Lafayette, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

101
FXUS63 KIND 190817
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
317 AM EST Thu Feb 19 2026

.KEY MESSAGES...

- Isolated thunderstorms this morning, localized large hail threat

- Scattered strong to severe storms likely this afternoon into the
  evening

- Primary threats damaging winds/isolated tornadoes with afternoon
  storms

- Colder for the weekend, with scattered light snow possible Sunday

&&

.SHORT TERM (Today and tonight)...
Issued at 315 AM EST Thu Feb 19 2026

A trough over the western US will eject eastward into the Plains
this morning, amplifying as it does so. Surface cyclogenesis is
occurring in the lee of the Rockies over western Kansas. The
resulting low is expected to intensify as it moves east-northeast,
ending up roughly over Chicago by 00z.

Strong southwesterly flow extends from New Mexico northeast into the
Great Lakes, as evidenced by fast-moving cirrus streaming over the
region. These clouds also signal broad lift arriving ahead of the
western trough. Low-level flow has once again become southerly in
response to the developing low to our west. Dew points have crept
upwards through the night, hovering in the 40s to near 50 at IND.

MORNING CONVECTION

ACARS soundings out of IND show steep mid-level lapse rates through
about 450mb. With low-level moisture increasing, this has lead to
elevated instability between 300-500 J/Kg. Guidance shows overall
instability increasing through the morning hours as warm moist air
continues to advect northward. ACARS soundings also show long
straight hodographs with nearly 50kt of effective shear.

Convection has already begun firing up over eastern IL and into
Warren County as of 07z. Radar imagery shows cells splitting,
indicative of the influence of strong unidirectional shear. As such,
the primary hazard through the morning hours will be large hail.
However, ACARS soundings show substantial dry air in the low/mid-
levels, and combined with the steep lapse rates, a few marginally
severe wind gusts cannot be ruled out.

Convective activity will likely focus on a developing warm front,
which extends across central IL and into northern IN. Cells that
fire up along this front may take on a deviant rightward motion,
which may allow activity to persist over our northern counties
through the morning hours.

AFTERNOON SEVERE POTENTIAL

Our attention then turns to the next round of convective potential
associated with the developing low. Guidance continues to hone in on
convective development over Missouri later this morning, coincident
with strong mid-level vorticity advection and surface convergence
ahead of the low center. This convection then races northeastward
into Illinois and eventually Indiana, strengthening as surface
heating increases available instability. Overall instability may
level off, however, as strong mid-level warming causes lapse rates
to relax.

In terms of potential hazards, a developing low-level jet beneath
the strong southwesterly flow aloft should enhance curvature within
the low-level hodograph (resulting in strong 0-1km shear between 15-
30kt / 150-250 m2/s2 SRH). Ongoing warm moist advection will bring
T/Td into the 60s/50s respectively, allowing for steep low-level
lapse rates and rich boundary layer instability. As such, the
potential for tornadoes exists, especially with any right-deviant
supercell. A possible mitigating factor is residual low/mid-level
dry air, which may cause storms to become cold pool dominant.
Southerly surface winds are not expected to be particularly
strong, which may limit how effectively this process can be
overcome.

The aforementioned low/mid-level dry air may allow for severe
wind gusts, especially as the low-level jet intensifies and low-
level lapse rates steepen. This may become the primary hazard
during the afternoon hours. The hail threat likely decreases with
time as mid-level warming lowers ELs causing storms to become
shallow in nature. Initial cells, especially supercells, will pose
the greatest hail threat.

TONIGHT

Once the system`s cold front / dry line passes through, the
convective threat comes to an end. FROPA occurs between 03z-06z from
west to east. Rapid clearing is anticipated with clear to partly
cloudy skies expected for a time overnight tonight.

Guidance is beginning to consolidate around the idea of strong
synoptic-scale winds on the back side of the low as it passes to our
north. CAMs in particular are quite aggressive, with gusts between 40-
45 knots. Winds likely increase from 06z onward, especially further
north closer to the low itself. A Wind Advisory may need to be
issued at some point, depending on the strength of the low and the
MSLP gradient surrounding it.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 315 AM EST Thu Feb 19 2026

Friday Through Sunday.

The synoptic pattern transitions sharply on Friday as the primary
upper-level low translates toward the Eastern Great Lakes. Central
Indiana will be positioned within a zone of strong CAA as 850mb
temperatures plummet below zero. A tight surface pressure gradient
will persist through Friday evening, maintaining brisk westerly
winds with gusts frequently reaching the 30-40 mph range with the
boundary layer around 4kft deep. This mixing will limit high
temperatures to the mid-40s, a significant departure from the record-
challenging warmth experienced earlier in the week.

Focus then shifts to a quick moving upper level low over the Great
Lakes that is expected to dive to the southeast, putting central
Indiana in a favorable position for cyclonic flow and steepening low-
level lapse rates. While deep-layer moisture is progged to be
meager, the cold air over the relatively warmer waters of Lake
Michigan could support a period of lake-enhanced snow showers.
Current ensemble probabilities favor the northeastern forecast area
for the highest frequency of these showers, with the potential for a
dusting to half an inch of accumulation.

Monday Through Wednesday.

By early next week, aforementioned low will transition into a more
traditional Nor`easter, allowing for a gradual transition to a more
zonal flow across the Ohio Valley. High pressure at the surface will
slide through the area, leading to a brief period of airmass
recovery and dry conditions. However, the pattern remains
progressive as a weaker, fast-moving shortwave approaches by
Wednesday. Forecast uncertainty for the mid-week period centers on
the depth of the return flow and whether enough moisture will
recover before the arrival of the next cold front. Current
projections suggest a return to high temperatures near 50 degrees
with low-end chances for rain.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1229 AM EST Thu Feb 19 2026

Impacts:

- IFR conditions developing predawn Thursday with the possibility of
  a few light showers and/or drizzle
- Scattered showers early Thursday, with thunderstorms from the mid
  afternoon to early evening
- Gusty SW winds possible Thursday night, gusts between 20-30kt.

Discussion:

Wind gusts have dropped off late this afternoon into the early
evening as the deep mixing through the boundary layer is lost. Winds
will back to southwest then southerly tonight and remain below
10kts. Skies will remain mostly clear through most of the evening
but mid and high level clouds currently over the Missouri Valley
will quickly expand east and envelop the region into the overnight.

With the approach of a warm front from the south late tonight...
ceilings will drop rapidly to near if not into IFR levels during the
predawn hours with pockets of light showers or drizzle producing
visibility restrictions as well through daybreak. Conditions will
improve late morning into the early afternoon as stronger S/SE
surface flow develops.

The approach of strong low pressure from the west with the warm
front in the area will set the stage for convective development over
Illinois during the first half of Thursday afternoon...spreading
east into central Indiana mid afternoon into the evening. IFR and
lower restrictions will accompany the heaviest convection.

The aforementioned system`s cold front passes through around 02z-
04z, ending the threat of convection. Clearing skies with a return
to VFR conditions is expected. Guidance shows strengthening winds,
potentially gusty, in the post-front environment. We`ve included
gusts up to 25kt for now, but winds could potentially be higher
especially further north and west.


&&

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

$$

SHORT TERM...Eckhoff
LONG TERM...White
AVIATION...Ryan/Eckhoff