Wind: E shifting to the NW Sunday morning 5-15 MPH
Blowing/ Drifting: Minimal
Pavement Impacts: Plowing and salting will be required
Summary: A cold core upper level disturbance will move directly over Indiana tonight and Sunday morning. After a dry period of weather through the daytime Saturday, a mix of rain and snow will overspread central IN by late evening. As the upper level disturbance moves overhead, the column of air should become just cold enough to allow the wintry mix to transition to all snow during the overnight. Embedded bands of moderate to heavy snow will develop early Sunday morning along and just north of the I-70 corridor. Today’s high resolution guidance has “honed in” on the heavier snow zone being located from Vermillion county northeast to Randolph county and points north. The system will pull east of the state Sunday afternoon, allowing the snow to come to an end through the morning (prior to dawn across western IN, shortly after sunrise immediate central, and mid-morning east-central).
Wind: E shifting to the NW Sunday morning 5-15 MPH
Blowing/ Drifting: Minimal
Pavement Impacts: Plowing and salting will be required
Summary: A cold core upper level disturbance will lift northeast out of north-central Texas tonight and directly over Indiana Saturday night and Sunday morning. After a dry period of weather through the daytime Saturday, a mix of rain and snow will overspread central IN by late evening. As the upper level disturbance moves overhead, the column of air should become just cold enough to allow the wintry mix to transition to all snow during the overnight. Embedded bands of moderate to heavy snow may develop early Sunday morning. The system will pull east of the state Sunday afternoon, allowing the snow to come to an end by mid to late morning.
Temperatures: 25° to 30° (location dependent, please see below)
Wind: East 5-15 MPH
Blowing/ Drifting: Non-existent
Pavement Impacts: Salting will be required
Summary: After a dry New Year’s Eve, moisture will advance north as a surface low tracks from the northwestern Gulf Coast into the Ohio Valley. As the precipitation arrives (around or just after midnight for far southwestern IN before spreading north, reaching Indianapolis by 4a, and north-central Indiana by 6a), it’ll encounter a shallow layer of cold air entrenched at the surface. Several hours of freezing rain can be expected north of a line from Terre Haute, Bloomington, and Cincinnati Friday morning where temperatures will remain below freezing the longest. South of that line, only a brief period of icing is expected before a transition to a cold rain. Further north, especially along and north of the I-70 corridor, temperatures will fall into the middle to upper 20s tonight and slowly rise into the lower 30s by late morning. All of the state will “warm” above freezing by Friday afternoon with any lingering moisture falling as a plain ole rain. Beforehand, an icy glaze is expected to develop predawn Friday and travel will be difficult in places- especially from central IN and points north. If at all possible, we recommend delaying travel until afternoon as conditions should slowly begin to improve by that point.
Wind: NE 10-20 MPH early in the event, shifting to the NW and decreasing to 5-10 MPH Wednesday
Blowing/ Drifting: Minimal
Pavement Impacts: Salting and plowing required
Summary: We don’t see any need to change our early stand on this event (originally issued Saturday morning). Data over the weekend trended away from the heavier snowfall amounts falling across our area only to have moved back to the snowy idea over the past 12-24 hours. Though while never expected to be a blockbuster event here, we always felt this was a classic setup to produce widespread accumulating snows across the region. The snow shield will lift northeast across the region overnight Tuesday into predawn Wednesday. We expect an arrival into the Indy metro and surrounding ‘burbs between 1a (southwest) and 3a (northeast). Once the snow arrives, it’ll settle in for the long haul, continuing (light to moderate intensity) for the better part of the daytime hours. Unfortunately, we fully expect slick roadways for the Wednesday morning rush. The snow will eventually end (southwest to northeast) between 3p and 7p Wednesday. We have no changes to our initial snowfall map below, first issued Saturday morning.
