TULSA, Oklahoma - A quiet and calm weather pattern will remain today before active weather returns to the eastern third of the state Wednesday night into the weekend with rain and thunderstorms in the forecast.   Lows will be in the upper 60s this morning with daytime highs moving into the mid-80s this afternoon along with a mix of sun and clouds.   Showers and storms will become more numerous by the middle to the end of the week including the weekend.   Pockets of moderate to heavy rainfall will be possible, more so by the weekend, with some locally heavy rainfall amounts possible.   This unusual pattern for August, now in the 3rd week, will keep daytime highs mostly 5 to 10 degrees below the normal average high.  

The upper level pattern will revolve around a strong trough of low pressure centered over the Great Lakes northward into the Hudson Bay region of Canada with a ridge of high pressure basically to the south and southwest of the state.   This essentially creates a northwest flow pattern across the central and southern U.S.  

The main thoughts regarding the evolution of the active weather remains mostly unchanged from yesterday.   This means the timing of the individual waves will be tweaked as we get closer to the midweek and weekend period.    But at this point in the forecast cycle we’ll keep Wednesday dry until the afternoon and evening with a slight chance of a few storms by late evening.  Some storm chances will need to be carried Thursday morning for the northern sections.  This pop may actually drop a little from previous sets but will stay around 30 to 40% for this forecast cycle.    This first wave will not have a high coverage.   This means the chances will remain moderate for our area.   The second wave will be in the form of at least two or even 3 distinct MCS (storm complex) chances including late Friday morning, Saturday morning and followed by Saturday night into Sunday morning.   The last system will be followed (or accompanied) by a surface front that will once again knock our temps down Sunday into early next week for a day or two.