AFTERNOON-OVERNIGHT: A stationary front remains in place across Indiana today. That has been the source of the morning rain across zones 1 and 5. However, we are starting to see skies clear across western Indiana currently.
Skies will continue to move out ahead of rain and storms that have developed with an area of upper-level 500 mb vorticity.
As the skies clear this afternoon ahead of these storms instability will build into the forecast area. While models are not overly impressive with CAPE values, 500-1000 J/Kg of CAPE will be possible from I -70 southward this afternoon.
Winds aloft this afternoon will strong across southern Indiana this afternoon/evening. 500 mb winds of 45-55 mph and 850 mb winds of 35-45 mph would be supportive of severe storms.
The 500 mb area of vorticity will continue to the east and northeast this evening. With all these things combined an enhanced severe weather threat will be likely from I-70 southward this afternoon into the evening as the area of storms heads west.
By 2-3 PM the area of storms will be entering western Indiana across southwestern zone 1 and zone 5.
Through the evening the storms will continue to the east and northeast. Likely impacting the Indianapolis area around 4-5 PM.
Through the evening upscale growth looks likely with this system as it develops into a bigger line of storms. By 6-7 PM the storms look to develop into a line and impact eastern Indiana and western Ohio. Storms look to impact the Cincinnati area around 6 PM.
Through the evening into the overnight the storms will move off to the east and south of the zones. I do think by 12-1 am many places will be dry. However, some isolated to widely scattered showers or t’storms across southern Indiana and southern Ohio will remain closer to the front.
Through the overnight rain and storms will fade out and only a few stray showers will remain across zones 1 and 5.
New rainfall totals through late tonight will average out around .30-.60”. However, places that get under some of the strong to severe storms could see 2-3.5” locally. I do think the better chances for heavier rain will be south of I-70. With the amount of rain that is forecast to fall in such as short time, localized flash flooding will be concern tonight as well.
Lows overnight will be in the upper 50’s north to mid 60’s south.
WEDNESDAY: Calm conditions will be in place to start the day on Wednesday with perhaps a few stray showers in place across the region. However, some patchy fog will be possible in areas.
Through the morning the fog will burn off across the area. This should give way to sunshine by mid-day on Wednesday across Indiana and Ohio.
Highs on Wednesday will be in the low 70’s north to around 80 south.
Through the afternoon sunshine will destabilize the environment allowing for CAPE values of 3000-5000 J/Kg to be possible in locations.
With high levels of instability, I won’t be shocked to see some isolated to widely scattered storms develop south of I-70. These look to develop after 2-3 PM in the afternoon.
Rain and storms will remain possible across southern Indiana by 7-8 PM.
Storms will remain possible through the evening. However, once we lose daytime heating Wednesday evening storms will fade out.
Wednesday night a warm front will lift north across Indiana. As it does, some isolated rain showers and storms will develop along the front around 1-2 AM Friday.
Through the overnight Wednesday into Thursday a few showers and storms will remain possible along the warm front, mainly across northern zone 1.
THURSDAY: A cold front will be moving across Illinois and into western Indiana around 7-8 AM. While a lot of the storms are forecast to die out before reaching the state, I still think some isolated storms will be possible.
As the cold front progresses across Indiana through the day on Thursday only some isolated storms look to be along it. By 1-2 PM the NAM 4km shows some of those areas of rain and storms.
Better chances of storms will exist across eastern Indiana and into Ohio later in the afternoon. By 4-5 PM storms look to develop along the cold front across eastern Indiana and western Ohio, including around the Cincinnati metro area.
Through the evening the cold front will move into Ohio, this will allow rain and storms to move into central Ohio and out of the forecast zones by 8-9 PM Thursday evening.
While instability will build into the afternoon with CAPE values of 3500-4000 J/Kg I do think any significant severe weather will be limited.
The reason being, the 500 mb jet and 850 mb jet are dramatically displaced from the front. So the upper-level support needed to get a bigger severe weather event will not be there. With that being said, high moisture content, a cold front, and high instability will likely still make for some strong to severe storms Thursday afternoon across eastern Indiana and into Ohio. We will fine-tune this forecast in the coming days!
Highs on Thursday will be in the low 70’s north to upper 70’s south. Winds will be breezy at times with gusts of 20-25 mph possible.
FRIDAY: An area of high pressure will ridge in on Friday. This will give us a very nice end to the week with sunny skies and dry conditions.
Highs on Friday will be in the upper 60’s north to mid 70’s south.
WEEKEND: Friday night into early Saturday a back door front will move through the region. As it does, the chance for some rain showers will increase across the area. Right now these don’t look heavy or real widespread, but the chance for those showers will exist.
Through the morning hours the front will move through and the showers will exit the region. By afternoon many places will be dry and precipitation free.
Highs will be cool with temperatures in the mid 50’s north to near 70 far south.
On Sunday an area of high pressure will be in control. Models are a bit unresolved on the forecast Sunday with some calling for afternoon rain, while others keep it to the south. If high pressure does build in as forecast, then I would lean more towards a dry day for most of the forecast area. However, it’s a forecast we will fine tune as we get closer to the forecast period.
7 DAY FORECAST (TEMPERATURES WILL VERY USUALLY COOLER NORTH/WARMER SOUTH)