textproduct: Indianapolis

KEY MESSAGES

- Areas of fog north this morning

- A Winter Weather Advisory for accumulating snow for much of the area tonight.

- Wind chills at night into the teens through Tuesday night...snow showers Wednesday night before wind chills fall to zero to 15*F

- Light snow to mixed precipitation is possible Friday into Saturday

SHORT TERM (Today and tonight)

Issued at 322 AM EST Mon Dec 1 2025

Bottom Line Up Front...

Snow is expected to move in late this afternoon and continue into the night before ending from west to east late tonight. Accumulations of 1 to 3 inches will be common, but some areas may receive more due to banding. A Winter Weather Advisory will be in effect for much of the area mainly tonight.

Early This Morning...

Fog has developed across some areas with deeper snow cover across the northern forecast area, with stratus developing elsewhere. Will continue to monitor closely for need of any Advisory, but for now will likely just have a Special Weather Statement for low visibility and slick spots. Temperatures will be cold.

This morning through mid-afternoon...

Much of the day will be quiet. Fog will lift during the morning. Stratus and thickening high and mid level clouds will keep skies mostly cloudy. Temperatures may be able to rise back into the lower and middle 30s, depending on the thickness of the clouds. Will have to monitor.

Late afternoon through Tonight...

A northern stream upper trough will bring lift to western portions of central Indiana late this afternoon, with the northwest forecast area seeing the best forcing then. There will be some initial dry air, but at the moment it does not to look to be as strong as the other day. The atmosphere will be cold enough for all precipitation to be snow. Will go likely PoPs northwest before 00Z with chance PoPs across much of the western forecast area by 00Z.

Broad forcing will move into the forecast area tonight from the northern stream trough, and moisture will be good enough for high PoPs. Later this evening into the overnight, forcing from the southern stream will influence the southern and eastern portions of the forecast area. Will go high PoPs all areas at some point during the night, and snow will be the precipitation type given the cold atmosphere.

There will be some features that add uncertainty to snow amounts to the area. First, frontogenetical forcing will help create banding. Some models hint and negative EPV above the frontogenesis, which could intensify the banding. That will have to be watched. These bands could create relatively large variations in amounts across a county.

In addition, questions remain on how far north and east the southern stream forcing will first start impacting the area. This puts southwestern portions of the forecast area, perhaps even as far northeast into the Indy area, into potentially lower amounts if the forcing arrives later and farther east.

Putting all of this together, will go with a Winter Weather Advisory for all but Sullivan and Knox Counties. Will start the northwest at 22Z and the remainder of the area at 00Z. The snow may start later in the eastern and southern forecast area, but kept the 00Z start time there for simplicity. Will go to 12Z Tuesday, but snow will end before then. Depending on exact timing, the Advisory may be canceled early if needed tonight.

Amounts of 1 to 3 inches look to be common, with lower amounts in the southwest. Four inch amounts will be possible in heavier bands. However, as noted above, amounts may vary a good amount even within a county due to banding.

Lows will generally be from around 20 to the middle 20s.

LONG TERM (Tuesday through Sunday)

Issued at 322 AM EST Mon Dec 1 2025

Cold winter pattern to continue to prevail across central Indiana into the upcoming weekend as a handful of short wave troughs streak west to east across central CONUS amid very broad polar trough's stagnant occupation of North America. Dry and cold conditions Tuesday into Wednesday ahead of snow showers later on Wednesday with arctic frontal passage...which will bring a frigid Wednesday night to Thursday night for at least northern zones. Less confidence for later in the long term where considerable model divergence surrounds potential for overrunning precipitation event through late week.

Recent forecast trends are indicating readings not quite so low south of I-70 where lack of snow pack should allow afternoons into the mid- to upper 30s most days. Although counties west of I-69 can expect a colder night on Wednesday night with readings down to near 10F northwest...highs Thursday across the CWA ranging from 15 to 30F and frigid Thursday night with single digits across the region's northern half and teens over the south. Wind chills, usually sub- freezing, are not expected to exceed the mid-20s this week for most northern zones, and for points south will stay in the 20s both Tuesday and Thursday. Overnight wind chills to drop into at least the teens for all points through Thursday night, with single digit values across the north Wednesday night and Thursday night.

In terms of comfortability, at least winds will be mainly lighter than much of the recent late November timeframe, with gusts only approaching 20 mph Wednesday into Thursday. The low certainty for the late week precip chances suggests lower liquid equivalents, with any hydrometeors most likely starting as light snow Friday and most likely ending as R-/L- if lingering into the middle of the weekend. In between these boundaries low chances of mixed precipitation exist, with the potential for minor travel hazards. The normal max/min at Indianapolis through the long term is 44/29.

AVIATION (12Z TAF Issuance)

Issued at 608 AM EST Mon Dec 1 2025

Impacts:

- IFR and worse stratus will impact most sites at some point this morning, with fog at KLAF - IFR and worse return after 00Z Tuesday in snow.

Discussion:

Low confidence forecast this morning as stratus meanders about the area. The stratus will gradually move west, and more is upstream in Ohio. The ceilings should lift this morning and may mix out back to VFR. Fog will continue early at KLAF before mixing out.

Later this afternoon, snow will move in from the west and continue into much of the night. IFR and worse conditions will occur in the snow.

IND WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from 5 PM this afternoon to 7 AM EST Tuesday for INZ021-028>031-035-036-043-044.

Winter Weather Advisory from 7 PM this evening to 7 AM EST Tuesday for INZ037>042-045>049-051>057-061>065-068>072.