AFTERNOON-EVENING: A stationary front remains in place this morning across zones 1 and 5. With the front in place rain showers have developed in the vicinity of the front.
Through the afternoon the stationary front will lift northward across Indiana and western Ohio as a warm front. This warm front will help lift the atmosphere allowing for scattered rain showers to continue across the area.
Through the late afternoon and into the evening there may be a bit of a lull in precipitation, especially south of I-70. However, by 8-9 PM rain and perhaps a couple of thunderstorms will develop once again across the forecast area.
Through the overnight scattered rain and storms will continue across zones 1 and 5. However, we will be watching a line of storms moving across Illinois. If these storms hold together this evening into the overnight they could bring some gusty winds and hail to portions of the forecast area. By 2-3 AM the RPM model shows this line entering western Indiana.
This line is forecast to move eastward overnight, likely weakening as it does. By 5-6 AM Tuesday morning the line of storms will be in place across south central Indiana, but it doesn’t look as impressive as earlier in the forecast period.
Lows overnight will be in the mid 50’s north to low 60’s south.
TUESDAY: Through the early morning hours on Thursday rain and storm coverage will begin to fade. While some isolated to widely scattered rain/storms looks to be in place by 8-9 AM, it will be nothing like what was in place through the overnight.
Through the morning into mid-day more storms look to form along a boundary across southern Indiana. This will likely be what’s left from the previous rain/storms. By 12 PM Tuesday storms will be developing along the boundary.
While the stationary front will be in place to the north tomorrow evening, there will be a surface boundary across zones 1 and possibly northern zone 5. Along this boundary rain and t’storms will develop through the afternoon. By 5-6 PM scattered storms will be ongoing across the aforementioned boundary.
Highs on Tuesday will be in the upper 60’s north to mid 70’s south. Winds will be strong at times with gusts of 25-30 mph possible.
Through the evening rain and storms will continue along the front. By 10-11 pm Tuesday evening storms will also be continuing across the boundary that looks to be located across the I-70 area.
With the threat of these storms impacting the same general area over and over (a phenomenon we call training). This would cause serious concerns regarding flash flooding potential through late Tuesday night into Wednesday. New hi-res forecast models do express this concern too. Both the RPM and NAM 4km show a large swath of 2-4” rainfall totals across southern Indiana into western Ohio. However, localized areas that do see multiple storms and are right on the boundary could see 4-6” of new rain over the next 36-48 hours!
I do think storms Tuesday afternoon could be on the strong to severe side, especially south of I-70 in southwestern Indiana where better instability is forecast to occur. CAPE values of 1500-2500 J/Kg will be present in that area.
At 500 mb winds will be surging in from the west at 40-50 mph. With the upper-level support in place and instability as well, some strong to severe storms will be possible Tuesday afternoon into the late evening.
The better chance of severe weather looks to be in place over southwestern Indiana in zone 5. However, if more sunshine/instability can be realized Tuesday then the severe weather threat could extend farther north and east. It’s a forecast we will have to fine-tune over the next 24 hours as we get closer to the forecast period.
By 2 AM Wednesday morning storms will remain in place across southern Indiana and into southern Ohio, including the Cincinnati area.
Lows Tuesday night into Wednesday will be in the upper 50’s north to mid 60’s south.
WEDNESDAY: Through the overnight into early Wednesday morning storms will move out of the forecast area. By 8-9 AM Wednesday morning only a few isolated rain showers will be in place.
Through the day on Wednesday we should see more dry time with only isolated showers sticking around. By 1-2 PM the NAM 4 km shows a few of those pesky showers remaining.
Highs on Wednesday will be in the mid 70s to low 80’s across the forecast area.
Wednesday evening a cold front will be approaching from the west. However, mostly dry conditions look to remain in place through the afternoon and evening, with perhaps some stray showers across southern Indiana.
THURSDAY-FRIDAY: Some rain chances will persist through the day on Thursday. However, better chances will move in along the eastward propagating cold front Thursday evening.
There are some timing issues amongst models regarding the frontal passage Thursday. The NAM and CMC are slower with the front bringing the cold front through Thursday night into Friday.
However, the GFS is faster with the front bringing it through late morning Thursday through the afternoon from west to east across zones 1 & 5. We will have to fine-tune the timing as we get closer to the forecast area.
Highs on Thursday will be in the low to upper 70’s.
Through most of the day on Friday an area of high pressure will ridge in and will gain control of our weather. This will allow sunny to mostly sunny skies to persist through the day.
By late in the evening into the overnight Friday a back door cold front will swing through the forecast area. As it does, isolated to scattered areas of rain will develop and move through overnight. However, it’s not looking like any serious rain will come from this disturbance.
7 DAY FORECAST FOR INDIANAPOLIS AND EVANSVILLE INDIANA (TEMPERATURES WILL RANGE FRONT NORTH TO SOUTH)