Calculating Average wind speed and direction

[HAFEDH78]

Hi Everyone,

I was wondering if someone could check if the following formulas make sense. I am trying to calculate the daily average wind speed and wind direction derived from values taken at 6hr intervals.

From wind speed and direction </SPAN>
> (meteorological wind direction (wdir): eg E=90, S=180, W=270) </SPAN>
> (1) calculate u and v </SPAN>
> u = -wspd*sin(wdir) </SPAN>
> v = -wspd*cos(wdir) </SPAN>
> </SPAN>
> (2) calculate the daily mean of each wind component: </SPAN>
> uave, vave </SPAN>
> </SPAN>
> (3) transform to wspd and wdir </SPAN>
> rad = 4.0*atan (1.0)/180. </SPAN>	0.017453</SPAN>
> WSPD = sqrt(uAve^2+vAve^2) </SPAN>
> WDIR = atan2(uAve,vAve)/rad +180. ; mean wind direction [0,360] </SPAN>
> </SPAN>
</SPAN>
</SPAN>

<TBODY>
</TBODY><COLGROUP><COL span=6></COLGROUP>

 

[Jeffrey Smith]

For those purists out there, I converted the user defined functions into cell formulas. Have fun with it.

Jeff

Excel 2010
	A	B	C	D	E
3		Magnitude	Direction	Vel X	Vel Y
4		1.00	341.00	-0.33	0.95
5		1.00	341.00	-0.33	0.95
6		1.00	301.00	-0.86	0.52
7		1.99	341.00	-0.65	1.88
8		0.10	341.00	-0.03	0.09
9		0.50	341.00	-0.16	0.47
10		0.50	341.00	-0.16	0.47
11		0.50	341.00	-0.16	0.47
12		2.00	12.00	0.42	1.96
13		1.00	341.00	-0.33	0.95
14		1.00	342.00	-0.31	0.95
15		1.00	343.00	-0.29	0.96
16		1.00	344.00	-0.28	0.96
17		1.00	345.00	-0.26	0.97
18		1.00	346.00	-0.24	0.97
19		1.00	347.00	-0.22	0.97
20		2.30	348.00	-0.48	2.25
21		1.10	318.00	-0.74	0.82
22		2.10	352.00	-0.29	2.08
23		1.50	351.00	-0.23	1.48
24
25	Average:	1.13	323.85	-0.30	1.06
26
27		Weighted Velocity	Weighted Direction
28		1.10	344.31
Weighted_Dir

Cell Formulas
Range	Formula
D4	=B4*COS(2*PI()*(90-C4)/360)
D25	=AVERAGE(D4:D23)
E4	=B4*SIN(2*PI()*(90-C4)/360)
E25	=AVERAGE(E4:E23)
B25	=AVERAGE(B4:B23)
B28	=SQRT(D25^2+E25^2)
C25	=AVERAGE(C4:C23)
C28	=IF(OR(180/PI()*ATAN2(E25,D25)<0,180/PI()*ATAN2(E25,D25)>360)=TRUE,ABS(360-ABS(180/PI()*ATAN2(E25,D25))),180/PI()*ATAN2(E25,D25))

 

[PDFSA]

Hi Jeffery Smith or anyone else.
Just a question are the formulas applicable to South and East?
Thanks