1 00:00:00,694 --> 00:00:03,361 (wind whooshes) 2 00:00:10,609 --> 00:00:13,941 - Weather is a key element in fire behavior. 3 00:00:13,941 --> 00:00:18,028 Monitoring temperature, relative humidity and wind 4 00:00:18,028 --> 00:00:22,741 allows you to anticipate how your fire is going to behave. 5 00:00:22,741 --> 00:00:25,191 In this video we are going to show you 6 00:00:25,191 --> 00:00:27,858 how to use the Belt Weather Kit. 7 00:00:31,484 --> 00:00:33,957 The Belt Weather Kit contains a variety of items 8 00:00:33,957 --> 00:00:36,374 to take weather observations. 9 00:00:37,602 --> 00:00:39,519 The sling psychrometer. 10 00:00:40,597 --> 00:00:44,115 The dry bulb measures ambient air temperature. 11 00:00:44,115 --> 00:00:45,714 The wet bulb measures the lowest temperature 12 00:00:45,714 --> 00:00:48,907 that can be reached under current ambient conditions 13 00:00:48,907 --> 00:00:51,240 by the evaporation of water. 14 00:00:52,669 --> 00:00:56,964 Note the wick on the wet bulb thermometer. 15 00:00:56,964 --> 00:00:59,739 Clean water, preferably distilled, 16 00:00:59,739 --> 00:01:02,804 is used to saturate the wet bulb thermometer. 17 00:01:02,804 --> 00:01:05,221 The anemomoter or wind gauge. 18 00:01:07,692 --> 00:01:09,747 The white ball in the center of the gauge 19 00:01:09,747 --> 00:01:11,497 indicates wind speed. 20 00:01:12,850 --> 00:01:14,081 Note the two small holes 21 00:01:14,081 --> 00:01:16,763 on the back and bottom of wind gauge. 22 00:01:16,763 --> 00:01:19,085 This is where wind enters the gauge. 23 00:01:19,085 --> 00:01:23,218 These two holes measure winds 10 miles per hour or less. 24 00:01:23,218 --> 00:01:25,064 Do not block them with your hand 25 00:01:25,064 --> 00:01:28,535 when taking weather observations. 26 00:01:28,535 --> 00:01:31,043 Note the hole on the top of wind gauge. 27 00:01:31,043 --> 00:01:33,156 Covering this hole measures wind speeds 28 00:01:33,156 --> 00:01:35,739 greater than 10 miles per hour. 29 00:01:36,755 --> 00:01:39,855 Compass for measuring wind direction. 30 00:01:39,855 --> 00:01:44,615 Wind direction is the direction the wind is coming from. 31 00:01:44,615 --> 00:01:46,263 The calculation tables allow you 32 00:01:46,263 --> 00:01:48,876 to obtain the relative humidity and dew point 33 00:01:48,876 --> 00:01:52,846 where the dry and wet bulb temperatures converge. 34 00:01:52,846 --> 00:01:55,006 Color coded tables that are easier to read 35 00:01:55,006 --> 00:01:57,932 are located in the Interagency Wildland Fire Module 36 00:01:57,932 --> 00:02:00,099 Field Guide, 2012 edition. 37 00:02:02,216 --> 00:02:05,966 The dry bulb readings are on the left side of the chart. 38 00:02:05,966 --> 00:02:10,470 The wet bulb reading are across the top of the chart. 39 00:02:10,470 --> 00:02:12,734 Note the elevation on the charts. 40 00:02:12,734 --> 00:02:14,638 The chart with your current elevation 41 00:02:14,638 --> 00:02:17,805 must be used to avoid faulty readings. 42 00:02:18,980 --> 00:02:23,147 For example, a dry bulb temperature of 88 degrees, 43 00:02:25,401 --> 00:02:28,734 and a wet bulb temperature of 62 degrees 44 00:02:31,450 --> 00:02:33,700 converge here on the table. 45 00:02:35,019 --> 00:02:38,572 This gives us outputs of 22% relative humidity, 46 00:02:38,572 --> 00:02:40,655 and a 45% dew point. 47 00:02:42,810 --> 00:02:45,858 Fire Weather Observer's Record Book. 48 00:02:45,858 --> 00:02:49,619 Weather observations will be recorded here. 49 00:02:49,619 --> 00:02:52,315 It is a good idea to fill out the header 50 00:02:52,315 --> 00:02:56,051 before taking weather observations. 51 00:02:56,051 --> 00:02:59,197 Recorded weather observations include 52 00:02:59,197 --> 00:03:02,864 time, dry bulb, wet bulb, relative humidity, 53 00:03:04,596 --> 00:03:06,679 wind speed and direction. 54 00:03:14,615 --> 00:03:16,833 Stand in an open shaded area, 55 00:03:16,833 --> 00:03:20,502 away from objects that might be struck while spinning sling. 56 00:03:20,502 --> 00:03:22,591 If in open country, use your body 57 00:03:22,591 --> 00:03:24,913 to shade the sling. 