239 FXUS63 KIWX 060907 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 507 AM EDT Sat Jun 6 2026 .KEY MESSAGES... - There is a marginal to slight risk for strong to severe storms today, especially between 2pm and 11 pm EDT. Confidence is medium. Damaging winds and large hail are the main threat. Frequent lightning and heavy rain are also expected. - Nearly daily chances (20-50 percent)for showers and storms through next weekend, especially Monday into Tuesday night (50-90 percent). - Hot and humid, especially from Wednesday into next weekend. Heat indices will be at or slightly above 100 degrees at times. Highs will be in the upper 80s, low-mid 90s. Lows in the 60s, low-mid 70s. && .DISCUSSION... Issued at 505 AM EDT Sat Jun 6 2026 Our CWA is still in a marginal to slight risk for today, though the slight risk was expanded into portions of IN. Generally the slight risk extends from San Pierre, IN (Starke Co) through Milford, IN (Kosciusko Co) into Pioneer, OH (Williams Co, IN) and southeastward of that line. For the afternoon, far northern Berrien County, MI is in general thunder vs. Marginal risk (ongoing storms are main threat). The greatest threat for severe weather will be mid to late afternoon into the evening (2-11 pm EDT). Strong storms are still possible through this morning/early afternoon. A broad line of convection dropped southeastward from WI across Lake MI and as of this writing (3:45 am ET) is just dropping into the South Bend, IN to Union City, MI area. Lightning intensity has tapered off in the last couple hours and breaks are beginning to show within the line as it continues to weaken. Still, the storms are dropping into an area of steeper mid level lapse rates and strong moisture transport, with dewpoints in the mid-upper 60s and even a couple nearing 70 (KPPO, KANQ). We're also seeing the base of the 500 mb trough approaching, with PVA increasing and a jet streak aloft. Bulk effective shear looks to be in the 30-40 knot range through the next 6 hours at least. We've also seen development in scattered convection ahead of the line as the forcing/moisture transport (LLJ) have increased with time. The main cold front is still further north across the northern Lower Peninsula draped down to southern WI/NW IL. Convection well ahead of that extends all the way into IL near KPIA north to Chicago...and is now in NW IN as far inland as Goshen/Rochester. Expect this area of convection to congeal with the incoming line, so have likely/categorical (55+) pops dropping southeastward through the late morning. At the moment, we have an SPS out for the storm coming off Lake MI for half inch hail and 50 mph winds...with a SMW out for Lake MI (expiring within the hour). This storm is the strongest at this moment. Otherwise, while a few storms could be strong don't expect widespread severe weather through the morning. In those cases perhaps some 40-50 mph winds and small hail. Frequent lightning and heavy downpours are expected. Through the afternoon we'll see the cold front drop southeastward, moving into a moist unstable airmass. Surface based cape even now is 1500-2000 J/kg in our NW though we are at this point seeing somewhat of a CAP. By late morning as the cap erodes, surface based instability rises and expands CWA-wide into the 1000-2500 J/kg range. Mid level lapse rates start out strong this morning at 6.5 to 7.5 C/Km, but by late afternoon we do see them start to drop to 5.5- 6.5 C/Km which is less favorable in terms of our severe weather threat. That being said, forcing from the cold front/mid level wave combined with ample surface instability/moisture is sufficient to keep things at least marginally severe (especially with 0-6km bulk shear on the order of 30 to 45 knots). The main threats will be damaging winds (15% prob in SPC outlooks) and large hail (5% SPC). It's possible we see a combination of multicell/line segments and potentially even a few discrete supercells. SPC keeps the tornado risk (2 percent) further east of our area for now, but we all know how supercells can get snippy in a hurry. 0-1km shear looks to be around 20-25 knots at points in the south (HRRR has slightly higher...). For now will see how things evolve and will focus messaging on Wind/Hail as those are much more likely. Sunday will be dry for most areas earlier in the day as our cold front stalls out somewhere in our far south/southwest CWA or possibly even just south/west of our area for a period. Later in the day as we build some instability models suggest we see a brief uptick in the convective activity. Kept pops (20-40 percent) confined to southwest of a line from Westville, IN to Berne, IN. Highs will be in the mid 80s for most areas. Stationary front lifts northeastward as a warm front Monday into Tuesday morning, stemming from a low over southern WI/Northern IL. As the low drifts eastward into Lake Erie through Wed AM, we'll see the weak/decaying cold front swing through and eventually wash out/stall as warm air advection ensues from a separate system to the west (pulling moisture from the gulf). The boundary looks to be along I 80-90 by Wed AM. Tuesday have 55-85 percent chances, then diminishing to 25 to 45 percent Wednesday. Highs will be in the mid-upper 80s on Mon- Tuesday, with heat indices climbing into the 90s for some locations. The main focus from Wednesday onward will be the heat and humidity, with high temperatures building into the upper 80s and low-mid 90s each day. Overnight temperatures in this period will be in the upper 60s and low to mid 70s, providing little relief from daytime heat. It's highly probable we'll need heat advisories at some point in this period, with heat indices of 95-105 degrees several days in a row. If the forecast pans out, we'd have about 4 consecutive days of heat advisory criteria, which would bump us into the extreme heat warning headline criteria. This is especially true given overnight temps in the low-mid 70s (and humid). Tricky aspect is that the heat indices of 100 or greater vary in exact location each day. At this juncture, it would be wise to prepare for the heat and perhaps reconsider any strenuous outdoor plans if possible. There will be daily chances (20-30 percent) for showers and storms given the heat and humidity, and the fact that we're on the periphery of an upper level ridge that gradually breaks down as a deep low pressure system lingers in northern Ontario close to Hudson/James bay. This will bring several shortwaves or surface fronts through our area. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 122 AM EDT Sat Jun 6 2026 A surface front will slowly drop south through the area, producing numerous showers with embedded thunderstorms through early this morning. Best chances for shower/thunderstorm activity looks to be around 08-11Z at KSBN and 09-13Z at KFWA. Periods of MVFR ceilings likely at KSBN with this activity with brief pockets of MVFR ceilings further south including KFWA. Conditions then become VFR through mid morning. Another round of storms is possible at KFWA and on south mainly between 19-22Z, though isolated activity can't be ruled out further into the evening. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...MCD AVIATION...Edwards