parameters to estimate the likelihood of severe weather events like tornadoes, large hail, and damaging winds.
How do you calculate the Total Totals Index?
TTI is calculated using the formula: TTI = 10((T850 – T500)/T850) + 20((qv,850 – qv,500)/qv,850) + 30((ws,850 – ws,500)/ws,850), where T is temperature, qv is moisture mixing ratio, and ws is wind speed at 850 and 500 hPa levels.
What values of TTI indicate severe thunderstorm potential?
A TTI value greater than or equal to 250 typically indicates a higher likelihood of severe thunderstorms, including tornadoes, large hail, and damaging winds.
Which atmospheric parameters does the TTI consider?
The TTI considers temperature (T), moisture mixing ratio (qv), and wind speed (ws) at 850 and 500 hPa pressure levels to assess severe thunderstorm potential.
How often should I calculate the TTI for accurate weather assessment?
It’s recommended to calculate the TTI regularly, especially during periods of unstable atmospheric conditions, to monitor changes in severe thunderstorm potential.
Can the TTI be used to predict tornadoes specifically?
While the TTI is useful for assessing severe thunderstorm potential, it’s not a specific predictor of tornadoes. Other factors like shear and instability must also be considered for tornado prediction.
What are the units for each component in the TTI formula?
The temperature difference (T850 – T500) is in degrees Celsius, moisture mixing ratio difference (qv,850 – qv,500) is in grams per kilogram, and wind speed difference (ws,850 – ws,500) is in meters per second.
Results are for informational purposes only and do not constitute professional advice.