The latest drought map isn't pretty. A large chunk of northeastern Oklahoma is now back in the dreaded "Exceptional" drought category, something we haven't seen since last fall. Check out the attached map, showing the latest Drought Monitor. Despite recent, spotty rainfall, widespread relief has yet to be realized. Fortunately, we are seeing quite a few changes that will help our parched land allow for some slow recovery. If we can't have the remnants of a tropical storm sit overhead, this pattern change might be the next best thing.
We are seeing some of that change today as a fairly strong cold front for August moves through the region. That front is able to move into Oklahoma because of a re-centering of the high pressure ridge/heat dome to our west and an unusually large trough digging in to the Midwest. This provides us with northwesterly upper-level wind flow, which brings system after system through our area, almost like a conveyer belt. This keeps the worst of the heat to our west and allows for periodic rain and storm chances. Even after the front shifts just to our south, the frontal boundary will waffle around and provide a regional focus for rain. Specifically, our rain chances will be with us through the weekend with clouds and cooler weather a sure bet.
Even losing the extreme heat slows down our drought intensification because it slows down the rate at which we lose moisture in the ground due to evaporation. This is why, if I were a betting man, I'd say we've reached the worst of our drought for the time being. It may not greatly improve since the road to rain recovery is a long one, but we may not see it worsen much further through Labor Day at least.
If you're wondering if we are done with the extreme heat of the summer, I'll have to remind you about last year. The end of summer finally brought much cooler, somewhat wetter conditions. Even then, though, we managed to get one last triple-digit heat day in on September 13th. We've got about another month to go before we see not just a pattern change, but a seasonal change. That seasonal change may also be accompanied by a gradual shift to El Niño. While each El Niño year is different, we tend to see wetter, cooler conditions in Oklahoma during the fall and winter due to a stronger subtropical jet stream, which flows overhead. At least August is beginning to show her kinder side to Oklahoma. After our recent fires and record-breaking heat, this pattern and eventual seasonal change will finally send us in the right direction for relief.