A NARROW BAND OF MOIST UNCONDITIONALLY UNSTABLE AIR JUST BEHIND THE FRONTTHE MOISTURE USUALLY EXTENDS TROUGH A DEEP LAYER (TO 300 MB)PWS 150-200% OR NORMALOROGRAPHIC LIFT PROVIDES MECHANISM TO RELEASE INSTABILITY
Times when the surface dewpoints extend westward to the front range should be monitored very closely
especially when the low-level winds are easterly or southeasterly
FROM CHAPPELL COMET NOTES