Pressure Tendency
Calculator
Results
- Pressure tendency band (0 steady to 3 rapid)
- 2
- Pressure change magnitude (hPa)
- 2.5
- Trend direction (1 rising, -1 falling, 0 steady)
- -1
Weather results
| Pressure tendency band (0 steady to 3 rapid) | 2 |
| Pressure change magnitude (hPa) | 2.5 |
| Trend direction (1 rising, -1 falling, 0 steady) | -1 |
formula-map diagram
- Pressure tendency band (0 steady to 3 rapid)
- 2
- Pressure change magnitude (hPa)
- 2.5
- Trend direction (1 rising, -1 falling, 0 steady)
- -1
Weather relationship
Formula
WMO tendency band on |Δp3h|: 0 <1 hPa steady, 1 1-2, 2 2-3, 3 ≥3 hPa (rapid); sign gives rising/falling= 2
Note
This is a simplified model: it applies the published standard formula to the numbers you entered and ignores local terrain, radiation, precipitation type and instrument error. Wind chill is the 2001 NWS/Environment Canada regression, valid at or below 10 °C with wind at or above 4.8 km/h; the heat index is the Rothfusz regression, reliable above about 27 °C; dew point uses the Magnus approximation (a = 17.27, b = 237.7 °C) over liquid water; wet bulb uses Stull's approximation at standard sea-level pressure; pressure and density altitude assume the International Standard Atmosphere and dry air. Do not use these results for aviation, structural or safety decisions without an official forecast or a qualified professional.