Lafayette, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

118
FXUS63 KIND 161909
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
309 PM 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

&&

.MESOSCALE UPDATE...
Issued at 309 PM EDT Sat May 16 2026

Currently there is a weakening band of elevated convection that is
traversing W-Central portions of Indiana as it encounters a more
stable air over E-Central section of the state (MUCINH 100-200 J/KG)
has moved. Temperatures have been stabilized greatly across the I-70
corridor, with readings still sub 70 F. Meanwhile, north and south
of this region, highs have warmed into the upper 70s to near 80 F.
Combined with dewpts in the 65-68F range, surface based instability
has risen to 2000 J/KG in northern portions to between 2500-3000
J/KG in southern portions of central IN.

Another in a series of MCVs over W Central IL will continue to
progress eastward. Surface analysis shows that an earlier outflow
boundary over far southern IN has begin to shift northward extending
from a meso-low near St. Louis eastward into far southern sections
of central IN. TS activity over central IL will continue to
intensify in the region of this meso-low and outflow boundary while
gradually shifting into SW portions of central IN through 2200Z.
Damaging winds and isolated large hail will be possible, however
effective shear values remain marginal from 30-35 kts. In addition
to an expected increasing severe weather threat an additional threat
for heavy rain/flooding may develop, especially in areas that saw
heavier rainfall earlier today.

&&

.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 (18Z TAF Issuance)...
Issued at 143 PM EDT Sat May 16 2026

Impacts:

- SHRA and -TSRA this afternoon, highest confidence through 22Z.

- Sporadic 18-22kt wind gusts at times today and again Sunday
  afternoon

- Low end MVFR ceilings with possible TSRA early Sunday morning.

Discussion:

Broken line of TS will continue to move E-SE across portions of
central Indiana through the afternoon...before an expected weakening
and ending during the evening. TS have been removed from KLAF as the
main boundary focus has shifted south. Elsewhere have a TEMPO or
PROB30 of -TSRA in the forecast through the 20-22Z period. Outside
of TS, gusty SW winds around 20 kts will continue until early
evening.

Overnight, a warm front will slowly lift northward. Moist ground and
some clearing skies will lead to a reduction in VIS to MVFR as well
as lowering ceilings into MVFR. Some guidance suggest possible
patchy fog, but confidence not high enough to lower into IFR
category. Associated with the warm frontal passage, there will be a
chance of scattered TS. Have introduced a PROB30 for early Sunday
morning earliest south, (7-12Z) to account for this potential.

As the warm front lifts northward, skies will clear with gust winds
out of the S-SW (180-190 deg) by late morning through the remainder
of the forecast.


&&

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

$$

MESOSCALE...Crosbie
AVIATION...Crosbie
DISCUSSION...White