Scattered strong thunderstorms through the afternoon and evening of the 12th, included isolated severe cells; an early afternoon downburst in Morgan County and an early evening storm that impacted the Terre Haute Airport. Locally heavy rainfall also impacted portions of Monroe County and Sullivan County, with the only minor flooding reported in Knox County.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS IND wrote it up.
Scattered strong thunderstorms through the afternoon and evening of the 12th, included isolated severe cells; an early afternoon downburst in Morgan County and an early evening storm that impacted the Terre Haute Airport. Locally heavy rainfall also impacted portions of Monroe County and Sullivan County, with the only minor flooding reported in Knox County.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Indianapolis, IN wrote its last area forecast discussion before the first event at Aug 12, 5:49 AM EST, 6 hours 56 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Indianapolis IN 649 AM EDT Tue Aug 12 2025 .KEY MESSAGES... - Patchy fog possible through daybreak and again late tonight. - Scattered storms possible at times this afternoon through Wednesday. Isolated storm threat may persist into Thursday. - Locally heavy rain and strong sub-severe wind gusts possible in storms. - Muggy conditions to persist; Potential for heat index values to near or exceed 100 this weekend. && .SHORT TERM (Today and tonight)... Issued at 231 AM EDT Tue Aug 12 2025 Clear skies and very light winds has helped patchy ground develop in a few spots with minor visibility reductions being reported. Look for patchy fog to persist through daybreak, mainly in climatologically favored locations, before quickly mixing out. Expect an upper trough to move through the region during the period providing more favorable large scale ascent compared to the past few days. At the surface, strengthening southerly flow will help advect gulf moisture northward. This setup combined with strong daytime heating supports the development of scattered diurnal convection in the afternoon. Forecast soundings depict steepening low-level lapse rates and moderate instability which could support strong sub-severe wind gusts. Weak deep-layer shear will limit severe weather potential, but cannot completely rule out an isolated damaging wind gust. Locally heavy rainfall is also possible as efficient rainfall rates are expected. While diurnally driven convection should dissipate during the evening due to the loss of daytime heating, a frontal boundary moving through this evening into the overnight hours could promote additional scattered showers or storms. Guidance suggest the boundary becomes very diffuse over the area tonight allowing for humid conditions to persist. Strong daytime heating and southerly flow should warm temperatures into the upper 80s and low 90s today. Muggy dewpoints and clouds overnight will help keep lows in the upper 60s to low 70s. Patchy fog development appears likely due to low-level moisture in place and light winds. More widespread fog development could occur if clouds manage to clear out. && .LONG TERM (Wednesday through Monday)... Issued at 231 AM EDT Tue Aug 12 2025 Wednesday will bring a second day with increased convective coverage across the region as a frontal boundary drops south and an upper trough passes through the eastern Midwest. The upper trough will shift east by Thursday as the remnant boundary moves south of the Ohio River...resulting in a brief respite from the recent heat and humidity of the last few days. Convective coverage will diminish back to more of an isolated afternoon threat at best late week and into the weekend as quasi- zonal flow gives way to a return to increasing mid level heights with the eastward expansion of the upper ridge into the Ohio Valley. Heat and humidity will return for the weekend into early next week with increasing uncertainty further out into next week as the presence of newly formed Tropical Storm Erin could very well be in the western Atlantic Ocean as a hurricane. This could serve as an effective block to any substantial pattern changes further west into the eastern half of the country. Wednesday through Thursday Night The aforementioned frontal boundary will be across the forecast area early Wednesday and is expected to drift south slowly to near the Ohio River through Wednesday night. Scattered convection will develop and reach peak coverage during the afternoon and early evening aided by the front and the potential for abundant instability as MLCAPE values rise to around 3000 j/kg. Shear and forcing aloft remain minimal at best which should limit broader coverage while also keeping storms pulsing in a largely subsevere and disorganized state. PWAT values peaking at near 2 inches lend further weight to locally heavy rainfall as the primary threat with gusty winds as a secondary risk within