632
fxus63 kiwx 171718
afdiwx
area forecast discussion
national weather service northern indiana
118 pm edt fri jul 17 2026
.key messages...
- air quality alerts continue today and into friday, in part
due to smoky conditions.
- chances (30% to 70%) for showers and thunderstorms this
afternoon and early evening. storms may produce heavy rain.
- thunderstorms on saturday afternoon may produce damaging wind
gusts.
- not as warm starting sunday.
&&
.discussion...
issued at 402 am edt fri jul 17 2026
a quasi-stationary/cool frontal boundary is currently draped
from the northwest to the southeast just south of our cwa. this
boundary helped to kick off a couple of isolated instability
thunderstorms last evening that were nearly stationary and
produced heavy downpours with pws of 1.5 to 1.75 inches over
the area. forecasted pws later today and on saturday push
closer to 2 inches with increased southerly flow and a bit of
moisture advection as surface dew points increase back into the
70s on saturday. shear values today will top out around 25 kts
while on saturday values about double to around 50 kts. dcapes
values today will top out around 2000 j/kg while tomorrow values
increase to around 3000 j/kg. today spc has a marginal risk of
severe storms over our southeastern portions of the area with
the boundary still in the vicinity. however, tomorrow better
synoptic forcing arrives with a shortwave pushing into the area
with an accompanying cold front and this will all lead to the
potential of stronger storms. spc currently has our area with
marginal to slight risks for severe storms. the main threats
look to be gusty outflow winds and heavy downpours that can lead
to localized nuisance flooding especially today with steering
flow on the weak side.
smoke and poor air quality continue today but should see a bit
more improvement later today as the flow increases aloft ahead
of the incoming shortwave. heat and humidity also continues
today and saturday with highs in the upper 80s to low 90s. in
the wake of the cold front sunday and monday will see a break
in the heat and humidity with highs in the lower 80s each day
and drier dew points ranging in the upper 50s to lower 60s. a
break in precipitation will also take place sunday through the
most of the day monday before another trough and cold front drops
into the region on monday evening into tuesday bringing another
batch of showers and thunderstorms as well as even cooler
temperatures arrive for the middle of next week with highs only
in the 70s on wednesday and thursday.
&&
.aviation /18z tafs through 18z saturday/...
issued at 111 pm edt fri jul 17 2026
two fold challenge with tafs mainly in the first 6 to 12 hours.
the first is the large plume of smoke persisting across the
area. a warm front, located to the sw of both locations, is set
to work ne over the next several hours and should being to
either break up or push and smoke to the ne. at the same time, a
moderately unstable atmosphere is located southwest of the front
with scattered showers and storms already developing across
central in. a few showers existed north of the front, but are
struggling to intensify. have made some minor changes to the
tafs to keep the smoke in a bit longer and confine convective
chances to along and south of the front. left as a prob30 given
concerns for coverage at this point. after sunset, storm
coverage should wind down with the warm front well north of the
area.
eventually a cold front is expected to drop south during the
afternoon and evening hours saturday with better chances for a
line of showers and storms. this looks to wait till after 18z so
no pops.
&&
.iwx watches/warnings/advisories...
in...air quality alert until midnight edt /11 pm cdt/ saturday
night for inz005>009-012>015-017-018-020-022>027-032>034-
103-104-116-203-204-216.
oh...air quality alert until midnight edt tonight for ohz001-002-
004-005-015-016-024-025.
mi...air quality alert until midnight edt saturday night for
miz078>081-177-277.
marine...dense smoke advisory until 8 pm edt this evening for lmz043-
046.
&&
$$
discussion...andersen
aviation...fisher