FXUS63 KIWX 181407 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1007 AM EDT Sat Jul 18 2026 .KEY MESSAGES... - Smoke from Canadian wildfires will continue to bring periods of poor air quality and reduced visibility through at least Monday. - Slight chance for severe storms this afternoon into the evening. Damaging winds and heavy downpours will be the main threats. - High swim risk conditions are expected by this afternoon along Lake MI beaches in Berrien County, MI and La Porte County, IN by late afternoon and evening. Moderate swim risk conditions are expected before that. Dangerous waves and currents are expected. && .UPDATE... Issued at 1006 AM EDT Sat Jul 18 2026 2 features of interest being monitored this morning. The first is a pre-frontal trough extending from Chicago to Flint MI. Showers and storms have persisted further north, but despite their best efforts new development to the SW has struggled. CAMs vary considerably on what, if anything, this feature will do as it progresses south and likely stalls or washes out. While not confident, have maintained some slgt chc pops into early afternoon. The main cold front, currently from northern Lower MI to SE Wisconsin, will continue its track SE and become the primary focus for showers and storms this afternoon. Models also vary with this feature on timing of initiation as subsequent location with a trend for development near/south of US-6 and then progressing south. Plenty of instability will exist with a stronger low level flow to not only keep storms moving but allow an increased risk for damaging winds. The greatest threat for more widespread wind damage resides just to the east of our area where an Enhanced Risk exists. Over our area, there was no changes to the SPC DY1 outlook. Again, made some token changes based on current models trends this afternoon to pops, but given lower confidence in where storms develop didn't go crazy with modifications. && .DISCUSSION... Issued at 515 AM EDT Sat Jul 18 2026 A shortwave trough moving through the cyclonic flow on the eastern side of high amplitude ridging over the Plains and into central Canada. A cold front associated with this shortwave will begin to push south into our area around midday. SBCAPE values of 2500-3000 J/kg will be available along with bulk shear values of 25 to around 50 kts. Surface dew points in the mid 70s will provide ample moisture and PW values are around the 2 inch mark today. Storms today should have a fairly progressive speed so will help keep the flooding risk a bit lower than the last couple of days when the steering flow was much slower. Helicity values are forecast to be only around 50 m2/s2 which will keep the risk of tornadic activity low. However, with any boundary in close proximity to storms there could be an isolated brief spin up or two. Lapse rates of 6.5-7.0 deg/km will help to allow for some hail production however not ideal for large hail especially with the very humid and warm lower levels but the melting of hail coupled with the heavier downpour potential will make outflow gusts the biggest threat with the storms today. SPC did add a fairly small section of enhanced to our far eastern portions of the CWA in Henry and Putnam counties of Ohio with the better dynamics further east of our area. However, the majority of the area is currently under a Slight risk today. In the wake of the cold front as it pushes southward a more northerly flow will arrive and this will make for hazardous beach conditions over the southeastern Lake Michigan and wave heights from 3 to 6 feet on the big lake. A Beach hazards statement has been issued to address this threat as well as a Small Craft Advisory. Drier airmass will also accompany the frontal passage. Sunday will be a bit cooler and drier with a more northwesterly flow aloft and high temperatures will be mainly in the low to mid 80s and dew points only in the 60s. We will also see a short break in precipitation chances on Sunday into Monday before another trough pushes into the lower Great Lakes region on Monday evening. This will also bring another chance of showers and thunderstorms to the area. A few of the storms may become strong to severe so will need to watch this in the coming days. A northwesterly flow aloft sets up again over the region by Tuesday and remains through the rest of next week and this will help to keep temperatures slightly cooler to near normal values. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 625 AM EDT Sat Jul 18 2026 Mostly VFR conditions expected through at least 15z today. A cold front will push southward after this time and bring scattered thunderstorms into the area as it pushes south through the evening period. MVFR to IFR vsbys in any thunderstorm downpours along with MVFR cigs. Mainly VFR conditions should return after the cold front pushes south through the area after 21z Sat for KSBN and after 01z Sun for KFWA. Gusty southwesterly winds early for both TAF sites before a shift to more northwesterly post frontal. Gusts up to 25 kts possible especially within or near thunderstorms. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Air Quality Alert until midnight EDT /11 PM CDT/ tonight for INZ005>009-012>015-017-018-020-022>027-032>034-103-104- 116-203-204-216. Beach Hazards Statement from 7 PM CDT this evening through late tonight for INZ103. OH...None. MI...Air Quality Alert until midnight EDT tonight for MIZ078>081- 177-277. Beach Hazards Statement from 5 PM EDT this afternoon through late tonight for MIZ177-277. MARINE...Small Craft Advisory from 2 PM this afternoon to 5 AM EDT Sunday for LMZ043. Small Craft Advisory from 5 PM this afternoon to 5 AM EDT Sunday for LMZ046. && $$ UPDATE...Fisher DISCUSSION...Andersen AVIATION...Andersen