Sudden weather shifts often bring thunderstorms, cold fronts, or unexpected precipitation. However, in rare cases, nighttime conditions can trigger a rapid temperature spike accompanied by strong, dry winds - this is known as a heat burst.
These events, driven by collapsing thunderstorms, can cause a rapid increase in surface temperatures by over 50°F (10°C) in minutes, with humidity dropping sharply. Though uncommon, heat bursts have been recorded in various regions, sometimes producing wind gusts exceeding 60 mph (100 km/h).
What Is a Heat Burst?
A heat burst is a rare meteorological event characterized by a sudden, rapid increase in temperature, a drop in humidity, and strong gusty winds. These bursts often occur late at night or early in the morning when thunderstorms begin to dissipate. During a heat burst, surface temperatures can rise sharply within minutes, creating an intense wave of hot, dry air.
Source: www.meteorologynews.com
The Science Behind Heat Bursts
Heat bursts originate from the remains of dying thunderstorms. Here’s how they unfold:
- A thunderstorm collapses. As a storm weakens, some of the rain in its upper layers evaporates before reaching the ground, cooling the air.
- Dry air descends rapidly. This cool, dry air becomes denser and starts sinking rapidly toward the surface. However, because the lower atmosphere is often dry at this stage, any remaining moisture has evaporated completely.
- Compression and heating. As the air rises, it undergoes adiabatic compression, meaning it heats up as it descends. This process rapidly raises temperatures, often by 50°F (10°C) or more within minutes.
- Strong winds. Along with the heat, heat bursts are characterized by gusty winds.
How Extreme Can Heat Bursts Get?
Heat bursts can spike temperatures by over 25°F in minutes, as seen in the following cases:
- June 15, 1960 - Kopperl, Texas: A heat burst reportedly raised the temperature from 26°C (79°F) to a scorching 52°C (127°F) in just minutes!
- May 22, 1996 - Chickasha, Oklahoma: A heat burst caused a sudden temperature jump from 29°C (84°F) to 44°C (112°F) while humidity dropped from 41% to 7%.
- July 2011 - Wichita, Kansas: A heat burst pushed temperatures up from 30°C (86°F) to 41°C (106°F) within minutes.
How Can You Spot a Heat Burst on Weather Radar?
Think you’ve spotted a heat burst? Check your radar - here’s what to look for:
- Dissipating thunderstorm clouds: Heat bursts only form when storms are collapsing.
- Sudden, localized temperature spikes: If an area experiences an unusual nighttime heat increase without a clear source, a heat burst might be the culprit.
- Strong wind gusts with no storm activity: Heat bursts often bring sudden dry gusts, sometimes exceeding 60 mph (100 km/h), without rain or lightning.
Source: National Weather Service
Can Heat Bursts Be Dangerous?
Yes! While they don’t last long, heat bursts can be hazardous due to their strong winds and extreme temperatures. Sudden wind gusts can knock down trees, power lines, and even small structures. The rapid drop in humidity can also dry out vegetation, increasing fire risk.
Heat Bursts vs. Microbursts: What’s the Difference?
Heat bursts and microbursts share similarities but have key distinctions:
| Feature | Heat Burst | Microburst |
|---|---|---|
| Air Temperature | Increases suddenly | Decreases suddenly |
| Humidity | Drops rapidly | May remain steady or increase |
| Wind Speed | Strong, dry gusts | Strong, wet or dry gusts |
| Cause | Descending dry air from a collapsing storm | Rapid downdraft of cool, dense air |
| Occurrence Time | Mostly at night | Can occur any time |
Can You Predict a Heat Burst?
Tracking a heat burst in real-time is tough, but here’s what meteorologists look for. However, if you’re a weather enthusiast tracking radar and local conditions, here are some clues:
- A dying thunderstorm with no remaining rain but intense upper-level winds
- Dry, warm conditions at the surface, which allow descending air to heat rapidly
- An unexpected, sharp temperature rise on a weather station report
Final Thoughts: A True Weather Puzzle
Heat bursts are a rare but powerful weather phenomenon. It can rapidly increase temperatures, lower humidity, and produce strong wind gusts. While difficult to predict, heat bursts often occur as thunderstorms dissipate, creating sudden and extreme localized conditions. Tracking radar data and monitoring temperature spikes can help identify these events in real time.
Have you ever experienced a heat burst? Share your observations with the Rain Viewer community and let’s analyze these unique atmospheric events together.
