Updated 01.04.24 @ 5:56p

An impressive high latitude blocking pattern is forecast to establish itself over the upcoming week to 10 days. Should this come to fruition as modeled, this will be one of the more textbook winter blocks we’ve seen in quite some time. While it doesn’t mean it “has” to get cold immediately, it certainly does immediately kickstart a very active and stormy regime. Storms will come at us almost in an every other day type fashion. Here’s the idea on the initial 3 storms forecast to impact central Indiana between now and this time next week.

I. Late Friday night and Saturday: It continues to look like a surface low will move along the north-central Gulf Coast with a trough of low pressure extending north into the lower Ohio Valley. Eventually, the surface low will make a move up the eastern seaboard, leading to heavy snow and mixed precipitation for portions of the big cities. Back here on the home front, we expect snow to overspread central Indiana from south to north late Friday evening (likely reaching the city, itself, between 11p and midnight). Periods of snow will likely continue until around sunrise and then diminish from southwest to northeast. By this point, a general area-wide 1″ to 2″ of wet snow is expected to fall. Since most, if not all, of this snow will fall when it’s dark, some light accumulation is now expected on area roadways. If you have travel plans overnight or early Saturday morning, allow extra time to safely reach your destination.

[– Snow removal Clients, salting and plowing will be likely late Friday night into early Saturday morning, prior to sunrise.]

Additional upper level energy will rotate across the central Ohio Valley Saturday night into Sunday morning, allowing for a renewed area of light precipitation to blossom. Most of this should fall as wet snow along and north of the I-70 corridor with mixed rain and snow south. An additional wet coating of snow is possible during this timeframe.

II. Monday night and Tuesday: This will be a significantly stronger storm system, capable of much heavier precipitation and high winds.

After a calm daytime Monday, precipitation should overspread the region from southwest to northeast after dark, likely reaching the I-70 corridor towards 8p to 10p. While we still have to hone in on the specific track of the surface low, there aren’t any big changes from the idea posted this morning. Heavy wet snow or mixed precipitation is likely at the onset across central Indiana before a transition to plain ole rain along and south of the I-70 corridor during the daytime Tuesday. (The timing of the arrival of precipitation coming during the late evening/ overnight is worrisome for winter weather impacts, even in the face of warm air advection/ marginal temperatures).

Further south, this should be an all rain event on the front end. The duration of mixed precipitation/ snow will have a big impact on central IN accumulation potential. Further north, an eventual change to a brief period of rain is also likely, but we think there will be heavy accumulation of snow (WSW criteria) before this takes place across the northern 1/3 of the state. This initial precipitation zone is at least a good starting point, but expect some additional changes as we go through the next day or two.

Notes/ Asides: Liquid equivalent precipitation should reach 1″ to 2″ across all of the state with system #2 and wind gusts to 40 MPH + will be a good bet. As colder air rushes in on the backside of the storm look for a period of wind-whipped light snow area-wide Wednesday morning.

III. Mid/ late next week: An additional strong storm is likely to develop along the front range during this time before tracking east northeast along a pressing arctic boundary. We’re heading into the type of pattern that’s conducive for quick deepening (strengthening) of the respective surface lows and don’t see any reason this won’t be the case yet again around this time next week. – Obviously, it’s far too early to try and get too cute with detailed specifics with system #3, but it’s worth keeping an eye on as we progress through the next several days.