textproduct: Indianapolis

KEY MESSAGES

- Pleasant again today amid increasing winds...gusts to 20-30 mph this afternoon

- Chances of showers/t-storms north late today/tonight...more widespread showers possible late Saturday-Saturday night

- Very warm and humid starting Sunday, periods of showers/t-storms

FORECAST UPDATE

Issued at 1014 AM EDT Fri Jun 5 2026

The forecast remains quite similar for today with unstable air mostly holding off to the west until late tonight. Still there is some uncertainty on PoPs and temperatures over NW central Indiana as debris from upstream convection creates additional cloud cover and limits the overall CAP. For now, the expectation is for a majority of the deep cloud cover to stay west, but the margin for error will be small and could bleed over into the Lafayette region. If this does occur, afternoon highs are likely to be in the upper 70s vs the mid 80s as currently forecasted.

DISCUSSION (Today through Thursday)

Issued at 335 AM EDT Fri Jun 5 2026

Transition from recent pleasant early-summer conditions to prolonged more-humid, and at times unsettled mid-summer pattern...to occur today and Saturday. Increasing, quasi-stacked southwesterly flow today to boost precipitable water aloft and surface dewpoints...although better forcing sliding by to the northwest of the region should only allow a few showers/stray rumble of thunder along the Upper Wabash Valley through early evening.

Several opportunities for showers and generally non-severe t-storms will follow tonight through Saturday night as small ripples of forcing slide west to east amid an overall zonal pattern...with cross product of these ingredients most likely north of I-70. Cannot rule out a couple marginally strong/severe gusts late tonight north/ west of Crawfordsville...although best chances for any organized or stronger convection will be Saturday night, especially along an axis north of the I-74 corridor, when marginally strong/severe gusts and perhaps isolated large hail are on the table.

Upper pattern to then rearrange into another H500 subtropical ridge, this time with the quasi-stationary axis aligned from the Great Lakes into eastern Canada...which will favor deep Gulf moisture into Indiana through much of the remaining period. High humidity can be expected, will dewpoints trending from upper 60s by Sunday morning, into at least the low 70s by Tuesday. Scattered to at times numerous showers and at least a few embedded t-storms can be expected through at least Wednesday. One low-confidence variable will be short wave/ vort max spinning northeastward through the western Midwest early next week which could enhance convection and present a greater potential for strong/severe cells...and possibly less-active conditions in its wake.

Potential for isolated flash flooding will trend upward through the early week for any areas receiving multiple rounds of heavier rains. Temperatures to range from lows near 70F to highs in the 80s under often considerable cloudiness. Potential for first-90s by the late week should the upper ridge build over the central US and allow ample sunshine back into Indiana. Indianapolis' highest reading so far this year was 88F on March 22.

AVIATION (18Z TAF Issuance)

Issued at 147 PM EDT Fri Jun 5 2026

Impacts:

- Isolated showers and storms tonight, mainly near LAF - Greater chance of showers/storms Saturday morning, MVFR or worse conditions possible. - MVFR ceilings possible at times Saturday

Discussion:

Southerly flow has increased ahead of surface low pressure passing across the Great Lakes. Winds have been between 10-20kt at times this afternoon, with occasional gusts to 25kt. Winds are expected to decrease after sunset as the boundary layer stabilizes while maintaining a southerly component.

The southerly flow will bring moisture northward, interacting with a cold front extending from the surface low southwestward into Indiana and Illinois. Scattered showers and thunderstorms are expected, with relatively low coverage through tonight and greater coverage Saturday morning. Several PROB30 groups have been included to highlight the timeframe with the greatest probability of seeing a shower or storm. MVFR or worse conditions are possible within showers/storms.

Sky cover is a bit tricky, and will depend on shower/storm coverage. Most of the time, however, VFR ceilings between 4000-10000 feet will prevail. A gradual trend toward MVFR ceilings is possible on Saturday as low-level moisture increases.

IND WATCHES/WARNINGS/ADVISORIES

None.