Central IN is still in play for a multi-day heavy rain event that begins this weekend and continues into the middle of next week.
The setup is still one that features a wavy cold front that will halt to a crawl (eventually becoming stationary) over central and southern IN over the weekend. Additionally, tropical moisture will continue to slowly push north, before curling northeast (following the frontal boundary) into the Ohio Valley. The image below from Monday displays the setup nicely.
Despite lackluster model output from our American suite (latest NAM and SREF data, for instance, paints rainfall totals under 1″ across most central IN neighborhoods), the European remains consistent on the evolution of things from this weekend into the middle of next week. We’ll lean more towards it’s solution at this juncture. Simply put, when you have a stalled frontal boundary entraining tropical moisture, expect problems. Precipitable water values will approach and even exceed 2″ at times this weekend. Dew points will remain in the upper 60s to lower 70s along and south of the boundary. Where the boundary stalls will be key in determining the heaviest rain totals and resulting flood problems that will ensue. For now, here’s the best idea we have in regards to local 4″+ totals between this weekend and next Wednesday.
It should also be pointed out that we’re not looking at all day rains Saturday through Wednesday, but instead “waves” of moisture throughout the period. Areas of locally heavy rain will be with us, but we’ll also see dry periods in between. Thankfully, as we move into the latter portions of next week, drier times should return.
We’ll be here through the weekend to keep you updated on things, as well as on social media. Stay tuned.
The precise placement of the front will serve as the focal point for heavy weekend rains. As we’d expect from this distance, modeling disagrees on the all-important specifics. Using a model blend, central Indiana is on the table for heavy late week-weekend rain as of now. Precipitable water values (PWATs) will be above 2″ and suggest the threat of torrential downpours, including localized flash flooding across the Ohio Valley. Eventually, the cold front will sweep the tropical-rich moisture away from the region and cooler, much less humid air will press in by this time next week.