It seems like most days this summer, even when many of us are dry, there’s a shower or storm somewhere in the area. And it all has to do with the large-scale pattern that we’ve been in. Rain and thunderstorm chances have been sneaking into the forecast even on the driest of days since we got into the summer. We’ve had some short-lived dry bouts when temperatures rise into the 90s and 100s. But the dominant feature has been northwesterly flow.
Flow from the northwest that typically triggers unsettled conditions in the form of showers and storms, especially this time of year. This flow can also spark severe storm chances. A common scenario that we see here in Kansas is storms starting in the evening, clustering into a complex while tracking through the area, and then these complexes can last into the morning and even into the afternoon of the following day. This kind of weather can also keep us relatively cooler than normal due to clouds and heavy rain.
Another pattern that we haven’t seen as much this summer is ridging. A ridge of high pressure builds, as well as heat and humidity. This heat dome blocks any storm systems from reaching us. Also, the large-scale clockwise flow isn’t as significant as northwesterly flow when it comes to sparking unsettled conditions.
We’ve still got the rest of summer to get through and it’s looking like the northwesterly flow will prevail, at least at times, as we heat back up this weekend and through the second full week of August. Days will be dry and hot but some isolated storms will be around during the evenings, overnights, and possibly into our mornings.
Also, the start of fall isn’t too far away and it’s a season of change. So as we get closer we may see more waves of energy dive in from the north and disrupt our weather at times during mid to late summer.