What is an MCS?

news image
Special Stories
8 Jun 2025 8:00 AM

MCS - A common summertime storm phenomenon, but what is it? MCS stands for Mesoscale Convective System, a term used to describe an organized cluster of thunderstorms that lasts for several hours and can span multiple states.

During the summer, MCSs often form overnight as individual afternoon thunderstorms merge into larger storm complexes. These systems are commonly linear in structure, forming squall lines that stretch for miles. The primary threats associated with MCSs include damaging winds and torrential rainfall, though hail and even tornadoes can also occur.

There are different types of MCSs:

  • MCC (Mesoscale Convective Complex): A large, circular, and long-lived cluster of storms.

  • Mesoscale Convective Vortex: A rarer form that can resemble a small hurricane.

  • Derecho: An especially destructive wind-driven MCS capable of causing widespread damage across hundreds of miles.

Understanding the risks associated with these systems is key. Always have multiple ways to receive weather alerts—especially at night, when many MCS events tend to occur.

All Weather News
More
Flash Flood Threat Persists This Week

Flash Flood Threat Persists This Week

WHAT TO EXPECTNew rounds of rainfall are expe

23 Jun 2026 10:30 AM
I-95 Corridor Under Severe Risk Through Tuesday

I-95 Corridor Under Severe Risk Through Tuesday

Devastating storms ripped through the heartla

23 Jun 2026 10:20 AM
Heat Returns to the West

Heat Returns to the West

This week, an upper level ridge takes over pa

23 Jun 2026 10:15 AM
Active Week Ahead For The Plains

Active Week Ahead For The Plains

Storms fired up across the plains, and a seve

23 Jun 2026 10:10 AM
Illinois Smashes Yearly Tornado Record in 2026

Illinois Smashes Yearly Tornado Record in 2026

We're only half way through 2026 and Illinois

23 Jun 2026 1:00 AM
Summer Solstice Kicks Off Father's Day Sunday

Summer Solstice Kicks Off Father's Day Sunday

Fathers across the country will have to share

21 Jun 2026 5:20 PM
Flood Risk Continues This Weekend for the Gulf Coast States

Flood Risk Continues This Weekend for the Gulf Coast States

Numerous flash flood warnings were issued as

21 Jun 2026 1:15 PM