424
fxus63 kiwx 091158
afdiwx
area forecast discussion
national weather service northern indiana
758 am edt tue jun 9 2026
.key messages...
- heat and humidity on the increase through thursday, with highs
in the mid-upper 80s and low 90s. heat indices on wednesday
and thursday will be around 100 degrees. lows will be in the
60s, low- mid 70s.
- daily chances (generally 40-80 percent) for showers and storms
this week. severe weather potential exists for both wednesday
and thursday during the late afternoon-evening and overnight
hours. there is higher confidence in the threat materializing
thursday evening into the overnight hours, especially west of
i 69. damaging winds and large hail are the primary threats. a
tornado or two may be possible, especially thursday
evening/night.
- lower chances (20-30 percent) for showers and storms return
sunday afternoon into monday, with temps cooling into the low
to mid 80s with decreased humidity.
&&
.discussion...
issued at 542 am edt tue jun 9 2026
main change from previous forecast: spc outlooks today-thu have been
upgraded from their previous status.
-today: a marginal risk/general thunder...marginal risk only in
white county, in this afternoon. isolated strong to severe storms
are possible, but confidence is low due to a lack of large scale
support.
-wednesday afternoon-overnight: a slight risk of severe weather for
areas along and north of us 24, mainly west of i 69. there is a
marginal risk elsewhere. damaging winds and large hail are the main
threat. confidence is low to medium in severe weather occurring.
-thursday afternoon-overnight: an enhanced risk of severe
weather for the far western forecast area (especially west of
in 15/us 31) and a slight to marginal risk elsewhere,
decreasing threat with eastward extent. damaging winds and
large hail are the main threat. a tornado or two cannot be
ruled out-especially in the enhanced area. confidence is medium
in severe weather occurring.
details...
today...as of this writing, there are numerous showers and isolated
thunderstorms associated with a northward lifting warm front--mainly
west of i 69 but especially west of us 31. expect this activity to
lift north and east through the late morning hours, with southwest
winds shifting west and lightening up behind a weakening trough late
this afternoon and evening. intensity should weaken as the boundary
moves eastward through the morning as we are into the more stable
time of day initially, with redevelopment possible this afternoon
along the incoming boundary during daytime heating. models disagree
on the exact placement of the showers/any storms, though they all
have some sort of activity today. that being said, some locations
may see more prolonged gaps in more scattered-numerous coverage than
others-with partly to mostly cloudy skies. spc clipped our far sw
cwa (white county, in) in a marginal risk today as they are closer
to the best axis of instability. suspect we`ll see potential into
the afternoon for a couple stronger storms further west/south as mid-
level lapse rates steepen to about 7c/km. gusty winds and some large
hail are possible-mainly close to the small marginal risk.
confidence is lower in the exact placement as models are quite
variable with where the focus will become if it doesn`t end up being
more widely scattered/isolated. highs will climb into the mid-upper
80s for most areas today with heat indices entering into the upper
80s, low-mid 90s for area mainly along and south of us 24. of
course, these could end up lower if we have more expansive cloud
cover and shower/storm coverage.
for wednesday...spc outlook is a slight risk for severe weather in
areas along and north of us 24, mainly west of i 69. there is a
marginal risk elsewhere. damaging winds and large hail are the main
threat. confidence is low to medium in severe weather occurring-best
potential in the slight risk area. our area is on the periphery of
the upper level ridge/surface high to the se by wednesday
afternoon/evening. shortwaves ripple through this flow in the
morning/early afternoon so there may be some activity through early
afternoon in portions of the area (per the rap and a few other
models). the hrrr stays mostly dry except a few cells popping with
daytime heating in mid-late afternoon (isolated). it brings in a
line or cluster of storms in the far west/northwest (especially near
lake mi) sometime between 5pm and 11pm edt. given there is abundant
moisture/instability around and if we can break through the initial
ridging aloft (with a shortwave or two to limit capping)...there
could be scattered/isolated strong-severe storms. the shear
increases towards the afternoon, in addition to steeper (7-8c/km)
500-700mb lapse rates building in from the west certainly by late
evening. damaging wind gusts are the most likely threat (15 percent
probs at spc)--larger hail will be more likely further west of our
area. spc does have the area along the lake mi shore and into
northern cass county, mi in the 2 percent tornado
probabilities...with 25-40kt 0-6km bulk shear/and a bit of helicity
along the incoming boundary. per the spc discussion the storms could
initially be more supercellular in il etc and move eastward where
they transition to more of a line segment with our indiana classic
spin ups possible. it`s possible we see little-no activity until
after 8 pm edt, then a drop off in intensity after 11 pm edt as
conditions become less favorable. given uncertainty in the storm
mode at the point of entry into our cwa and the later timing
possibility-confidence is low to medium (greatest in the far west).