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Wind: NE 10-20 MPH early in the event, shifting to the NW and decreasing to 5-10 MPH Wednesday
Blowing/ Drifting: Minimal
Pavement Impacts: Salting and plowing required
Summary: An area of low pressure will move across northern Texas (Monday night and Tuesday morning) northeast into the lower Ohio Valley (Wednesday morning). In response to this feature, a secondary surface low will form in the northern Gulf of Mexico Tuesday night and it’s this surface low that will eventually “steal the show” moving northeast and being located off the Carolina coast Wednesday before eventually blowing up into a good ole fashioned nor’easter Wednesday night and Thursday. Before this energy transfer takes place, we should see a stripe of accumulating snow extend northeast into the Ohio Valley Tuesday night and Wednesday. From this distance, it appears as if central IN is in store for the 1st widespread snow event of the season, but the devil’s still in the details. We’ll have to monitor the energy transfer closely. Additionally, it’ll be important to keep eyes on the developing Gulf low. Should this system generate convection in more rapid fashion than currently thought, it would steal some of the moisture from the initial low into the OHV. As it is, the early thinking here is that this is a 1″ to 3″ type event for our immediate region. Should the Gulf low organize a little slower, the possibility is there for heavier totals. Widespread snow should diminish and come to an end late Wednesday morning (west) and by afternoon (east). Thursday and Friday look dry and cold.
Blowing/ Drifting: Moderate, especially with late afternoon-evening lake-effect snow band.
Pavement Impacts: Salting required; plowing required within lake-effect snow band.
Summary: We’ll undergo a transition from “system” snow (mostly light) this morning into early afternoon to a more localized, but robust lake-effect snow event late afternoon and this evening. At least for central portions of the state, this is the better opportunity for accumulating snow. As temperatures continue to fall and the wind direction becomes better aligned, a band of lake effect snow is expected to develop initially across northwestern Indiana late morning. It’s this band of snow that should continue to get better organized and heavier as we move into late afternoon and the evening hours and be driven well inland. Eventually, this lake snow band should reach areas as far south as Indianapolis (and surrounding ‘burbs) by late afternoon, potentially including the 5 o’clock rush for parts of the city. Snowfall intensity within this band is expected to be heavy enough to whiten roadways and create slick spots. For most this will only last an hour or two before the band pivots east and impacts east-central Indiana for a longer period of time into the overnight and early Tuesday morning. If you find yourself under this lake effect snow band, a quick 1″ to 2″ can be expected
Blowing Drifting: Minimal to Moderate in lake enhanced zone, as well as east-central IN
Pavement Impacts: Salting required; plowing likely required in lake enhanced zone, as well as east-central IN
Summary: While not nearly as robust as what guidance earlier this week printed out, the season’s first widespread wintry event looms Sunday night into Monday. This is a byproduct of phasing between the southern and northern jet stream (initially set off by the evolving strongly positive PNA), but there are important differences in the speed of the initial vort. max being a bit more progressive that will keep this from bombing out like earlier guidance showed. Consequently, this will result in a much further east system (may still not have seen that eastward trend finish). While our forecast specifically focuses on Indiana, if you have travel plans east of here into Ohio early next week, please pay special attention to the local National Weather Service products as impacts will be greater from heavy snow and strong winds.
Locally, we anticipate precipitation overspreading central Indiana (from southwest to northeast) around, or just after, midnight Sunday night. Initially, this should be in the form of a cold rain before precipitation transitions to wet snow prior to sunrise. Moderate snow should be falling across east-central Indiana from the mid morning hours Monday into early afternoon. Additionally, by this point, a more organized band of lake-effect snow should be firing up off Lake Michigan. This is a bit of a wild card as a combination of ingredients favor a pretty robust lake snow band making it further south than typical. As the wind direction veers towards more of a northwesterly flow late Monday afternoon and evening, it’s possible this lake effect snow band pivots into the Indy metro and surrounding ‘burbs. We’ll keep a close eye on this as time draws closer. Within this snow band, heavier accumulations are possible. Snow showers will continue into Tuesday morning before diminishing.
Confidence: Medium
Next Update: Tonight (video package, including longer range update).
