EVENING – OVERNIGHT: An area of high pressure remains in place today, but we are closely watching an area of low pressure developing across the southern Great Plains. This will be the focal point for zones 1/5 over the next 24-48 hours.
Clearing is taking place across the zones this afternoon. I do believe we will continue to clear out through the evening into the overnight.
However, late tonight into early Tuesday morning a warm front will start to move north into southern Indiana. Along and ahead of the front clouds will be on the increase through late tonight.
TUESDAY: The warm front will continue to lift northward across Indiana through the morning hours. Along and north of the front showers and perhaps an isolated t’storm will develop and move across the region. A few showers will be possible after 9-10 am Tuesday morning.
Once we get south of the warm front Tuesday, isolated showers and storms will remain possible through the afternoon. However, better chances for rain and storms will increase across western Indiana around 4-5 pm as a cold front moves closer to the region.
Highs on Tuesday will be in the mid 50’s to mid 60’s.
As the cold front moves closer to the region conditions will become favorable for severe weather especially across the southern portions of Indiana. By late afternoon upper level winds at 500 mb will streak in from the southwest at upwards of 100 mph!
At lower levels (850 mb) winds will be moving in from the southwest at 65-75 mph! With increasing wind speed with height there will be support for storms to become severe.
While instability for tomorrow may be limited, unseasonably high amounts of moisture (and shear) will likely help make up for it. Dew points across the southern portions of Indiana will be in the mid 50’s to low 60’s!
With storms in the forecast all these storms will have to do is tap into/mix the winds aloft to the surface. That would ample energy to create severe wind gusts Tuesday evening into Tuesday night. The best risk for severe weather looks to be from I-70 southward with damaging winds and a few tornadoes possible.
By 7-8 PM the cold front will be in place across the IN/IL state line. T’storms will be likely across western Indiana at this point, some of which could be strong/severe.
The front will race eastward across Indiana through the night-time hours Tuesday. Right now the timing for storms in Indianapolis looks to be around 9-10 pm. Again, strong to severe storms will be possible at this time.
By 12-1 am Wednesday the front will be moving across eastern Indiana and into Ohio taking the line of rain and storms with it. I do think that after 10 pm – 12 am the severe weather threat will start to diminish.
Winds on Tuesday will be strong with gusts of 35-46 mph possible!
By 5 am the main area of storms will move out of the forecast zones. However, a few isolated rain showers or sprinkles may continue overnight in locations. However, I expect this to remain in liquid form.
New rainfall totals of .4-.75” will be more common across Indiana and Ohio, the areas that get under a t’storm could see upwards of 1” or so.
WEDNESDAY: While the area of low pressure and attendant cold front will move to the east of the region some lingering moisture will aid in cloud cover and even some light precipitation. I think initially Wednesday we start as rain, but with temperatures right around freezing in the afternoon and dew points of 28-31 degrees a change over to a mix or light snow will be possible.
With that being said, very little snow accumulations are anticipated with only a coating to a couple of tenths of an inch possible across northern zone 1.
THURSDAY – FRIDAY: An area of high pressure looks to ridge into the region Thursday. This will allow for calmer weather for Thursday and most of Friday. Partly cloudy to mostly sunny skies are forecast to end the week.
Highs will be in the 30’s on Thursday, but warming into the 40’s on Friday.