58 00:03:24,913 --> 00:03:27,595 If possible, take your weather observations 59 00:03:27,595 --> 00:03:30,927 over a fuel bed that is representative of the fuels 60 00:03:30,927 --> 00:03:33,260 that the fire is burning in. 61 00:03:36,616 --> 00:03:38,555 If your sling has been in your pack, 62 00:03:38,555 --> 00:03:41,800 you may need to hang it in a tree, or in the shade, 63 00:03:41,800 --> 00:03:45,800 to let it adjust to the outside air temperature. 64 00:03:48,232 --> 00:03:52,028 Fill out the header of your Fire Weathers Observer's Record 65 00:03:52,028 --> 00:03:55,945 while sling adjusts to outside air temperature. 66 00:03:57,438 --> 00:03:59,052 Use the wind gauge and compass 67 00:03:59,052 --> 00:04:02,052 to measure wind speed and direction. 68 00:04:05,066 --> 00:04:06,860 Saturate the wick of the wet bulb 69 00:04:06,860 --> 00:04:09,559 with clean, mineral free water. 70 00:04:09,559 --> 00:04:12,418 If you have a new wick on your wet bulb thermometer, 71 00:04:12,418 --> 00:04:16,585 you may need to let the wick soak to become fully saturated. 72 00:04:21,195 --> 00:04:24,539 When using the sling, face the wind to avoid the influence 73 00:04:24,539 --> 00:04:27,706 of your body heat on the thermometers. 74 00:04:30,037 --> 00:04:34,328 Ventilate the thermometers by spinning at full arm's length. 75 00:04:34,328 --> 00:04:36,949 Your arm should be parallel to the ground. 76 00:04:36,949 --> 00:04:38,616 Spin for one minute. 77 00:04:46,006 --> 00:04:48,201 Note the wet bulb temperature. 78 00:04:48,201 --> 00:04:51,651 Spin for another 40 or 50 times and read again. 79 00:04:51,651 --> 00:04:53,930 If the wet bulb is lower than the first reading, 80 00:04:53,930 --> 00:04:58,892 continue to spin and read until it will go no lower. 81 00:04:58,892 --> 00:05:01,452 Read and record the lowest point. 82 00:05:01,452 --> 00:05:03,939 If the wet bulb is not read at the lowest point, 83 00:05:03,939 --> 00:05:08,106 the calculated relative humidity will be too high. 84 00:05:08,986 --> 00:05:10,205 Read the dry bulb immediately 85 00:05:10,205 --> 00:05:14,372 after the lowest wet bulb reading is obtained, and record. 86 00:05:15,946 --> 00:05:18,774 Cross reference dry and wet bulb temperatures 87 00:05:18,774 --> 00:05:20,542 to determine the relative humidity 88 00:05:20,542 --> 00:05:22,875 from the tables, and record. 89 00:05:25,049 --> 00:05:29,132 You have now completed Fire Weather Observations. 90 00:05:30,173 --> 00:05:31,818 The most accurate weather observation 91 00:05:31,818 --> 00:05:34,683 is of little use unless it is properly communicated 92 00:05:34,683 --> 00:05:38,535 in a timely fashion to those who need it. 93 00:05:38,535 --> 00:05:40,510 Make sure that current observations 94 00:05:40,510 --> 00:05:42,741 are reported verbally over the radio 95 00:05:42,741 --> 00:05:45,408 to ensure situational awareness. 96 00:05:52,408 --> 00:05:56,575 Not ventilating the sling long enough to reach equilibrium. 97 00:05:57,613 --> 00:06:01,780 Not getting the wick wet enough, or letting it dry out. 98 00:06:02,819 --> 00:06:05,440 Holding the sling too close to the body 99 00:06:05,440 --> 00:06:09,621 or taking too long to read the thermometers. 100 00:06:09,621 --> 00:06:13,888 Touching the bulb ends with the hands while reading. 101 00:06:13,888 --> 00:06:16,221 Not facing into the breeze. 102 00:06:17,935 --> 00:06:20,300 Not being at the same aspect and elevation 103 00:06:20,300 --> 00:06:21,883 as fire or project. 104 00:06:23,067 --> 00:06:25,150 Minimize fire influences. 105 00:06:26,066 --> 00:06:30,028 Taking observations too close to the fire or in black 106 00:06:30,028 --> 00:06:32,246 will cause too high of temperatures 107 00:06:32,246 --> 00:06:34,996 and too low of relative humidity. 108 00:06:37,915 --> 00:06:42,082 Weather has a significant influence on fire behavior. 109 00:06:43,474 --> 00:06:45,705 Utilizing weather observations 110 00:06:45,705 --> 00:06:47,936 and monitoring fire weather conditions 111 00:06:47,936 --> 00:06:50,477 will allow you base all actions on current 112 00:06:50,477 --> 00:06:52,392 and expected fire behavior. 113 00:06:52,392 --> 00:06:54,111 (machine whirring) 114 00:06:54,111 --> 00:06:56,268 The Belt Weather Kit remains the standard 115 00:06:56,268 --> 00:06:59,523 and most accurate set of weather observation tools 116 00:06:59,523 --> 00:07:02,356 on wild land and prescribed fires. 117 00:07:04,949 --> 00:07:07,116 (grating)