textproduct: Indianapolis

KEY MESSAGES

- Occasion 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...mainly Saturday night into Monday night

DISCUSSION (Today through Thursday)

Issued at 403 AM EDT Fri Aug 7 2026

Today through Saturday night...

High humidity and seasonably warm conditions will continue through this weekend across Indiana amid at times southwesterly breezes and overall higher heights from stronger upper trough retracted to Upper Midwest and north. A few weak ingredients for convection should come together at times, especially through early evening and perhaps again for several hours Saturday, although confidence is low at any given time for more than widely scattered showers and/or more than isolated non-impactful storms. Rain chances to trend from west to east today through early evening, with lower certainty for this morning's POPs and higher confidence in at least briefly scattered coverage from this afternoon along/south of I-70 and especially later today over eastern counties. Greatest potential impacts will continue to be ponding of low-lying areas from localized downpours.

Potential for more scattered convection around the midday to early evening timeframe on Saturday should small wave coming from northern Illinois arrive late enough to catch daytime heating, which is not expected. More likely scenario is isolated showers early Saturday and perhaps a few organized RW/TRW- after 18Z south/east of Indianapolis. Only foreseeable impact would again be high water following any downpours.

Sunday through Thursday...

From a synoptic standpoint, next week will be characterized by quasi- zonal or very weakly cyclonic flow, with broad subtropical ridging stretching from the southeastern CONUS into the Four Corners region, evolving into a more amplified pattern as the ridge near and just east of the west coast, with stronger upper level troughing dropping into the upper Midwest and Great Lakes regions late week.

This will translate into near normal temperatures early in the week cooling slightly to just below normal by the latter part of the work week. Additionally, low to moderate precipitation chances early in the week will accompany low amplitude, low predictability shortwave disturbances, with somewhat higher rain chances late in the week as larger scale troughing enters the picture.

Despite the more limited rain chances early and higher chances late in the week, heavy rainfall will remain a primary concern throughout the week, as GEFS Integrated Water Vapor Transport progs show robust moisture advection into or near the region much of the week, with regional precipitable water values near to well above climatological mean, and seasonably high wet bulb zero heights on the order of 12- 14kft much of the week all pointing toward high rainfall efficiency in a background setting of plentiful recent rains.

Experimental machine learning guidance suggests at least a low chance for a few strong to severe storms at times, but predictability limits inherent in the overall synoptic pattern along with those accompanying convection that is largely thermodynamically/cold pool driven limit the ability to focus in more detail on a particular period for severe risk, aside from stating the obvious that late afternoon to evening time frames would likely be the primary concern for most days at least until late in the week when more significant synoptic forcing becomes a factor.

AVIATION (12Z TAF Issuance)

Issued at 706 AM EDT Fri Aug 7 2026

Impacts:

- IFR/worse VIS/CIG possible in FG/stratus thru 13Z, mainly at KLAF - Chance for showers or thunderstorms, particularly late in period - Wind gusts up to mainly 14-18KT this afternoon

Discussion:

Fog will provide at times LIFR at KLAF through 13Z...with MVFR possible at other terminals through 13Z. VFR will otherwise generally prevail near central Indiana terminals through Saturday morning...although occasional convective showers could provide brief MVFR, albeit with low confidence on where or when. -SHRA/TSRA chances will increase this afternoon...with isolated coverage possible tonight, yet certainty too low to include in any TAF.

Light/variable winds early today...will become southwesterly at 8- 10KT today, gusting up to 18KT this afternoon.

IND WATCHES/WARNINGS/ADVISORIES

Dense Fog Advisory until 9 AM EDT this morning for INZ021- 028>031-035>039-043>047.