NO HARM, NO FOUL...
How many times in a basketball game have I seen a player give an opponent a little nudge with the body or an elbow to throw his game off balance. It has an impact but the referees look the other way and say, play on. No harm no foul. We're going to pull that trick in our weather this weekend and I think it will pay off in better weather. I'll explain in a minute.
First, here's the satellite Friday afternoon and you can see a tongue of moisture surging from the Gulf of Mexico into the heart of my area. This is the old squeeze play where high pressure to the east and low pressure to the west are working in tandem to funnel moisture into a cyclonic channel. It's a narrow band but an effective cloud and shower producer. The end result was that Friday was another dreary damp day.
All we need to do to brighten our skies and limit rain chances going forward is push that moisture convergence left or right 150 miles. This is where the the atmosphere nudges (or pushes) the high westward over the weekend. This is called pattern retrogression and the harmless push will give us some breaks in the clouds that will ensure a warm, muggy weekend. It should also bring a rain-free Saturday and Sunday to most of my region with chances overall 20 percent or less. In the animation you can watch the high back from Ohio to Mississippi over the next 48 hours.
Assuming all works as planned highs Saturday and Sunday should reach the low 80s. Of more importance will be the high levels of water vapor that will make things feel nice and sticky. See the dew points in the mid 60s to low 70s from Wisconsin to the Gulf of Mexico. That's a robust feed of moisture.
One of the things we talked about yesterday was the ability of such a moisture rich environment to create heavy rains, especially when there is forcing to drive precipitation. Next week, a front will sink into the area around Tuesday and is then shown vacillating around the region much of the next 6 or 7 days. The precise location of the front will be critical to where convective systems form and ultimately track. This is the type of set-up you look for to produce heavy rain events, one that can cause hydrologic concerns such as flash flooding. Now, I'm not gifted enough to define where this zone gets established but the trend continues for some part of the central Midwest to see significant rains sometime next week and beyond. The challenge is to define the general location most at risk which is far from certain. Just to give you an idea of the chaos on the table, here's what the Friday afternoon GFS showed for total rain the next 10 days.
Just six hours later the GFS has backed off showing 10 day totals like this. Amounts just northwest of the Quad Cities went from 11 inches to less than one inch.
Needless to say, there are a wide range of solutions which need to be resolved in the coming days regarding rains next week. If the front gets a good push south the drier solution wins out. If not, soggy times lay ahead. Stay tuned, the final chapter is yet to be written.
The weekend however boils down to clouds and how warm it actually gets. Playing it conservative, I think both Saturday and Sunday will end up 80-82 even with a minimal amount of sunshine. If we get more than advertised, 83-85 is not out of the question. Throw in some humidity and you have yourself a preview of what the next 3 months are likely to bring. Have a sensational weekend and roll weather...TS