139
FXUS63 KIND 171444
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1044 AM EDT Tue Jun 17 2025

.KEY MESSAGES...

- Humid today with scattered showers and storms possible, especially
  southeast, with briefly heavy downpours possible.

- Potential severe weather Wednesday afternoon to Wednesday night

- Much warmer this weekend with near Heat Advisory conditions by
  Sunday

&&

.FORECAST UPDATE...
Issued at 1044 AM EDT Tue Jun 17 2025

No major updates needed to the forecast this morning. Made some
minor tweaks to temps, dew points, and sky cover to account for
recent observational trends. Continue to expect mostly cloudy skies
with gradually lifting ceilings. Scattered showers and perhaps a few
isolated thunderstorms are possible, especially south of I-70.

&&

.SHORT TERM (Today and tonight)...
Issued at 341 AM EDT Tue Jun 17 2025

Weak and elongated areas of low pressure along a weakening
quasistationary boundary to our south, along with a modest upper
level shortwave, will produce potential for scattered showers and
thunderstorms today, with the highest chances across the
southeastern third to half of the area, nearest the deeper moisture.

Despite precipitable water values near or in excess of 90th
percentile, limited forcing and coverage should limit rainfall
totals and largely prevent significant hydrologic concerns today
into tonight, with only locally heavy downpours and isolated flood
concerns to keep an eye on.

Increasing dry air aloft and weak subsidence in between today`s
departing shortwave and the next approaching system, along with
nocturnal stabilization, should provide for several dry hours this
evening into tonight for much of the area, with only an isolated
shower or storm possible primarily on the fringes of central Indiana.

Temperatures will likely remain steady or drop only slightly the
rest of tonight, with ongoing cloud cover and precip limiting
warming today to the low to mid 80s, with a gradient from east to
west across the area - some breaks in the cloud this afternoon
across the west will allow temperatures to jump a bit above the rest
of the area. Lingering low level moisture will prevent lows from
falling much below the 70 degree mark overnight tonight.

This low level moisture will also provide potential for at least
patchy light fog in climatologically favored locations - rural and
low-lying/valley areas - tonight and again tomorrow night.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 341 AM EDT Tue Jun 17 2025

Going into Wednesday, a meso-low/MCV moving eastward from the
remnants of a previous MCS could be the may be a catalyst for
thunderstorms development across the Ohio Valley Wednesday afternoon
into evening. Severe storms could develop off of this system as
there will be a good amount of heat and moisture as well as mod to
strong buoyancy and a weak to moderate capped environment.

There is some uncertainty with how strong the capping will be over
the area but latest models have not been as gung-ho with the cap as
previous runs. Another concern is if the convection will line up
with the best severe weather parameters. Should storms develop
during the afternoon hours, there is concern for damaging storms to
occur. Thinking that some showers and storms could move through
during the morning hours, which may rob the atmosphere of some of
it`s instability, and then another better chance of showers and
storms overnight, but then the lack of heating and lower CAPE could
keep storms sub-severe. If ingredients come together, damaging winds
will be the main threat but hail, a tornado or two, and heavy rain/
localized flooding could all also be a concern. Thunderstorms will
move out by Thursday morning with the pattern shift to the warmer
and more humid airmass settling in by Friday.

A strong upper level ridge will dominate the weather pattern for
Friday into the weekend with the center of the high expected to be
overhead Saturday into Sunday with weak southerly surface flow. This
will help to push temperatures into the low 90s with dew points
gradually rising into the mid 70s towards Sunday. Peak heat indices
will rise into the low 100s with the potential for pockets as high
as 105. Heat Risk maps show widespread major conditions Sunday and
Monday which makes sense with both the hot daytime conditions and
mild and muggy nights. Heat headlines will likely be needed,
especially when you factor in the relatively mild start to summer
and this being the first widespread 90s and first widespread days of
dew points in the mid 70s.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 646 AM EDT Tue Jun 17 2025

Impacts:

- MVFR or worse ceilings expected through midday to early afternoon

- Showers and thunderstorms possible at times through the period,
  particularly this afternoon, with chances highest at BMG

Discussion:

Abundant low level moisture continues to produce low stratus across
the area, with ceilings ranging from 200 to 2000 feet across the
area, with most sites IFR at this point. A gradual improvement is
expected through the morning, with VFR returning from 16-18Z at most
sites, though MVFR ceilings may persist longer at BMG.

Scattered showers and thunderstorms are expected at times,
particularly this afternoon, with chances highest at BMG and across
south and southeastern portions of the area. Will carry PROB30
groups at BMG for thunderstorms this afternoon, with no mention
elsewhere at this time given uncertainty.

Winds will be below 10KT through the period, generally between 190-
220 degrees.


&&

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

$$

UPDATE...Eckhoff
SHORT TERM...Nield
LONG TERM...KF
AVIATION...Nield