The set-up:

A cold front is stalled across TN and lower Ohio Valleys this morning.  Meanwhile, upper level energy is moving out of the north-central Plains.  This upper level energy will continue to slide southeast and “feed” a developing surface low along the stalled front by evening.  Strong frontogenesis is forecast and this will aid in development of localized heavy snow bands and associated intense snowfall rates by afternoon, continuing into the evening.  (If you’re interested in learning more about frontogenesis and it’s impact on winter weather, please read this fantastic paper).  Here’s our updated snowfall forecast.  Please note snow amounts won’t necessarily follow the clean lines below, but this is our best idea as of now.

Timing:

We expect initial light to moderate snow to impact northern areas this morning, but it’s not until this afternoon when the “real deal” begins.  The onset of heavy snow will set-up just north of the city and the “bulls eye” with this event from a heavy snow perspective may very well paint itself across Indy’s northern suburbs, including several hours of heavy, wet snow from 12p-5p.  Moderate to heavy snow will then shift south to encompass the city, itself, mid to late afternoon, including the rush hour.  We highly recommend getting home early today if at all possible as the heaviest snowfall rates for the city, itself, will likely center on the evening rush.  Things will likely be very, very messy for travel as heavy wet snow falls.  In periods of heaviest snow, visibility near zero can be expected, especially just north of the city.

Snowfall should begin to diminish and pull east between 7p-8p for most of central Indiana.  Cold air will follow as lows tonight dip into the middle teens for most with a significant snowpack down.  Highs Thursday will only top out around 20.

As always, be sure to follow us on social media (Twitter: @indywx, Facebook: IndyWx.com, Instagram: IndyWxCom) for more updates on the go!  Be safe and happy snow to all!