472
FXUS63 KIND 072207
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
607 PM EDT Sun Jun 7 2026

.KEY MESSAGES...

- Scattered showers/t-storms this evening and especially Monday,
  with greater coverage in afternoon...isolated flooding possible

- Humid and very warm this week...daily rain chances continue
  through Friday...readings near 90F on Thursday

- Slightly cooler weather for the weekend with lower rain chances

&&

.MESOSCALE UPDATE...
Issued at 607 PM EDT Sun Jun 7 2026

Surface and radar analysis shows a composite outflow boundary
extending roughly along the I-74 corridor from southern Rush county
all the way back into Warren and Fountain counties. ACARs sounding
from KIND show around 1.9 inches of PWAT. Multiple storm scale
boundary interactions, diabatic processes and meso-beta scale low
pressure area circulations enhancing mass convergence will continue
to support a heavy rain/flooding threat. Recent CREST streamflow
data suggests that localized areas of flash flooding may develop in
the 1-2 hrs across E-NE portions of the Indy Metro area, namely
NE Marion County, SE Hamilton County, most of Hancock County and
southern Madison County.

Additional attention is also being focused along the outflow
boundary in Warren, Fountain and Tippecanoe counties. These areas
received between 4 and 7 inches of rain and any additional
significant rainfall from developing convection may support a
quick transition to flash flooding. This area remains in WPC`s Day
1 slight risk for flash flooding.

In addition to the flash flooding threat, sufficient strong low
level vorticity and 0-3 KM CAPE from 125-150 J/KG over northeastern
portions of central Indiana favor some potential for brief
landspout/non-supercell tornado through 9 PM.

Expectation is with loss of daytime heating, convection will quickly
diminish. However localized areas of longevity may continue until 02-
03Z (10-11 PM) if diabatic processes can overcome the decreasing
larger scale instability diminishment.

&&

.DISCUSSION (This evening through Sunday)...
Issued at 428 PM EDT Sun Jun 7 2026

Surface analysis this afternoon shows a frontal boundary across
northern Central Indiana, stretching into Central Ohio. This
boundary was caught between high pressure over the Great Lakes and
another high over the southeastern states. Warm and humid southerly
flow was in place across the majority of Central Indiana. Dew point
temperatures were in the upper 60s to lower 70s. Aloft, an upper
trough was found over the Central Plains states, slowly pushing
northeast. Water vapor shows a plume of tropical moisture ahead of
the trough flowing into the Mississippi and Ohio River valleys,
providing deeper moisture within the column. Radar shows some shower
development associated with upper moisture developing across
Indiana. GOES19 shows CU development across Central Indiana.

HRRR this afternoon continues to suggest light shower development
through the afternoon, associated with the NW-SE upper level moisture
band surging northward. SPC mesoanalysis suggests CAPE over 2000
J/KG in place across our forecast area. THus continue sct rain
shower development will continue to be expected, particularly along
and north of I-74.

As heating is lost this evening, showers are expected to diminish,
leading to a mostly cloudy night. GOES19 shows plentiful cloud cover
ahead of the trough pushing northward into Central Indiana within
the tropical plume. This is expected to be with us overnight. Dew
points near 70 will only allow lows to fall to around 70 overnight,
resulting in a warm and humid night.

Monday and Monday Night...

The upper trough axis to the west is expected to approach Indiana
tonight and arrive over Indiana on Monday. Ample forcing within the
flow aloft will help to drive precipitation, as plentiful moisture
will be win place with surface high surface dew points and a
tropical plume aloft. Forecast soundings show a saturated column by
Monday afternoon with high pwats over 1.8 inches. Heavy rain will be
possible that could result in flooding, especially in areas like
Covington and Attica which received several inches yesterday. HRRR
is also on board for the moment, spreading scattered showers and
storms across Indiana. Thus will use high pops. Clouds and rain may
hamper high temperatures as we may only reach around 80.

Rain is expected to continue to on Monday evening before diminishing
overnight. The upper trough axis is expected to push into Ohio on
Monday night. This results in the arrival of subsidence as seen
within forecast soundings as top down drying comes into play.

Tuesday...

The upper trough will still be in place over Ohio on Tuesday and
models continue to suggest some lingering lower level moisture
during the morning hours. This could lead to some very light rain
showers as through the morning, particularly across the eastern
parts of the forecast area. Much better clearing is expected to
arrive by afternoon as the trough axis exits farther east. Forecast
soundings at that time suggest a dry column on Tuesday afternoon,
but warm temperatures in the upper 80s.

