How Our Hailstorm Prediction Algorithm Works

Hailstorms are an extremely costly natural disaster in Canada, occurring mainly during the spring and summer months when weather conditions allow for the development of powerful thunderstorms. These thunderstorms in turn form hailstones, which are dense balls of ice that fall to the ground, often causing significant property damage. Alberta is known as the hail capital of Canada, experiencing by far the most hailstorms, however there are currently a lack of resources being dedicated to the prediction, detection, and mitigation of the damage caused by hailstorms.

ConvectAlert Analytics was created to bring better weather data to Canadians. By bridging the gap between the information that skilled meteorologists have access to, and the general public, ConvectAlert brings actionable weather data to Canadian businesses in a way that you don't have to be an atmospheric scientist to understand.

The objective of this demo is to show how ConvectAlert's HailNow Alert Service works. The service is just one of the ways ConvectAlert aims to reduce severe weather damage for businesses, however it's fundamental to providing advance warning of incoming hailstorms, allowing businesses to activate severe weather plans and reduce preventable hail damage.

July 13, 2025 was a typical summer day in Southern Alberta, with warm and humid conditions, leading weather forecasters to anticipate a risk for severe thunderstorms roughly from Calgary down towards the Montana border, as is shown in the map above. While it wasn't predicted to be an especially dangerous day for thunderstorms, weather models were in very good agreement about severe thunderstorms occurring somewhere within the Calgary-Lethbridge corridor. In addition to this, weather models such as the HRDPS were consistently calling for a severe thunderstorm to pass directly through Calgary in the evening hours.

Our alert service operates by continuously monitoring real-time radar data and applying our detection algorithm to identify storms that meet specific criteria for hail production potential. When a storm is detected that exceeds our predefined thresholds for creating alert polygons, the system begins tracking the storm's movement and characteristics. The system issues actual alerts when the storm's intensity and predicted path indicate a high probability of significant hail impact on protected areas, allowing businesses and property owners to take protective action with sufficient lead time.

The triggering thresholds for creating polygons are based on a combination of radar reflectivity values, storm structure indicators, and environmental parameters that suggest the storm is capable of producing hail. For actually issuing alerts, the system requires that the storm not only meets the polygon creation criteria but also shows sustained intensity and a predicted path that intersects with areas of interest, ensuring that alerts are only sent when there is a genuine threat.

The above gif shows the weather radar and alert polygon from 7:18pm as the thunderstorm was passing just north of Cochrane. The predicted path of the storm shown is derived from our proprietary ConvectAlert algorithm, which analyzes the storm's previous movement, size, and intensity in order to predict where it'll track in the future. This algorithm is used to determine the area that's most likely to be impacted by the hailstorm in the near future.

This image shows the radar data combined with the alert service's active alerts over the city of Calgary at 7:30pm. The areas highlighted on the map are where the algorithm has identified a high probability of damaging hail occurring in the next 30 minutes.

Let's assume you have a business at the location shown on the map in East Calgary. Based on a 30 minute lead time, you'd first receive a hailstorm alert at 7:30pm upon entering the warning area. Being within the warning area in this case would mean that your business would be at imminent risk of being hit by a hailstorm within the next 30 minutes.

Upon learning this information, your business may decide to implement its severe weather management plan, and do things such as cover vehicles with protective covers, move equipment indoors, or move customers & staff indoors for protection.

• Car dealerships: Dealerships using the HailNow alerting system can use the advance notice to deploy temporary car covers to protect vehicles from hail damage.
• Aviation businesses: Aircraft operators can stow, cover, or move aircraft from at-risk areas.
• Outdoor events: Earlier warning of approaching storms allows event organizers to activate thunderstorm protocols sooner, allowing for safer and more timely action to protect attendees and equipment.
• Construction companies: Activities like concrete pours can be postponed well in advance of approaching storms, additionally hail-sensitive equipment and materials can be moved to reduce hail damages.

Higher-quality weather alerts has many applications across many industries which suffer impacts from severe weather. In many cases simply having 15 extra minutes of advance warning can have a significant impact on the types and degree of action that can be taken to reduce hail damage, or prevent it altogether.

Our HailNow Alert Service takes a new approach to weather alerts, providing more accurate, precise and timely notifications than traditional weather providers. Rather than making guesses based off vague, imprecise publicly available weather forecasts, ConvectAlert provides businesses with professional and actionable weather information, without being overly technical.

HailNow alerts can be tailored for different levels of protection and business needs, whether that's critical alerts only, or alerts days in advance of severe weather potential, or both. We recommend the highest level of protection for businesses such as car dealerships or aircraft operators which may suffer costs well into the 6 figures if impacted by a hailstorm. Lower levels of protection may be suitable for businesses willing to take more risk, or those requiring only basic levels of protection.