028
FXUS63 KIWX 151833
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
233 PM EDT Sun Jun 15 2025

.KEY MESSAGES...

- Warming trend continues into Monday and Tuesday. Peak afternoon
  heat indices near 90 degrees by Tuesday.

- There is a low (20-40%) chance for widely scattered showers
  and storms along and southeast of the US 24 corridor Monday
  afternoon-night.

- Multiple rounds of showers and storms likely late Tuesday
  night through Wednesday night. There is the potential for
  severe storms and heavy rainfall on Wednesday.

- The warmest and most humid air of the season arrives next
  weekend.

&&

.DISCUSSION...
Issued at 233 PM EDT Sun Jun 15 2025

The western fringes of low level ridging will maintain dry
conditions locally into tonight and Monday morning as an instability
axis remains off to the south and west. A weak sfc trough and deeper
moisture does lift north into areas mainly south of the US 24
corridor Monday afternoon-night in response to a convectively
induced shortwave (now over far southwest Missouri) propagating east-
northeast through the Ohio Valley. This may be enough to generate
widely scattered showers/storms in our southeast with a slight
expansion/increase to PoPs.

A warmer, more humid, airmass will overspread the entire area
Tuesday into Wednesday. The better low level return flow and
primary MUCAPE axis likely remains off to the west for much of
Tuesday in between shortwaves for only a low chance PoP (20-30%).

Multiple rounds of more organized convection still looking likely
late Tuesday night through Wednesday evening as a more pronounced
shortwave and associated frontal wave ejects east-northeast from the
Central Plains to the lower Great Lakes. Increasing low-mid level
southwest flow preceding the wave provides impressive moisture
transport (~70F sfc dewpoints and 1.80" plus pwats) hinting at a
heavy rain/flooding threat, and potentially an organized severe risk
by Wednesday afternoon-evening. The evolution of a potential morning
convective complex, and where the primary MCS outflow/cold pool
boundary lies out by peak heating will dictate where this severe
risk materializes during the PM hours on Wednesday. Confidence is
obviously low regarding these mesoscale details 4 days out, but
definitely something to monitor in the coming days.

Thereafter, expect a brief cooldown post-frontal into Thursday, with
the warmest and most humid air of the season arriving by next
weekend under an upper level ridge expanding northeast into the
Great Lakes.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1236 PM EDT Sun Jun 15 2025

No significant changes to the TAFs this afternoon. High
pressure over the eastern Great Lakes will promote VFR
conditions and light wind. Wind becomes southeasterly late in
the TAF period but remains light near 5-8 knots.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Steinwedel
AVIATION...Brown