Kite's Heatwave for Cattle
What is a heatwave?
A heatwave is defined as a period of 3 days when the HLI is well above the average conditions for your feedlot location. The severity of the heatwave is dependent on your location. Kite uses 45 years of site-specific climate data to work out “what is average” for your site. It also looks at the weather for the past 30 days. If the heatwave is early in the season or is a sudden change from the last 30 days, the severity of the heatwave is increased.
Kite determines a heatwave using the same methodology as the Bureau of Meteorology, except Kite uses the HLI (BOM only looks at temperature) and is therefore more relevant to assessing the risk of heat stress.
The Kite team has spent many hours pouring over data sets from last summer's big events. Thanks to the feedlots who sent us their cattle observations, we have determined that the heatwave intensity (HWI) is a valid method to identify conditions that may cause excessive heat load at feedlots if the situation is not managed.
The Heatwave Intensity is calculated once per day. Unlike the HLI/AHLU model for determining your risk, it does not determine the risk for each cattle population. The heatwave Intensity tells you what the environmental risks are. “How extreme are the weather conditions for my site compared to what is normal?”. Therefore, you will need to review your HLI threshold calculator to determine which cattle are most at risk and then put measures in place to mitigate the risk well before the heatwave arrives. Kite provides a 14-day outlook of heatwaves (and rain). The weather conditions that generally result in a heatwave are well forecast 7-10 days out, the severity or exact day of the peak may vary as the event becomes nearer.
Events such as a rapid change in HLI or short acute events are not going to be picked up by the heatwave warning (which need to be extreme conditions for at least 3 days) and therefore we strongly encourage all sites use the heatwave as an added layer of protection on top of the AHLU warnings.
Where can I find it?
The heatwave level is presented on the Outlook dashboard. It is available to all subscription levels.
What does it mean?
A heatwave is defined by the amount of excess heat over a 3 day period. If the excess heat is above the top 5% (about the hottest 20 days per year) it is categorized as a heatwave. The intensity level of the heatwave (HWI) is defined in the table below.
Heatwave Warning | Heatwave Intensity (HWI) | |
|---|---|---|
No alert | 0 | No heatwave present |
Low | 0 - 0.25 | Low-intensity heatwave identified that could represent the start or the end of a higher-intensity heatwave |
Moderate | 0.25 - 1 | Moderate intensity heatwave that may result in heat load in higher-risk animals. May also result in heat load if it is the first heatwave of the season or if pens are wet. |
High | 1 - 2 | High level heatwave may result in heat load in high to medium-risk animals. |
Extreme | >2 | Extreme heatwave |
How can I interpret the heatwave warning to keep my cattle safe?
As this is a new indicator for everyone it will take some time to determine what intensity heatwave is important for your cattle and feedlot setup. Generally, for a standard animal acclimatised to the local conditions the moderate intensity heatwave corresponds with an AHLU>20, a high intensity heatwave is closer to 100 and an extreme intensity heatwave is >150. This may vary across regions because the HWI is based on how hot the conditions are compared to your local climate.
For example, the conditions experienced in January 2023 in southern Queensland and northern NSW were high to extreme for several days across most sites. Extreme events are very rare, but if feedlots are not well prepared (clean pens, high-risk cattle moved to low-risk pens and on heat rations) well in advance, they can cause cattle losses.
How can I get an SMS alert for the heatwave warnings?
In the Settings menu, go to the Alerts tab, then click on the subscribe button next to the Heatwave Alert, and click Save. You will now receive an SMS message when there is a Moderate, High or Extreme heatwave forecast in the next seven days.
The heatwave SMS alerts are available for Premium and Standard subscription levels only.