SkyStef's weather page
 

home  |  e-mail    

 

 



Wind gust calculator via Ivens method
(only works with internet explorer)

Tmax or T at begin of shower: °C
ThetaW 850 hPa: °C
ThetaW 500 hPa: °C
Windspeed 850 hPa kts
Windspeed 250 hPa: kts

Calculated max. wind gust
kt     km/h

Prob > 27 kt Prob > 40 kt
%    %   

 

 

Used formula:
 

When Tw850 ≥ 9°C
ffx = 15.9 + 0.174 * U850 * sqrt(Tx - Tw850) + 0.057 * U250 * sqrt(Tx - Tw850) + 0.92 * (Tw850 - Tw500)

When Tw850 <9°C
ffx = 14.9 + 0.976 * U850 + 1.27 * (Tw850 - Tw500)

(Tx = Tmax in °C,  Thetaw = Tw850  in °C,  U = windspeed in kt,  ffx = max. gust in kt)

 

 

Source:
Ivens, A.A.M. Forecasting the maximum wind velocity in squalls.
Proc. Symp.& Mesoscale Analysis & Forecasting, Vancouver, Canada, 17-19 August 1987, ESA SP-282 (August 1987)

 

Note: Java script must be enabled