Slow moving thunderstorms are currently producing small hail and torrential rainfall north of Lafayette (as of 5:45p Thursday). We have reports of 1″ to as much as 1.5″ of rain falling near Battle Ground in less than an hour.
Eventually these storms should pick up momentum and head off to the southeast later tonight.
This is only the beginning of daily rain and storm chances in a warm and humid air mass through the weekend and on into early next week. The culprit? An upper level ridge centered over the southern Plains and “spokes” of energy, or upper level disturbances, rotating around the periphery of the hot dome to our southwest.
An increasingly muggy air mass will take hold of the region as we close the work week, with dew points approaching 70° at times. The term “air you can wear” comes to mind. As impulses of energy interact with this tropical air mass, thunderstorms will blossom- particularly in the afternoon and evening hours.
We’ll have to nail down specifics with storm coverage and timing within our short-term forecast products and updates, but each day into early next week will feature coverage of storms across central Indiana. Future forecast radar products show scattered to numerous storms around Friday evening and again Saturday. Get used to this look.
Looking down the road, a “sticky” summer feel will remain intact through next week, but changes are brewing in the longer range. These changes would support a cooler regime developing just past mid-June (in the 10 to 15 day time frame). While the duration is up for debate, it’ll be nice for at least a few days of cooler air…
While impossible to nail down exactly which back yards would see beneficial rainfall, it would be an overall more conducive pattern for widespread showers and thunderstorms for our general region. We’ll have to lean on high resolution, shorter-term models as time draws closer to gain more insight around more precise timing and track details, but we continue to trend our forecast wetter Friday through Sunday than we’ve been over the past couple weeks- Alberto remnants excluded.
Our attention will then shift to the potential of strong thunderstorms late Sunday. Higher resolution guidance suggests storms will begin to rumble into western Indiana late Sunday evening (around 9p to 10p) before tracking east into the overnight hours.
With a stalled front nearby, shower and thunderstorm chances will remain in our forecast into the middle of the week. While it won’t rain the entire time, unsettled conditions will remain into Wednesday before high pressure provides drier conditions Thursday and most of Friday.
Otherwise, look for considerable cloudiness and highs topping out in the lower 70s today.
As we look ahead to the end of May, there really aren’t any significant changes to the overall warmer than normal theme we’ve enjoyed so far this month. Longer range guidance off of the European ensemble continues to support broad scale upper ridging across the Mid West and Ohio Valley and a corresponding warmer than average regime. From a precipitation perspective, the next couple of weeks do look more active compared to the dry start to the month. Case in point, the balance of the upcoming week will be dominated by a stalled frontal boundary. While we’ll have to fine tune exactly where the front stalls, daily chances of showers and thunderstorms (scattered fashion) can be expected.
2.) Overall, a drier air mass will build into central Indiana today and Thursday (cooler, too) before moisture returns to close the week. Scattered showers and embedded thunder are more likely Friday and again late Sunday into Monday.
3.) Looking ahead, we notice a more active pattern is presented off the overnight GEFS model. The heat ridge backs west and sets up a busy “ring of fire” pattern with a northwest flow aloft across our region. We have a ways to go before developing consistency and overall confidence, but this is at least an encouraging sign. The end result, should this come to fruition, would be a significantly wetter open to June.