Weather systems are changing more slowly during this time of the year, and when a high pressure system sits off the East Coast the result for us is gentle warm southerly breezes. The high pressure is named a Bermuda High due to its central location in the vicinity of the island nation, and the clockwise circulation brings warm air up the coastal plain. We are experiencing this now, and fortunately the fact that it happens on a weekend makes it more enjoyable still.
Once again, the jet stream is the reason for this tranquility. During summer months when the difference in temperature between the Polar regions and the mid latitudes is less than in winter, the jet stream changes from a more direct west to east flow and becomes a meandering wave. “Wave” may not be a term that you think about with air but just like the water waves, air is a fluid and behaves according to the same laws of physics. In this case, imagine the jet stream meandering far to the north and then far to the south as it progresses toward the east. The weather systems that are being pushed along by this wave appear to stay stationary overhead for a longer period of time than during winter’s speedy flow.
Sometimes the meandering flow can become disjointed – separated if you will – and a weather system will become isolated from the main jet stream. This is described as a “cutoff” because it is in fact cut off from the flow, and the jet separates to the north and south of it. That is the case for the upcoming week as the forecast models have a cutoff low pressure developing over the Great Lakes and moving our way. Clouds, rain and anything but summer delight for a while.
Enjoy the perfect summer conditions while they are with us and rest assured they will return sometime.