When fighting wildland fires, information is power. Fire behavior is driven by topography, fuels and weather. Accurate readings of temperature, humidity, wind speed and wind direction are critical to predicting future fire behavior and building a plan of attack. Firefighters need the most accurate information available to choose the right tactics and equipment to battle an ongoing burn. This data is just as important when planning a prescribed burn to ensure it does not spread out of control. Kestrel Weather Meters provide fast and accurate measurement of the critical weather conditions impacting the behavior of wildland fires and prescribed burns.
Why weather observations matter
Firefighters take weather observations during a wildfire or prescribed burn in order to track conditions and share information with other members of their team. Understanding how conditions are changing and when to adjust tactics is key to managing a fire and keeping firefighters safe. These weather observations help fire meteorologists build their forecasts and weather pattern models, which then drive fire behavior forecasts. At the end of the day, meteorologists analyze the earlier weather observations and fire behavior and compare those against their forecasts, helping them to improve their predictions and awareness going forward.
Speed is of the essence
The firefighting environment is fast-moving, dangerous and high stress. The tools a firefighter uses must feel like second nature and work quickly and accurately. Finding wet bulb temperature using a traditional sling psychrometer can take several minutes. In real world field conditions, wicks get dirty and must be replaced, distilled water isn’t always available, searching for and reading old paper charts causes delays, and hand written weather observations can be difficult to read. In contrast, a Kestrel Fire Weather Meter can provide wind speed, relative humidity, temperature, probability of ignition (PIG), psychrometric wet bulb temperature, altitude, pressure trends, barometric pressure, dew point temperatures, heat stress index and wind chill environmental measurements in seconds in any conditions and then transmit those measurements where they need to go using iOS or Android devices.
Inaccurate readings are harmful
It doesn’t matter how quickly weather readings are available if they aren’t accurate. Not only is the standard belt weather kit more laborious to use than a Kestrel Fire Weather Meter, a Kestrel is also more likely to give consistent, accurate readings. Sling psychrometer relative humidity readings have been shown through government research, on average, to read high by 9.4% or more* due to any of the following common mistakes: not swinging the psychrometer long enough, not saturating the wick, taking too long to read the thermometers, touching the bulb ends while reading, and not facing into the breeze, meaning the wet-bulb temperature reading will be too warm and the relative humidity will read too high.
In addition to being properly operated, belt weather kits must be properly maintained. Each fire can cause defects, old parts can break from overuse and in the case of electronic sensors, they must be routinely calibrated to ensure accuracy. Body heat, sweat, dirt, ash and direct sunlight can all negatively affect the accuracy of sensors and their storage is crucial to their effectiveness.
One of the most frequent sources of error in fire behavior forecasting is difficult to read weather observations or insufficient data and trends. Using a Kestrel meter to take measurements means the data is automatically and continuously logged on the device, and several models offer wireless connectivity to send weather data to mobile devices among a crew’s key team members. Being able to send easily readable weather observations and historical data trends eliminates yet another opportunity for user error and provides a complete picture of conditions on the fire.
“As a United States Aerial Delivered Firefighter, I require the best gear available to accomplish our missions. The Kestrel Fire Weather Pro weather meter provides me with the highest technology made to date. I count on precise measurements on a fire or any other emergency incident. Kestrel is my choice for professionals,” explains Jason A. Ramos, a veteran firefighter and author of the memoir, Smokejumper.
Preventing heat stress related injuries
Measuring Wet Bulb Globe Temperature (WBGT) and applying ACSM and ACGIH guidelines during firefighting operations and during training is recommended by the National Institute for Occupational Safety and Health to keep firefighters safe and prevent heat stroke related injury and death.** WBGT is the most accurate model for predicting human heat stress. WBGT is based on an equation that uses a combination of environmental factors (temperature, humidity, wind speed and solar radiation) to calculate a reading that estimates human heat stress. Not to be confused with “heat index”, which measures only temperature and humidity, WBGT is used by the military and Occupational Safety and Health Administrations (OSHA) to protect and prevent heat related injuries. The Kestrel 5400 measures WBGT and with preprogramed safety zones and an alert light and buzzer is an ideal tool for field and training simulations.
Features and capabilities at a glance
- The Kestrel DROP D3FW Fire Weather Monitor with LiNK™ wireless data connectivity is ideal for data logging temperature and humidity on a prescribed burn site to view trends and plan the safest burn times. DROP measurements can be viewed real-time and data logs can be retrieved from 100’ away and then exported via email with an iOS or Android device and the free Kestrel LiNK app. The DROP D3FW is available for $129.
- The Kestrel 3500FW Fire Weather Meter offers fast, accurate on-the-spot measurement of weather conditions including wind speed, temperature, humidity, pressure and altitude, and includes a waterproof Probability of Ignition (“PIG”) reference card. The Kestrel 3500FW Fire Weather Meter sells for $199.
- The Kestrel 5500FW Fire Weather Meter Pro provides all necessary measurements for fire weather observation including wind direction and pre-programed PIG and Fine Dead Fuel Moisture (“FDFM”) measurements. It may be used as a handheld unit or mounted to a tripod with the secure vane mount, creating a fully capable compact weather station. The 5500FW logs key measurements even when off, providing in-depth insight into trends. With optional LiNK wireless connectivity, measurements can be viewed remotely and data logs can be downloaded and shared with the free Kestrel LiNK app (approximately 100’ range). Pricing for the 5500FW Fire Weather Pro starts at $355 to $422 with LiNK.
- The Kestrel 5400FW Fire Weather Pro WBGT with LiNK, Compass and Vane Mount is the all-in-one fire weather and heat safety meter. This unit sells for $609 and includes all the capabilities of the 5500FW with the addition of WBGT monitoring and user settable visual and audio alerts to warn when conditions are not safe. WBGT is the most accurate model for predicting human heat stress and adds critical insight into preventing heat injury during conditioning training and while working on a fire line.
Basic weather conditions are crucial information for firefighters. These conditions lead to predictions in flame length, rate of spread, probability of ignition and fuel moisture. Accurate readings lead to more accurate predictions and readings that are available quickly and in multiple locations due to LiNK wireless connectivity mean that firefighters on and off the fire can use the data to quickly and safely preserve lives, property and resources.
For more information, go to www.kestrelfireweather.com
* Technical Report ECOM-5399 – FIELD COMPARISON BETWEEN SLING PSYCHROMETER AND METEOROLOGICAL MEASURING SET AN/TMQ-22
By Ronald W. Waite. Atmospheric Sciences Laboratory White Sands Missile Range, New Mexico; August 1971. Pg 29
“ 3. If care is taken in making measurements with the sling psychrometer, the relative humidity error can be accurate to +/- 4% RH;
4. From reviewing the data taken by all operator personnel it appears
that the sling psychrometer readings will he in error by at least +9%
Comparison of Sling Psychrometer to Digital Weather Meters, Chuck McKugh & Lary Bradshaw Fire, Fuels, Smoke Program RMRS, Fire Sciences Lab Missoula, Montana
** Death in the Line of Duty…A summary of a NIOSH fire fighter fatality investigation http://www.cdc.gov/niosh/fire/reports/face201117.html