textproduct: Indianapolis

KEY MESSAGES

- Isolated to scattered showers possible today, primarily across southwest central Indiana

- Hot and humid conditions return Sunday and Monday with highs reaching the 90s

- Storm complexes possible Sunday night and Monday nights

FORECAST UPDATE

Issued at 951 AM EDT Sat Jul 25 2026

Low cloud cover is overspreading the area this morning ahead of a warm front that will gradually push through the region. Some light showers or sprinkles will occur in a few areas today, with chances highest through early afternoon. Only minor adjustments required to PoPs, along with tweaks to max temp per latest high resolution guidance.

DISCUSSION (Today through Friday)

Issued at 254 AM EDT Sat Jul 25 2026

Today through tonight...

A mid-upper level shortwave moving through the region today will promote increasing clouds. Modest forcing from the disturbance combined with deeper moisture advecting into the area supports the potential for scattered showers. The greatest coverage should be across southwestern counties where the strongest forcing and deeper moisture overlap. There remains some uncertainty regarding precipitation chances further north and east due to lingering dry air in the lower levels, but isolated showers cannot be ruled out. Look for temperatures to remain cooler than normal due to extensive cloud cover and showers. Highs will generally be near the upper 70s to near 80F. Highs may be slightly cooler than currently forecasted depending on cloud cover.

Chances for showers taper off late today into the evening hours once the aforementioned wave shifts east. Lingering low-level moisture and light winds may promote fog development tonight.

Sunday through next week...

Model guidance depicts an amplified upper ridge centered near the Rockies with northwesterly flow across the Great Lakes Region during the latter half of the period. This should allow for shortwaves to pass through the region late this weekend into next week. These disturbances along with deeper moisture advecting into central Indiana will return chances for convection to the forecast at times. Weak surface high pressure and an EML advecting towards the region within southwesterly should keep weather conditions mostly quiet through much of the day Sunday.

By Sunday night into Monday, most guidance suggest storm clusters or MCSs begin to develop within a very unstable environment across the Great Lakes Region and propagating south or southeastward into the Ohio Valley. Monday night currently looks to have the better chance for impacts across central Indiana based on the current axis of the ridge, but that looks to generally be more focused towards northeast Indiana. That being said, there may be a southwestward trend in where the storm complexes may impact as the global models often pin the initiation point too far north and don't track the progression along the theta-e gradient as well as some of the higher resolution models.

Diverging model solutions leads to lower confidence regarding exact details during this period, but strong instability and enhancement of mid-upper level flow from the passing shortwaves could support the threat for severe weather. High DCAPE values aided by steep lapse rates and the expected linear storm mode favors primarily a damaging wind gust threat. PWAT values around 2.00 inches along with warm rain processes may also result in localized flooding.

Warm air advection ahead of the aforementioned disturbances should warm temperatures well into the 80s to lower 90s Sunday through Tuesday. Dewpoints returning to the low-mid 70s will likely lead to peak heat indices around 100 to 105 degrees on Monday. Some uncertainty remains though as convection or convective cloud debris could limit diurnal heating.

Following the cold frontal passage early Tuesday, drier continental air will briefly build into the Great Lakes, pushing the primary thunderstorm boundary south toward the Ohio River. High temperatures on Tuesday and Wednesday will hover in the upper 80s with reduced dewpoints. However, global ensembles agree on sub-tropical ridge amplification over the Ohio Valley by Thursday and Friday. 500 MB heights rising above 590dm, combined with strong solar insolation and evapotranspiration, will drive maximum temperatures into the mid- 90s with heat index values approaching triple digits by the end of the period.

AVIATION (18Z TAF Issuance)

Issued at 118 PM EDT Sat Jul 25 2026

Impacts:

- Widespread MVFR or worse conditions expected much of the period, particularly late tonight at the outlying sites, when LIFR conditions appear likely

Discussion:

Widespread MVFR or worse conditions are expected much of this TAF period, and are currently present just west of IND, impacting the other 3 TAF sites as a warm front slowly pushes into the area.

Some TEMPO IFR is likely early in the period at HUF/BMG. A brief period of MVFR is possible this evening before fog and low clouds redevelop and worsen, with LIFR appearing likely at all but IND, which may remain low end MVFR, though will carry a BCFG mention here as well.

Winds are generally out of the south to southwest at 5-6KT this afternoon. Winds will likely be calm at the outlying sites, remaining light and variable at IND overnight. Poor flying conditions will improve somewhat late in the period but may remain restricted into Sunday afternoon.

IND WATCHES/WARNINGS/ADVISORIES

None.