textproduct: Indianapolis

KEY MESSAGES

- Rain becoming widespread today with chances for thunderstorms and locally heavy rainfall through Thursday

- Much warmer late week into the weekend with near record warmth Friday

- Additional threats for rain and thunderstorms this weekend into next week will increase the risk for flooding across central Indiana

FORECAST UPDATE

Issued at 954 AM EST Tue Mar 3 2026

The forecast remains in relatively good shape, but some slight adjustment was made to temperatures and POPs. Current KIND radar imagery shows widespread rain overspreading central Indiana. This precipitation is associated with strong isentropic ascent ahead of a gradually northward lifting frontal boundary.

The boundary is expected to stall out across central Indiana keeping rain chances high through the day with extensive cloud cover. Look for limited diurnal heating today, but warm air advection will warm up temperatures into the mid 40s north to around the mid-upper 50s across the far south.

Highs were slightly decreased given limited daytime heating and precipitation continuing through the day. POPs were also slightly adjusted to match current observations. Winds will remain light and variable today as the staled boundary meanders.

SHORT TERM (Today and tonight)

Issued at 317 AM EST Tue Mar 3 2026

Rain will become widespread across the area today as a warm front lifts into the region and the combination of subtle upper level disturbances and large scale ascent from a jet stream aloft act to produce precipitation - the opening salvo in what looks to be an active week for central Indiana.

Development of some weak elevated convective instability late today into tonight suggests a threat for isolated thunderstorms this afternoon and tonight, though no severe storms are expected. Anomalous moisture will be present, with model precipitable water values near or in excess of climatological max for the time of year, so some substantial rainfall totals are likely through tonight. WPC Superensemble means through tonight are in excess of one inch, with higher end members approaching two inches, though this seems unlikely in the absence of more substantial forcing or widespread convection. Fortunately, medium to longer term dryness (though small portions of south central Indiana are at least within about 75 percent of normal over the past 90 days) will allow the area to fairly easily handle the modest rainfall rates expected. Hydrologic concerns will become more pressing with time, however, as several inches of rain will be possible over the longer term.

A substantial temperature gradient is expected today, particularly south across the warm front, and uncertainty in this area is high. Northern portions of the area will likely not get out of the 40s, with areas from Indianapolis southward ranging from around 50 to the low 60s, depending upon northward progress of the boundary.

LONG TERM (Wednesday through Monday)

Issued at 317 AM EST Tue Mar 3 2026

Repeated rounds of rainfall are expected through much of the work week as upper level waves move along a slow moving frontal zone in the region mid week, with quasizonal upper level flow gradually transitioning to deeper western troughing and eastern ridging late in the week and into the weekend. This pattern shift will force the boundary northward and allow transport of substantially anomalous warmth and moisture into the region through the end of the work week, with temperatures by late week as much as 20 to 30 degrees above normal and precipitable water values remaining near or in excess of climatological maxima.

While the primary concern will remain moderate to heavy rainfall amounts, a strong storm or two cannot be ruled out, mainly near the boundary on Wednesday, though this threat is low and primarily related to isolated large hail.

Given the significant warmth and moisture present late week, will need to monitor for a possible conditional severe threat there as well, primarily Saturday with a cold frontal passage.

Total rainfall amounts through the next week may approach 3 to 5 inches in portions of the area, and while the prolonged time frame and antecedent conditions will help to mitigate the immediate impacts, fairly widespread minor flooding looks to be a good bet along main stem rivers, and the areal flood threat will increase with time and repeated rounds of rainfall.

AVIATION (12Z TAF Issuance)

Issued at 617 AM EST Tue Mar 3 2026

Impacts:

- IFR or worse conditions throughout the period in fog and low ceilings

- Rain becoming widespread by 13-15Z across the sites

Discussion:

Widespread IFR or worse conditions remain in place at most sites, and those not currently experiencing them will do so in the next couple of hours.

Upper level disturbances moving along a warm front will produce widespread rainfall beginning just after daybreak, which will remain fairly widespread much of the period. Visibilities in rain will largely be MVFR with occasional drops to IFR in more intense showers, but widespread IFR or worse ceilings are expected to persist.

Winds will generally be east/southeasterly early, becoming more southerly and then variable with time, below 10KT.

IND WATCHES/WARNINGS/ADVISORIES

None.