any collapsing storm cell. Convection will diminish Wednesday night as the front shifts south and weak high pressure and subsidence build in. A subtle wave aloft will track through the region on Thursday but with limited moisture and the mid level subsidence...expect only isolated showers and storms during the afternoon focused mainly across eastern counties. Temperatures will cool slightly from the early week heat with highs both days in the mid to upper 80s. Humidity levels will also fall back most noticeably on Thursday as drier air advecting south may enable dewpoints to fall into the low to mid 60s over northern portions of the forecast area. Friday through Monday The slightly cooler air for midweek will be short lived as the expansion of upper ridging will bring multiple days of heat and humidity that could rival the late July heat wave in terms of temps and heat indices. Highs will rise into the lower and mid 90s by the weekend with dewpoints recovering into the 70s. There is growing confidence that peak heat indices in the afternoons Saturday through Monday will rise into the low 100s over parts of the forecast area. The return of upper level ridging and warmer air aloft will trend towards a lower convective risk through the period with coverage likely to be isolated at best and limited to peak heating hours of the afternoon and early evening. Extended model guidance does try to bring a wave aloft southeast from the upper Midwest...forcing a retrograde of the upper ridge by the middle of next week. But as mentioned above...the arrival of Erin into the western basin of the Atlantic Ocean is a wildcard that could trend more to a blocky upper level regime resulting in little change in airmass through much of next week. && .AVIATION (12Z TAF Issuance)... Issued at 648 AM EDT Tue Aug 12 2025 Impacts: - Patchy fog possible through daybreak, mainly at KBMG - Chance for convection after 18Z at all sites, possibly lingering into the evening for a few sites - Fog likely at the outlying TAF sites tonight with MVFR or worse visibilities, uncertainty in fog potential near IND Discussion: Patchy fog near BMG will continue over the next hour or two before dissipating. Diurnal convection is expected to develop after 18Z today, but odds are only enough to prompt a PROB30. Additional convection is possible this evening into the overnight, primarily near LAF/HUF as a front approaches. Confidence in precipitation near IND/BMG is lower so only included a -SHRA mention for HUF/LAF from 01-06Z tonight. Expect predominately southerly winds during the period before turning more westerly tonight into Wednesday with speeds around or less than 10kts. Low-level moisture and winds becoming light again tonight will likely promote fog development, primarily at the outlying TAF sites. Confidence in fog potential at IND is too low for an explicit mention. && .IND WATCHES/WARNINGS/ADVISORIES... None. && SHORT TERM...Melo LONG TERM...Ryan AVIATION...Melo
Hazardous Weather Outlook National Weather Service Indianapolis IN 326 AM EDT Tue Aug 12 2025 INZ021-028>031-035>049-051>057-060>065-067>072-130730- Carroll-Warren-Tippecanoe-Clinton-Howard-Fountain-Montgomery-Boone- Tipton-Hamilton-Madison-Delaware-Randolph-Vermillion-Parke-Putnam- Hendricks-Marion-Hancock-Henry-Vigo-Clay-Owen-Morgan-Johnson-Shelby- Rush-Sullivan-Greene-Monroe-Brown-Bartholomew-Decatur-Knox-Daviess- Martin-Lawrence-Jackson-Jennings- 326 AM EDT Tue Aug 12 2025 This hazardous weather outlook is for central Indiana. .DAY ONE...Today and Tonight. Scattered thunderstorms are possible this afternoon through tonight. Locally heavy rainfall and cloud to ground lightning are the primary threats but gusty winds are also possible. An isolated damaging wind gust cannot be ruled out. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Scattered thunderstorm are possible on Wednesday with an isolated storm threat persisting into Thursday. Isolated storm chances return late weekend into next week. Locally heavy rain and cloud to ground lightning will remain the primary threats. Hot and humid conditions return by this weekend with peak heat indices during the afternoon in the upper 90s to around 100 degrees. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated. && More information, along with other weather, hydrological and climate information can be found at http://weather.gov/ind
The Indianapolis radar (KIND), 19 km away, was scanning. The volume nearest the first event began at 17:44 UTC.
2 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds downed trees and powerlines at Mooresville Acres.
Measured thunderstorm winds at KHUF Terre Haute Regional Airport reached 58 mph at both 1724 and 1726 EST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Indiana in 2025Every state in 2025This day in weather historyWarnings in Indiana, August 2025
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1290001, 1290002.