>What is CAPE?
CAPE is a measure of instability in the atmosphere. It is also called MUCAPE, which means Most Unstable Convective Available Potential Energy. Certain values indicate when severe storms can form. Typically, values of 2000 j/kg are the beginning of instability good enough for storms.
How unstable can CAPE values get?
The most I have ever seen on a map is 6000 j/kg. That is EXTREMELY unstable.
How can I determine if the atmosphere is unstable?
One you find a CAPE map, see the below table for guidance.
1-500 j/kg: Stable.
500-1000 j/kg: Relatively stable.
1000-2000 j/kg: Unstable.
2000-3000 j/kg: Very unstable.
3000-4000 j/kg: Extremely unstable.
4000+ j/kg: Rare. So unstable that a simple rain shower could make a tornado.
Where can I find a CAPE map?
1. Go to the Storm Prediction Center website.
2. Click ‘Mesoanalysis’.
3. Click on the region where you live.
4. Mouse over the tab ‘Thermodynamics’.
5. Click on ‘CAPE- Most-Unstable / LPL Height’.