Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center


 
 

 

Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
  GOES-East Satellite
  GOES-West Satellite
  National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
   Winter Weather
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.

Model Analyses and Forecasts Atl

Meteorological Conversions and Calculations
 

The Beaufort Wind Scale
WPC HEAT INDEX FORECASTS  
Force Name

 Wind Speed knots       mph

Consequence
0 Calm 0 0 Smoke rises vertically

Wave height: 0 m - Sea: Like a mirror

1 Light air 1-3 1-3 Smoke drifts with air

Wave height: 0.1 m (.25 ft) - Sea: Ripples - No foam crests

2 Light breeze 4-6 4-7 Weather vanes become active

Wave height: 0.2-0.3 m (0.5-1 ft) - Sea: Small wavelets - Not breaking

3 Gentle breeze 7-10 8-12 Leaves and small twigs move

Wave height: 0.6-1 m (2-3 ft) - Sea: Small wavelets - Crests begin to break

4 Moderate breeze 11-16 13-18 Small branches sway

Wave height: 1-1.5 m - Sea: Small waves becoming longer, numerous whitecaps.

5 Fresh breeze 17-21 19-24 Small trees sway - Waves break

Wave height: 2-2.5 m (6-8 ft) - Sea: Moderate waves - Many whitecaps

6 Strong breeze 22-27 25-31 Large branches sway

Wave height: 3-4 m (9.5-13 ft) - Sea: Larger waves forming - Whitecaps everywhere

7 Near gale 28-33 32-38 Whole trees sway - difficult to walk

Wave height: 4-5.5 m (13.5-19 ft) - Sea: Sea heaps up - White foam blown around

8 Gale 34-40 39-46 Twigs break off trees

Wave height: 5.5-7.5 m (18-25 ft) - Sea: Edges of crests break into spindrifts

9 Strong gale 41-47 47-54 Shingles blow off roofs

Wave height: 7-10 m (23-32 ft) - Sea: High waves - Sea rolls - Reduced visibility

10 Storm 48-55 55-63 Trees uprooted - Damage to buildings

Wave height: 9-12.5 m (29-41 ft) - Sea: Very high waves with overhanging crests

11 Violent Storm 56-63 64-73 Widespread damage

Wave height: 11.5-16 m (37-52 ft) - Sea: Exceptionally high waves

12 Hurricane Over 63 Over 73 Violent destruction

Wave height: 16+ m (52+ ft) - Sea: Sea completely white - Excessive foam

   

Wind Speed Converter

More Meteorological Conversions and Calculations
 

NOAA/ National Weather Service
National Centers for Environmental Prediction
Weather Prediction Center
5830 University Research Court
College Park, Maryland 20740
Weather Prediction Center Web Team
Disclaimer
Credits
Glossary
Privacy Policy
About Us
Career Opportunities
Page last modified: Tuesday, 05-Mar-2013 13:08:41 UTC