high temperatures/heat indices wednesday will depend on the amount
of convection/cloud cover that may limit temperatures...but for now
have mid-upper 80s and a couple spots in the low 90s for highs. this
brings heat indices up to around 100 degrees. an advisory will be
needed if we can materialize these temps. held off for now given
lower confidence in early daytime clouds/weather.
for thursday afternoon/overnight...spc has an enhanced risk of
severe weather for the far western forecast area (especially west of
in 15/us 31) and a slight to marginal risk elsewhere, decreasing
threat with eastward extent. damaging winds and large hail are the
main threat. a tornado or two cannot be ruled out-especially in the
enhanced area. confidence is medium in severe weather occurring. the
majority of the day could end up being dry as we are beneath a bit
of ridging in the mid/upper levels, so beyond some morning activity
lingering or just a few isolated afternoon cells popping in the
blistering heat/humidity during the late afternoon, the main show
will likely be after sunset. highs thursday will be in the upper 80s
and low-mid 90s (hottest just inland from lake mi and in nw oh).
heat indices once again will be around 100 degrees, possibly
prompting the need for a heat advisory (especially given wed may
also be advisory level).
storms take off in mn/wi/il and progress eastward within a strongly
forced and moist, unstable environment with high deep layer
shear/strong low level shear and steep mid-level lapse rates. these
storms (likely supercells and/or bowing segments) will move east-
northeast with a surface low through the overnight. models did slow
the progression of this system/associated storms from previous
runs...which means we are on the border of less favorable timing for
severe threat in terms of maximized instability. outside of maybe a
few isolated storms popping in the afternoon, it`s probably going to
be closer to 8-10 pm edt before the greatest threat arrives in the
west. per the nam and a couple others...it could be as late as 11 pm
to 1 am edt for the enhanced area further west, progressing e-se
into the morning.
additionally, for our area, mid level lapse rates remain around 6.5-
7c/km...but it depends on the model (some have 5.5 to 6.5c/km at
least in our area...not as favorable). storms will diminish in
intensity somewhat as they go eastward into the overnight/early fri
am hours. with any supercells or bowing segments of course comes the
potential for a tornado or two, which is certainly possible given
the abundant low level moisture and strong ll shear. confidence
stays medium due to the aforementioned timing delays.
friday into early next week will be cooler and less humid, with low-
end (20-30 percent) chances for showers and storms mainly fri am and
again sun/mon. highs will be in the upper 70s, low-mid 80s with the
coolest and least humid conditions towards sun/mon.
&&
.aviation /12z tafs through 12z wednesday/...
issued at 746 am edt tue jun 9 2026
predominantly mvfr to ifr conditions to start the period, with
chances for showers and thunderstorms at both terminals. breezy
southwest winds this afternoon shift west-northwest and become
light overnight. rain this morning has come to an end at ksbn,
with upstream ceilings of 400-700 ft (vis 4-5sm) expected to
creep further eastward. this should improve after 15z where we
see a lull in any significant activity and ceilings lift to
high-end mvfr/vfr for the afternoon. have vcts 18-00z as models
generate afternoon convection with the weak wave/surface
boundary moving through at peak heating. mvfr/ifr
ceilings/visibilities are possible with any heavier
showers/storms.
at kfwa, rain is just now impacting the terminal with bkn015
ceilings. upstream an area of convection just near south whitley
and rochester, in is expanding eastward, with lightningcast
probabilities for kfwa in the 10-30 percent range within the
hour. have -shra/vcts and a tempo in through 15z, along with
potential for 700 ft ceilings/2-3sm visibilities. it is possible
lightning trends decrease in the next half
similarly to ksbn, expect a lull in activity after 16z or so
with mvfr ceilings becoming vfr. thunderstorm activity is a
little less certain in terms of timing, but have the prob 30 in
from 19-01z at first with gusty winds possible/ifr vis. have
another prob30 after 01z as many of the models keep rain and/or
convection around the terminal through at least 3z if not
slightly later.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...none.
&&
$$
discussion...mcd
aviation...mcd