textproduct: Indianapolis

KEY MESSAGES

- Generally dry weather and a steady warming trend mid to late week

- Peak heat indices around 100 degrees each afternoon mid-late week

- Chances for showers and storms return Friday through the weekend, primarily during the afternoon and evening

DISCUSSION (This evening through Monday)

Issued at 300 PM EDT Mon Jul 13 2026

This afternoon through Thursday night...

Model guidance depicts upper ridging and surface high pressure remaining centered across the central CONUS. These features will provide quiet weather during the first half of the forecast period. Gradually increasing 850mb temperatures from the upper ridge shifting overhead combined with deeper moisture returning northward towards the middle of the week may lead to heat indices as high as 100 degrees or a few degrees above, primarily Wednesday or Thursday afternoon.

Expect light and variable winds at times due to a weak pressure gradient from the surface high. The weak flow leaves some uncertainty on how high dewpoints will be towards the middle or end of this week as moisture could be slow to return northward. How much evapotranspiration occurs and the depth of diurnal mixing are other factor to monitor in the coming days. Slightly higher dewpoints could lead to portions of central Indiana approaching heat advisory criteria. These trends will continue to be monitored closely.

Friday through the weekend...

Long range guidance is generally in good agreement regarding the upper level pattern, but model solutions begin to diverge by this point leading to lower confidence. Models generally depict the upper level ridge breaking down while northwest flow and upper troughing develops into the weekend. By Friday, deeper moisture will likely already be in place with most models suggesting dewpoints in the low 70s. Daytime heating atop this humid airmass supports the potential for scattered diurnal convection as large scale subsidence from the aforementioned ridge weakens.

A shortwave passing through the region late Saturday through early Sunday will provide another opportunity for showers and thunderstorms, primarily Saturday afternoon into the evening hours. Low chances for convection linger into Sunday, but this will depend on the strength of the system moving in late Saturday. A more organized low pressure system like the GFS is suggesting would filter in drier air behind the associated front resulting in more tranquil weather. The ECMWF stalls the boundary just north of central Indiana, keeping the warm-humid airmass in place along with chances for convection. Exact details will remain uncertain until models become better aligned.

AVIATION (18Z TAF Issuance)

Issued at 122 PM EDT Mon Jul 13 2026

Impacts:

- None

Discussion:

VFR conditions expected through the TAF period with northeasterly winds of 8-12kts this afternoon. There could be a few gusts up to 19kts, but this should remain infrequent enough to not warrant a mention in the TAF at this time. Skies will be mostly clear through the period with diurnally driven cu around 050 possible, mainly near BMG. Winds may become light and variable or calm at times tonight into Tuesday for some sites as surface high pressure moves overhead.

IND WATCHES/WARNINGS/ADVISORIES

None.