910
FXUS63 KIND 171400
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1000 AM EDT Fri Apr 17 2026

.KEY MESSAGES...

- Near record warm temperatures today

- Showers and thunderstorms tonight into Saturday

- Some severe storms are possible, mainly late this evening
  into early overnight across western portions of the area

- Much cooler Sunday into Monday with the potential for
  frost and near freezing temperatures early Monday morning

&&

.FORECAST UPDATE...
Issued at 959 AM EDT Fri Apr 17 2026

A weak frontal boundary is progressing northward through central IL
and southern IN this morning. Along this boundary modest upward
motion is tapping into the limited moisture above the PBL, leading
to isolated elevated showers and storms. As this continues to the
NE an inverstion around 750mb, as seen on ACARs soundings, will
likely inhibit convection, but for the next 3 to 4 hours isolated
PoPs have been added from Terre Haute to Bedford and points to
the SW of this line.

&&

.DISCUSSION (Today through Thursday)...
Issued at 243 AM EDT Fri Apr 17 2026

Early This Morning...

Satellite and observations show fog overspreading portions of
northern Indiana. There hasn`t been much trend southward for the
widespread and dense fog. Guidance isn`t bullish on fog either for
central Indiana. With Lafayette already dipping down below 6SM, will
include a mention of patchy fog in portions of the northern forecast
area before sunrise.

Today...

Near record temperatures are possible today across the area. Warm
advection and mixing will lead to high temperatures in the lower and
middle 80s. 850mb temperatures are at or above the 90th percentile.
Indy`s record is 87 degrees, set in 1896. Readings won`t get that
high, but they could get within 4 degrees or so of that record.

A surface trough/warm front will move across the area today and
could create some isolated convection across the southwest third or
so of the area this afternoon into early evening.

Tonight and Saturday...

A large upper trough will move into the area with a strong surface
cold front ahead of it. Good moisture advection will pump moisture
into the area (Integrated Vapor Transport fields are near 30 year
climatological maxima for this time of year). Forcing and moisture
will lead to convection moving across central Indiana, especially
overnight into Saturday morning.

Shear and instability will allow convection to become severe west of
central Indiana late this afternoon and into this evening. Depending
on the strength and organization of the cold pools with this
convection, severe storms may survive into mainly western portions
of the forecast area late this evening into the early overnight.
Damaging winds will be the primary threat, but isolated tornadoes
will be possible as well in any spin-ups in the line of storms.

Convection will continue but weaken as it moves east overnight.
Locally heavy rain will be possible given the moisture content of
the atmosphere.

Showers and some storms will continue Saturday as the front itself
moves through. Depending on the speed of the front and convection,
some reintensification is possible in the far southeast Saturday
afternoon before it exits. Temperatures will fall Saturday as cold
advection kicks in behind the front.

Saturday night through Sunday night...

Colder air and clearing skies may allow patchy frost to form in
protected areas Saturday night, but winds should keep frost from
most areas. A secondary cold front will move through on Sunday.
Wouldn`t be surprised if a few light showers accompany it, but
confidence isn`t high enough to include at this time.

Lows Sunday night could get to near or below freezing in the far
northeast forecast area. Elsewhere will see mid and upper 30s. Frost
will also be a concern as winds diminish.

Monday and beyond...

Below normal temperatures will continue Monday, but above normal
readings quickly return for Tuesday into Friday, with near 80
degrees possible by Thursday. A front could bring low rain chances
at times Wednesday through Friday, but confidence is low at this
time.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 630 AM EDT Fri Apr 17 2026

Impacts:

- Wind gusts around 20kt this afternoon and evening
- Convection likely, mainly after 03Z Saturday

Discussion:

Patchy fog looks to remain at KLAF early in the period. IFR and
worse possible as visibility bounces around, but the shallow
ground fog will mix out quickly.

Some VFR cumulus will pop up this afternoon, and isolated convection
is possible after 21Z. Better chances for convection arrive after
03-05Z west and after 05-07Z east. Showers and embedded storms will
continue at times into Saturday. While predominant MVFR ceilings
should wait until near or after 12Z Saturday, MVFR and worse are
possible in convection.


&&

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

$$

UPDATE...Updike
AVIATION...50
DISCUSSION...50