541
fxus63 kiwx 252318
afdiwx
area forecast discussion
national weather service northern indiana
718 pm edt wed mar 25 2026
.key messages...
- very warm on thursday with highs in the 80s south of us 24,
with most other locations seeing highs in the 70s. sharply
colder thursday night and friday.
- there is an 80% to 90% chance for showers and storms thursday
evening. storms could be severe with damaging wind gusts,
large hail, heavy rain and tornadoes. the greatest severe
weather threat is between 5pm and 11pm edt.
&&
.discussion...
issued at 212 pm edt wed mar 25 2026
persistent, large upper-level ridging remains in place over much of
the southwest and south-central us. energetic flow spills atop this
ridge and over the great lakes. within this flow is a sharp upper-
level low that floats through tonight bringing a 30-60% chance
of showers (and perhaps a rumble of thunder) to areas primarily
south of us 30. abundant low-level dry air will cut into
rainfall amounts while meager mucape of less than 500 j/kg
raises questions about the risk of thunder. with the freezing
layer near 10k ft, cannot rule out instances of pea-size hail
from the tallest cores tonight.
of greater interest is the risk of severe thunderstorms thursday
evening. warm, moist advection is set to prevail tonight
resulting in near-steady temperatures in the 50s early thursday
morning with dew points rising into the 50s and approaching 60.
a warm front is forecast to stall east-west across far southern
michigan. how quickly this front gets shunted south by
deepening canadian low pressure is critical for how
thunderstorms evolve. a strong cap needs to be overcome as
well.
the general thinking continues to be that isolated
thunderstorms develop over northern illinois and quickly congeal
into a line that drops southeast through the forecast area. the
window of opportunity remains about 5p to 11p edt, with
damaging wind and heavy rain the primary hazards from line
segments. any discrete storms that develop within the warm
sector could produce large hail and even a tornado. mucape in
excess of 1,000 j/kg and 0-6km shear of 55-60 knots bolster
forecast confidence, while the trigger to break the cap is
likely the combination of an incoming cold front and a
strengthening low- level jet across central il. rain rates of 1"
per hour and boundary-parallel flow will raise the concern for
flooding as the night progresses, but forward speed of the cold
front may limit this risk overall. dry conditions prevail for
most of the area by daybreak friday.
sharply cooler on friday, especially along the lakeshore where
northerly flow may keep those communities locked into the 30s all
day as high pressure becomes centered over western iowa. return flow
saturday offers slight improvement into the 40s. warmer sunday and
through at least the start of next week as high pressure over the
southeast us promotes warming along with increased chances for
showers and storms.
&&
.aviation /00z tafs through 00z friday/...
issued at 718 pm edt wed mar 25 2026
llj strengthens overnight in advance of the next trough
approaching the great lakes. this will lead to some marginal
llws conditions at both sites overnight. increasing waa will
also touch off a few showers and storms around kfwa. confidence
in coverage and thunder chances is low so will hold with just a
prob30 for now. mvfr stratus likely at ksbn during the day
thursday with some low-end potential it could reach kfwa. main
window for thunderstorms will be 22-04z at ksbn and 00-06z at
kfwa as a cold front slides through the area. severe storms are
possible.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...gale watch from thursday evening through friday morning for
lmz043-046.
&&
$$
discussion...brown
aviation...agd