textproduct: Indianapolis

KEY MESSAGES

- Widespread frost and localized freezing temperatures will occur this morning

- A Freeze Warning is in effect for much of eastern and portions of central Indiana, Frost Advisory elsewhere

- Dry and quiet weather persists through the next 7 days with temperatures rebounding well above normal by midweek

DISCUSSION (Today through Saturday)

Issued at 205 AM EDT Sun Oct 18 2026

Current observations show low 30s to mid 30s dew points across the area of which matches up with the ongoing forecast of near to below freezing temperatures over N/NE portions of central Indiana and widespread frost over the remainder of the area. The one caveat to this is E/SE portions of the Freeze Warning where current dew points of 35-37.

The surface high will push off to the east on throughout the day, allowing for weak S/SE flow to develop over the Ohio Valley by this afternoon. This along with mostly clear skies will lead to a slight rebound in temperatures with highs on Sunday expected to be in the low 60s. Clear skies and dry surface conditions will continue large diurnal swings, but there will be enough of an air mass change to keep temperatures above freezing Sunday night into Monday morning. Frost potential will remain high over NE portions of the area, but headlines will depend if any hard freezes occur this morning.

Upper level riding will continue to build throughout the beginning of next week leading to subsidence and dry conditions. Continued S/SW flow west of the surface high will maintain the steady warming trend early next week as well. 850mb temperatures are expected to increase above 10C by Tuesday. This along with dry adiabatic lapse rates in the PBL should lead to daily temperature above seasonal normals Monday through Wednesday. Expect large diurnal swings to continue with lows in the 40s.

By later in the week, mid to low level northerly flow upstream of a building ridge will likely curtail daily temperature gains late next week into the weekend with highs remaining in the low 70s. Subsidence will remain high with continued large diurnal temperature swings and dry conditions.

AVIATION (06Z TAF Issuance)

Issued at 1243 AM EDT Sun Oct 18 2026

Impacts:

- None

Discussion:

VFR conditions are expected through the period.

A dry atmosphere will keep skies clear. Surface high pressure will provide calm to light winds overnight, with winds becoming southerly at less than 10kt on Sunday as the high moves east.

IND WATCHES/WARNINGS/ADVISORIES

Frost Advisory until 9 AM EDT this morning for INZ021-028-029- 035-043>045-047-051>055-060>064-067>072.

Freeze Warning until 9 AM EDT this morning for INZ030-031- 036>042-046-048-049-056-057-065.