textproduct: Indianapolis

KEY MESSAGES

- Lingering snow showers early this morning across our northern counties.

- Gusty winds 20-30 mph with wind chills dropping to near zero this morning. Winds diminish through the day today.

- Light accumulating snow tonight into Friday morning, up to an inch or two possible.

- Locally heavy brief snow showers possible Friday night into Saturday.

- Well-below normal temperatures this weekend into early next week with subzero wind chills at times.

FORECAST UPDATE

Issued at 939 AM EST Thu Jan 15 2026

Lake enhanced snow showers and flurries continue in a band across the center part of the forecast area. Have added mention of scattered snow showers and flurries to the forecast. Minimal accumulation is expected.

The band will shift west and weaken as flow changes across Lake Michigan this morning. Adjusted PoPs and flurries mention as needed, and will continue to monitor for any additional changes.

Also upped sky cover to account for clouds from the band.

Left temperatures alone for now, but may have to adjust depending on how long cloud cover persists.

SHORT TERM (Today and tonight)

Issued at 258 AM EST Thu Jan 15 2026

Deep troughing have moved across Indiana over the past 24 hours bringing much colder weather and occasional snow showers. A few snow showers continue across our northeast, associated with a lengthy lake-effect snow band off of Lake Michigan. This activity may continue on and off through morning across our northern counties.

Strong northwesterly winds continue between 15-20 mph gusting to 30 mph. This should diminish with time as transient shortwave ridging builds in from the west. Skies should begin to clear as the subsident shortwave ridge arrives. However, high clouds will begin arriving later in the afternoon associated with a second deep trough immediately behind it.

This trough approaches the region tonight, inducing cyclogenesis far to our north over Lake Superior. Strong mass reponse will allow winds to become southwesterly with relatively strong (but brief) warm air advection. Temperatures may not drop all that much tonight from the prior day's high temp.

Snowfall Potential...

Of particular interest is precipitation potential in the form of snow. Isentropic lift associated with the brief bout of warm air advection along with favorable dynamics aloft (exit region of jet, vorticity advection), will allow for a period of snow after about 02z tonight. Given the fast-moving nature of the system amounts should be light, generally a coating (south) to an inch or two (north).

Snow should end Friday morning with warm air advection continuing. Temperatures may warm up to near 40 on Friday before an even stronger Arctic front arrives Friday night. Snow shower potential returns coincident with the front's arrive and within the unstable post-frontal environment. Model snow squall parameter is quite high between 1-5 across much of Indiana. As such, few heavier snow showers are possible which may lead to quick drops in visibility and hazardous driving conditions.

LONG TERM (Friday through Wednesday)

Issued at 258 AM EST Thu Jan 15 2026

Last bit of the short term's light snow to linger into Friday morning before readings creep above freezing Friday afternoon. This will be the last period with near-normal temperatures before a broad and deep upper trough descends over most of North America through the solid majority of the long term...effortlessly providing prolonged frigid, subfreezing mid-winter conditions. Associated arctic air mass to plunge down the Plains through the early workweek and cross the Midwest around the Tuesday night timeframe. At least moderate confidence in a reinforcing, smaller area of surface high pressure to maintain cold advective flow into Indiana through the remainder of the mid-week... under an eventually modifying, zonal upper pattern.

Through this arctic outbreak, the hemisphere's effective north pole, sporting a mere 480 dm 1000-500 mb thickness...is progged to curl from northwestern Ontario across Lake Superior and to Maine during the Monday to Wednesday timeframe. This will all translate to readings over central Indiana easily 10-15 degrees below normal from Saturday through at least Tuesday night. Many locations north of the I-70 corridor will not climb out of the teens Sunday- Tuesday...while widespread single-digit minimums can be expected for at least two overnights.

Weaker surface low pressure lingering near Lake Huron will likely provide enough of a surface gradient with the arctic ridge to provide light to moderate breezes over the region, with winds possibly gusting up to 20-25 mph at times...especially around the early work week when the broad upper trough's western short wave crosses the Midwest. Moderate certainty in widespread subzero wind chills on multiple nights from Saturday night to Tuesday morning...with Advisory criteria possibly on the table for northern Indiana.

At least scattered no-impact snow flurries can be expected through the arctic outbreak, as is usually the case across the CWA in such cold/troughy set-ups. Likely also a period of better-organized snow showers when the cold air first arrives Friday night into Saturday, when the conditionally unstable thermal profile should be saturated in the dendritic growth zone around the 800-700 mb layer.

AVIATION (18Z TAF Issuance)

Issued at 1222 PM EST Thu Jan 15 2026

Impacts:

- Light Snow developing after 07Z with brief IFR vsbys possible until 15Z.

- Convective Snow showers tomorrow afternoon with brief LIFR possible

- Gusty SW winds 20-25 kts developing after 14Z

Discussion:

Lingering lake effect clouds with a few flurries will end by 19Z for KIND. Skies will be mostly clear across the TAF sites this afternoon until increasing cirrus/mid level cloud decks develops this evening. A pronounced dry layer centered around 850 mb this evening (dewpoint depressions around 30-35 deg C) will lead to slower than earlier anticipated snow developing in the warm advection pattern overnight. Therefore have delayed the timing of snow until the 07-10Z period from west to east. There will be a period of IFR visibility in the steadier snowband for a 2-4 hr window until 15Z. By afternoon as colder air moves in aloft, there is sufficient instability that scattered convective snow showers are expected. For now, will carry prob30 for vsby under 3/4SM since location of banding remains uncertain. In addition, strengthening low level flow will mix down to the surface in the wake of the warm front by late morning lasting into the afternoon with SW wind gusts from 20-25 kts (possibly higher in snow bursts).

IND WATCHES/WARNINGS/ADVISORIES

None.