River Flood Warning 84, NWS Indianapolis, IN

Area Forecast Discussion
National Weather Service Indianapolis IN
950 AM EDT Tue May 19 2026

.KEY MESSAGES...

- Severe storms and locally heavy rain possible again this afternoon
  and evening, with damaging winds and localized flooding the
  primary concerns

- Cooler mid week with a brief break from rain chances, before
  showers and storms return to the forecast late week into the
  holiday weekend

&&

.FORECAST UPDATE...
Issued at 950 AM EDT Tue May 19 2026

Satellite imagery shows clearing across central Indiana with signs
of a remnant outflow boundary from upstream convection last night.
Thicker overcast skies are found to the west of this outflow
boundary, slowly moving eastward this morning. There should be a
couple of hours of efficient solar insolation this morning before
these clouds arrive. High-resolution guidance that shows the
clearing well also depicts rapid destabilization (to between 1500-
2500 J/Kg MLCAPE) through this period. As such, renewed convective
activity appears likely again this afternoon.

In terms of hazards, RAP soundings indicate that some mid-level dry
air may be present today. Shear is modest, under 25 knots on
average. However, steep lapse rates and DCAPE values around 1000
J/Kg could lead to downbursts and efficient cold pool production. The
25 knots of shear may also be enough to allow for loose organization
into multicell clusters. Therefore, strong to damaging wind gusts
are possible with storms today.

The wind threat diminishes after sunset as the column moistens and
lapse rates weaken slightly. RAP soundings show the atmosphere
becoming more efficient for rainfall production overnight (deep warm
cloud layer, saturation to the EL, and moist adiabatic lapse rates).
A cold front sagging south across Indiana will interact with an MCV
approaching from the southwest, prolonging large-scale lift tonight.
Most guidance is on board with showers and thunderstorms continuing
on and off through the night. There is a signal for heavy rain
within most guidance with pockets of 1 to 3 inches across the
southern half of our area. QPF coverage in guidance isn't as
widespread as yesterday, but these pockets tend to line up where the
heaviest rain fell. Additional flooding may be possible tonight and
trends will need to be monitored closely.

&&

.DISCUSSION (Today through Monday)...
Issued at 342 AM EDT Tue May 19 2026

Today and Tonight -

Quiet but mostly cloudy conditions are expected early this morning.
The rapidly weakening northern extent of a line of showers currently
over western Illinois will move into the area this morning and may
produce some light rain in spots, though somewhat more substantial
rain and thunderstorm chances will wait until later in the day when
the cold front approaches the region.

Ample instability and modest deep layer shear will exist to promote
organization of developing convection this afternoon, and at least a
localized severe threat, primarily driven by wind, will exist. This
threat will persist into the evening hours when the front pushes
through.

Hydrologic concerns, particularly given precipitable water values
near the top end of climatology and widespread significant rainfall
yesterday of 1.5 to 3+ inches, will be at least an equal concern to
the severe threat, with flash flood guidance values as low as three
quarters of an inch in one hour across central Indiana. HREF
probability matched means indicate at least a low chance of reaching
these amounts in a few areas through tonight, though perhaps not
quite enough for another flood watch.

Wednesday through Monday -

Once the front has pushed south of the area, it will stall out a
bit, though high pressure passing through the Great Lakes in its
wake will keep it suppressed to the south and allow for both a brief
cooldown and a break in precip chances from late Wednesday into
Thursday evening.

Rain chances return late week into early next week as a large upper
level low swings through the northern tier of the country and pulls
a warmer and moist airmass back into the area, though chances with
the exception of Friday will be low for the time being given
significant model inconsistencies and resulting uncertainty.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 653 AM EDT Tue May 19 2026

Impacts:

- Wind gusts Tuesday 20-27KT

- Showers and thunderstorms possible late this afternoon into this
  evening

Discussion:

A few showers or isolated storms are present over north central
Indiana this morning, which will necessitate some VCSH early in the
period.

Winds will strengthen as mixing ramps up Tuesday morning, with gusts
of 20-27KT likely through the day, generally from 210-230 degrees.

Showers and thunderstorms will be possible late in the day as a cold
front approaches and passes through the area. Winds with frontal
passage will veer to westerly and northwesterly late in the period,
with gusts ending in typical diurnal fashion this evening.

Ceilings post frontal will likely drop into MVFR, though some IFR
cannot be entirely ruled out. Later packages will refine this.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

UPDATE...Eckhoff
AVIATION...Nield
DISCUSSION...Nield

Hazardous Weather Outlook
National Weather Service Indianapolis IN
352 AM EDT Tue May 19 2026

INZ021-028>031-035>049-051>057-060>065-067>072-200800-
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-
352 AM EDT Tue May 19 2026

This hazardous weather outlook is for central Indiana.

.DAY ONE...Today and Tonight.

Thunderstorms are likely this afternoon into this evening. Severe
storms will be possible, with damaging winds the primary threat.
Storms will also be capable of producing heavy rainfall and localized
flooding.

The most likely time frame for severe weather and flooding will be
between 4 PM and 11 PM.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Additional chances for thunderstorms return Friday into the holiday
weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed from approximately 4 PM to 11 PM
this afternoon and evening.

&&

More information, along with other weather, hydrological and climate
information can be found at http://weather.gov/ind

Preliminary Local Storm Report
National Weather Service Indianapolis IN
1029 AM EDT Tue May 19 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0247 PM     Tstm Wnd Dmg     1 NE Carmel             39.98N 86.10W
05/18/2026                   Hamilton           IN   Public

            Delayed report. Power lines down. Report
            from social media.

&&