783
FXUS63 KIND 160129
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
929 PM EDT Sun Jun 15 2025

.KEY MESSAGES...

- At times active weather pattern this week with daily rain/storm
  chances through Thursday

- Severe weather possible late Wed - Wed Night

- Generally humid this week...upper 80s/low 90s likely next weekend

- Heat related illnesses are possible by next weekend

&&

.FORECAST UPDATE...
Issued at 927 PM EDT Sun Jun 15 2025

Forcing associated with a mesoscale low has remained to the SW with
all diurnally induced showers now dissipated. Conditions are
expected to remain mostly dry through tonight, until the
aforementioned low arrives tomorrow morning into the afternoon. Patch
ground fog is possible with a still vary moist PBL and strong upward
latent heat fluxes overnight, but the expectation is for this to not
be dense, with visibility only reducing to 2-5SM in some
locations.

Grid updates are out.

&&

.SHORT TERM (This evening through Monday)...
Issued at 309 PM EDT Sun Jun 15 2025

A residual boundary/inverted trough extending from a surface low
over eastern KY/OH back into southern Indiana will be the focus for
scattered showers and isolated thunderstorms across the SE 1/3 of
the forecast area this afternoon with pops running from 20-50
percent, highest in the far SE. Observed 12Z sounding from ILX shows
the weak shortwave ridging influence /subsident layers aloft/ and
lack of any appreciable low level convergence, combined with reduced
heating/more cloud cover will keep the chances of precipitation to
near zero in the remainder of the central Indiana the rest of the
afternoon.

Precipitation in the SE 1/3 of the forecast area will quickly end
this evening with loss of daytime heating, thanks to marginal BL
convergence and increasingly poor deep layer lapse rates. Although
increasing low to mid level cloud cover should limit fog development
except southern portions of central Indiana where the skies will be
clear to partly cloudy the longest overnight and patchy fog is
possible after midnight.

Multiple convectively generated MCVs over the southern plains/MO
valley will move eastward phasing with and increasing the broader
shortwave trough that remains over the MS valley. Increasing mid
level forcing, lift from these mesoscale and synoptic scale features
will support increasing precipitation across the area starting late
Monday morning continuing into the afternoon hours. Forecast
soundings support some threat for thunderstorms during the afternoon
if skies can clear some, but at the moment only will keep slight
chance of thunderstorms giving the uncertainties in degree of
heating/destabilization during the afternoon hours.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 309 PM EDT Sun Jun 15 2025

General consensus in the medium range models in showing the slow
moving MS valley shortwave trough will finally start progressing
faster eastward Monday night into Tuesday as jetstream energy
increases along the CONUS/Canadian border in advance of a stronger
trough moving into the northern Rockies/Plains. Models disagree on
the amount of precipitation across central Indiana with this system
/the NAM being the driest outlier/ but given the ensemble of other
solutions and the degree of deep layer forcing/moisture, confidence
is high that 60-80% pops are appropriate for this event with details
on amounts still yet to be determined.

In the wake of this shortwave, the airmass will begin to dry out
slightly Tuesday night into early Wednesday. Attention turns to
the next /stronger/ shortwave trough moving out of the northern
plains into the Great Lakes/MS valley on Wednesday. The severe
thunderstorm threat increases with this system thanks to
increasing kinematic and moderately unstable thermodynamic fields
developing during the day. SPC has most of central Indiana in the
Day 4 slight risk outlook with the potential for damaging winds
likely the highest threat. Current timing of the greatest severe
weather threat is late Wednesday afternoon in the west lasting
into the early morning hours of Thursday in the east.

A weak cold front associated with this shortwave is currently
progged to move through central Indiana on Thursday with a chance of
thunderstorms possible in the eastern areas during the afternoon.
The quietest day of the period looks to be Friday behind that front
with slightly cooler and lower humidity conditions and no chance of
precipitation.

As the upper ridge builds eastward from the Plains into the Ohio
Valley next weekend, dry conditions look to persist. Markedly
increasing temperatures /Indianapolis` first 90F reading of the
year/ look to develop by Sunday. In addition, high dewpoints in
the 70-75F range will lead to heat indices 100-105F by Sunday. As
a result the potential for heat related illnesses and the
potential need for heat headlines will exist.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 727 PM EDT Sun Jun 15 2025

Impacts:

- Areas of MVFR developing later tonight
- Scattered light showers developing at KBMG tomorrow morning,
  potentially at KHUF and KIND tomorrow afternoon

Discussion:

Clouds will increase area wide overnight with MVFR conditions
returning at all terminals except. IFR ceilings are possible at
KBMG, but confidence in occurrence is too low to include at this
time. IFR VIS may make a return at KBMG towards morning thanks to
light winds and more recent nearby rainfall today.

A weak boundary over south-cntral IN will support some scattered
showers and isolated TS near KBMG tomorrow morning into the
afternoon, with much lower threat at KIND and KHUF.

&&

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

$$

UPDATE...Updike
SHORT TERM...Crosbie
LONG TERM...Crosbie
AVIATION...Updike