Source: WCCB Charlotte

June 16. By Dave Vieser. If you sense that this spring has been cooler than normal, you’re right. It’s all part of an unusual weather pattern in the atmosphere called an Omega Blocking Pattern. In this case, the blocking element has been an upper-air, low-pressure system stacked up over New England, which has stubbornly stayed put for weeks.

An Omega block occurs when two low-pressure systems become cut off from the main flow of the jet stream, sandwiching a high-pressure system between them.

“Our temperatures have been below normal since mid-May,” said meteorologist Bill Martin from the National Weather Service Spartanburg office. “We have been in this Omega Block for much of that time and it’s unusual in that the block is lasting longer than normal. Blocks typically last a few days to a couple weeks.“

This particular pattern has given us lower humidity and cooler temps. For example, this week in the Lake Norman area, high and low temperatures have been running about 3-4 degrees below normal. Martin said that the blocking pattern also had something to do with all the Canadian smoke reaching into our area as well as farther north.

How often do we experience such a weather pattern?

Martin says they occur like this only once every five or so years. While no one can say for sure, chances are that the weather pattern will change soon, bringing us more summer like weather as we approach June 21, the first day of summer.