It’s that time of year again.
The jet stream begins to shift north as the seasons change from Spring to Summer. Warm and humid air from the Gulf of Mexico is carried northward into the eastern United States. That “you can wear” feeling returns, and with it, the afternoon thunderstorm you can almost put your watch on.
These air mass thunderstorms (explainer here, if you’re interested) occur without any large systems nearby. They rely on daytime heating and ready humidity to form. They can be random, isolated, and move erratically. While they can sometimes become serious, especially as they decompose, they pose a much greater threat to people outdoors on a hot summer day: Lightning.
A common misconception about light is that you must be able to see the storm or be under it for lightning to strike you. It is simply wrong.
These summer thunderstorms have a lot of instability due to daytime heating and the high dew point that allows them to grow very high. Cloud tops from 40kft to even 60kft are not uncommon in summer.
As the anvils on these thunderstorms develop, positive lightnings (thunderbolts originating from the higher layers/anvils) are likely to travel 10 to 12 miles ahead of the main portion of the storm. So if you’re enjoying time outside in this warmer weather, it’s important to remember that even if you can’t see the storm, if you hear thunder, you could lightning strike.
Let’s review some lightning safety tips to be better prepared this summer:
- First and foremost: if you hear thunder, get inside immediately. Don’t wait until you can see the storm.
- Your shelter should be surrounded. No booths, peaches, etc.
- If a closed shelter is not available to you, get in your car (with metal roof, no soft top) and pull up the windows.
- If you cannot find a suitable shelter:
- Descend from high areas such as hills, ridges, and peaks
- DO NOT lie flat on the ground but instead crouch down in a ball-like position, head down and hands over your ears so that you are crouched low and have minimal contact with the ground.
- DO NOT take shelter under a tree.
- Move out of the water
- Keep away from conductive objects such as power lines or windmills.
These safety tips come straight from NWS Lightning Protection Tips page. Check it out for more lightning tips and information.
At Weather.us and Weathermodels.com, we have several products to help you predict or track lightning:
- Lightning analysis (weather.us)
- NOAA OPC Lightning Density (weathermodels.com)
- One-hour lightning parameters are available via HRRR, RRFS-A, NCEP HiRes-FV3, NCEP HIRESW-ARW and NCEP HIRESW-NSSL (weathermodels.com)
- 6 hour flash density via HRRR and ECMWF (weathermodels.com)
- Lightning density via ECMWF IFS and ECMWF RAPID (weather.us)
Remember, keep an eye on the weather on these hot, humid days. And, to borrow a phrase from the NWS. “When the thunder roars, go inside!”
About the author
Meghan Gulledge
Meteorologist – ’22 Mississippi State Writer for Weather.us and Weathermodels.com. Focus on weather communication. BoyMom x1, CatMom x5. Twitter: @MegGulledgeWX