Tuesday Night...

There is low confidence for precipitation on Tuesday Night at the
moment. Models are showing sufficient low and mid level saturation
overnight as a poorly defined upper wave passes, amid what should be
ridging building in the wake of the departed trough. The lower
levels appear unorganized also, just depicting warm and humid
southerly flow in place. Thus will continue to keep some mention of
pops in the forecast due to model trends, but confidence is low.

Wednesday...

More warm and humid SW flow will be in place on Wednesday with
little in the way of forcing available other than diurnal heating.
Forecast sounding suggest typical afternoon and evening instability
showers will be possible given the warm and humid air mass. Will
include pops for now. Low confidence.

Thursday and Friday.

The commencement of the long-term period on Thursday and Friday
features central Indiana deeply embedded within a progressive,
moisture-rich warm sector. Recent global deterministic runs of the
GFS and ECMWF, along with support from the GEFS and EPS ensemble
means, show a consensus that a stagnant subtropical ridge off the
Carolinas will keep the local area under a regime of steady low-
level warm air advection and moisture convergence. Boundary layer
moisture will be robust for mid-June, with surface dewpoints progged
to consistently reach into the upper 60s and lower 70s. Strong
diabatic heating operating on this high theta-e airmass will lift
afternoon maximum temperatures into the upper 80s and lower 90s on
Thursday, yielding highly unstable atmospheric profiles. Soundings
show MLCAPE values exceeding 2000 to 2500 J/kg during peak afternoon
heating. While mid-level lapse rates remain somewhat modest, the
lack of significant convective inhibition means that isolated to
scattered pulse-type thunderstorms will easily trigger along any
remnant mesoscale outflow boundaries.

A more organized severe weather and heavy rainfall threat
materializes by late Thursday into early Friday as a deeper mid-
level trough pivots out of the Upper Midwest and pushes a cold front
toward central Indiana. This synoptic feature will provide the
necessary large-scale dynamic ascent and wind shear to organize the
highly unstable environment. Forecast models indicate 0-6 km bulk
shear vectors increasing to 35 to 45 knots, shifting the convective
mode from unorganized pulse cells into a forward-propagating linear
structure or robust multi-cell clusters. Damaging straight-line
winds and isolated large hail will be the primary hazards with any
severe cores ahead of the front. Furthermore, precipitable water
values are projected to climb toward 1.75 to 2.00 inches, which sits
well above the 90th percentile for early June. These high moisture
profiles indicate extreme precipitation efficiency, and any training
convective elements ahead of the slow-moving boundary will pose a
localized flash flooding threat, particularly across areas with
saturated antecedent soils.

Saturday and Sunday.

A pattern shift then takes place late Friday night into Saturday
morning as the surface cold front clears the southern counties of
Indiana. Strong anticyclonic building will commence as a sprawling
1024 mb Canadian high pressure system drops southward across the
Great Lakes. Robust cold air advection will take hold through
Saturday morning, driven by a sharp northwesterly wind shift. Deep-
layer subsidence and dry air entrainment will rapidly clear out the
tropical moisture plume, forcing precipitable water values down to
under 0.75 inches by Saturday afternoon. There are some signs of
another system towards Sunday with the Canadian model and its
ensembles showing a mesoscale driven system, but confidence is very
low at this time, especially considering how far it lies from the
other global models.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1206 PM EDT Sun Jun 7 2026

Impacts:

- VFR this afternoon and tonight; showers possible especially near
LAF.
- MVFR Cigs expected on Monday with Rain

Discussion:

Diurnal heating amid the warm and humid air mass in place across
Central Indiana will lead to CU development this afternoon along
with scattered rain showers. A lingering boundary from near LAF to
Richmond IN will continue to be a focus for development this
afternoon and evening. Cigs this afternoon will be VFR.

As heating is lost tonight any showers should diminish, but warm air
advection and moisture arriving ahead of an upper trough will
continue to keep CIGS in place.

Upper forcing and more moisture is expected to arrive on late Monday
morning. This will lift the frontal boundary farther north but more
widespread rain showers will be expected within the warmer and moist
air mass. MVFR Cigs will be expected.


&&

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

$$

MESOSCALE...Crosbie
AVIATION...Puma
DISCUSSION...Puma