Lafayette, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

097
FXUS63 KIND 170650
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
250 AM EDT Sun May 17 2026

.KEY MESSAGES...

- Very warm through Tuesday with highs in the mid to upper 80s

- Scattered severe storms possible both Monday and Tuesday with
  damaging winds, large hail and localized flooding

- Storms will end Wednesday as the front shifts south, but unsettled
  weather may return late week into next weekend

&&

.DISCUSSION (Today through Saturday)...
Issued at 250 AM EDT Sun May 17 2026

A deep upper level trough will develop across the Intermountain West
by early in the week promoting an amp-lified regime aloft and
downstream ridging over the eastern part of the country. This will
bring a very warm and unstable airmass into the Ohio Valley today
through the first half of the upcoming week. The ridge will
gradually flatten as the trough shifts east enabling a strong cold
front to track into the region by late Tuesday. While there will be
periodic chances for thunderstorms throughout the first half of the
week...the greatest potential for severe weather and heavy rainfall
will come Tuesday afternoon and night as a strong cold front crosses
the region. High pressure will bring a briefly drier period midweek
before greater uncertainty develops late week into the holiday
weekend as the front tries to lift back north into the region.

Today through Tuesday Night

Mid and high level cloud debris lingered over the region early this
morning with a warm front extending across the southern half of the
forecast area. 06Z temperatures were in the 60s.

The atmosphere was worked over substantially from the storms
Saturday afternoon with the current ACARS sounding from KIND showing
very little instability present above a boundary layer inversion.
Convection has recently fired near KCVG in vicinity of the warm
front and in tandem with a weak wave aloft. There remains some
potential for isolated storms to build back to the W/NW along the
front into the eastern part of the forecast area over the next few
hours and will keep low precip chances to account. The warm front
will continue its northward lift through daybreak and should be
north of the forecast area by mid to late morning.

Once the front moves north of the region...any low convective risk
will be over for the day as the forecast area settles into the warm
sector with a strong mid level cap near 750mb. Diminishing clouds
and increasing winds as the pressure gradient tightens will set the
stage for a rapid influx of much warmer air into the region for this
afternoon. Low level thermals support highs rising into the mid and
upper 80s with plenty of sunshine. Deeper subsidence will be
advected north into the region tonight which will keep skies mainly
clear with warm overnight readings.

Robust convective development will take place late today into this
evening over the northern Plains and upper Mississippi Valley
shifting east in a weakening state through the night. The remnants
of the line will approach the Wabash Valley by midday Monday with
the possibility for convection to redevelop along the old boundary
Monday afternoon within a warm and unstable airmass over the
forecast area. Model soundings show steepening mid level lapse rates
with modest instability and sufficient shear that would support the
risk for the strongest cells to produce damaging winds and large
hail as it moves across the forecast area. Localized flooding will
be a threat as well with ample low level moisture present
highlighted by PWATs approaching 1.75 inches. High temperatures will
be tricky and dependent on timing of the convection. Mid to upper
80s will be possible if storms hold off until later in the afternoon
but any earlier arrival will limit temp rises.

Showers may linger Monday night focused over the southern half of
the forecast area but the overall trend will be for drier conditions
as weak ridging aloft briefly develops across the region. The
ridging will be  as the eastward expansion of the western
trough will flatten the flow aloft Tuesday and finally allow the
cold front to make solid eastward progression into the area by late
day. A highly unstable airmass across the region will interact with
the approaching front and an increasing low level jet to initiate
robust convection across the forecast area Tuesday afternoon and
evening. Steep mid level lapse rates above 7C/km and dry adiabatic
flow through the boundary layer are supportive of a damaging wind
risk. Large hail will be a threat with any stronger core owing to
the plentiful instability within the hail growth zone. Low level
thermals again support temperatures well into the 80s prior to
convective development.

Convection will continue Tuesday night as the front sags southeast.
Flooding is likely to become a greater concern as the low level jet
veers to more of a westerly direction with the potential for cells
to backbuild along the boundary overnight.

Wednesday through Saturday

Convection is likely to be ongoing Wednesday morning but will
gradually end from northwest to southeast during the day as the
front moves into the Tennessee Valley and high pressure builds into
the Great Lakes. Model consensus is beginning to hone in on the
possibility that the boundary becomes stalled across the Tennessee
Valley through Thursday. The high passing to the north should keep
mainly dry and cooler conditions across the region but the potential
nearby presence of the front to the south will likely warrant
maintaining low precip chances across far southern portions of the
forecast area. Highs both Wednesday and Thursday will slide back
into the upper 60s and low 70s for most of the area.

Lower confidence exists late week into next weekend as the departure
of the high pressure to the east and the development of a split flow
regime aloft may allow for the aforementioned front to lift back
into the region which would introduce the potential for at least
scattered convection Friday and continuing into the holiday weekend.
The presence of a broad ensemble spread makes employing any detail
regarding the timing and coverage of any rainfall challenging at
this point. Highs will return to the mid and upper 70s for next
weekend.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1230 AM EDT Sun May 17 2026

Impacts:

- Southerly gusts peaking at 20 to 25kt this afternoon

Discussion:

Cloud debris lingers over the region early this morning from earlier
convection. Will see high clouds persist through the rest of the
night as a warm front slowly lifts north through central Indiana.
The threat for convection through daybreak has lowered with the
atmosphere heavily worked over from storms on Saturday. Cannot rule
out scattered convection in the vicinity of a weak wave aloft over
eastern Indiana but that is not expected to impact the terminals.

The warm front will shift north of the terminals after daybreak with
skies clearing and S/SW winds becoming gusty by late morning as a
tighter pressure gradient develops. May see some flat diurnal cu
under a well noted cap for the afternoon. Cu and wind gusts will
both diminish towards sunset.

&&

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

&&

$$

AVIATION...Ryan
DISCUSSION...Ryan