Appendix

Wind Chill
(wind speed vs. air temperature)
calm 35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 -45
5 32 27 22 16 11 6 0 -5 -10 -15 -21 -26 -31 -36 -42 -47 -52
10 22 16 10 3 -3 -9 -15 -22 -27 -34 -40 -46 -52 -58 -64 -71 -77
15 16 9 2 -5 -11 -18 -25 -31 -38 -45 -51 -58 -65 -72 -78 -85 -92
20 12 4 -3 -10 -17 -24 -31 -39 -46 -53 -60 -67 -74 -81 -88 -95 -103
25 8 1 -7 -15 -22 -29 -36 -44 -51 -59 -66 -74 -81 -88 -96 -103 -110
30 6 -2 -10 -18 -25 -33 -41 -49 -56 -64 -71 -79 -86 -93 -101 -109 -116
35 4 -4 -12 -20 -27 -35 -43 -52 -58 -67 -74 -82 -89 -97 -105 -113 -120
40 3 -5 -13 -21 -29 -37 -45 -53 -60 -69 -76 -84 -92 -100 -107 -115 -123
45 2 -6 -14 -22 -30 -38 -46 -54 -62 -70 -78 -85 -93 -102 -109 -117 -125

Wind chill is based on the rate of heat loss from exposed skin caused by the combined effects of the wind and cold. In other words, how cold it actually "feels". Ex. A wind speed of 15 mph with an air temperature of 10 above zero produce a wind chill of -18 degrees.

Conversions:

Fahrenheit to Celsius C = 5/9 ( F - 32 )
Celsius to Fahrenheit F = 9/5 C + 32

Miles per hour to knots: 1.15 miles per hour for every knot

1 inch of mercury = 33.865 millibars (mb)

 


 

Heat Index
(air temperature vs. relative humidity)

 

temp 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
115 103 107 111 115 120 127 135 143 151                
110 99 102 105 108 112 117 123 130 137 143 151            
105 95 97 100 102 105 109 113 118 123 129 135 142 149        
100 91 93 95 97 99 101 104 107 110 115 120 126 132 136 144    
95 87 88 90 91 93 94 96 98 101 104 107 110 114 119 124 130 136
90 83 84 85 86 87 88 90 91 93 95 96 98 100 102 106 109 113
85 78 79 80 81 82 83 84 85 86 87 88 89 90 91 93 95 97
80 73 74 75 76 77 77 78 79 79 80 81 81 82 83 85 86 86
75 69 69 70 71 72 72 73 73 74 74 75 75 76 76 77 77 78
70 64 64 65 65 66 66 67 67 68 68 69 69 70 70 70 70 71

 

The heat index is an accurate measure of how hot it really feels when realitive humidity is added to the actual air temperature. Ex. An air temperature of 90 degrees, combined with a relative humidity of 60%, would make it feel more like 100 degrees.

 


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