textproduct: Indianapolis

KEY MESSAGES

- Showers with embedded thunderstorms late Wednesday into Wednesday evening

- Strong to severe thunderstorms are possible late Wednesday. Damaging wind gusts are the primary threat.

- Scattered to numerous showers with much colder air late week. A few snowflakes possible as well Friday morning

- Dry weather returns this weekend into next week with a slow warming trend

DISCUSSION (This evening through Tuesday)

Issued at 258 PM EST Tue Nov 10 2026

A subtle surface trough is progressing through Indiana this afternoon and a wind shift has occurred around 1pm. Winds were light out of the southwest and are now out of the north-northwest from Indianapolis northward. This weak boundary is expected to stall across central Indiana this evening.

Winds should become light and variable overnight as the boundary layer stabilizes. With clear skies in place we are expecting excellent radiational cooling potential overnight. We have therefore went a bit below guidance for low temperatures with weight towards MOS and high-res short term guidance. This leads to forecast low temperatures in the upper 30s over rural areas and low 40s in urbanized locations.

With subtle moisture convergence in place along the weak boundary, patchy fog is possible overnight given the ideal radiative cooling potnetial. Fog may be locally dense along the axis of the boundary once it stalls. Areas from Terre Haute to Indianapolis eastward have the best chance of locally dense fog. Elsewhere, fog is possible but to a lesser degree.

Wednesday

Satellite shows a potent vort max over the Dakotas as of this writing (1pm Tuesday). This system is diving southeastward embedded within broad west-northwesterly flow aloft. Ensemble guidance shows the vort max amplifying with time as it moves towards Indiana. This amplification will help induce surface cyclogenesis tonight. By Wednesday morning, all guidance shows a closed surface low over northern Illinois roughly around 1007mb. Surface winds around the developing low increase throughout the day Wednesday, with a cold front taking shape by mid day.

A narrow band of higher moisture is modeled to lift northward along and ahead of the cold front. With cooling temperatures aloft, lapse rates are expected to increase allowing for modest MLCAPE around 500 J/Kg. Shear may be quite robust, between 35-45kt effective, especially across southern Indiana. Shear vectors are easterly and perpendicular to the cold front. As such, cellular/discrete convection is anticipated with eventual upscale growth.

As for potential hazards, it appears the isolated strong/damaging wind gust are the most probable. With steep lapse rates it wouldn't take much to mix some momentum aloft to the surface. However, the low-level jet appears quite weak so the threat will be limited. There is enough low-level shear and turning with height to allow for a very isolated tornado threat. This is dependent on how much moisture lifts northward and how strong the low-level jet gets. Right now, this threat appears to be a very low chance...but worth mentioning. Some small hail is possible but potential updraft strength does not appear enough for severe hail.

Wednesday Night into Friday

Strong northerly flow behind Wednesday's departing system will lead to wind gusts in the 30-40 mph range. Cold air advection should limit temperature recovery during the day Thursday. Lows in the lower 40s may only rebound into the upper 40s despite some sunshine peeking through. Additionally, precipitation is likely to develop by mid day Thursday as the core of the upper-level vort max arrives. Steeping lapse rates and fetch off of Lake Michigan should lead to showery/convective precipitation. Temperatures aloft may be cold enough for graupel or snow to mix in at times late Thursday into Thursday night. Precipitation diminishes for most of the region by sunset with only a narrow band lingering immediately downwind of Lake Michigan. Lows Thursday night into Friday morning look to be in the low to mid 30s. Highs friday top out in the high 40s mostly cloudy skies. Clouds should begin clearing during the afternoon but may persist longer downwind of the lake.

Saturday through Early Next Week

The upper low will shift east into the Canadian Maritimes by Sunday with an overall transition to broad ridging aloft that will persist well into next week. Widespread near to below freezing temperatures are expected on Saturday and Sunday mornings under clear skies and light winds. Other than the potential for lingering scattered diurnal cu on Saturday as the upper low moves away... expect a return to mainly clear skies that will likely extend into the middle of next week as strong high pressure settles over the region. The onset of warm advection will usher in a slow warming trend with highs rising from the mid and upper 40s on Saturday back into the mid and upper 50s by next Tuesday and Wednesday.

AVIATION (18Z TAF Issuance)

Issued at 1239 PM EST Tue Nov 10 2026

Impacts:

- Patchy fog tonight, IFR or worse possible.

Discussion:

VFR conditions are anticipated for the remainder of the day Tuesday, continuing into tonight. Patchy fog is expected to develop which may lead to poor flying conditions...IFR or worse. The best chance of fog is from IND to HUF. Lesser chances at LAF and BMG but still enough to include as a tempo group.

Fog gradually dissipates after sunrise Wednesday with increasing mid to high-level cloud cover ahead of an approaching low pressure system. Eventually, a BKN to OVC mid-level cloud deck is expected late in the day Wednesday around 22z-00z.

Scattered showers and a few embedded thunderstorms are likely beginning just after the end of the TAF period.

Winds should remain light and variable, perhaps calm, overnight tonight into Wednesday. Light southwesterly surface winds are possible by mid day ahead of the approaching low.

IND WATCHES/WARNINGS/ADVISORIES

None.