textproduct: Indianapolis

KEY MESSAGES

- Ongoing flooding will continue this morning

- A few showers are possible this afternoon and again Saturday

- Better chances for rain return Sunday into Monday

- Below normal temperatures will continue for much of the period

FORECAST UPDATE

Issued at 859 AM EDT Thu Jun 18 2026

Surface analysis late this morning shows low pressure in place over southern Ontario, providing cyclonic flow across Indiana. High pressure was found across the NW plains states. A frontal boundary was found still lingering across southern Indiana and nrn KY. A secondary cold front was found over lower MI and NRN IL. GOES19 shows convection near the Ohio river, associated with the frontal boundary. Otherwise, some high clouds were pushing across IL toward IN within the WNW flow aloft. A few showers were found with this over NRN MO.

This afternoon...The weak cold front to the north is expected to sag southward across Indiana. Meanwhile the clouds and precip to the west within the quick NW flow aloft will also reach Central Indiana this afternoon. These two features will combine to provide an increase in cloud cover this afternoon along with chances for some light rain showers. Forecast soundings show the arrival of some mid level saturation this afternoon, however lower levels remain dry. HRRR suggests some scattered light rain showers this afternoon, with best chances along and south of I-70. Any amounts should remain rather light.

Cold air advection is in play today on NW winds. This will result in high temperatures in the lower to mid 70s.

DISCUSSION (Today through Wednesday)

Issued at 301 AM EDT Thu Jun 18 2026

Early This Morning...

Convection will continue across the southern forecast area where instability remains but will be slowly weakening. Severe storm threat should end before 08Z as the leading edge of the convection sinks south of central Indiana, limiting the inflow of storms to the north. Threat will transition to flooding with repeated rounds of storms moving through. Current thoughts are that by the end of the Flood Watch valid time, most areas will have transitioned to ongoing flood advisories/warnings, so will let it expire.

Today...

By 12Z rain should be south of the forecast area, so will start the day off dry. However, some additional upper forcing will move through this afternoon and could generate some sprinkles or a few showers. Will have some slight chance PoPs across portions of the southern half or so of the forecast area this afternoon.

Highs will be in the lower to middle 70s north to around 80 south. There is some uncertainty with these numbers as cloud cover with the afternoon sprinkles/showers may keep readings down.

Tonight and Friday...

High pressure will build in and bring quiet weather to the area during this period. Below normal temperatures will continue with lows in the 50s tonight and highs mainly in the 70s Friday.

Saturday...

A weak system in northwest flow will bring some forcing to the area on Saturday. However, moisture will be limited. Will have some slight chance PoPs with this system. Below normal readings in the middle 70s to around 80 will continue for high temperatures.

Sunday and Monday...

An upper level wave and surface low pressure system will move through the area during this time. There remains some questions in timing of these, but for now it appears that the highest PoPs will be Sunday night. This system may be able to tap into some moisture and bring near an inch of rain.

Tuesday and beyond...

High pressure will try to keep the area dry mid-week next week, but some upper energy may try to squeeze out a few showers around Wednesday. Temperatures will continue to be below normal for much of the area.

AVIATION (18Z TAF Issuance)

Issued at 1255 PM EDT Thu Jun 18 2026

Impacts:

- VFR this TAF period

Discussion:

VFR conditions are expected through the period.

Some mid and high clouds will pass across the HUF and IND TAF sites this afternoon. Some very light rain showers will be possible as they pass. A window of VCSH was used to account for this.

High pressure and an associated dry air mass will arrive across Central Indiana tonight. This will lead to dry weather with minimal cloud cover, and continued VFR conditions.

Some VFR cigs will be possible by late Friday morning as daytime heating allows CU development.

IND WATCHES/WARNINGS/ADVISORIES

None.