534
FXUS63 KIND 091832
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
232 PM EDT Mon Mar 9 2026

.KEY MESSAGES...

- Widespread minor/moderate river flooding continues south of I-70

- Locally heavy rainfall is expected late Tuesday into Wednesday,
  which will exacerbate or prolong ongoing flooding

- Scattered severe storms with all hazards are possible Tuesday
  night and Wednesday

- Well above normal temperatures expected through Wednesday

- Cooler temperatures for late this week

&&

.SHORT TERM (This evening through Tuesday)...
Issued at 232 PM EDT Mon Mar 9 2026

The short term will be heavily influenced by the emergence of a deep
trough, currently situated over the SW CONUS. For today, a shortwave
on the downwind portion of the trough will move across the Ozarks.
Here is central Indiana, strong S/SSW winds ahead of this wave have
pushed much warmer air into the area, with temperatures nearing or
exceeding 70 across the state. There is a corridor of low stratus
pushing in along a low level moisture axis ahead of the wave. This
has now reaching SW Indiana, and is slowly creeping into central
portions of the state. That said, the near surface column has
started to destabilize this afternoon, with this stratus layer
showing increasing signs of mixing as it progresses to the NE. For
now, the expectation is for broken sky cover to reach the I-74
corridor, and points to the the N/W of Indianapolis by the late
afternoon.

Next, this deep wave will continue its push eastward, with a split
jet streak forming across the mid and upper Mississippi Valleys
tonight and tomorrow. Within this split jet stream, a modest surface
low is expected to develop, with confluence zones creating a
instability gradient over central Illinois tomorrow afternoon. This
will be the main focus for initiation during the afternoon tomorrow,
as the remainder of the warm sector is likely to be too capped and
cloudy for broad synoptic rising motion to be sufficient for
initiation.

As far as the parameter spacing near this W/E boundary, there is a
corridor of steep mid level lapse rates, but we will likely need to
see some clearing and low level warming to get strong near surface
lapse rates to occur. That said, low level moisture will be plenty,
and once convective inhibition is overcome, there will likely be
multiple cells that develop along this boundary. All severe weather
threats will be possible, with hail as the main threat initially.
That said, as these cells push east, right-turners will likely have
sufficient enough streamwise vorticity for tornadic development.
The largest area of uncertainty is on placement, with the boundary
varying by 50-100 miles as of the 12z suite, but with a general
southward trend. The further south this boundary is, the greater
threat for severe weather for central Indiana. Given that these
supercells are likely to follow a similar track, there will be a
flash flood threat over portions of central Illinois and Indiana
depending on where the boundary is positioned.

Overnight, greater upstream initiation post 00Z will likely grow
upscale into central Indiana overnight with a marginal threat of
severe wind gusts. PWATs within the moisture axis Tuesday night will
also be abnormally high, with pockets of heavy rain likely.
Currently the expectation is generally 1-2" across central Indiana,
but there will likely be pockets of higher and lower totals
depending on mesoscale influences. The greatest flooding concern
Tuesday night is across southern portions of the area where FFG is
will be low due to heavy rains last week, and already elevated river
levels.

&&

.LONG TERM (Tuesday night through Monday)...
Issued at 232 PM EDT Mon Mar 9 2026

Rain/Convection will be ongoing at the start of Wednesday. Some
strong to potentially severe convection is possible. Advection will
try to overcome the diurnal trend to lower instability during the
morning, but there is also the possibility that a cold pool could
get far enough ahead of the convection to weaken it.

Rain and some convection will continue ahead of the cold front as it
moves across the area into the afternoon. If some instability is
able to build during the day ahead of convection, strong to severe
storms may return in the afternoon across the southeastern forecast
area.

High moisture content in the atmosphere will lead to the threat of
locally heavy rain and flooding Wednesday.

Temperatures will fall quickly on Wednesday behind the cold front as
it passes, with readings potentially falling 20 degrees in 3 hours.

A couple of low pressure systems will impact the area during the
remainder of the long term period. One will bring low PoPs to the
northern forecast area on Thursday night. A stronger system will
bring better rain chances around Sunday.

Below normal temperatures will return briefly on Thursday behind the
first system, then readings will become above normal again into the
weekend. Highs in the 60s are expected most areas by Sunday. Monday,
behind the low pressure system, well below normal temperatures will
return with highs only in the 30s.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 101 PM EDT Mon Mar 9 2026

Impacts:

- Gusts to 20-25kt this afternoon
- MVFR ceilings overspreading the sites this afternoon
- IFR possible at times tonight

Discussion:

Area of lower clouds will continue to push north and northeast this
afternoon, bringing MVFR ceilings to most sites. There are holes
developing behind the leading edge, so confidence is not as high as
desired in the ceiling forecast for KIND/KBMG.

Ceilings will fill in/lower overnight as moisture is trapped under
an inversion. Some break up in the ceilings is possible Tuesday
afternoon. Patchy drizzle is possible overnight.


&&

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

$$

SHORT TERM...Updike
LONG TERM...50/Updike
AVIATION...50