Unusual Pattern Brings Rain & Cool-Down

Our "summer-as-usual" weather pattern is going on hiatus as an unusual upper-level low pressure system moves directly into Oklahoma. It's unusual enough this time of year to get any sort of substantial storm system to make this far south when the jet stream steers those systems along the northern tier of the U.S. However, this system is coming in from the northeast, which is VERY uncommon. This is what we call a retrograding system, where it is cut off from the main flow of the jet stream and moves in the opposite direction of the usual westerlies.

So what does this mean for us? For one, it means additional clouds and cooler temperatures starting Sunday morning. This kind of system will take the edge off of the heat and give much of the region a nice soaking rain. Thunderstorms, even a severe one or two, are possible, but this will be a more widespread rain event than is common in our summers. Not everyone will come out as big-time rainfall winners, but we'll all benefit from the cool-down and clouds. The best chance for rain totals greater than one inch lie west of Highway 75 where deeper moisture and the best forcing for the rain will be. Central and western Oklahoma would love a big drink of rain although anyone would benefit from it after the dry spell.

This system will continue its rather quick westward movement. Its influence will be over us for a couple days, which means a continued chance of rain and cooler-than-normal temperatures through midweek. After that, it does appear "summer-as-usual" returns, but this time we should be in better shape – hopefully a better greener than we are now.

I'll have all the latest updates on the weekend shows on News on 6. In the meantime, you can follow me on Twitter: @GroganontheGO and like my Facebook page!