Summer Keeps A Strong Hold on the Region
So far this September, our high temperatures have been holding steady well into the 90s each day while our average temperatures have started that seasonal descent. At about this point in the summer (or fall, depending on your perspective), we usually have that first meaningful cold front of the season. It kicks starts our incremental downward trend in temperatures. That has yet to show up nor does it look promising in the near future.
The stubborn ridge of high pressure in the jet stream is finally shifting east and positioning the heat dome over the southeastern U.S. Meanwhile, a trough (or dip) in the jet stream will advance our direction from the West Coast, sending a weak cold front to Green Country by Thursday night. The weather pattern is fairly steady-state until then with only a slight drop in temperatures through midweek owing mostly to more cloud cover potential. That pattern is shown below.
Thursday night still offers a good shot at widespread showers and thunderstorms, especially from Tulsa northward. This would be the first meaningful rain in nearly 2 weeks. We can afford that kind of dry spell given how wet our year to date has been. However, that moisture (maybe over an inch of rain in northeast Oklahoma) will be welcome. The severe threat remains low given less-than-ideal wind shear and instability. That should not discount the potential for flash flooding since these storms may be slow movers or train over the same locations near the Oklahoma-Kansas line. Below is the timeline for rainfall chances late this week. Some showers may linger into Friday night or Saturday, but the chances of outdoor interruptions are low for high school football games or outdoor plans over the weekend.
The real relief from the heat comes Friday when leftover cloud cover and showers will keep the air from warming that much. For the first day this month, our highs should be in the 80s. That is actually average for this time of year! The relief will not last long though. The progressive nature of the upper-level air flow will force the boundary back north again over the weekend and send the heat readily back into the region. Thus, by Sunday, we are back to that familiar September swelter. Below is our high temperatures departure trend into next week.
As we look further down the road, the jet stream will remain positioned further north than average. That keeps the building colder air locked away into Canada. Next week may not be *quite* as hot as this week. That sun angle keeps getting lower and less intense. However, it will certainly not feel like fall for up to two weeks. The Outlook below shows how we are not alone in the stubborn summer pattern. Keep the pool open, in other words!
Our long-range models do bring a fall-like cold front our way right as we switch to autumn on the calendar. Good timing! However, that lies in an uncertain realm beyond reasonable forecasting at this point. EVENTUALLY, though, that will come to pass!
Tuesday is also the peak of Hurricane season. While we are seeing a brief lull in more organized activity in the Atlantic, the weather pattern remains conducive for renewed development as several tropical waves traverse westward across the ocean. In about a week or just beyond, we could have another named menace near the Caribbean.