| TABLE A: THE FUJITA TORNADO DAMAGE SCALE | ||
| F0 | < 73 |
Light damage. Some damage to chimneys; branches broken off trees; shallow-rooted trees pushed over; sign boards damaged. |
| F1 | 73-112 |
Moderate damage. Peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos blown off roads. |
| F2 | 113-157 |
Considerable damage. Roofs torn off frame houses; mobile homes demolished; boxcars overturned; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground. |
| F3 | 158-206 |
Severe damage. Roofs and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off the ground and thrown. |
| F4 | 207-260 |
Devastating damage. Well-constructed houses leveled; structures with weak foundations blown away some distance; cars thrown and large missiles generated. |
| F5 | 261-318 |
Incredible damage. Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 109 yds; trees debarked; incredible phenomena will occur. |
|
*WINDS: Do not use F-scale winds literally. These precise wind speed numbers are actually guesses and have never been scientifically verified. Different wind speeds may cause similar-looking damage from place to place-even from building to building Source: Storm Prediction Center, NWS, NOAA |
||
| TABLE B: THE SAFFIR-SIMPSON HURRICANE SCALE | |||
| 1 | 74-95 mph (64-82 kt) |
4-5 ft
|
No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs. Also, some coastal road flooding and minor pier damage. |
| 2 | 96-110 mph (83-95 kt) |
6-8 ft
|
Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center. Small craft in unprotected anchorages break moorings. |
| 3 | 111-130 mph (96-113 kt) |
9-12 ft
|
Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences within several blocks of the shoreline may be required. |
| 4 | 131-155 mph (114-135 kt) |
13-18 ft
|
More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles. |
| 5 | > 155 mph (135 kt) |
> 18 ft
|
Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of all structures located less than 15 ft above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5-10 miles of the shoreline may be required. |
Wind: prime indicator of hurricane category, speeds are one minute averages at 30 feet above the surface Surge: typical storm surge above normal (highly variable depending on configuration of coast and continental shelf Source: Tropical Prediction Center, NWS, NOAA |
|||
| TABLE C: THE PALMER DROUGHT SEVERITY INDEX | ||
| -1.0 to -1.9 | Abnormally Dry
|
Going into drought: short-term dryness slowing planting, growth of crops or pastures; fire risk above average. Coming out of drought: some lingering water deficits; pastures or crops not fully recovered. |
| -2.0 to -2.9 | Moderate Drought
|
Some damage to crops, pastures; fire risk high; streams, reservoirs, or wells low, some water shortages developing or imminent, voluntary water use restrictions requested |
| -3.0 to -3.9 | Severe Drought
|
Crop or pasture losses likely; fire risk very high; water shortages common; water restrictions imposed |
| -4.0 to -4.9 | Extreme Drought
|
Major crop/pasture losses; extreme fire danger; widespread water shortages or restrictions |
| -5.0 to -5.9 | Exceptional Drought
|
Exceptional and widespread crop/pasture losses; exceptional fire risk; shortages of water in reservoirs, streams, and wells, creating water emergencies |
