Caution, challenging rain forecast ahead.
That’s right, it’s another week where Kansas Citians could watch their lawns turn brown as generous rain falls just west of the metro. Last week, nearly ten inches of rain fell in Franklin County, Kansas. Kansas City International picked up a meager two hundredths of an inch of rain. This week could offer up a similar fate. The weather pattern looks a lot like last week, perhaps a little different but enough similarities that make missing out on rain a real possibility as the week unfolds.
Tonight, could be the key
We might know by Wednesday morning if this is going to be another week of frustrating forecasts. Computer guidance suggests a good chance of rain in Kansas City, either Wednesday morning or by early Wednesday afternoon. We will have a better feeling whether rain will fall in Kansas City on Wednesday just by looking to our north this afternoon. Thunderstorms over the northern parts of the Missouri River Valley could hold the clue to tonight’s forecast.
The setup is there for severe thunderstorms to develop over South Dakota. The Storm Prediction Center placed an “Enhanced Risk” of severe weather over a large portion of eastern South Dakota. In other words, a large thunderstorm complex that could bring us rain by morning could get its start in South Dakota and Nebraska later today.
Look at the radar this afternoon
Keep an eye on the area of highlighted above in yellow and orange. Showers and thunderstorms today early afternoon were just starting to fire up. I’ve pointed a red arrow to this region on the map below. If this area is lit up with rain and thunderstorms by this evening, then we will know there’s a higher chance that thunderstorms will follow the upper level winds down the Missouri Valley and close to Kansas City by Wednesday morning.
Could rain miss us again
Once again, like last week, we have to watch the direction the upper level winds carry these thunderstorms. The upper level winds may keep the bulk of the stormy weather west of Kansas City tonight and during the day Wednesday. Just look at the Forecast Track below and see how the bulk of the rain is forecast to move into central Kansas.
This is where the edge of hotter air is located, and night-time thunderstorms like to move along these boundaries. Yes, the data says Kansas City has a chance. But it did the same thing last week and we ended up dry. So, rain chances Wednesday are probably no higher than 40% for the metro. That means not everyone sees rain. And the chance of rain could be even lower east of the Kansas, Missouri state-line.
Could rain miss Kansas City Thursday morning too?
This process may repeat itself Thursday morning. Computer guidance suggest thunderstorms will form along the hot air boundary in central Kansas late Wednesday night. This time they will move east and could end up just clipping the metro. That means if you live east of Kansas City, chances are, the rain will miss you. Here’s a radar simulation snapshot from Thursday morning around 7 a.m.
But it looks like it’s headed right for us.
Radar looked like this too last week before the showers fell apart and shifted south of Kansas City. Unfortunately, this means the hardest hit areas this week are the same areas that saw damaging floods last week. A quick glance at the rainfall accumulation outlook shows no more than two more inches of rain possible between tonight and Friday morning. That doesn’t mean two inches each day, but rather a total of two inches of rain over the next three days.
So, what should we do?
I’d keep watering the lawn and flowers until we break this mini dry spell. Note how the guidance paints about a quarter inch of rain over the Kansas City area. That’s not a lot and just keep in mind there could be even less rain in your backyard than what is shown on the above graphic.
It’s August, and thunderstorms tend to be random this month and can be very hard to predict amounts and placement. Like I said at the top of this blog, this is a challenging rainfall forecast but a clue to amount of rain we see in the coming days will be found in what happens with tonight’s thunderstorms.