11:20 PM: Evening data is coming in and I’ve made a slight tweak to the forecast, but it remains largely intact.
I adjusted the dividing line between 1″ to 2″ and 2″ to 4″ a little north. I am still looking for 2″ to 3″ of snow in Indianapolis. Areas further north, in Howard County for instance, could pick-up 4″ to 5.5″ of snow.
6:16 PM: A weather system will move over central Indiana on Christmas Eve providing a White Christmas for much of the state.
The weather system is just beginning to come together as of Saturday afternoon.
It will spread snow from the Rocky Mountains to Maine over the next 36-hours. Ahead of the storm numerous states have Winter Storm Warnings, Watches and Winter Weather Advisories posted – spanning over 2,000 miles.
Snow is expected to begin falling Sunday morning. Through the morning, the snow will stay along/north of I-70. Later in the afternoon, a surge of colder air will move in from the northwest, pushing snow south of I-70. Accumulating snow should end by 9pm from west to east across the CBS4 viewing area.
HOW MUCH SNOW
Saturday morning’s computer models are more aggressive with snowfall totals. That is due to two things. 1) A slight uptick in available moisture. 2) Colder air and upper-level energy will enhance snow production.
On average, computer models are suggesting approximately 0.19″ of moisture to work with. Over the course of the day, with cold temperatures aloft and at the surface, snow should be produced at an average of 16:1 liquid to snow ratio. There is a chance this ratio may be too low. When calculating the numbers that go in to the snow forecast map, I used ratio’s ranging from 12:1 to as much as 19:1.
To be a little more specific here is my snow forecast for a few cities around central Indiana:
- Bloomington: 1″ to 2.5″
- Columbus: 1″ to 2.5″
- Crawfordsville: 3″ to 4″
- Indianapolis: 2″ to 3.5″
- Lafayette: 3.5″ to 5.5″
- Muncie: 3″ to 4.5″
- Peru: 4.5″ to 6″
- Terre Haute: 1.5″ to 2.5″
INDIANAPOLIS WHITE CHRISTMAS
If Indianapolis has 1″ of snow on the ground Christmas day, this will be the first White Christmas in the Circle City since 2010.