Another mostly dry day over Indiana today, and it should look very similar to yesterday. The heat made its presence known yesterday and humidity values were high as well. Today looks like nearly a duplicate. We still can’t rule out a couple of pop of showers, but generally, the scattered action looks to have the best potential up in NW parts of the state toward evening and up through midnight. Most of us will see nothing.
Better organized shower and thunderstorm activity moves in for tomorrow and hangs out through Friday. We expect .25”-1” rain totals over about 60% of the state combined over the 2-day period. This is part of a frontal complex that will be moving in from the west.
The main feature of our forecast this morning is the remains of tropical system Gordon. Gordon will be making landfall later this week in MS and LA and will then work north through the lower and mid-Mississippi valley, before hooking northeast. Gordon will start to push into SW Indiana Saturday, bringing .25”-1” rains to the SW quadrant of the state. From there, the action just continues and spread from Saturday night through Sunday. That period will be fraught with 1-3 inch rains over 100% of the state. We are concerned that rain totals can actually exceed that 3” upper bound (see the map below), but we will be conservative for now, as the overall rain totals will be completely dependent on the track that Gordon’s remains take.
Leftover showers hold through the day Monday and can add to our cumulative rain totals. Monday action likely is limited to a few hundredths to a quarter of an inch, but coverage can still be around 80% of the state. We do finally start to dry down over most of the state on Tuesday, but see persistent showers over far southern Indiana, from US 50 southward. From US 50 to the river we can see Tuesday rains bring an additional .25”-.75”. This should bring to an end the wettest part of our entire forecast. The map below shows cumulative rain potential now through next Tuesday.
After all of that, we do eventually get a nice dry period starting next Wednesday. We will be rain-free through the end of the 10-day period (through next Friday) and we will start off the 11-16 day extended period with the more dry weather for the weekend through the following Monday. Our next chance of rain looks to develop around the 18th and 19th (Tuesday and Wednesday) with rain totals of a half to 1.5” coming from slow-moving rains moving across the state. We expect 90% coverage from that system. Then we go back to dry weather for the 20th on forward through at least the 23rd.
Temperatures will be warm again today, as we have already hinted at above. Yesterday was a “to 10” day when compared to all previous September 4th’s on record, as most of the state was near or above 90 degrees. Heat indexes were higher. Today and tomorrow will be well above normal again, but then, as rains intensify Friday through the weekend and early next week, we see temps pull back to normal and below normal levels. However, the cooler push will be tough to notice, as humidity levels will be high, it will be stuffy and therefore feel much warmer. Then, the balance of our forecast sees temps go back above normal for the rest of the 10-day period and the extended window as well. We will need the warmer temps to help with dry down after all of the rain over the next 6 days.