WTOC Wind Scales - WTOC-TV: Savannah, Beaufort, SC, News, Weather & Sports

Scales to Estimate Wind Velocity


Saffir / Simpson
Hurricane Damage Potential Scale

Category

1

2

3

4

5

Winds (MPH)

74-95

96-110

111-130

131-155

higher than 155

Winds (Knots)

65-82

83-95

96-113

114-135

higher than 135

Pressure (inches)

Above 28.90

28.90-28.50

28.49-27.90

27.89-27.15

Below 27.15

Pressure (Mb)

Above 980

979-965

964-945

944-920

Below 920

Storm Surge (ft)

4-5

6-8

9-12

13-18

19-25

Damage

Minimal

Moderate

Extensive

Extreme

Catastrophic



Fujita-Pearson Tornado Intensity Scale

Category

F0

F1

F2

F3

F4

F5

Winds (MPH)
Old Scale

40-72

73-112

113-157

158-206

207-260

261-318

Winds (MPH)
New Scale

65-85

86-110

111-135

136-165

166-200

Over 200

Path Length (Miles)

0-1

1-3.1

3.2-9.9

10-31

32-99

100-315

Path Width (Yards)

0-17

18-55

56-175

176-556

557-1,584

1,760-5,456

Expected Damage

Minimal

Moderate

Considerable

Severe

Devastating

Incredible



Beaufort Wind Scale

#

MPH

Definition

Conditions at Sea

Conditions on Land

0

0

Calm

Sea like a mirror

Smoke rises vertically

1

1-4

Light air

Ripples on the water

Smoke drifts with wind, Spanish Moss sways

2

5-7

Light Breeze

Small wavelets

Leaves rustle

3

8-12

Gentle Breeze

Large wavelets, scattered whitecaps

Leaves and small twigs in constant motion

4

13-18

Moderate Breeze

Small waves, frequent whitecaps

Small branches move, dust raised

5

19-24

Fresh Breeze

Moderate waves, many whitecaps

Medium branches move, debris moves about

6

25-31

Strong Breeze

Large waves, white foam, some spray

Large branches in motion, wires whistle,wind heard in pines

7

32-38

Near Gale

6-10 foot seas, foam blown in streaks

Whole tree in motion, difficult in walking, roar heard in pines

8

39-45

Gale

8-12 foot seas, foam everywhere

Twigs break off trees,lawn furniture rocks, dangerous to be out

9

46-53

Strong Gale

10-16 foot seas, foam / spray,restricted visibility

Large branches break, lawn furniture moved, car rocked by wind

10

54-63

Storm

12-18 foot seas, sea appears white

Trees uprooted, roof shingles damaged, car motion affected


11

64-74

Violent Storm

16-20 foot seas, white sea and froth

Structural damage,lawn furniture airborne, difficult to drive car

12

75->

Hurricane

Seas greater than 20 feet, air filled with foam and spray

Widespread damage, power lines down everywhere. Cars blown off road, trees broken

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