textproduct: Indianapolis

KEY MESSAGES

- Dry yet pleasant fall weather will prevail through this weekend

- Light winds and partly/mostly clear skies will oversee near to slightly above normal temperatures

FORECAST UPDATE

Issued at 948 PM EDT Tue Oct 20 2026

Similar to recent evenings, clear skies and light winds have led to a rapid temperature fall, especially in favored cold spots. Adjusted hourly forecasts to match current observational trends. Also nudged down low temperatures as well, mainly in those favored cold spots.

Patchy ground fog will likely develop later tonight. However, the more widespread fog expected to develop from low level moisture advection from the northeast will likely remain out of the local area.

DISCUSSION (This evening through Tuesday)

Issued at 225 PM EDT Tue Oct 20 2026

Quiet weather is expected through the next seven days as surface high pressure remains dominant across the region. Guidance is in good agreement through the end of the week, showing upper ridging amplifying as it builds eastward across the region. Large scale subsidence will continue to keep the forecast dry. A weak cold front may push in from the northeast Thursday Night into Friday. The boundary appears very weak with temperatures only expected to drop a few degrees at most.

Temperatures will slightly warm over the weekend due to return flow as surface high pressure shifts east of central Indiana. Highs in the upper 60s to low 70s Friday should warm into the low-mid 70s by Sunday. Long range guidance begins to diverge regarding the upper level pattern towards the end of the weekend. A southern stream wave will likely get pulled northward and absorbed into the northern stream trough. Models differ on the overall evolution of these two features which leads to greater uncertainty in the extended forecast.

A cold front associated with the northern stream trough should eventually move through central Indiana around the early to middle of next week, but confidence on specific details such as timing remain limited. There also appears to be a non-zero chance for light precipitation from the approaching boundary. Some guidance depicts a narrow band of sufficient moisture surging north ahead of the boundary and weak forcing supporting the potential. These solutions remain the outlier though with most guidance suggesting the limited moisture return will not be enough to overcome lingering dry air. The forecast remains completely dry for the time being until guidance becomes better aligned. Once the front eventually moves through, a cooler trend towards seasonal temperatures can be expected.

AVIATION (00Z TAF Issuance)

Issued at 618 PM EDT Tue Oct 20 2026

Impacts:

- Brief MVFR visibility in fog around 12Z for some sites

Discussion:

Mainly VFR conditions are expected through the period with surface high pressure remaining in control. Winds will be light and will continue to vary in direction during the period.

Ground fog is possible around 12Z. At the moment, am only confident enough to add at KLAF/KBMG, but certainly cannot rule it out anywhere. A larger area of advection fog looks to remain northeast of the TAF sites.

IND WATCHES/WARNINGS/ADVISORIES

None.