textproduct: Indianapolis

KEY MESSAGES

- Colder Today. Much Colder Tonight.

- A COLD WEATHER ADVISORY is in effect along and north of a Terre Haute to Muncie Line.

- Near zero or Subzero lows possible Thursday and Friday nights along with potentially dangerous wind chills at or below -10F.

- Winter Storm Watch Sat-Sun with potential for significant accumulating snow

- Very cold temperatures persist into next week with potentially dangerous wind chills possible at times.

SHORT TERM (Today and tonight)

Issued at 210 AM EST Thu Jan 22 2026

Surface analysis early this morning showed a weak, dry frontal boundary stretching from near MIE to BMG and then southwest to western KY. GOES19 shows a thin area of clouds with this feature. This weak front was pin-wheeling around much stronger low pressure in place over eastern Ontario. Very strong, arctic high pressure was found over the Central and northern plains states. A moderate, cyclonic, pressure gradient was found across Central Indiana, allowing for some gusty winds.

Today and Tonight...

A quiet and colder day will be in store. The upper pattern remains unchanged today and tonight from the past few days, showing broad cyclonic flow across the northern CONUS east of the Rockies. Again, Indiana remains in a area favorable for subsidence within this flow and little to no forcing passes today or tonight.

Within the lower levels strong high pressure over the central Plains is present and will push east to the Ohio Valley today and tonight. Forecast soundings today show a dry column, indicative of mostly sunny skies. Tonight, some upper level saturation is shown to arrive. This will just result in some passing high clouds.

Regarding temperatures, weak cold air advection is in place today, but much stronger cold air advection arrives tonight as 850mb temps plunge to -16C by Friday morning. This will lead to colder temperatures today with highs only reaching the upper 20s and lower 30.

Temperatures will really plunge tonight when the cold air advection strengthens, falling into the teens in the evening and to the single digits overnight. This with a moderate pressure gradient in place will lead wind chill values around -15F, particularly north of a HUF- MIE line. Thus a cold weather advisory will be issued for those areas.

LONG TERM (Friday through Wednesday)

Issued at 210 AM EST Thu Jan 22 2026

Friday Through Sunday.

The primary focus of the long term period remains a potent and highly impactful winter storm system slated to traverse the region this weekend. Ensemble guidance continues to coalesce around a solution that brings a deep, moisture-rich plume of Gulf air into contact with an entrenched, brutally cold Arctic airmass. While the exact track of the surface low remains subject to minor shifts, the overall synoptic setup, featuring a strong high pressure center to the north and a sharpening baroclinic zone favors a significant winter weather event for much of the Ohio Valley. Confidence is increasing in a widespread snowfall event, particularly for areas south of I-70 even as there remains some questions on overall totals. Ensemble means suggest the highest probabilities for greater than 4-6 inches of snow reside across the southern portions of the forecast area, where the best overlap of frontogenetical forcing and deep moisture resides.

Where we have higher confidence is in very cold temperatures through the duration of this event, with highs on Saturday and Sunday struggling to reach the mid-teens and overnight lows plummeting into the single digits to potentially below zero. This will create a very deep DGZ. Because of the sub-freezing depth of the airmass, SLRs are expected to be well above the climatological 10:1 average. We are currently forecasting ratios in the 15:1 to 18:1 range, meaning even modest amounts of liquid equivalent could lead to accumulations and rapid reductions in visibility.

All that being said, there remains a fairly significant failure mode for the system as the surface low and associated subtropical jet will remain well south of even the Tennessee Valley. Winter storms that far south often overperform on their northern fringe with models likely overdoing QPF on the northern periphery of the system where central Indiana lies. The strong Arctic high to our north will maintain a steady northeasterly wind through the course of the event advecting cool and dry air into the area with dew points in the single digits to low teens further complicates the QPF forecast. Some of the 00Z model guidance has begun to pick up on a more narrow axis of heavier precipitation, but will need to see this trend continue before making major adjustments to the forecast. Models are likely also keeping the precipitation window for too long with GFS and Euro showing snowfall over much of a 36 hour window when the true window is likely to be lower.

After collaboration with neighbors, we have gone ahead and issued a Winter Storm Watch for the I-70 corridor and points to the south where confidence is highest in at least 3+ inches of snow with the thought that the northern portion of the Watch may end up in an Advisory while the far south ends up in a Warning. This gives us the flexibility to continue to monitor forecast trends and adjust accordingly.

Monday and Wednesday.

The pattern looks to remain active but cold heading through the middle of next week, as a trough persists over the Eastern US following the departure of the weekend system. This setup will maintain northwest flow across central Indiana, keeping highs in the 20s and lows in the single digits or teens through Tuesday with lower chances for sub-zero temperatures.

AVIATION (06Z TAF Issuance)

Issued at 1158 PM EST Wed Jan 21 2026

Impacts:

- VFR conditions this TAF period

- Southerly winds gradually shifting from the south to the northwest during the period.

Discussion:

VFR conditions are expected through the period. Strong and very cold arctic high pressure over the central and northern plains will build across Central Indiana after 08Z-10Z. A few mid clouds as seen on GOES19 will quickly push across the TAF sites during the overnight period, leading to the mostly clear skies found in its wake. A very active and quick upper flow in place across Indiana will allow for the occasional high cloud streaming across Indiana, but cigs for the most part will remain unlimited VFR through at least 00Z Friday as the high pressure builds across the area.

Aft 00Z Friday, forecast soundings show some saturation aloft. This is indicative of invading high CI cigs associated with expected active southern jet.

IND WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory from 1 AM Friday to 1 PM EST Saturday for INZ021-028>031-035>049-051-052.

Winter Storm Watch from Saturday morning through Sunday evening for INZ042-045>049-051>057-060>065-067>072.