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
Tropics: Pacific Staying Active, Atlantic Staying Quiet

Tropics: Pacific Staying Active, Atlantic Staying Quiet

Isaias ended the late-season streak of no hur

16 Oct 2026 11:25 PM
Severe Storms to Frosty Temps, Big Changes for the Midwest and Northeast

Severe Storms to Frosty Temps, Big Changes for the Midwest and Northeast

UPDATEA Severe T'Storm Watch is in effect for

16 Oct 2026 9:00 PM
Several Fires Break Out in SoCal Amid Santa Ana Wind Event

Several Fires Break Out in SoCal Amid Santa Ana Wind Event

Santa Ana winds helped several fires grow qui

16 Oct 2026 6:35 PM
Flooding & Severe Storms Persist in the Southern Plains

Flooding & Severe Storms Persist in the Southern Plains

Extreme rainfall has been hitting areas of Te

16 Oct 2026 2:00 AM
Hot Weather Baking the Heartland This Week, Cooler Air Incoming

Hot Weather Baking the Heartland This Week, Cooler Air Incoming

More records fell on Thursday afternoon and e

16 Oct 2026 1:50 AM
Cooler Air & Lingering Snow for The Rockies

Cooler Air & Lingering Snow for The Rockies

A digging trough is bringing cooler temperatu

15 Oct 2026 10:00 AM
Rachel Spreading Moisture Across the Southwest

Rachel Spreading Moisture Across the Southwest

Rachel came ashore in far northwestern Mexico

13 Oct 2026 12:10 AM