Another stagnant blocking-type pattern is known as the cut-off high or ‘ring of fire’. This arises when an area of high pressure lingers over a region, thereby leading to a prolonged stretch of hot and dry weather for those under it’s influence while bouts of convective weather ride around it’s periphery.

This is a reasonably common occurrence during the summer months when the jet can lift north and high pressure cells to the south can become cut off from it’s steering effects, becoming effectively stationary for days at a time.

The areas controlled by this high will have a stable, dry and above-normal temperature pattern in place but the anticyclonic flow around the rim or ‘ring’ can lead to a series of potent thunderstorms revolving around it’s outer edges. This is considered one of the better configurations to produce the more highly-organized mesoscale convective systems (or simply MCS) which can be more persistent and able to resist weakening than their garden variety brethren that often degrade without their daytime heating element. These MCS are a subject for another blog post down the line, however.

This overall setup can be easily discerned on satellite or radar once entrenched as generally clear skies will dominate the hub of the ring where the HP holds sway and stormy conditions rotate in a clockwise fashion around it’s perimeter.

This is a simple graphical example:


Blocking Episodes

Part 1 – The Omega Block

Part 2 – The Ring of Fire

If you happened upon this looking for another well-known Ring of Fire, I won’t want you to leave disappointed 😉