textproduct: Indianapolis

KEY MESSAGES

- Numerous showers and scattered thunderstorms expected at times this afternoon into tonight

- Flood Watch in effect through 8 AM EDT Sunday for much of central IN; Rainfall amounts of 1 to 3 inches are possible with locally higher amounts

- Isolated severe t-storms are possible with damaging wind gusts and an isolated tornado threat, mainly over E/SE central Indiana

- Rain chances will persist through the weekend with additional chances at times next week

DISCUSSION (This evening through Saturday)

Issued at 147 PM EDT Sat Aug 1 2026

This afternoon through tonight...

Current KIND radar imagery depicts increasing coverage of showers across central IN after a brief lull in precipitation.Increasing large scale ascent from an approaching mid-upper level vort max centered over IL combined with low-level theta-e advection ahead of an associated low pressure system will continue to promote additional convective development. Expect widespread showers this afternoon along with scattered thunderstorms once sufficient destabilization occurs.

Efficient rainfall rates and repeated rounds of showers/storms from the slow moving system could result in localized flash flooding through daybreak Sunday. An associated warm front lifting north is expected to stall near or just north of the I-70 corridor into the evening hours which may also increase the threat for flooding as slow moving storms could train over the same areas. A FLOOD WATCH is now in effect for much of the forecast area through 8 AM EDT Sunday with rainfall amounts of 1 to 3 inches expected. Locally higher amounts of 4+ inches are possible.

Modest to moderate destabilization later this afternoon combined with sufficient effective wind shear supports the threat for isolated severe thunderstorms, mainly for E/SE portions of central Indiana. Forecast soundings depict gradually steepening lapse rates and mid-level dry air contributing to DCAPE values around 900 to 1100 J/KG which may result in isolated damaging wind gusts. Low- level veering hodographs from the warm front lifting north could also promote an isolated tornado threat.

Some uncertainty still remains regarding the overall severe threat. Mesoscale details such as how far north the warm front moves and the degree of destabilization or low-level buoyancy later this afternoon will ultimately determine the severe weather risk. The flooding threat is the greatest concern, but isolated severe weather remains possible over mainly E/SE portions of central Indiana. If any severe weather occurs it would likely be from around 2 to 9PM EDT before instability weakens.

Sunday through Monday...

The aforementioned low pressure system is expected to still be over the area on Sunday as it slowly crawls southeastward. Broad cyclonic flow and lingering moisture will promote scattered or numerous showers. A low flooding threat may linger into Sunday, but very limited instability and weaker forcing should lead to lower rainfall rates. Look for coverage of showers to decrease late in the day into Sunday night with the system gradually departing.

Surface high pressure building in Monday will provide mostly quiet weather. However, lingering moisture and daytime heating may support isolated showers or a stray storm across far southeastern counties late in the day.

Tuesday onward...

Long range guidance generally shows the aforementioned system becoming cutoff once again and retrograding towards the Ohio Valley Tuesday into Wednesday. Deeper moisture advecting back into the southeast half of central Indiana along with weak dynamics from the system and diurnal heating keeps low chances for precipitation in the forecast, mainly during the afternoon or evening. Multiple embedded shortwaves traversing the region Thursday through end of the week will promote additional convective chances. Exact details remain uncertain at this time due to diverging model solutions.

AVIATION (18Z TAF Issuance)

Issued at 225 PM EDT Sat Aug 1 2026

Impacts:

- At most, MVFR ceilings through period, down to IFR and even LIFR at times tonight into the morning hours

- SHRA much of the time, with isolated TSRA possible

Discussion:

Low Pressure over Illinois will advance to Indiana during this period, with bands of showers pivoting around the low are expected to pass through the day. Ceilings are expected to be MVFR at most through the period with IFR to LIFR possible at times mainly within the rain bands and late tonight into tomorrow morning.

Isolated TSRA will be possible at times with best chances this afternoon. Winds will be shifting through the period as well around the low, with calm to light and variable as the low moves overhead, mainly moving across the south.

IND WATCHES/WARNINGS/ADVISORIES

Flood Watch through Sunday morning for INZ021-028>031-035>049- 051>057-062>065.