Clouds became much more noticeable yesterday as the day went on, and they are associated with Irma as she churns across the Deep South. On her trek through the TN Valley over the next day and a half, she will throw more clouds and even a bit of precipitation up our way.
Today should be mostly dry. Scattered showers start to develop tonight, mostly over central and southern Indiana, and then we have scattered showers through the day Wednesday. We are bumping our coverage somewhat, bringing 60% coverage of combined rain totals of mostly a few hundredths to .3”. We think the most general coverage of rain will be a tenth or two. East central and then southern Indiana are the best zones for rain coverage between tonight and the end of the day tomorrow. The map shows cumulative rains through tomorrow evening, although we should note that we think the rains in southeast Indiana are way over done, and this particular model is very overzealous. Our precipitation breakdown is much more conservative. But, this does show the distribution of moisture fairly well. Temps will be warming today, but will be capped by clouds and light moisture tomorrow.
Drier weather returns with sunshine trying to poke through at some point Thursday midday or afternoon. We have no rain chances in here for Thursday late, Friday and most of the weekend. There is still a weak upper level disturbance crossing the great lakes Sunday afternoon and evening, which may drag a few scattered showers down into Indiana, mostly north of US30. These outlooks on this event are unchanged, meaning 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. Where there may be some tweaks forthcoming, though, will be with the follow-up system for Monday. Models have mysteriously deleted the strong storm potential for Monday afternoon. We are not ready to make dramatic changes to our outlook yet…as convection as impressive as we were seeing just does not “disappear”. However, it does bear watching…because without that secondary push of moisture, we could find ourselves dry right on through most of the rest of the month of September. So, any change to the rain potential for next Monday has the potential to dramatically reshape the precipitation landscape for the entire month. For now, we will leave rain chances Monday afternoon through early Tuesday morning at a half to 1.5” with coverage at 70%. But, we are monitoring closely.
The rest of the 10 day window and the extended 11-16 day window look dry. Strong upper level high-pressure is likely to be in control, and we may not see our next front moving toward Indiana until closer to the 26th. So, no changes in the extended period this morning.
Temps stall out later this week near normal, but should stay near normal for most of next week into the week following. We do not see any well above normal temps spreading in here, but yet cannot say that we have any elevated frost risk either.