textproduct: Indianapolis

KEY MESSAGES

- Winter Storm Warning today through Monday morning

- Snow amounts as high as 10 inches in southern Indiana, high confidence in 6+ near I-70 and points south

- Cold Weather Advisory through noon, additional dangerous cold Sunday night through much of the upcoming week

FORECAST UPDATE

Issued at 1010 AM EST Sat Jan 24 2026

Overnight forecast is in good shape. Tricky forecast with regard to accumulating snow onset timing due to residual dry layer in the lower troposphere. Moderate ascent tied to the entrance region of strong jet streak to our north is enough for only gradual moistening of this layer. Closest observations with snow are in far western/southern Illinois now, and onset for our southwest counties should be early this afternoon and may not be until evening across the far north/east. Will refine this timing in the next couple hours as we continue to monitor observations. Will let the Cold Weather Advisory drop at noon.

SHORT TERM (Today through Sunday)

Issued at 307 AM EST Sat Jan 24 2026

Today Through Sunday.

Synoptic Overview. As of early this morning, surface high pressure remains entrenched across the Upper Midwest with a 1045mb surface high centered over far southern Wisconsin, which is helping to maintain a deep arctic air mass across the Ohio Valley. Synoptic-scale focus shifts to a positively tilted and increasingly elongated upper-level trough propped to lift from the Southern Plains into the Ohio Valley tonight into tomorrow as the aforementioned high begins to break down. Unlike a classic winter closed low with an associated TROWAL, this stretched configuration will limit the potential for rapid cyclogenesis or the development of a robust warm conveyor belt this far north into the Ohio Valley. Instead, central Indiana will deal with a long-duration overrunning event where modest but persistent isentropic lift interacts with a saturated and deep DGZ.

Timing and Evolution.

Initial saturation of the mid levels will occur through the morning, though a lingering dry layer near the surface associated with the weakening Arctic high may delay the onset of accumulating snow. Current guidance suggests snow will begin to overspread the southwest counties shortly after noon, reaching the Indianapolis metro towards the mid afternoon but remaining light. Farther north, toward Lafayette and Kokomo, the onset may be delayed until the evening to potentially overnight due to more substantial dry air entrainment. The most intense forcing and highest snowfall rates are likely late Saturday night through Sunday morning. Models are picking up on a brief lull towards the late morning before another surge of forcing helps to bring another round of heavier snow towards the mid afternoon hours Sunday. Because the trough remains elongated, snow is expected to persist for over 24 hours, only gradually tapering to flurries from west to east Sunday evening as the system's axis shifts toward the Appalachians. Accumulating snow will end by around 7PM for most of central Indiana and by 10 PM in the east.

Snowfall Totals.

Forecast snowfall totals for the I-70 corridor, including the Indianapolis metro, generally fall within the 6 to 10 inch range, with higher amounts of 8 to 12 inches possible for areas south of a Terre Haute to Bloomington to Columbus line. While hourly rates will likely remain between 0.5 and 1.0 inch, the sheer longevity of the event will allow for these impressive totals. Compaction may help to limit the final totals, especially with a very fluffy snow. Thermal profiles are extremely favorable for high-efficiency snow, as model soundings show the most significant lift occurring directly within the DGZ. Consequently, SLRs are expected to average between 12:1 and 14:1 in the south and closer to 18:1 in the north where the colder air allows for more columns vs dendrites. Another concern going into the afternoon hours on Sunday will be northerly gusts of 20-25 mph which may cause drifting with the very powdery snow.

Forecast Caveats and Uncertainty.

The primary caveat to this forecast lies in the potential for dry air intruding into the northern periphery of the system and limiting the snowfall. If the surface high to the north remains more suppressed or if the upper-level trough undergoes further stretching, the northern gradient of the snow shield could sharpen which has been a general trend in some of the higher resolution models over the last 12 hours. This would result in lower totals for the Lafayette to Muncie corridor, possibly as low as 3-4 inches. Additionally, because the forcing is broad rather than concentrated, any subtle shift in the track of the weak surface low could shift the axis of heaviest accumulation 30 to 50 miles in either direction. There are less caveats to the south other than the aforementioned compacting limiting final totals.

Temperatures.

Bitterly cold temperatures will define the thermodynamic environment of this storm. Highs today and Sunday will struggle to reach the mid- teens, with overnight lows plummeting into the single digits or near zero. Wind chill values will remain dangerous through the morning hours with wind chills generally in the -20 to -10 range as of early this morning. They are expected to rise above -10 this afternoon and remain above -10 until Sunday night when additional Cold Weather headlines will likely be needed. Because surface temperatures are so far below freezing, chemical treatments like salt will have severely limited effectiveness.

LONG TERM (Sunday Night through Friday)

Issued at 307 AM EST Sat Jan 24 2026

Lingering snow from this weekend's system should come to an end during the initial hours of the long term period. Immediately behind the snow will be another surge of dangerously cold weather as a cold front moves through. Lows each night, from Sunday night through the end of the week, are expected to be near 0 degrees. Higher winds on Monday and Tuesday, with gusts of 15 to 25 mph, wind chills will likely plummet to -10F to -20F but could feel even colder at times. Additional cold weather headlines will likely be needed again for the start of the new work week. Winds appear to let up some the remainder of the week but minimum wind chills below 0 should persist. Daytime highs won't provide much relief either as highs in the teens and 20s are expected through the week. Continue to limit time outdoors and check on vulnerable neighbors.

Other than the initial lingering snow, passing surface highs will help to keep much of long term dry. An exception to the dry weather could come midweek as there is a chance of additional snow across central Indiana.

AVIATION (12Z TAF Issuance)

Issued at 642 AM EST Sat Jan 24 2026

Impacts:

- Snow arrives this afternoon with MVFR conditions and IFR vis at times through the end of the TAF period

Discussion:

As the first wave of the winter storm approaches, snow will move into the area from the southwest this afternoon and persist beyond the TAF period. Intensity will increase overnight into Sunday morning when IFR vis is most likely. BMG, HUF, and IND may a few inches of snow by 12z with more expected through the day Sunday.

Winds will stay largely from the NE at less than 10kts.

IND WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until noon EST today for INZ021-028>031- 035>049-051>057-060>065-067>072.

Winter Storm Warning from 7 PM this evening to 7 AM EST Monday for INZ021-028>031-035>042.

Winter Storm Warning until 7 AM EST Monday for INZ043>049- 051>057-060>065-067>072.