637
FXUS63 KIND 160516
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
116 AM EDT Sat May 16 2026

.KEY MESSAGES...

- Multiple rounds of storms today with a few strong to severe
  storms possible

- Storm chances return Monday along with much warmer than normal
  temperatures

- A frontal passage Tuesday into Wednesday will bring additional
  chances for strong to severe storms along with cooler weather afterwards

&&

.DISCUSSION (Today through Friday)...
Issued at 115 AM EDT Sat May 16 2026

Overview.

Central Indiana is entering an  active and transitional weather
pattern characterized by substantial increases in both temperature
and moisture. The primary takeaway for the coming days is the return
of frequent precipitation chances along with an early-season surge
of heat. Multiple atmospheric disturbances will track across the
region, bringing periodic rounds of showers and thunderstorms. While
some intervals of dry weather are expected, particularly on Sunday,
the overarching pattern through much of next week will favor
localized heavy rainfall and occasional threats for strong to severe
thunderstorms.

Today through Sunday.

Forecasting confidence for the weekend is heavily dependent on
typical springtime variations in convective cloud debris, though
high-resolution convective-allowing models are beginning to find
consensus on the overall setup. An upper-level atmospheric
disturbance is scheduled to arrive from the southwest early this
morning, while a decaying complex of thunderstorms tracks in from
the northwest.

Best guesses on storm timing suggest the initial round of morning
showers and cloud cover will exit by midday, leaving a window for
afternoon destabilization. If skies clear rapidly, CAPE will surge
toward one thousand joules per kilogram. Paired with roughly 30 kts
of vertical wind shear, this environment will be sufficient to
trigger scattered strong to potentially severe thunderstorms.
Furthermore, atmospheric moisture profiles exhibit PW values over
1.5 inches, meaning any sustained storm will be capable of producing
torrential rainfall rates.

By Sunday, the main surface warm front will lift northward toward
the Great Lakes, placing the region firmly within a humid warm
sector. Latest high-resolution guidance indicates a much lower
coverage of storms on Sunday as the primary atmospheric dynamics
shift north and a more stout cap limits storm coverage. The forecast
will maintain a lower probability of precipitation, but any isolated
afternoon storms that manage to breach the atmospheric capping
inversion could pose a localized wind threat due to steep low-level
lapse rates and efficient diurnal heating.

Monday through Friday.

A robust signal exists within global ensemble prediction systems for
an unseasonably hot and potentially volatile period early next week.
An amplified upper-level ridge of high pressure will anchor itself
near the East Coast, establishing deep southwesterly flow across the
Ohio Valley. This configuration will transport a tropical airmass
northward, driving surface dew points into the upper 60s. Ensemble
means are in strong agreement that high temperatures will climb into
the middle to upper 80s on Monday and Tuesday, which is nearly
fifteen degrees above historical averages for mid-May.

The main threat for impactful and hazardous weather centers around
the Monday night through Tuesday timeframe. Ensemble clusters show a
potent upper-level trough digging into the central Plains, which
will drive a strong cold front toward Indiana. Ahead of this
boundary, a powerful LLJ will maximize wind shear and moisture
convergence. This  combination of high instability and strong
dynamics raises the potential for an organized severe weather event,
with damaging straight-line winds and large hail acting as the
primary threats.

A high degree of ensemble spread remains regarding how quickly the
cold front departs, with some solutions stalling the boundary into
Wednesday. However, there is decent consensus that a much cooler,
stable, and more seasonable airmass will filter into the region
behind the front, ensuring a quiet and dry conditions towards the
weekend.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 115 AM EDT Sat May 16 2026

Impacts:

- SHRA and TSRA today, highest confidence from 14Z to 20Z

- Sporadic 18-22kt wind gusts at times today

Discussion:

VFR conditions expected outside of reduced vsbys/cigs during
convection today. Confidence is highest in the 14Z to 20Z timeframe,
but period storms are likely to continue into the evening. MVFR to
briefly IFR vsbys expected in the strongest storms of the day along
with MVFR cigs. Outside of storms, cigs should be closer to 040.
Southerly winds will occasionally gust upwards of 22kts during the
afternoon and evening with gusts ending after 01Z.

&&

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

$$

AVIATION...White
DISCUSSION...White