South Bend, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

835
FXUS63 KIWX 160743
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
343 AM EDT Sat May 16 2026

.KEY MESSAGES...

- A warming trend continues with highs in the low 80s this weekend
  then mid to upper 80s Monday and Tuesday.

- Increasing humidity and moisture through the weekend allow for
  daily periodic rain and storm chances.

- Scattered storms this afternoon and evening will pose threats for
  heavy rain and damaging wind gusts.

- Strong to severe storms possible again on Monday and Tuesday
  as wet and stormy conditions linger into midweek. SPC has
  introduced a Slight Risk (level 2 of 5) for severe weather on
  Monday, mainly north of US 30.

&&

.DISCUSSION...
Issued at 341 AM EDT Sat May 16 2026

Satellite and radar imagery shows strong to severe thunderstorms
persisting across southern Wisconsin and northern Illinois early
this morning ahead of a cold front. This activity will track east in
the coming hours arriving to central Lower Michigan just before
daybreak, outrunning the more favorable environment still to our
west. Hi-res model guidance depicts storms bypassing us to the
north until later in the day, when another surge of rain and
storms arrives from the southwest. Should any storms make it
into our area, steep mid level lapse rates of 7.5-8C and MUCAPE
of up to 750-1000 J/kg will promote isolated opportunties for
small hail and gusty winds. I expect these storms to remain sub-
severe, with additional activity coming later in the morning
and afternoon hours as storms redevelop. Should the morning
round to our north put out an outflow boundary, storms may
redevelop this afternoon aside a better plume of moisture and
instability as an upper level disturbance moves through Indiana.
A moist and warm airmass will overspread the area today and the
Gulf connection continues to develop with breezy southerly
winds and continued WAA. Highs in the upper 70s to low 80s and
dewpoints rising to around 60 will provide an increasingly
favorable environment for marginally severe storms. Should any
strong to severe storms develop, of which the greatest chances
(30-60%) will be along and south US 30, the main threats will be
heavy rainfall and isolated damaging wind gusts as MUCAPE
increases to 1000-2000 J/kg throughout the day. Winds parallel
to the stalled boundary could yield backbuilding or training;
With PWATs above 1.5", rainfall rates should easily be 1-2" per
hour at times. Limiting factors today include a lack of
organized shear (only about 30 kts of bulk shear) and mostly
cloudy skies today (lack of sunshine for destabilization).

While daily periodic chances for rain and storms exist through early
next week, Sunday has the lowest chances. The stalled boundary gets
pulled northward as an upper level trough deepens across the western
US. Isolated rain and storms will be possible (20-30% chances) in
the morning. I`ve held onto the NBM PoPs for the morning to align
with neighboring offices, but wouldn`t be surprised if they are
reduced with subsequent shifts given increasing confidence that much
of the daytime hours will be dry as we end up well in the warm
sector of the next system that arrives early in the week. Highs
climb into the low to mid 80s with southwest winds pulling in more
moisture into the Ohio River Valley and Upper Great Lakes regions.

The hot and humid pattern continues with additional opportunties
for severe weather as deterministic and ensemble model guidance
shows a much more progressive, active pattern into early next
week. Moisture surges Monday with strong moisture transport off
of the Gulf as dewpoints climb well into the upper 60s and highs
rise to the mid to upper 80s with PWATs of 1.5" to 2". Our
forecast area continues to be part of an expansive warm sector
by Monday with breezy southerly winds allowing for an
impressively strong Gulf connection extending into the Great
Lakes and Ohio River Valley regions. As the aforementioned upper
level trough digs across the central Plains, scattered strong
to severe thunderstorms may develop, especially in the
afternoon/evening into the early overnight hours. SPC has
introduced a Slight Risk (level 2 of 5) for severe weather on
Monday, mainly north of US 30. SBCAPE of 2000-2500 J/kg will be
present during peak heating late Monday afternoon, although
there is uncertainty in how much and how quickly it could wane.
A strong LLJ will ramp up in the afternoon and evening as low
level lapse rates steepen too. The potential for high
instability, strong moisture transport, and favorable
atmospheric dynamics indicate that all hazards will be possible
Monday as an organized severe weather event could take shape.

Depending on what happens Monday and how much the atmosphere can
recover Tuesday, the cold frontal passage then may also spark
another opportunity for strong to severe storms. The timing of
the cold front is uncertain as it slows down due to high
pressure building in the Atlantic offshore of the Southeast US.
Cooler, drier weather follows midweek in the wake of the cold
frontal passage.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 115 AM EDT Sat May 16 2026

Thunderstorms continue to our west in southern Wisconsin and
northern Illinois. As these storms progress eastward early this
morning, they should get into Lower Michigan around 08-09Z. It
is unknown if they will maintain their strength or make it into
northern Indiana, but have maintained a TEMPO group at KSBN to
account for this possibility. Considerable uncertainty remains
as to what happens later this afternoon/evening, but if these
pre-daybreak storms produce an outflow boundary, storms may
redevelop later this afternoon along it. Greatest
chances will be at KFWA, where a PROB30 has been maintained for
this afternoon and early evening. Main threats will be isolated
strong wind gusts of 40-50 kts and heavy rain. In both rounds
of storms, MVFR ceilings and visibilities will be possible.
Southerly winds will ramp up later this morning, sustained
around 12-15 kts and gusting up to 20-25 kts by the afternoon.

&&

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

&&

$$

UPDATE...Fisher
DISCUSSION...Johnson
AVIATION...Johnson