Brief: Heavy Snow & Sleet
Forecaster: McMillan
What: Heavy Snow & Sleet
When: 12a to 8a Wednesday
Temperatures: Upper 20s to lower 30s
Wind: E 15-25 MPH
Blowing/ Drifting: Moderate before mixing with sleet
The setup remains the same as a warm front lifts north during the overnight. Copious amounts of moisture will arrive into central Indiana and with cold air in place, a period of moderate to heavy snow will develop. Timing into the city, itself, should come around, or just before, midnight. While the snow will be of the heavy, wet variety, gusty easterly winds will result in blowing and drifting snow (especially on north-south roadways) before precipitation transitions to sleet. We’ve “beefed” our accumulation forecast up to include a 3″ to 5″ band across east-central Indiana, including Indianapolis, as short-term guidance is indicating a period of significant “forcing” (or lift in the atmosphere) that will lead to heavy snowfall rates before the transition to sleet. A couple of hours with snowfall rates in excess of 1″ per hour will likely be observed in that 1a to 3a window. Precipitation will transition to sleet and a period of freezing rain between 3a and 5a from south to north, before turning to all rain in the city before sunrise. Further north, a transition to rain won’t be noticed until after 8a, but the majority of precipitation will likely be over with by that point (just lingering drizzle and fog).
Confidence: High
As upper level energy tracks northeast this evening, strong frontogenesis will help a “
Obviously this will create concerns for power outages, but the other major worry is for developing blizzard-like conditions and whiteouts through the late afternoon into tonight.
We’ll have additional updates later this afternoon here on IndyWx.com and on our social media accounts.
The bulk of the northern half of the state is still expected to receive predominantly snow with this storm. However, things get much more tricky along the I-70 corridor (10 to 20 miles either side) as temperatures will be “marginal” early on in the event (aloft and at the surface) and will lead to quite the headache for the first several hours of this storm. Even as of this update, confidence is low on precipitation type for the I-70 corridor, itself. A difference of half a degree (F) can mean a world of difference with precipitation type (snow, freezing rain, sleet, or rain). Admittedly, concern is growing for the potential of icing in this area before the deeper cold air can arrive and switch things over to snow. On the other hand, should precipitation rates be heavy enough, it’s certainly possible these heavier rates will cool the entire column of air quicker than high resolution modeling currently suggests and a quicker transition to snow would result. “Boom or bust” potential is higher than normal along the immediate I-70 corridor.
Stay tuned and please know we’ll have another update posted Saturday morning.
We’re left tonight with bitterly cold conditions that will continue to grip the region through midweek. Most of us Tuesday morning will be below zero. A moderating trend will develop by late week, continuing through the weekend!