Lafayette, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

483
FXUS63 KIND 031842
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
242 PM EDT Fri Jul 3 2026

.KEY MESSAGES...

- Extreme Heat Warning in effect through 8 PM, Heat Advisory
  afterwards through 9PM Saturday

- Thunderstorm chances will increase after 7PM today with downbursts
  possible

- Greater storm coverage for Saturday with a lower threat for severe
  weather; Storms may impact outdoor activities on Saturday
  afternoon and Saturday Night.

&&

.DISCUSSION (This evening through Friday)...
Issued at 241 PM EDT Fri Jul 3 2026

Surface analysis early this afternoon shows strong high pressure in
place over WVA. Low pressure was found over western KS. Aloft, water
vapor showed a strong area of high pressure over the Carolinas and
VA, and a tropical plume of moisture was streaming north across TX
and OK toward the upper midwest. Indiana was still under the
influence of of this strong high pressure system, allowing a
stagnant air mass, with very warm temperatures. Within the
convective plume, an upper level disturbance over northern Illinois
was interacting with the very hot, unstable airmass and convection
was developing. Heat Index readings across Central Indiana were
reaching the 105-110 range.

Tonight...A few stray thunderstorms will be possible this afternoon
and early evening, but this diurnal convection is expected to wane
this evening as heating is lost. The upper steering flow across the
southern Great Lakes is expected to sag southward overnight as this
past weeks/s ridge departs to the east. Although this could allow
for some overnight convection across far northwest Central Indiana,
it will mainly set the state for the more active weather expected
for the next two days. Thus after very isolated storms are gone this
evening, mainly partly cloudy skies will be expected with another
hit and humid night with dew points still remaining in the 70s.

Saturday and Saturday Night...Mainly dry and humid weather will
begin the day. However, models show the upper flow will have sagged
south across Central Indiana, and our area will no longer be
protected from forcing dynamics by ridging. Models suggest a
moderate short wave passing on Saturday Night. There will be little
change in the air mass prior to this feature arriving, allowing for
a favorable column for storms. CAPE on Saturday afternoon is
expected to reach over 2500 J/KG with pwats over 1.75. HRRR suggests
widespread late afternoon convective devlopment across central
Indiana persisting into the evening hours as the warm, unstable air
mass interacts with the passing short wave. Timing of these storms
could impacts fireworks displays on Saturday night. Due to the high
pwats, torrential rainfall will be possible.

Regarding temperatures, a slightly cooler day will be expected as
high clouds from upstream convection may be passing during the
morning hours and afternoon convection may limit max heating to the
mid 90s.

Sunday and Sunday Night...As we begin Sunday morning, dry weather
should be present as we start the day. The warm and humid air mass
will still be in place as southwest lower level flow remain due to
surface high pressure remaining in place over the Carolinas and weak
low pressure north of Indiana. The upper flow will allow yet another
short wave to approach Central Indiana from the northwest. Again,
forecast soundings appear favorable for convection, with steep lapse
rates and favorable CAPE in play. This will once again lead to
diurnal afternoon and evening showers and thunderstorms. The upper
forcing looks to arrive during the late afternoon and into the
evening. This should result in another round of widespread
thunderstorms. Severe storms cannot cannot be ruled out and due to
the high pwats, again heavy rain will still be in play.

Monday through Friday

The upper ridge axis will retrograde early next week positioning
central Indiana on the periphery of an active, progressive northwest
flow regime aloft. As a series of low-amplitude shortwave troughs
and embedded convective impulses traverse the Great Lakes and Ohio
Valley...expect daily opportunities for scattered showers and
thunderstorms to continue.

Convective potential remains largely diurnally driven and mesoscale
dependent on Monday and Tuesday focusing along residual outflow
boundaries. Pulse severe hazards...specifically localized
downbursts...will remain a secondary threat but with lower overall
coverage as thermodynamics become less intense. Weak surface ridging
on Tuesday may actually limit convection to isolated at best.

For the second half of next week...extended ensemble guidance
indicates a deeper and more cohesive northern stream shortwave
digging out of southern Canada. This feature will push a cold front
southward through the region by Thursday with a greater risk for
more robust and organized convection. In the wake of this frontal
passage, strong Canadian high pressure will overspread the area and
introduce a much drier and cooler airmass into the region. This will
effectively suppress temperatures and humidity back to near to
slightly below seasonal averages by the end of next week into next
weekend.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 104 PM EDT Fri Jul 3 2026

Impacts:

- Isolated TSRA, mainly from through 04Z; otherwise VFR.

Discussion:

VFR conditions will expected through much of this TAF period.
Diurnal heating will allow for isolated convection this afternoon
and evening as steep lapse rates plentiful CAPE is available.  This
has led to sct-bkn CU across the area with one storm south of BMG
developing.

As heating is lost tonight, any storms will subside, leading to just
VFR Conditions.

More storms will be possible on Saturday afternoon, especially
across northern Indiana as sagging upper flow there begins to
provide forcing combining with the hot, humid, unstable air mass in
place.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM EDT this evening for INZ021-
028>031-035>049-051>057-060>065-067>072.

Heat Advisory from 8 PM this evening to 9 PM EDT Saturday for
INZ021-028>031-035>049-051>057-060>065-067>072.

&&

$$

AVIATION...Puma
DISCUSSION...Puma/Ryan