PROFICIENCY & EFFICIENCY 90 MAINTENANCE 96 PROFICIENCY >> 98 TECHNIQUE 101 NEVER AGAIN CAPE values of less than 1,000 joules per kilogram generally represent weak instability; 1,000 to 2,500 J/kg, moderate instability; 2,500 to 4,000 J/ kg, strong instability; and greater than 4,000 J/kg, extreme instability. Nowcasting thunderstorms Modeling the short-term weather BY THOMAS A. HORNE MIKE FIZER 86 | AOPA PILOT June 2018