Total Totals Index
Resolve named vertical/cross/total totals from fixed 850/500-hPa observations; unlike K index, no 700-hPa moisture layer and no storm occurrence/safety classification.
Description
Total Totals combines thermal contrast and low-level moisture at fixed 850 and 500 hPa levels.
Total Totals combines thermal contrast and low-level moisture at fixed 850 and 500 hPa levels. Its components have distinct meanings.1
Resolve named vertical/cross/total totals from fixed 850/500-hPa observations; unlike K index, no 700-hPa moisture layer and no storm occurrence/safety classification.
When to use Total Totals Index
Use this tool to resolve named vertical/cross/total totals from fixed 850/500-hPa observations; unlike K index, no 700-hPa moisture layer and no storm occurrence/safety classification.
Prepare the sounding profile or forecast verification counts. Check pressure levels, wind conventions, units and any requested layer bounds.
How to use Total Totals Index and understand its results
- Prepare the sounding profile or forecast verification counts. Check pressure levels, wind conventions, units and any requested layer bounds.
- Enter temperature850C, dewpoint850C, temperature500C using the field table and calculation rules, then run the tool.
- Read verticalTotalsC, crossTotalsC, totalTotalsC. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| temperature850C | Temperature850 c | number | Required |
| dewpoint850C | Dewpoint850 c | number | Required |
| temperature500C | Temperature500 c | number | Required |
Enter Celsius observations and require 850-hPa dewpoint no greater than its temperature. Return all three temperature-difference index values.2
vertical = T850−T500; cross = Td850−T500; total = vertical+cross Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| verticalTotalsC | Vertical totals c | number |
| crossTotalsC | Cross totals c | number |
| totalTotalsC | Total totals c | number |
{
"input": {
"temperature850C": 20,
"dewpoint850C": 10,
"temperature500C": -10
},
"output": {
"verticalTotalsC": 30,
"crossTotalsC": 20,
"totalTotalsC": 50
}
}Limitations and assumptions
No 700-hPa moisture term or storm occurrence classification is included.
Numbers and computed results must be finite; overflow produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use SWEAT Index Severe: Evaluate named SWEAT with dewpoint/total-totals truncation and conventional direction/speed gates on shear term, explicit knots/wind-from degrees; not a calibrated warning or severe-weather probability. For a complementary task, use Trade Wind Inversion Base Height Lookup: Identify measured contiguous inversion layers at caller lapse threshold and report observed base/top brackets; no climatological trade-wind lookup or inference of inversion between unresolved samples.
Further background: Convective environmental parameters and indices.
References
-
Convective environmental parameters and indices — National Weather Service
-
Total Totals Index — tool.io
Similar or alternative tools
- SWEAT Index Severe
Evaluate named SWEAT with dewpoint/total-totals truncation and conventional direction/speed gates on shear term, explicit knots/wind-from degrees; not a calibrated warning or severe-weather probability.
- Trade Wind Inversion Base Height Lookup
Identify measured contiguous inversion layers at caller lapse threshold and report observed base/top brackets; no climatological trade-wind lookup or inference of inversion between unresolved samples.