It’s been a long day, but we’d like nothing more than to be right here in the good ole forecast office, digging into data for our next winter storm with you. While “part 2” of the storm remains just offshore as of this post, it’ll likely be trudging onshore by the time you read this early Saturday morning. That said, the initial wave of accumulating snow (and for some, ice) will arrive as early as late Saturday night/ wee morning hours (well before sunrise) Sunday in the form of an overrunning event- where comparably warmer, more moist air is lifted up and overruns the cold air at the surface.
Early ideas suggest we undergo a period of moderate to heavy wintry precipitation as early as 3-ish Sunday morning, extending into the late morning hours. Particularly, we bracket the hours of 3am to 10am Sunday for the initial wave of wintry weather. This will be a mixed bag of precipitation, including snow, sleet, and freezing rain across central Indiana. An early look at the high resolution simulated radar courtesy of the NAM shows this well- valid 7am Sunday morning. Image is courtesy of the fine folks over at Weatherbell Analytics.
After a “lull” in the accumulating wintry precipitation from late morning/ early afternoon Sunday, we’ll likely deal with another round of moderate to heavy accumulating wintry precipitation Sunday afternoon into Sunday night. It’s important to note this is where we have more questions than answers in regards to the interaction of a juiced up southern stream of the jet- infused by the powerhouse late season winter storm (still spinning just off shore as of this update). Powerful arctic high pressure will be sinking south and could result in a more suppressed track of the low. Should this be the correct scenario snow totals would likely be towards the lower end of the ongoing 6-8″ forecast we hoisted back on Thursday morning. That said, one can’t ignore the pattern as it’s one notorious for heavy snow producers across central Indiana. A scan over heavy snow events of the past here across central Indiana show similar setups that have yielded impressive snow totals. Just as the potential of suppression has to be noted, so should the potential of a slightly more north trend that models may currently see as time gets closer.
In closing tonight, 12z model data should really begin to hone in on the area most likely to see heaviest snow and/ or ice accumulations. Our ongoing forecast of storm totals remains unchanged for now of 6-8″. Stay tuned, friends.