textproduct: Indianapolis

KEY MESSAGES

- Patchy fog possible late tonight into Tuesday morning.

- Mostly dry through midweek with mix of rain and snow chances returning late Thursday.

- Rain is likely late Saturday into Sunday although uncertainty remains on the exact timing and amounts.

- Ice Jam development remains a concern this week with milder temperatures expected.

- Generally near seasonal temperatures this week, except Tuesday and again early next week when highs are expected to be in the 40s and 50s.

SHORT TERM (This evening through Tuesday)

Issued at 327 PM EST Mon Feb 9 2026

Satellite imagery shows stratus associated with broad isentropic lift exiting to our northeast. Simultaneously, high cirrus is advancing in from the northwest ahead of a shortwave ejecting from the northern Rockies. This shortwave is modeled to progress eastward and interact with an existing low over south central Canada.

A potent low-level jet is expected to develop late tonight in response to the developing system. Guidance shows strong southwesterly flow in the 925mb to 850mb layer between 45 to 55 knots. Impressive warm air advection takes hold after about 06z, though mainly above the surface. Within the boundary layer, radiational cooling combined with warm air advection aloft will help strengthen a sharp near-surface inversion. Limited momentum transfer is expected overnight with only light winds at ground level.

As mentioned above, temperatures tonight should be dominated by radiative effects with limited impact from ongoing warm air advection. Guidance may be a bit too warm for lows, as model snow depth seems to melt off too fast this afternoon. Current dew point depressions are greater than 20 degrees, with wet bulb zero values below freezing. Therefore, the current snow pack may be more resilient than guidance suggests. That being said, the impact current snow cover has on temperatures may be greater than guidance indicates...especially during the overnight period.

During the day, however, that may not be the case. Today, for instance, is running above guidance despite the current snow cover and its associated high albedo. A stronger sun angle and light winds help in this regard. Tomorrow may be similar, as high-level clouds diminish substantially around sunrise. There is one caveat, however, that could make tomorrow's temperatures a bit of a challenge. That caveat is moisture advection.

In addition to strong warm air advection, moisture will also be lifted northward. Warm moist air over a cold dense snowpack is an ideal setup for advection fog. We've included patchy fog to the forecast for the southern half of our CWA. We maintained patchy wording since it's uncertain as to how much fog develops or lifts into a low stratus layer. The southern edge of the current snowpack is well to our southwest. It's not unreasonable to think that fog develops further southwest, and lifts with northward extent as it encounters the deeper inversion over central Indiana.

Shold fog or stratus form, it will likely have a great impact on high temperatures. Areas that remain socked in likely trend well- below guidance and places that experience full sunshine likely trend above guidance. For now we'll aim more with 50th percentile temperatures, which shows low 50s to our southwest and low 40s to our northeast. Given the expected wind direction, the best chance of lingering fog/stratus is across the southeastern third of our CWA. Taking all this into consideration, forecast uncertainty is unusually high for the short term period.

..Sunday/Monday

Uncertainty in the speed of the shortwave leads to gradually reduction in precip Sunday with NBM PoPs diminishing west to east. A broad and strong long wave trough is expected to develop along the west coast Sunday into Monday will help force a broad upper ridge over the plains into the MS valley. Monday looks to be the first day of widespread well above normal temps (50s) area wide.

AVIATION (00Z TAF Issuance)

Issued at 552 PM EST Mon Feb 9 2026

Impacts:

- Low level wind shear after 06Z Tuesday - VFR this evening and overnight - MVFR possible on Tuesday afternoon

Discussion:

GOES19 shows high level cirrus streaming across Indiana amid weak, broad ridging stretching from the northern plains into Central Indiana. These high clouds will continue to stream across Indiana this evening.

A moderate LLJ over 40 knts is expected to push across Indiana ahead of a approaching cold front overnight. This will create the possibility of some LLWS overnight.

As the front passes on Tuesday afternoon, some lower level MVFR Cigs will be possible as the cold air advection begins. Overall the forecast column will remain too dry for any precipitation. Forecast soundings do hint at some lower level saturation on Tuesday afternoon.

IND WATCHES/WARNINGS/ADVISORIES

None.