031
FXUS63 KIND 170430
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1230 AM EDT Sun May 17 2026

.KEY MESSAGES...

- Isolated to scattered showers and storms possible tonight

- Storm chances return Monday along with much warmer than normal
  temperatures Sunday through Tuesday with highs in the 80s.

- A frontal passage Tuesday into early Wednesday will bring additional
  chances of severe storms along with cooler and drier weather
  for the later part of next week.

&&

.FORECAST UPDATE...
Issued at 955 PM EDT Sat May 16 2026

The severe weather threat has diminished across central IN as the
environment is convectively overturned. Current KIND radar imagery
depicts lingering light precipitation across south-central IN with
quiet conditions further north. Expect the light rain to continue
shifting east and taper off over the next few hours. Subtle warm air
advection from a weak warm front lifting north will then support the
potential for isolated to scattered showers and storms.

Some guidance suggest patchy fog could develop overnight. Slightly
elevated surface flow should limit the development of fog, but
sheltered locations where winds are weaker could see patchy fog.
Muggy dewpoints will keep temperatures mild overnight in the low to
mid 60s.

&&

.DISCUSSION (This evening through Saturday)...
Issued at 355 PM EDT Sat May 16 2026

Tonight....

Convection tied to the MCV will continue to move eastward before
gradually diminish late evening. Threat for isolated severe
winds/hail will be possible through 02Z /10 PM EDT/. Overnight, a
slowly NE moving warm front combined with a 30-40 kt low level jet
will likely support renewed elevated convective development after
05Z. PoPs have been raised a category to account for this increasing
potential.

Sunday/Sunday Night...

Scattered TS will come to an end early Sunday (before 15Z) as the
warm front lifts northward. Gusty S-SW winds will develop by late
morning lasting into the afternoon owing to an increasing surface
pressure gradient and modest low level flow in the boundary layer.
High temps are expected to easily rise in the 80s area wide by
afternoon with 850 temps around 17-18C. Combined with dewpoints in
the lwo-mid 60s, heat indices are expected to be in the mid-upper
80s, close to the warmest apparent temps since late March. Skies are
expected to be mostly clear Sunday and Sunday night with just
afternoon cumulus and increasing cirrus overnight from Plains
thunderstorm activity.

Monday/Monday Night...

Model consensus is that a relatively innocuous mid level vort
max/lead shortwave trough associated with the southern jetstream
/per sat off of Baja CA coast/ will move NE across Mexico and TX and
into the Ozarks/Mid MS valley by Monday afternoon. With weak
inhibition and moderate instability /MLCAPE around 2000 J/KG/
noted on forecast soundings, scattered TS are expected for form just
west of central IN during the mid-late afternoon. Weak 0-6 km shear
will limit threat for more significant severe threat, but moderate
anvil venting and low level flow may support a low end hail/damaging
wind threat if activity can become organized linearly. This activity
is expected to weaken overnight Monday night with loss of heating
amidst weak forcing. High temps on Monday are once again expected to
be well above normal, despite some increase in clouds cover with 80s
areawide.

Tuesday/Tuesday Night...

A cold front will push southward across the plains and upper
Midwest, however timing of the front is somewhat uncertain 3 days
out. Thunderstorm activity is expected to be numerous along the
front with deep layer forcing and moderate instability
/CAPE 2000-3000 J/KG/. Convective mode is expected to be fairly
linear convective with damaging winds the primary threat, per the
SPC Day 4 slight risk outlook. In addition, locally heavy rainfall
may lead to minor flooding.

Wednesday into Saturday....

The primary cold front is expected to push across central Indiana
early on Wednesday. In the wake of the front, cooler and drier air
is expected through Thursday. Thereafter, there is some disagreement
with the strength of the shortwave trough moving into the Rockies
and Plains and the consequent timing and coverage of additional
precip development moving back into central Indiana going into the
Memorial Day weekend/500 festivities. High temps are expected to be
below normal Wed and Thursday rising to near normal by Saturday.

&&

.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.

&&

$$

UPDATE...Melo
AVIATION...Ryan
DISCUSSION...Crosbie