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Temperatures: Middle 30s falling into the middle 20s by Wednesday night
Wind: North 15-25 MPH, increasing to 25-40 MPH Wednesday night and gusty
Blowing/ Drifting: Moderate to significant by Wednesday evening, continuing into Thursday morning
Pavement Impacts: Salting and plowing likely will be required
There has been a significant shift in the majority of model data today regarding the track of our midweek storm system. This has to do with a variety of elements, but most notably, the fact that the upper level energy at one time thought to come together to result in one primary storm during the first half of the work week, now looks to come in two parts: Monday into Tuesday, followed by a separate storm Wednesday into Thursday (this was what at one time was illustrated by the models a week+ ago). The debate now will continue for the next 24 hours around the deepening Storm #2 goes through, and this will have significant impacts on what central Indiana experiences in the Wednesday through Thursday time period. We think an initial wave of low pressure will organize along and just south of the Ohio River Tuesday night before tracking northeast and strengthening along the way into the eastern Great Lakes by Wednesday night. Should this, indeed, be the case, moisture would become widespread (after a relative “lull” Tuesday evening) across central Indiana Wednesday morning. With cold air funneling into the area by this time, the predominant precipitation type would fall as snow across central Indiana, including Indianapolis. Initially, this would be a wet type of snow before transitioning to a more powdery nature Wednesday evening.
As the storm begins to deepen to our northeast, blowing and drifting snow would become a concern on west-east roadways Wednesday evening into Wednesday night as the pressure gradient increases. By this time frame, north and eventually northwest winds would gust over 30 MPH with temperatures falling through the 20s. “System” snow would come to an end Thursday morning, but lake effect will continue across the traditional primary Snowbelt of northern Indiana (please note the amounts above do not account for the additional lake effect snow that would fall for Laporte, St. Joseph, and Elkhart counties). Additional lighter snow is a good bet for all as we close the work week out Friday, courtesy of upper level energy diving southeast across the state.
One additional note: We’ve been receiving a lot of questions around whether or not the southeast shift will continue with the model updates tonight. While some slight additional southeast movement in the axis of heaviest snow is still possible, there will be a limit due to the interaction between the deepening surface wave and area of high pressure. We will continue to keep a close eye on the data overnight and update things accordingly if needed early tomorrow morning.
A winter storm will impact the Ohio Valley through the 2nd half of the work week.
What: Accumulating snow and sleet
When: Wednesday afternoon through Thursday evening
Temperatures: Lower 30s falling into the 10s by Thursday evening
Wind: Southeast 10-15 MPH Wednesday afternoon shifting to the north Wednesday night and northwest Thursday. Winds will gust 20-30 MPH Thursday evening.
Blowing/ Drifting: Light to moderate by Thursday evening
Pavement Impacts: Salting and plowing will be required
A busy 48 hours awaits for central Indiana as a winter storm begins to impact the region. Mid and high level cloudiness will continue spreading over the region this evening and give way to a lowering and thickening cloud deck overnight and Wednesday morning. This is all thanks to a developing area of low pressure over the Ark-la-tex region. This surface low will track northeast into the TN Valley Wednesday and into the central Appalachians Wednesday night into Thursday morning. Long time residents of the Hoosier state know this is a favorable track for impactful wintry weather across these parts and this will be no exception.
Moisture will begin to lift northeast during the day Wednesday and reach the I-70 corridor around or just after lunchtime. Across the southern half of Indiana, this moisture should primarily fall in the form of a cold rain (perhaps a bit of sleet initially as the precipitation moves in). However, further north, trouble will ensue. The air won’t only be colder at the surface, but the depth of cold air will be much deeper. This will result in precipitation that should predominantly fall in the form of a sleet-snow “concoction” along and north of the I-70 corridor where we think an axis of 2″ to 4″ of snow/ sleet will accumulate with this storm- including Indianapolis. Further north, less sleet is anticipated and will result in heavier snowfall totals. The northern Indianapolis ‘burbs and points north to include Lafayette, Kokomo, Logansport, Ft. Wayne, and Muncie can expect 4″ to 6″ of snow with this storm system. Most of that will fall Wednesday afternoon into Wednesday night with additional lighter snowfall accumulation occurring with “wrap around” snow showers and embedded squalls Thursday afternoon into evening. (The Indiana Snowbelt (you know who you are :-)) can expect additional heavier snow accumulation, courtesy of lake effect).
A brief, but potent shot of arctic air will pour into the region Thursday afternoon and set us up for widespread single digits by Friday morning, including the threat of some sub-zero temperatures where the heaviest snowpack is laid down.
