Lafayette, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

376
FXUS63 KIND 230814
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
314 AM EST Tue Dec 23 2025

.KEY MESSAGES...

- Light rain and drizzle continuing through the early morning hours
before drying out this afternoon

- Well above normal temperatures from today into the weekend...with
  rain/fog expected Wednesday night

- Transition back to colder conditions through late weekend/early
  next week

&&

.SHORT TERM (Today and tonight)...
Issued at 314 AM EST Tue Dec 23 2025

Main focus for the short term period will be tracking a combination
of light rain and drizzle through the early morning hours across the
Ohio Valley. Latest satellite imagery shows widespread stratus
stretching from the Gulf Coast northward toward the I-70 corridor
collocated with a strong 35-40 kt low level jet advecting low level
moisture northward. Local soundings around the region show a strong
inversion almost 2km agl associated with warm air advection aloft.
This inversion is keeping the copious amount of Gulf moisture
trapped within the boundary layer resulting in the widespread
stratus and rapidly rising humidity levels. Subtle waves aloft are
providing just enough lift to squeeze out light showers and drizzle
under the low stratus, with the greatest chance for any light
precipitation along and south of the I-70 corridor through the early
morning hours.

The main forecast challenge for the rest of the day will be
determining how quick low stratus lifts and breaks up over portions
of the state. Deeper moisture across South Central Indiana may hold
on longer than what some guidance suggests as the sun angle is at
its lowest point of the year and solar heating is at its weakest. A
frontal boundary does push in from the north through the day
advecting in drier air from west and northwest. This drier air can
already be seen on Satellite imagery with a sharp cut off from low
stratus to clear skies over Illinois. Expect Northwest and North
Central Indiana to clear out first as the front nears this
afternoon, with clouds holding on longer further south where drier
air may take longer to reach.

Despite some areas remaining cloudy, the warmer airmass in place
ahead of the front should still support high temperatures well above
average for this time of year in the 50s and potentially 60s in areas
that clear out quicker before the frontal passage. West southwest
winds ahead of the front may gust 20-25 mph at times, especially in
areas where more sunshine is observed leading to better low level
mixing.

High pressure moves across the Great Lakes region tonight clearing
out much of the state and weakening the pressure gradient. Lighter
winds and clearing skies will allow temperatures to plummet later
tonight. There is not much cold air incoming with this area of high
pressure; however radiational cooling will result in a strong
nocturnal inversion setting up as the surface drops to the upper 20s
to mid 30s while 925mb temperatures near 50F. Any cloud cover
stubborn to clear out over southern and southwest Indiana will help
keep temperatures from falling near the freezing mark. Have a sharp
north to south temperature gradient south of I-70 for tonight with
better chances for temperatures to reach the freezing mark near I-70
and points north while cloudier areas further south remain in the
mid 30s to near 40.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 314 AM EST Tue Dec 23 2025

Wednesday through Saturday...

The middle of the week will maintain well above normal temperatures,
albeit with less confidence in 60-degree readings for most of
central Indiana...as weakness riding the parent upper ridge likely
cross the region, often dragging a stationary/cold frontal zone in a
WNW-ESE proximity over the Midwest.  Resultant conditions will
feature often considerable cloudiness, light/moderate breezes whose
heading will depend on if a weak circulation is
approaching/departing, as well if the southern extents of chilly
Canadian high pressure are trying to build into the region for a few
hours.  Rain showers/fog will be most likely Wednesday night with
low pressure scheduled to cross Indiana, with light amounts expected
and low confidence for any location.
High certainty in Christmas Day continuing above normal
temperatures, but now with lighter northeast breezes holding low 60s
most likely to southern portions of the region.

Late week to potentially trend more unseasonable assuming next
transient low pressure riding the broad subtropical ridge, passing
west to east, tracks near/north of the CWA.  The overall retracted
upper flow will combine with heights eventually plunging down the
Pacific coast to support a quasi-split flow...with stronger low
pressure well to our north and a weaker circulations or two closer
to the I-70 corridor.  Overall gradient should allow for
occasionally stronger southwest winds that could advect widespread
60s to the region, with possible mid to upper 50s dewpoints bringing
a feel of springtime humidity.  Occasional showers are also on the
table, especially in the 12 hours ahead of a passing wave.

Sunday and Monday...

Strengthening cold frontal zone to cross Midwest around the middle
of the weekend...ahead of plunging polar air mass that is progged to
amplify H500 trough over eastern CONUS.  Core of corresponding
bitter cold to cross Great Lakes/Northeast, with central Indiana set-
up for a couple nights in the teens early next week, and most likely
a sub-freezing daytime to end the period.  Associated winds should
be reasonable for a 30-degree change, with robust to potentially
gusty conditions around the end of the weekend...and lighter breezes
favoring single digit overnight wind chills early next week.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1252 AM EST Tue Dec 23 2025

Impacts:

- Ceilings lowering to IFR levels through the night with DZ
increasing

- Combination of DZ and BR bring IFR vsbys at times overnight

- LLWS 250/40kt decreasing by sunrise

Discussion:

Patchy IFR ceilings are already in the area, and are expected to
continue to lower some through the overnight hours. Based on
upstream observations this evening, larger low level dew point
depressions have kept cigs above IFR levels and vis largely MVFR to
VFR. TIDS 0.3 deg reflectivity shows shallow showers and areas of
drizzle already developing overhead as a 35-40 kt low level jet
continues to advect low level moisture in the area. Went more
optimistic for both cigs and vis overnight based on observations and
trends this evening, however there is still a small threat for brief
periods of IFR/LIFR cigs and vis at times.

Conditions will slowly improve later this morning, with the
potential for VFR returning to most sites Tuesday afternoon.

Non-convective LLWS from a weakening 35-40 kt southwesterly low
level jet overhead will continue over the next several hours. The
strongest winds within the LLJ weaken and push eastward after 09z-
12z.


&&

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

$$

SHORT TERM...CM
LONG TERM...AGM
AVIATION...CM