Hazard Level | 0 | 1 | 2 | 3 | 4 | 5 |
Threat to life or property and/or economic impact |
Nil | Minimal | Small | Medium | Significant | Very Significant |
Grassland Fire Danger Index | Very High | Extreme | Catastrophic | |||
Heat Index (°F) | 100° | 105° for 3 hours/ Advisory |
110° for 3 hours/ Warning |
110° for 3 hours/ Warning for 3 days |
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Wind Chill (°F) | 0° | -15° for 3 hours/ Advisory |
-25° for 3 hours/ Warning |
-25° for 3 hours/ Warning for 3 days |
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Blowing Dust or Smoke | Blowing Dust Advisory (3/8sm - 1sm) |
Blowing Dust Warning Visibility < 3/8sm |
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Other Obstruction to Visibility (statute miles) | Nil | Obstruction to Visibility in grids |
Patchy 1/2sm | Advisory | Widespread <1/8sm |
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Wind (non-convective) |
Advisory | High Wind Warning | High Wind Warning for 3 hours or more | Hurricane Force | ||
Frost/Freeze | Nil | Frost mentioned |
Frost Advisory |
Freeze Warning |
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Lightning | Nil | Thunder mentioned | ||||
Hail | Nil | Below Significant Weather Alert |
Significant Weather Alert | Severe Hail Likely | >= 2 inches | > 3 inches |
Wind (convective) |
Nil | Below Significant Weather Alert |
Significant Weather Alert |
Severe Wind Likely | 75 mph | Derecho |
Tornado | Nil | Cold Air Funnels |
Chance | Likely Tornado < EF4 |
EF4-EF5 | |
Winter Weather | Nil | Mentioned | Below Winter Weather Advisory Criteria |
Advisory or Watch |
Warning | Paralyzing Winter Weather (ie., 1 inch or more ice or blizzard w/ heavy snow) |
River Flood | Nil | Action Stage Likely |
Flood Warning (minor-moderate) |
Major Flooding |
Record Flooding | |
Flood/Flash flood | Nil | Flood Warnings Possible (FLW) |
Likely Flood Warnings (FLW); Possible Flash Flood Warnings (FFW), Flood/Flash Flood Watches (FFA) |
Widespread Flooding, or high probability of Flash Flood Warnings (FFW) |
Dam Break/ Catastrophic Flooding |