Western Regional Climate Center

Wind Rose



GREAT FALLS AP, MT.  WIND ROSE.                                               
HOURLY WIND STATISTICS FOR THE PERIOD 920101-961231
DAYS OF THE YEAR USED              :  0101 - 0131

TIME      - TIME OF DAY (L.S.T.)
SPEED     - AVERAGE (SCALAR) SPEED IN MPH
U-VEL     - EAST-WEST VELOCITY, POSITIVE TO EAST
V-VEL     - NORTH-SOUTH VELOCITY, POSITIVE TO NORTH
RESSPD    - VECTOR AVERAGE (RESULTANT) SPEED IN MPH
RESDIR    - VECTOR AVERAGE (RESULTANT) DIRECTION
DIRCON    - DIRECTIONAL CONSTANCY (RESSPD/SPEED)
NUMSPD    - NUMBER OF SPEED OBSERVATIONS
NUMDIR    - NUMBER OF DIRECTION OBSERVATIONS

TIME  SPEED  U-VEL  V-VEL RESSPD RESDIR DIRCON NUMSPD NUMDIR
----  -----  -----  ----- ------ ------ ------ ------ ------

  0    11.9    6.2    6.1    8.6   225.  0.725   143   143
  1    12.0    6.4    6.1    8.8   226.  0.737   140   140
  2    12.4    6.5    7.0    9.5   223.  0.766   139   139
  3    12.2    6.7    6.7    9.5   225.  0.777   139   139
  4    12.2    6.7    6.3    9.2   227.  0.749   139   139
  5    12.0    6.6    6.1    9.0   227.  0.752   134   134
  6    11.9    6.4    5.9    8.7   227.  0.733   137   137
  7    12.1    6.4    6.2    8.9   226.  0.738   133   133
  8    12.3    6.5    6.3    9.0   226.  0.736   134   134
  9    11.8    6.3    5.9    8.7   227.  0.734   129   129
 10    12.2    6.7    6.3    9.2   226.  0.753   127   127
 11    13.5    8.0    6.8   10.5   230.  0.775   128   128
 12    13.9    8.3    6.9   10.8   230.  0.775   127   127
 13    14.4    8.9    6.8   11.2   233.  0.779   129   129
 14    14.7    9.0    6.0   10.8   236.  0.736   129   129
 15    13.5    7.4    5.6    9.3   233.  0.690   130   130
 16    12.6    6.5    5.2    8.3   232.  0.656   130   130
 17    12.3    5.5    5.3    7.7   226.  0.623   135   135
 18    12.3    5.9    6.2    8.5   224.  0.691   139   139
 19    12.1    5.6    5.9    8.1   223.  0.674   138   138
 20    12.0    5.8    6.1    8.4   224.  0.698   141   141
 21    11.9    5.9    5.6    8.1   227.  0.686   139   139
 22    11.8    5.6    5.8    8.1   224.  0.683   141   141
 23    12.1    6.1    5.9    8.4   226.  0.697   142   142

 ALL   12.5    6.6    6.1    9.0   227.  0.723  3242  3242

--------------------------------------------------

GREAT FALLS AP, MT.  WIND ROSE.                                               
WIND ROSE.  PERCENTAGE OF TIME WIND IS IN INDICATED 
            SPEED/DIRECTION CATEGORY.  "SPEED" IS THE 
            AVERAGE SPEED WHEN WIND IS FROM THAT DIRECTION.

HOURS USED FOR WIND ROSE ("1" - USED, "0" - NOT USED) : 
0     6    12    18   23   (L.S.T.)
|     |     |     |    |
------------------------
111111111111111111111111
TOTAL NUMBER OF OBSERVATIONS USED :   3242
Overall period of data : 920101 - 961231
Date window            : 0101 - 0131

                    SPEED CATEGORY (MPH)                       ALL      AVE 
 DIR   0- 5  6-10 11-15 16-20 21-25 26-30 31-35 36-40  40 +   SPEEDS   SPEED
 ---- ----- ----- ----- ----- ----- ----- ----- ----- -----   -----   -----
   N    7.2   2.0   1.2   0.3   0.0   0.0   0.0   0.0   0.0    10.7      3.8
 NNE    0.5   0.8   0.1   0.0   0.0   0.0   0.0   0.0   0.0     1.4      6.9
  NE    0.3   1.7   0.1   0.0   0.0   0.0   0.0   0.0   0.0     2.1      7.6
 ENE    0.6   1.6   0.5   0.0   0.0   0.0   0.0   0.0   0.0     2.6      7.9
   E    2.2   2.2   0.1   0.0   0.0   0.0   0.0   0.0   0.0     4.6      5.9
 ESE    0.7   1.0   0.0   0.0   0.0   0.0   0.0   0.0   0.0     1.7      5.6
  SE    0.4   0.4   0.0   0.0   0.0   0.0   0.0   0.0   0.0     0.7      5.8
 SSE    0.4   0.3   0.0   0.0   0.0   0.0   0.0   0.0   0.0     0.8      5.6
   S    0.6   2.3   0.9   0.3   0.1   0.0   0.0   0.0   0.0     4.1      9.6
 SSW    0.6   3.0   4.5   3.7   2.0   0.4   0.2   0.0   0.0    14.4     14.9
  SW    0.6   5.5   7.8   7.8   9.7   2.9   0.7   0.1   0.0    35.2     17.6
 WSW    1.0   2.8   1.5   1.7   1.4   0.4   0.2   0.1   0.0     9.0     14.1
   W    1.2   2.1   0.5   0.2   0.5   0.1   0.0   0.0   0.0     4.5      9.7
 WNW    0.6   1.1   0.2   0.1   0.0   0.0   0.0   0.0   0.0     2.0      7.1
  NW    0.8   1.3   0.5   0.2   0.1   0.0   0.0   0.0   0.0     2.8      8.6
 NNW    0.7   1.0   1.0   0.4   0.1   0.0   0.0   0.0   0.0     3.4     10.4

 ALL   18.4  29.1  19.0  14.8  13.8   3.8   1.1   0.2   0.0   100.0     12.5

For more information, contact
Western Regional Climate Center,
email: wrcc@dri.edu
phone: 775-674-7010
fax: 775-674-7016