Lafayette, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

259
FXUS63 KIND 050532
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
132 AM EDT Sun Jul 5 2026

.KEY MESSAGES...

- Isolated to scattered storms again this afternoon and evening,
  severe weather is not expected

- Slow moving storms may produce pockets of flooding

- Gradual cooling trend through the week with daily chances for
  showers and storms

&&

.DISCUSSION (Today through Saturday)...
Issued at 131 AM EDT Sun Jul 5 2026

Overview.

Scattered afternoon and evening thunderstorms are expected for
Sunday and Monday amid continued warm and humid conditions, albeit
not as warm as the last few days. A stronger cold front mid-week
will bring more widespread rain chances to central Indiana, followed
by a transition to much cooler and drier weather for the latter half
of the week.

Through Daybreak.

Patchy to areas of fog will continue through the night with some
pockets of locally dense fog. The combination of residual moisture
from the afternoon and evening storms is combining with widespread
condensation nuclei from firework debris/smoke to enhance the fog
potential. This fog will generally remain non-dense at 1-3 miles,
but some fog-favored areas such as valleys may see periods of dense
fog through 8AM.

Today Through Monday.

Central Indiana will remain positioned on the northern periphery of
a suppressed sub-tropical ridge centered over the Gulf Coast states,
leaving the local area under a weak northwest flow regime aloft. The
boundary layer will remain characterized by high moisture content,
with surface dew points lingering in the low to mid 70s. Combined
with daytime ambient temperatures rising into the upper 80s to
around 90 degrees, a moderately unstable airmass will develop each
day. MLCAPE values are forecast to reach 2000 to 2500 J/kg during
peak heating.

Given the absence of strong, large-scale synoptic forcing,
convective initiation will depend heavily on mesoscale features,
such as residual outflow boundaries from previous convection and
localized differential heating zones. Consequently, convective
timing will be primarily diurnal, maximizing between 19Z and 02Z
each afternoon and evening. Kinematic support remains weak, with 0-6
km bulk shear values under 15 knots, ensuring an unorganized,
outflow-dominant pulse storm mode. Soundings indicate that while
instability is lower than previous days, precipitable water values
around 1.8 to 2.0 inches and steep low-level lapse rates will still
support localized heavy downpours and transient downbursts capable
of isolated wind damage. The primary forecast uncertainty revolves
around spatial coverage, as convective-allowing models continue to
diverge on exactly where mesoscale boundaries will focus
development. Convection should diminish rapidly each evening with
the loss of solar insolation.

Tuesday Through Saturday.

The multi-day synoptic transition will begin on Tuesday as a brief
period of shortwave ridging ahead of a developing northern stream
system keeps scattered, mainly diurnal convective chances in place.
By Wednesday, a potent, high-amplitude longwave trough is forecast
to dig out of south-central Canada and phase into the Great Lakes
region. This feature will drive a sharp surface cold front southward
across Indiana Wednesday afternoon and evening. Robust large-scale
ascent combined with strong linear low-level convergence along the
front will support a high probability of widespread showers and
thunderstorms. While deep-layer shear is modeled to increase ahead
of the trough axis, the overall severe weather potential will depend
on the precise timing of the frontal boundary and the magnitude of
pre-frontal destabilization.

In the wake of the frontal passage, an airmass exchange will occur
Thursday through Saturday. High-amplitude troughing will establish
itself over the eastern United States, while a strong Canadian high
pressure center builds southward into the Midwest. This will
lead to some cold air advection across the Ohio Valley, gradually
bringing a cooler and drier continental air mass. High
temperatures for the late-week period will drop into the lower
80s, which is slightly below seasonal averages. That trend looks
to continue into early next week with dew points dropping into the
50s and highs near 80.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 131 AM EDT Sun Jul 5 2026

Impacts:

- MVFR to briefly IFR cigs/vsbys through 13Z with low stratus/fog
- Additional storms may develop across area this afternoon

Discussion:

Light winds, cooler temperatures, and residual warm ground will
support MVFR to briefly IFR visibilities along with low MVFR/high
IFR stratus. Any areas of fog will end quickly after sunrise with
the MVFR status persisting through the early afternoon.
Destabilization will lead to potential for another round of showers
and storms Sunday afternoon with low confidence on specific timing.
Best chances will be at LAF and IND. Winds will generally be out of
the south at 2-4kts through daybreak and out of the west at 5-10kts
afterwards.

&&

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

$$

AVIATION...White
DISCUSSION...White