We start off the week answering the questions that were being asked last week, namely “will we see any of the effects of Irma up here”. Now that the storm has made landfall and is slowly churning through the Deep South, we are ready to track the remains. And yes…we will see some effects of the storm in Indiana…but not very much.
Before we get there, though, let’s talk about the next few days. We are still under the influence of high pressure over the state today, with nice south winds coming up the backside of a major high that is pushing off to the east. This will allow temps to be a few degrees warmer today than yesterday, and a few degrees warmer tomorrow over today. Actually, we will see temps finally get back to normal tomorrow after an extended cool period. We do not think that we are going too much above normal any time in the upcoming forecast period.
We start to see some clouds from Irma come in tomorrow night, and then for Wednesday and a good chunk of Thursday we see those clouds lingering, with a few scattered showers. South and southeast Indiana gets the best chance of these hit and miss showers, but we won’t rule them out elsewhere either. Combined over the 2 day period, we think coverage of rain will be no better than about 50%, with rain totals mostly under a quarter of an inch. However, clouds will be seen over 80-90% of the state…and that will keep temps down a bit. However, that is basically the only true effects of the hurricane remains up in our neck of the woods. The remains of Harvey were much more impressive than the remains of Irma will be.
Behind that disturbance, we are back to dry weather again to finish out the week for Friday, Saturday, and Sunday. Sunday afternoon and evening we see a fairly minor disturbance coming across northeast IL, southern WI and MI that may drag a few scattered showers down into Indiana, mostly north of US30. These showers can bring a few hundredths to perhaps a third of an inch, but coverage will be only about 40% over areas from US 30 northward, and under 10% over areas outside of that zone. However, this likely does really prime the atmosphere for a much bigger system for Monday afternoon into early Tuesday morning. This wave comes across the great lakes and brings a big swath of rain and heavy thunderstorm action to Indiana and western OH. Rain totals can be from half to 1.5” with coverage at 70%. Western Indiana may be able to miss out on this wave (the western third of the state), but eastern and particularly northeastern parts of Indiana look like they can get hammered. It will be interesting to see of this system can maintain its strength and organization as we move closer to its arrival. But for now, it looks very potent.
Behind that front, we are dry for the rest of the 10 day period, for next Tuesday afternoon, Wednesday and into Thursday. In fact, the 11-16 day forecast period kicks off dry, with a strong upper level high over the Great Lakes. Our next good potential front could be delayed until closer to the 26th with rains slowly moving over the western Corn Belt from the 23rd through the 25th, but running into serious resistance moving into the eastern Corn Belt due to that strong upper-level high eroding the moisture as it moves across the Mississippi River into central Illinois.
Overall, we are calling temperatures near normal for the upcoming 16 day period. The coolest times will be with the increase in cloud cover a few days from now, and then behind the strong front that starts off next week. We do not see any spectacular warm up to well above normal levels through the coming 2 weeks.