Afternoon Ventilation Index
National Weather Service
Grand Junction, CO
Grand Junction, CO
About the Ventilation Index (VI)
Mixing Height times Transport Wind = VI
Mixing Height = Calculated for forecast max temperature
Transport Wind = Average wind speed from SFC to Mixing Height (knots)
Shown in Knot Feet
Mixing Height = Calculated for forecast max temperature
Transport Wind = Average wind speed from SFC to Mixing Height (knots)
Shown in Knot Feet
Valid: Sunday November 23, 2008
Valid: Monday November 24, 2008
Valid: Tuesday November 25, 2008
| Category | Range | Units |
|---|---|---|
| POOR | < 40,000 | Knot Feet |
| FAIR | 40,000 to 59,999 | Knot Feet |
| GOOD | 60,000 to 99,999 | Knot Feet |
| VERY GOOD | 100,000 to 149,999 | Knot Feet |
| EXCELLENT | >= 150,000 | Knot Feet |
