textproduct: Indianapolis

KEY MESSAGES

- Occasional showers/t-storms today into next week.

- Localized ponding/flooding of low-lying areas will be possible where repeated rounds of downpours occur

- An isolated strong/severe storm cannot be ruled out.

FORECAST UPDATE

Issued at 1003 PM EDT Thu Aug 6 2026

Only minor forecast adjustments necessary this evening.

Have limited PoPs to slight chance until later tonight, with limited convective potential driven primarily by broad ascent in the right entrance region of a departing jet streak and a subtle, weak enhancement of the low level jet as the night wears on. Convection this evening even prior to onset of diurnal cooling was limited in scope and struggled to persist.

Temps will likely drop to near or slightly above dewpoints, in the upper 60s to low 70s, and this is in line with previous forecast.

DISCUSSION (This evening through Thursday)

Issued at 236 PM EDT Thu Aug 6 2026

Surface analysis this morning shows a broad Bermuda high pressure system in place, providing warm, southerly gulf flow to Indiana and the Ohio Valley. Remnants of the convective cluster over MO/IL and Indiana continue to weaken and drift east with warming tops. This was providing a large mid level cloud deck across the region. Radar shows some showers still waning near the Wabash River, but some new development was noted over NE Indiana, where a bit more sun and heating was found. Aloft a broad, shallow trough was in place east of the Rockies across the northern CONUS, with an axis near the Mississippi River. Dew points across Central Indiana were in the 60s.

Tonight...

Although some convective development will be possible late this afternoon due to diurnal heating, cloud cover has limited this somewhat. Overall, the trend for convection overnight will be diminishing, leading to partly to mostly cloudy skies overnight. Although our area will remain mainly under the influence of the surface high pressure, another short wave of forcing should be working through the upper midwest overnight, bringing more mid cloud for late tonight and Friday. Forecast soundings show a non saturated but moist column in place over Indiana with pwats over 1.7 inches. Thus another warm and humid night will be expected with clouds in the area and dew points in the upper 60s.

Friday and Friday Night...

The upper pattern will persist with weak troughing remaining in place across Indiana and Illinois. Models hint at another short wave passing on Friday Night. Meanwhile, Forecast soundings again suggest a favorable situation for diurnal convection with favorable CAPE and and high pwats. HRRR suggests late afternoon and evening convection once again, thus given these favorable ingredients, pops will continue to be needed, with the best window from 21Z-01Z. There will be little change in the air mass as the surface high continues to keep mainly warm and humid southerly flow in place, resulting in highs in the middle 80s and lows in the upper 60s.

Saturday and Saturday Night...

Indiana will again start the day with the warm and humid airmass in place. Again, depending upon the evolution of these convective systems, convective debris could be lingering as well as any storm remnants. Another short wave is suggested to pass within the NW flow aloft on Saturday, but confidence on timing these weak systems is low. The air mass remains favorable for convection with high dewpoints and some instability in place, but much more mid level drying is in place at that time. There does appear to be some agreement toward subsidence and drying on Saturday Night in the wake of this wave, thus will trend the overall day toward dry weather late in the day and on Saturday Night.

Sunday through Thursday...

Little overall change in the upper pattern is expected through this period. Models suggest broad, shallow troughing in place across the northern CONUS east of the Rockies. This will lead to continued NW flow aloft with several embedded short waves poised to pass across Indiana within the flow aloft. Confidence in any of these waves is low at this time. However models do suggest a weak passing frontal boundary on Tuesday and Thursday. Given this, best chances for precip will likely be on these days.

Forecast soundings through the week suggest steep lapse rates present with sufficient instability to support convection. Thus this in combination with the expected passing waves will necessitate pops in each day of the forecast. Temperatures look remain above normal given the warm and humid southerly surface flow in place.

AVIATION (06Z TAF Issuance)

Issued at 1238 AM EDT Fri Aug 7 2026

Impacts:

- MVFR conditions possible late tonight, brief IFR possible LAF

- Chance for showers or thunderstorms, particularly this afternoon

- Wind gusts around 18KT this afternoon

Discussion:

Light winds and ample low level moisture will likely produce MVFR ceilings and/or visibilities late tonight to around daybreak. Periods of IFR are possible at LAF and will be contained in a TEMPO group. Any restrictions will mix out quickly after sunrise.

Friday afternoon, chances will increase for showers and thunderstorms, and will stick with the VCTS from the prior package after 18Z, ending by 00Z Saturday. Isolated showers and storms will be possible tonight as well, but too uncertain for inclusion.

Winds will be light and variable to calm overnight, becoming southwesterly at 8-10KT gusting to around 18KT Friday afternoon.

IND WATCHES/WARNINGS/ADVISORIES

None.