260
FXUS63 KIND 090706
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
306 AM EDT Tue Jun 9 2026

.KEY MESSAGES...

- Scattered showers/t-storms today and again tonight. Isolated
  flooding possible

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

- Slightly cooler weather for the weekend with lower rain chances

&&

.DISCUSSION (Today through Monday)...
Issued at 304 AM EDT Tue Jun 9 2026

Anomalous upper-level ridging persists over the northeastern US and
eastern Canada. Troughing dominates over the northern Rockies. The
jet stream wraps around the base of the trough and into the northern
Plains, extending northward into Canada north of the Great Lakes. As
such, an active storm track has been observed over the northern
Plains with multiple days of severe weather. Here in Indiana, a
subtle vort max displaced from the progressive jet has been
meandering nearby for a few days now. Combined with rich moisture
moving northward from the Gulf, this feature has allowed for
scattered showers and thunderstorms. The lack of strong flow aloft
has limited severe potential, but heavy rainfall and occasional
flooding have been a persistent threat. With the vort max expected
to remain in the vicinity for another day, additional showers and
thunderstorms are expected today. Coverage will again be isolated to
scattered, with locally heavy rainfall rates.

Guidance is in good agreement showing the vort max exiting the
region tonight. Southwesterly flow develops as the western troughing
edges eastward a bit. Subtle height falls associated with nearby
troughing should lead to steepening lapse rates tonight. Though
forcing from the vort max is gone, there may be enough isentropic
upglide to promote thunderstorm development overnight into early
Wednesday. Convection may be deeper given steeper mid-level lapse
rates. Some uncertainty remains regarding the development of a low-
level jet tonight. Some CAM guidance shows a slight increase in the
925 to 850 mb mean flow but overall the signal is weak. Should a low-
level jet develop, convection that initiates via warm advective
processes may begin back-building on the ensuing cold pool. Corfidi
upshear vectors are under 10kt, which may lead to flooding potential.

A Flood Watch was considered but we will hold off for now, since
much of the convective activity over the next 24 to 48 hours looks
to be widely scattered. Additionally, the probability of a back-
building MCS tonight into early Wednesday is low, owing to the
relatively subtle forcing. Trends will need to be closely monitored,
however.

The renewed warm advection is expected to bring hot weather over the
next few days, with highs near 90 possible Wednesday and Thursday.
Dew points in the 70s could lead to heat indices near 100 at times.
Heat stress risk (HeatRisk) climbs into moderate to major territory
both days, since overnight lows in the 70s will offer little day to
day relief.

Thunderstorm potential returns Thursday into Thursday night, due to
a cold front arriving from the northwest. Timing of the front may
work in our favor, since most guidance show a 03z-09z arrival. By
that point, much of the daytime instability will be lost.
Additionally, the parent trough is low amplitude and the best
forcing may pass well to our north. Wind shear decreases quickly
with southward extent as well. The most likely scenario, as of right
now, would be any upstream convection that consolidates into an MCS
would likely become outflow dominant as it moves southeastward.
Guidance is a bit mixed on whether convective activity reaches
central Indiana at all...but regardless, any activity that makes it
will probably be in a weakening state as it moves through.

Once the cold front moves through early Friday a cooler air mass
will settle in. Upper-level troughing, slowly moving east through
the week, reaches the Great Lakes region simultaneously. Ensemble
guidance is in decent agreement showing persistent troughing through
the weekend and into early next week. A cooling trend appears likely
with temperatures trending back towards normal (highs near 80, lows
near 60).

&&

.AVIATION (06Z TAF Issuance)...
Issued at 147 AM EDT Tue Jun 9 2026

Impacts:

- MVFR cigs after 13Z
- Occasional -SHRA and isolated TSRA, mainly between 08Z and 13Z
- -SHRA/TSRA possible again this evening near BMG

Discussion:

Isolated showers and thunderstorms are possible this morning as low
pressure passes to the north of Indiana. Coverage and timing will be
tricky to narrow down, as shower/storm activity is widely scattered
and should remain so through the morning hours. The most probable
time frame is between 08z and 13z. After that, there may be a bit of
a break in activity but a stray shower/storm cannot be ruled out at
any point today. Shower/storm chances increase again this evening,
especially near BMG.

Ceilings have remained in VFR territory for the most part outside
shower activity. Guidance remains pessimistic, but upstream
observations show mainly VFR conditions through Illinois. Will delay
the onset of MVFR conditions in the TAFs until after 13z or so,
given observational trends. MVFR conditions are still expected as
shower activity increases this morning.

Winds should remain out of the south/southwest, peaking during the
afternoon hours and diminishing after 00z this evening.


&&

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

$$

AVIATION...Eckhoff
DISCUSSION...Eckhoff