FXUS63 KIWX 211045

AFDIWX



Area Forecast Discussion

National Weather Service Northern Indiana

645 AM EDT Sun Jun 21 2026



.KEY MESSAGES...



- Widespread rain is expected this evening and overnight. Most

  locations will see around an inch with pockets of two inches

  or more possible.



- The severe risk is low but a few strong storms can't be ruled

  out south of Highway 24.



- High waves and dangerous currents are expected on Lake

  Michigan beaches Monday.



- The rest of the week will feature slightly below normal

  temperatures and periodic chances for light rain.



&&



.DISCUSSION...

Issued at 254 AM EDT Sun Jun 21 2026



Convectively modified shortwave(s) currently moving through the 

Central Plains will continue eastward today and impact our area this 

evening/overnight. Some right entrance upper jet dynamics and 

ejecting MCV will support modest surface cyclogenesis with a 40+ kt 

LLJ nosing into our southern CWA. Unfortunately, the exact details 

remain murky even less than 24 hours out due to complications from 

multiple upstream MCS's. Cluster of convection currently over KS/NE 

is expected to eject eastward through the morning (fueled by steady 

LLJ/moisture convergence) and capitalize on some modest 

destabilization south of I-70 this afternoon. This cluster of 

convection will sweep across Indiana during the evening hours but 

the exact track remains uncertain as does the exact location of the 

all-important surface frontal boundary. Bulk of guidance keeps this 

surface boundary and associated severe risk just south of our CWA. 

However, still some members suggesting it will sneak into our far 

southern counties. Still think the severe risk is low. While 

shear/helicity values are supportive of a severe risk, midlevel 

lapse rates are very poor and surface dewpoints are only around 60F 

(even south of the front). Even the northward-displaced models (3km 

NAM) still show awfully stable profiles in the lowest 3-5 kft that 

will be difficult to support any damaging wind/tornado risk. Our far 

south (south of US-24) still bears some watching this evening but a 

lot of factors would have to come together to yield a severe risk 

and the chances of that appear low at this point. We will continue 

to monitor upstream convection closely through the morning though.



The other aspect to this event will be the potential for some 

moderate-heavy rain. Here again, important mesoscale details remain 

unresolved. My suspicion is that a progressive MCS just to our south 

will rob better moisture from our CWA, as suggested by some of the 

latest CAM's, keeping rainfall amounts generally around an inch or 

perhaps even less. However, some elevated deformation/fgen oriented 

parallel to the mean flow could set up the potential for some 

training moderate rain even in our northern zones. Also, the better 

moisture/instability and MCS track could still sneak into far S/SE 

zones. Deep warm cloud layers and PW values near 2" certainly bear 

watching and could support isolated pockets of heavy rain/minor 

flooding but uncertainty in convective evolution and overall modest 

ingredients continue to preclude a flood watch here. Most of our 

area missed out on heavy rain Wed night and we should be able to 

handle a widespread 1", even with pockets of around 2".



SCT, light rain showers likely persist through most of the day 

Monday as a secondary shortwave moves through the region and 

northerly flow will likely keep highs in the low 70s. Shortwave 

ridging/subsidence yields one dry/pleasant day on Tue but another 

trough brings more light rain chances late Wed into Thu and again 

late Fri into Sat (perhaps some heavier rain with that one). Highs 

remain in the upper 70s/near 80 until finally a strong ridge 

develops next weekend and pushes highs back to near 90 to end the 

month.



&&



.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...

Issued at 645 AM EDT Sun Jun 21 2026



Shortwave ejects into the region tonight and brings widespread 

rain, MVFR ceilings, and a few embedded thunderstorms. The best 

chance for storms will be at KFWA where better moisture and 

instability reside. Best thunder chances appear to be roughly

01-05Z but that timing could still change. IFR ceilings are 

also expected at KFWA after 06Z as cooler air filters into the 

area and combines with very moist low levels.



&&



.IWX WATCHES/WARNINGS/ADVISORIES...

IN...None.

OH...None.

MI...None.

MARINE...None.



&&



$$



DISCUSSION...AGD

AVIATION...AGD