CURRENTLY: The area of low pressure remains to our south and east. Precipitation continues to occur across the forecast region as this storm system moves through. As of about 9:20 PM rain was occurring across most of Indiana and eastern Illinois. However, across southern and some eastern portions of Illinois the cold air is working in and changing that precipitation over to snow as seen on radar and reported via NWS/MPING.
Aloft cold air is actually working in quicker than anticipated. Although that is in place we are still waiting on the arrival of freezing conditions at the surface before any winter precipitation will occur in Indiana. With that being said, it’s not far behind in Illinois and will arrive through the overnight.
OVERNIGHT: The rain will continue to change over to snow from west to east as we progress farther into the evening and overnight. Right now the timing for a rain to snow changeover in the Indianapolis Metro area looks to be shortly after midnight (as supported by the RPM). While the HRRR is closer to 1-2 AM cold air appears to be working in faster so we will anticipate the changeover a bit sooner.
With these snow bands some heavy periods of snow should be expected as they move to the east and northeast across Indiana. I won’t be surprised to see times of near or at 1” an hour snowfall rates in locations.
By 4-5 AM most of the rain occurring across Indiana will have changed completely over to snow with snow still occurring across portions of Michigan. Rain will continue across Ohio and perhaps very eastern Indiana through late tonight/early Sunday morning. Across Illinois and western Indiana a few light snow showers or flurries may remain but the system looks to be coming to an end by this time.
The majority of the snow will come to an end across the Indianapolis area by 7-8 AM Sunday morning with perhaps a few light snow showers or flurries remaining. However, snow will still be continuing across eastern Indiana and into western Ohio. Again, there will likely be times of heavy snow across the region.
Morning through mid-day Sunday the area of low pressure will move off to the regions northeast. As it does the main area of snow will move across Ohio and eastern Michigan. Likely exiting the entire forecast region by 2-3 PM.
Overall we will not make any changes to the previously issued snowfall forecast.
Overnight temperatures are going to fall very quickly as the cold front sweeps across the region. Lows are forecast to be in the lower teens across western zones 6/7/8 with lows in the 20’s across most of Indiana. With this in mind flash freezing will remain a concern as roadways will be wet from rain and snowfall.
Winds overnight will be on the increase as we get on the back side of the area of low pressure with gusts up to 40 mph possible.
Sunday looks to remain mostly to completely overcast across the region, perhaps clearing late. However, we are not anticipating enough sunshine to aid in the melting of any snow or ice on surfaces.