AFTERNOON-OVERNIGHT: A mix of sun and clouds persists over zones 1 and 5 currently. While most places are dry there are a few areas of rain and a couple of storms around, mainly across western Ohio with another area of rain entering southwestern Indiana.
Through the early afternoon a few isolated to scattered areas of rain and storms may develop. Better chances for rain by 1-2 PM will be across southern Indiana and out closer to Columbus, OH.
Through the afternoon into the evening an upper-level disturbance will approach the forecast area from the west. Along this, rain and t’storms will be ongoing.
By 6-7 PM rain and some storms will be entering western and southwestern Indiana from Illinois. While they move in it does look like they will be breaking apart. However, strong winds, hail, and heavy rain will be possible.
Through the evening the upper-level energy will move into the forecast area. While isolated to scattered storms will remain possible across Ohio, better chances of rain will be moving into central Indiana this evening around 10-11 PM.
Through the overnight the upper-level vorticity max is forecast to strengthen across western/northwestern Indiana. As it does, rain and thunderstorms coverage will increase in both coverage and intensity across eastern Indiana and western Ohio by 2-4 AM.
Through the overnight the upper-level vorticity max will be making its way east through Ohio. The NAM 4km keeps the storms around Indiana through the morning hours. However, I think better rain/storm chances will likely exist closer to the 500 mb feature across central Ohio.
Lows overnight will be in the low to upper 60’s.
THURSDAY: By 7-8 AM Thursday morning at least a few isolated areas of rain and storms will be ongoing across zones 1 and 5. The NAM 4 km model is pretty aggressive with the precipitation; I am not confident it will be as intense or widespread as the model suggests. Mainly because it has been overly aggressive with morning precipitation lately.
Isolated rain and t’storms will remain possible through the morning mainly from I-70 south across Indiana and Ohio. However, it does appear these will be pretty hit and miss.
Through the morning into the afternoon models do vary on the overall forecast. The NAM 4km model suggests only isolated to scattered storms develop across the forecast area.
However, the NAM 12 km continues to show another area of upper-level energy moving into the state through the afternoon. By 1-2 PM you can notice the pieces of energy sprawled out across Indiana and into Illinois. These could lead to either a single large cluster or a couple smaller clusters of thunderstorms Thursday afternoon.
These clusters or MCS type systems can be very complicated to forecast in advance so make sure to check back with us for the latest!
While the overall environment will not be conducive for severe weather Thursday, models do hint as some higher pockets of instability to the measure of 1500-2200 J/Kg. This coupled with very high moisture content would be enough to support strong to severe winds with storms, especially if a MCS type system were to develop.
Through the afternoon and into the evening on Thursday at least widely scattered storms will be possible. Again, some could be on the strong to perhaps briefly severe side with damaging winds, hail, and heavy rain all possible.
Highs on Thursday will be in the upper 70’s to mid 80’s.
Through the overnight into Friday we will lose daytime heating, so while a few isolated showers or maybe a t’storm will remain, the overnight looks pretty quiet.
Lows Thursday into Friday will be in the 60’s.
FRIDAY: the morning hours on Friday do look to start out mostly dry with perhaps a few isolated areas of rain near Columbus, Ohio and northward. However, the main thing we will be watching is some positively advecting vorticity coming out of Illinois.
As this pushes northward through the morning hours rain and t’storms will develop along and ahead of the vorticity. These will spread into the forecast zones later on into the day.
Through the day a better push of ran will exist across Illinois. However, across Indiana rain chances don’t look to arrive until later. This may allow pockets of moderate instability to form with 1500-2000 J/Kg of CAPE possible in areas.
At 850 mb winds will be moving in from the southwest at 30-45 mph.
With these two features along with a very moist air mass in place, strong to severe storms will be possible Friday afternoon. A large part of this will depend on early morning rain/instability. If the instability can build across western and central Indiana Friday, severe weather can’t be ruled out. Main risks would be damaging winds, hail, and perhaps a brief spin-up.
The NAM 4km does do a good job showing t’storms developing in the unstable environment by 1-2 PM Friday afternoon across western Indiana.
Through the afternoon into the evening the storms do continue to move into central Indiana by 5-6 PM.
By 8-9 PM storms will continue their eastward movement. However, the low-level jet looks to be displaced from the storms once they get into eastern Indiana and Ohio. So they will likely start to lose some of their severe t’storm characteristics.
These will move off to the east into Ohio through the late evening on Friday. However, I would expect them to be weakening as they do with perhaps a few still capable of some strong winds.
Highs on Friday will be in the upper 70’s west to mid to perhaps upper 80’s east.
Through the overnight scattered rain will remain possible across both zones 1 and 5. However, many places will be dry.
WEEKEND: Saturday will start off dry but cloudy across most of the forecast area. Perhaps with only some sunshine getting through across central/southern Ohio.
Through late morning into the early afternoon rain and scattered storms will start to redevelop across western Indiana and central Ohio. By 1-2 PM in the afternoon these storms will be ongoing.
Through the evening better rain chances look to be in place across western Indiana and central portions of Ohio. Likely where better instability was realized earlier on the day, therefore supporting convection and precipitation through the afternoon/evening.
Through the evening hours rain and storms will start to weaken and move out of zones 1 and 5. I will emphasize, while there will be times of rain on Saturday, there will also be plenty of dry time as well.
Highs on Saturday will be in the upper 70’s to mid 80’s.
Heavy rainfall and possibly localized flooding will be a concern over the next several days. The NAM 12 km is a little less aggressive with rainfall with an average of about .45-.90”, with localized areas of 2-3”.
However, the NAM 4 km is much more aggressive showing widespread 1.75+” totals and localized areas od 4-6”. While I do think 4-6” may be a bit aggressive, I do not doubt localized areas of 3-4” or so will be possible given that the atmosphere will be full saturated.
Sunday looks to be a drier less active day across the forecast area. The morning hours will start off warm and quiet.
By afternoon some isolated areas of rain or a storm will develop. However, I think most areas will be dry throughout the day. So if you have plans for Memorial Day weekend or for race in Indy, don’t cancel them for the threat of rain.
Since memorial day is the holiday that “kicks off summer” it will most definitely feel like it outside with temperatures in the low 80’s north to possibly near 90 far south towards the Ohio River!
I do want to emphasize that there are many challenges over the next several days regarding the overall forecast. Model disagreement, an active pattern, along with a warm, moist environment make for very challenging times. I encourage everyone to follow us on social media for the latest information. If you have questions please feel free to ask us by giving us a call, text, or email! Thank you.