FXUS63 KIWX 190659
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
259 AM EDT Tue May 19 2026

.KEY MESSAGES...

- Strong to severe storms are possible today between 3-11 PM
  EDT. 

- Damaging wind gusts to 60 mph and heavy rain are the 
  main threats. Low but non-zero risk for hail and an isolated 
  tornado.

- Warm and humid again today with highs in the mid to upper 80s.

- Cooler with seasonable temperatures and dry midweek. Highs only in 
the 60s Wednesday and Thursday. 

- Next chance for rain and a few storms arrive Friday. 

&&

.DISCUSSION...
Issued at 259 AM EDT Tue May 19 2026

Satellite and radar imagery currently shows a line of strong to 
severe thunderstorms entering Illinois. This activity is expected to 
weaken as it moves east, but a few isolated showers cannot be ruled 
out around daybreak (15-20% chances) in our forecast area. Ahead of 
an approaching cold front, strong to severe storms will be possible 
this afternoon and evening. Our area will be well into the warm 
sector today; Dewpoints will increase to around 70 degrees in 
response to a strong southwest LLJ ramping up throughout the day. 
Moisture combines with daytime heating (highs in the mid to upper 
80s) to support SBCAPE of 2000-2500 J/kg. Destabilization should 
occur this afternoon, with chances for strong to severe storms 
highest between 3-11 PM EDT today. The greatest risk area will be 
along and south of US 24, where a Slight Risk (level 2 of 5) for 
severe weather is in place. SPC actually pulled the Slight Risk from 
our northwest half of the forecast area, which I agree with as the 
US 24 corridor will have ample time to heat up and destabilize this 
afternoon before the cold front arrives. Shear is still expected to 
be weak given a fairly unidirectional vertical wind profile, but it 
will be better than the past few days at 20 to 30 kts. With weaker 
shear, the favored storm mode will be multicell clusters or line 
segments. Given DCAPE of around 1000 J/kg this afternoon and evening 
and steep low level lapse rates of 7-8 C/km, damaging winds will be 
the main threat today. In addition, forecast soundings do show some 
veering between 0-1km, low level SRH up to 200 m2/s2, and LCLs below 
1000m, so an isolated tornado is possible today. This potential is 
greatest in NW Ohio, which will have the longest time to heat up and 
destabilize today as the cold front takes its time moving in from 
west to east. With PWATs around 1.25-1.5", even if storm clusters 
are not severe, they will likely be efficient with rainfall rates in 
excess of 1"/hr.

It will be noticeably drier with much more seasonable conditions 
midweek behind the cold front. High pressure builds in on 
Wednesday and Thursday across the Great Lakes region. Highs will
be in the 60s and it will feel much cooler than the previous 
stretch of warm and humid days. Next chance for rain and a few 
storms arrive Friday as a low pressure system lifts into the 
Ohio River Valley. Highs Friday and Saturday will be in the 70s.
Summer-like temperatures in the 80s return by late in the 
weekend into early next week with additional daily periodic 
chances for rain/storms.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 106 AM EDT Tue May 19 2026

VFR conditions will continue through midday. Winds have
diminished to around 10 kts for now, but will quickly ramp up
after sunrise and through the morning hours. Breezy southwesterly
winds will gust as high as 30 kts today, even outside of any 
showers or storms. An approaching cold front will bring chances
for showers and storms today, but confidence is low on exactly
where. The strongest storms may end up east of IN-15 towards 
KFWA, but have maintained a PROB30 at KSBN for 17-20Z and a few 
hours later at KFWA from 19-22Z. MVFR ceilingsand visibilities 
will be possible within any storms. The main threats today will 
be heavy rain and damaging wind gusts up to 50kts.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for LMZ043-
     046.

&&

$$

DISCUSSION...Johnson
AVIATION...Fisher