textproduct: Indianapolis

KEY MESSAGES

- Patchy fog possible late tonight.

- Scattered strong to severe storms likely Thursday afternoon into evening with the primary threats damaging winds/isolated tornadoes.

- Colder for the weekend, with scattered light snow possible Sunday.

SHORT TERM (This evening through Thursday)

Issued at 327 PM EST Wed Feb 18 2026

Tonight...

The lead shortwave trough progressing through the Great Lakes has carried with it a psuedo-dryline into northern portions of Indiana into eastern Illinois. Mixing of drier air aloft in the BL has shunted the moisture axis eastward this afternoon extending along the Ohio River valley, with several weaker moisture discontinuities/surface pressure troughs noted on surface analysis and radar imagery across central Indiana. As the dryline boundary slows down its eastward advancement this evening owing to decoupling/weakening of the stronger flow aloft, expect it to stall across western portions of central Indiana. Another in a series of shortwave troughs will rotate out of the west coast longwave trough into the central plains tonight. Associated with this feature, surface/low level pressure/height falls will aid in the boundary/moisture axis to retreat northwestward. The pattern looks favorable for patchy fog to form late tonight. A greater threat for dense fog would exist if not for the increasing mid level FGEN clouds moving in after midnight as well as surface winds remaining in the 5- 7 kt range. In addition, subtle low level forcing with the frontal boundary may support a few showers/sprinkles towards morning.

Thursday...

A few light shallow convective showers/sprinkles will be possible in the morning before the effective warm front shifts away from central Indiana. Meanwhile, a surface low pressure will deepen over the lower MO valley during the morning moving towards the Quad cities area by 00Z. An associated dryline will move into the MS valley by early-mid afternoon (18-20Z). Convection is expected to initiate along this dryline during this period, moving quickly towards and into central Indiana by late afternoon/early evening (21-00Z). Dewpoints within the moisture axis are expected to be between 54- 57F. Forecast soundings depict two pronounced inversion across central Indiana, one centered around 850 mb being an effective remnant base of the EML from Wednesdays dryline, and the second one a subsidence inversion centered between 400-500mb, on the equatorward side of the strong upper level jetstream core of 130-150 kt. As a result, instability is not overly impressive (500-800 j/kg of MUCAPE). Strong deep layer shear profiles (0-6 km from 60-80 kts) support supercell characteristics, but there is still some concern that the threat for a deep enough cloud layer (with aforementioned 400-500mb inversion) for charge separation/lightning will be mitigated. Therefore have opted to carry high pops but scattered TS wording. As far as hazards go, relatively fast storm motions will support some damaging wind potential although low level lapse rates will be marginally supportive. Forecast hodographs show around 150- 200 m2/s2 0-1 SRH after 22Z, so the threat for isolated tornadoes is also possible with any storms that are already rotating. The threat for severe hail seems mitigated given the following reasons (shallow layer of buoyancy, relatively mild BL temps (60s) and lack of a deeper layer of steep lapse rates limiting updraft intensity, despite strong vertical shear profiles.

Thursday Night...

Rain/Thunder/Severe threat should come to an end quickly between 03- 06Z with passage of surface trough/remnant dryline. A cold front will move into central Indiana after 06Z. Steep low level lapse rates and strong CAA behind the front will support increasing westerly wind gusts up to 30 mph towards 12Z. In addition a few light sprinkles will be possible across areas north of I-70 on the fringes of strong mid level forcing.

LONG TERM (Thursday night through Wednesday)

Issued at 327 PM EST Wed Feb 18 2026

Friday and Saturday...

More seasonable temperatures return for Friday into Saturday behind the low pressure system. A tighter pressure gradient along with cold advection will bring breezy conditions Friday, with gusts into the 30 to 40 mph range possible, especially north.

Sunday and Monday...

An upper level low will move southeast through the Great Lakes region around Sunday, bringing a brief return to winter to central Indiana. Some uncertainty remains in the timing and strength of the upper low, so specifics on timing and PoPs may change. At least some scattered light snow showers will be around the area on Sunday, with the potential for up to a dusting of snow, mainly across the northeastern forecast area.

Temperatures will top out in the 30s on Sunday and Monday. Lows Monday night will be in the teens for some areas.

Tuesday and beyond...

Temperatures will moderate as the upper low exits the area. A weaker upper trough could bring some light precipitation on Wednesday. Highs by Wednesday may return to around 50 degrees.

AVIATION (00Z TAF Issuance)

Issued at 615 PM EST Wed Feb 18 2026

Impacts:

- IFR conditions developing predawn Thursday with the possibility of a few light showers and/or drizzle - Scattered showers early Thursday, with thunderstorms from the mid afternoon to early evening

Discussion:

Wind gusts have dropped off late this afternoon into the early evening as the deep mixing through the boundary layer is lost. Winds will back to southwest then southerly tonight and remain below 10kts. Skies will remain mostly clear through most of the evening but mid and high level clouds currently over the Missouri Valley will quickly expand east and envelop the region into the overnight.

With the approach of a warm front from the south late tonight... ceilings will drop rapidly to near if not into IFR levels during the predawn hours with pockets of light showers or drizzle producing visibility restrictions as well through daybreak. Conditions will improve late morning into the early afternoon as stronger S/SE surface flow develops.

The approach of strong low pressure from the west with the warm front in the area will set the stage for convective development over Illinois during the first half of Thursday afternoon...spreading east into central Indiana mid afternoon into the evening. IFR and lower restrictions will accompany the heaviest convection.

IND WATCHES/WARNINGS/ADVISORIES

None.