Category: Forecast Discussion

Initial Snowfall Ideas; No Let Up In Sight With This Pattern…

As we approach the time for many Super Bowl parties to kick off, we wanted to go ahead and post some initial snowfall numbers for our upcoming winter storm Tuesday afternoon into Wednesday.  It’s important to note that model data will be able to fully sample the storm later tonight so we’ll fine tune things Monday morning, but here’s our early idea…

We think snow (wintry mix across south-central Indiana) moves in as early as Tuesday afternoon, with the period of heaviest precipitation falling Tuesday night into the wee morning hours Wednesday.  This will be a quick moving storm and, as such, will impact precipitation totals from reaching even higher amounts.  Additionally, we’re also noting the chance central and southern Indiana gets into the dry slot late Tuesday night into Wednesday morning.  As of right now, our forecast snowfall totals are based on 1. a relatively fast moving storm system and 2. the current likelihood of being dry-slotted across portions of central Indiana.  It will be important to note where the all-too-popular (for snow lovers) deformation zone sets up shop as heavier snow totals, in excess of half a foot, will likely fall within this band.  Additionally, an icy mixture of sleet and freezing rain may fall across south-central Indiana (current thinking places this icy mix south of I-70) and this could lead to tree limb and power line damage in spots.  Stay tuned…

Here’s what area radars may look like Tuesday night into Wednesday morning.  This data is courtesy of the fine folks over at Weatherbell Analytics.

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Our thinking hasn’t changed on the overall track of the low (track map originally posted here Saturday night).

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Quick Bullet Point Thoughts:

  • Snow will overspread central Indiana Tuesday afternoon
  • Heaviest snow will fall Tuesday night- where it remains all snow 4-6″ is our initial call
  • An icy mix of sleet and freezing rain could lead to significant ice accumulations down state (greater than 0.25″ ice accumulation)
  • Closely monitoring the forward motion of the storm and potential dry slot working into the region late Tuesday night-Wednesday morning

By the way, we’re tracking another winter storm for the upcoming weekend and we’ll discuss this in more detail in the days to come… Enjoy the game!

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More Thoughts On Our Next Winter Storm…

As we continue to draw ever closer to our next significant winter storm, we wanted to provide some of our latest thoughts.  This isn’t a post that will hash out…

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Accumulating Snow Saturday Night?

In the short term, a wintry mix of sleet, freezing rain, and snow will transition to all rain across the entire region Saturday.  That said, if traveling early Saturday morning, please leave extra time to reach your destination and plan to take it slow on the roads as a mixed bag of wintry precipitation will fall on central Indiana tonight.  Most snow accumulations will range from 1″ or less.

After a cold and damp Saturday, we’ll have to pay close attention to the chance of snow mixing with the rain Saturday evening before possibly turning rather quickly to a heavy, wet snow Saturday night/ wee morning hours Sunday.  A cold front will slip south Saturday evening.  Additionally, a disturbance will move slowly northeast along the pressing front and result in widespread precipitation falling on the back side of the boundary (in the colder air) late Saturday night into Sunday morning.  As of Friday evening, guidance suggests a frontal passage in the city between 6-7 o’clock and cold air will begin to filter back into the region at that time period.

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While we’ll have to keep a close eye on things during the afternoon Saturday, confidence is growing on the opportunity for a stripe of accumulating snow being laid down through central Indiana late Saturday night into the wee morning hours Sunday.  Just how much?  We wouldn’t be surprised if some amounts of 2-3″ are reported by daybreak Sunday, including in, and around, the greater Indianapolis region.  Most of this snow would accumulate within two-three hours so this will be what we call a “thumping” snow.  Stay tuned.

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Complicated And Complex…

If you have travel plans across central Indiana Friday and Friday night, please make sure you leave plenty of time to get to your destination and prepare for a variety of precipitation types.  In fact, it’s entirely possible (depending on what time of day you’re traveling) that you have to deal with rain across south-central Indiana and snow by the time you arrive into the northern Indianapolis suburbs, complete with an icy mixture “in between.”

Digging through the weather playbook for Friday into Saturday:

A cold front is expected to move through the region Friday morning, allowing a wind shift out of the north to arrive into the city in the early to mid morning Friday. We’ll have to be in “nowcast” mode Friday to determine just exactly how far south the front makes it as this will go a long way into determining precipitation types across central Indiana.

Ultimately, a wave of low pressure will move along the front Saturday, which will help milder air push north and result in a changeover from a wintry mix to all rain during the majority of the day Saturday. In fact, there’s the chance portions of central Indiana may not have to deal with much, if any, precipitation through the majority of the day Saturday- especially south.  Before that, however, we’ll have to deal with a wide variety of wintry precipitation issues Friday and Friday night…  Warmer low level air will be drawn northward and overrun the colder air at the surface Friday and Friday night.  What will initially be a period of snow Friday will transition to an icy mixture of sleet and freezing rain Friday night and all rain Saturday.  That said, we note the milder push will be brief, and colder air will pour back into the region on gusty northwest winds Saturday night. This may result in a brief period of light snow Saturday night (not a big deal).

We think the latest high-resolution, short-term, NAM model (courtesy from the fine folks over at Weatherbell Analytics model suite) has a very good handle on accumulation ideas Friday and Saturday and is in best agreement with our analysis laid out above.  This is a look at forecast snow accumulation between now and Saturday night, but we also note there will be some light sleet and freezing rain accumulation on top of any snow that falls Friday. As far as that snow goes, we think a 1-2″ band is laid down from the city and points north, increasing further as you travel into north-central and northern Indiana.

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A Word About Early Next Week…

We posted earlier this morning on the near term (below) and Friday and Saturday remain quite challenging and complicated.  Precipitation type and amounts will have to be resolved as we…

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