Wind is the movement of air caused by pressure differences at the earth’s surface, which in turn are caused by the differential heating of the earth’s surface by the sun. Winds play a key role in the global transport of heat and energy. The wind regime at the surface is influenced by local topography. Wind measuring sites need to be open, level and free from obstructions due to buildings and trees etc., for this reason wind speed and direction are measured generally at 10m above ground level.
Wind has been measured in Ireland since the late 19th century. Wind speed and direction are measured at synoptic weather stations. Up until the 1990s, wind speed and direction were measured by Dines pressure tube anemometers, these operate on the basis of the pressure caused by the wind blowing into an opening on the wind facing end of a wind vane, since the early 1990s these have been replaced by cup and vane anemometers, with wind speed measured by rotating cups, and direction by a separate wind vane.
The wind at a particular location can be influenced by a number of factors such as obstruction by buildings or trees, the nature of the terrain (roughness) and deflection by nearby mountains or hills. Inhomogenieties arise in wind data time series due to changes in instrumentation and changes in station exposure due to new buildings, tree growth etc. in the vicinity of the station. Data used in this section have not been homogenised or corrected for roughness.
Wind speed and direction are continuously recorded and tabulated, either manually or automatically depending on the station location and type. Gust speeds are also recorded, as are the times of highest daily gusts and the mean wind speed and direction at the time of the highest gust and the highest 10 minute mean speed in a 24 hour period.
Time Series and Trends: Mean annual wind speeds and the number of days per year with gale gusts (a gust of greater than 17.5 m/s or 34kt) are shown below for Valentia and Dublin Airport.
In non-icing conditions: 45 m/sec (100 mph) peak, or 34 m/sec (75 mph) sustained*
In icing conditions: 34 m/sec (75 mph) peak, or 18 m/sec( 40 mph) sustained*
± 0.5 m/s (± 1.1 mph) ± 3% 17 to 30 m/s (38 to 67 mph) ± 4% 30 to 44 m/s (67 to 99 mph)
± 5 degrees
0.19 m/s (0.42 mph)
0.5 m/s (1.1 mph)
0.5 m/s (1.1 mph)
Approximately 3 m (9.8 ft)
0.8 m (2.6 ft)
Cup revolutions are accumulated every three seconds for the duration of the logging interval. Wind speed is the average speed for the entire logging interval. Gust speed is the highest three-second wind recorded during the logging interval.
Unit vector components of wind direction are accumulated every three seconds for duration of logging interval. Average direction is calculated from the average of these.
Operating Temperature Range
-40°C to +75°C (-40°F to +167°F)
2 to 5 years typical depending upon environmental conditions
Anodized aluminum housing, injection-molded plastic cups, stainless steel fasteners, Acetal base, and black anodized aluminum mounting rod.
Stainless steel shielded ball bearing
108 mm (4.25 in.)
Approximately 305 mm (12.5 in.)
317 mm (12.5 in.) H x 419 mm (16.5 in.) W, 12.7 mm (0.5 in.) diameter mounting pole
000 FONT15 KNHC 041442 PWSAT5 REMNANTS OF VICTOR WIND SPEED PROBABILITIES NUMBER 21 NWS NATIONAL HURRICANE CENTER MIAMI FL AL202021 1500 UTC MON OCT 04 2021 AT 1500Z THE REMNANTS OF VICTOR WERE LOCATED NEAR LATITUDE 18.8 NORTH...LONGITUDE 45.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 25 KTS ...30 MPH...45 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z MON AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z MON 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI PERIODS TO TO TO TO TO TO TO 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI 12Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ...THERE IS NO OFFICIAL FORECAST FOR THIS DATE/TIME... AND THEREFORE NO WIND SPEED PROBABILITIES CAN BE CALCULATED... $$ FORECASTER REINHART
Wind speed is the rate of horizontally moving air past a fixed point, and can be measured by an anemometer. Wind speed is caused when air moves from high to low pressure, which is often driven by changes in temperature.
Current Wind Speed – AcuRite's Atlas™ transmits wind speed data every 10 seconds and the 3-in-1 Weather Sensor and 5-in-1 Weather Sensor transmit wind speed data every 18 seconds. Current wind speed is the highest wind speed recorded over that 10 – 18-second window.
Average Wind Speed – An average of all wind speed readings collected over the past 2 minutes.
Peak Wind Speed – A rolling value showing the highest wind speed recorded over the past 60 minutes.
To smithereens. Representatives of the company's designers only loudly groaned this was a completely new word in automatic weapons. Das ist fantastical. But in the office, Victoria scratched her right eyebrow and left ear, hearing the whispering of this trinity with a thin female ear, everything is clear.
On the offer to leave our MP for verification, we refused, and immediately two such hefty security guards entered the office.