FXUS63 KIWX 150007
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
807 PM EDT Tue Apr 14 2026

.KEY MESSAGES...

- While confidence is high for multiple rounds of showers and
  thunderstorms into Wednesday, it remains lower regarding
  timing, placement and impacts in any given area. All modes of
  severe weather are possible, with heightened concerns either
  side of the MI/IN state line.

- Additional chances for showers and storms exist Wednesday
  night into Saturday, but each days risk will key in on the
  previous days outcomes.

- Increasing concerns for at least some hydro issues with
  swaths of locally heavy rain expected on already saturated
  grounds and high river and lake levels. A Flood Watch has been
  issued for portions of the area where the greatest confidence
  exists at this time.

&&

.DISCUSSION...
Issued at 324 PM EDT Tue Apr 14 2026

A very challenging forecast is in store over the next couple of days
as the active pattern continues. The focus for this package will
reside on the next 24 to 36 hours with minimal changes or discussion
on later periods.While CAMs vary considerably on evolution of
convection through tonight there is 2 general areas to keep an eye
on for both a severe threat and possibly a heavy rain threat.

Skies have generally cleared out behind the morning area of showers
and storms, allowing for destabilization across the area (SPC Meso
indicating SBCAPE of 1500-2500 j/kg with higher levels to the west).
18Z soundings from KILX and KDVN show a powder keg waiting with a
strong cap/EML to be overcome.

Our first area of concern will be storms that fire most likely in
central IL, but could also start along/south of US-24 along a
remnant outflow from this mornings convection. Plenty of shear and
steep lapse rates will result in rapid intensification of the storms
which then move generally east with time. Large hail would be the
main threat, but strong winds and possibly some tornado concerns are
in play as well. The window for this looks to be from 20Z to maybe
2Z. SWOMCD #422 goes into greater detail on concerns. Have went with
chc pops for now in the south until we see how the convection sets
up. Heavy rain would also be a concern with plenty of moisture in
place.

Focus then shifts to expected rapid storm development somewhere in
the NE IA/NW IL area in the near future. Specifics can be found in
SWOMCD #419 highlighting an eventual Tornado watch as far east as
the Chicago area. It is this activity that will become our concern
late this evening into the overnight hours with CAMs all over the
place on the handling of it. Sufficient signals do exist for the
northern third to half of the area most likely in the crosshairs of
1 or 2 batches of storms and an increased threat for severe weather
and heavy rainfall. SPC upgraded locations N of US-6 earlier today
to Enhanced with all modes possible (trending towards damaging winds
with time). The copious amount of rainfall expected could cause a
greater overall flood concern than the south given a longer
potential duration. A Flood Watch was issued earlier for the
northern half of the area where confidence in cover and intensity is
greater. That does NOT mean southern areas are not at risk for
flooding concerns. WPC Excessive Rainfall Outlook placed the entire
area in a Slight risk to highlight the concerns.

Limited changes have been made into Wednesday and Wednesday night as
final evolution and impacts of overnight convection may dictate later
chances. SPC has the area in a Marginal Risk for severe storms, with
the focus likely being the afternoon or evening hours. Hydro
concerns could also be there (hence the watch in effect through 8 pm
Wed.

A trough moves through with renewed chances for showers and
thunderstorms. The severe threat doesn't appear to be as high at
this point (Marginal risk for the time being), but something to
watch. The trough will quickly exit with an increasing SW flow
behind it again as a much deeper trough moved across the Plains are
into the area this weekend. Additional severe storms appear possible
Saturday with DY6 outlook placing a 15% prob for severe over the
area. Behind the front, a shot of colder air and gusty winds arrives
for Sunday and Monday as highs drop into the 50s (some 40s?) before
moderation starts.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 753 PM EDT Tue Apr 14 2026

The active weather pattern will continue with times of showers
and scattered thunderstorms through the period. Anomalously mild
and very moist conditions for mid April will continue as diurnal
heating and weak disturbances continue to generate storms
upstream. MVFR to occasional IFR conditions are expected.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Flood Watch through Wednesday evening for INZ005>009-012-014-
     103-104-116-203-204-216.
OH...Flood Watch through Wednesday evening for OHZ001-002-004-005.
MI...Flood Watch through Wednesday evening for MIZ078>081-177-277.
MARINE...None.

&&

$$

DISCUSSION...Fisher
AVIATION...Skipper