Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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143 FXUS63 KIWX 102233 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 633 PM EDT Thu Sep 10 2026 .KEY MESSAGES... - Mainly dry through Friday with seasonable temperatures and low humidity. - Next chances for rain/storms will be Saturday, with the highest chances of 40-60% south of US 24. - Dry, slightly warmer, and more humid Sunday and Monday. && .DISCUSSION... Issued at 124 PM EDT Thu Sep 10 2026 Surface high pressure building across the Midwest and eventually into the Great Lakes later tonight will yield mainly dry conditions through Friday. The cold front that was supposed to come through yesterday slowed quite a bit from what was originally anticipated and stalled just to our northwest this morning; as that front now makes its way through our forecast area today, an area of showers is passing through north-central Indiana as seen on current radar. While I can`t rule out an isolated storm, a tight moisture gradient in the low levels and SBCAPE of 1000 J/kg or less should keep widespread chances at bay. Highs in the upper 70s are expected today. It will be noticeably less humid with dewpoints only in the 50s once the front passes through and northwest flow ensues on the backside, ushering in much drier air tonight. Much like last night, patchy dense fog is possible given clear skies and light winds. Should radiation fog occur, visibilities should not be as low as they were this morning given a lack of saturation at the surface. I would expect that areas south of US 24 would be most primed for fog to develop today given the showers currently moving through. Friday will be a fantastic day with high pressure overhead providing low humidity, highs near 80 degrees, and lots of sunshine! Our next chances for rain and storms arrive starting before daybreak Saturday and continuing, especially south of US 24 once again, throughout the day Saturday. Far northwest Indiana and southwest Lower Michigan may stay entirely dry given that the better dynamics for this rain/storm potential will be to our southeast. A warm front will lift northward Saturday, and with a developing upper level trough over the Great Lakes, scattered showers and storms appear increasingly likely for our southeast half. There is some uncertainty on how far north and west the rain will get, with our highest PoPs of about 40-60% south of US 24 on Saturday. The ECMWF has the trough at 500mb slightly more amplified and further east by Saturday afternoon than the GFS and NAM do so that will make a difference too as to where and when the highest PoPs occur. Severe weather is not expected at this time on Saturday. Zonal flow continues aloft as yet another upper level ridge builds across the central CONUS, so have maintained warmer than normal temperatures and low chances (20%) for PoPs through Sunday and Monday. Since it is still several days out, there is still a lot of uncertainty in how the overall synoptic pattern evolves early next week. Some models have a frontal system coming through the Midwest and Upper Great Lakes Tuesday while others keep the upper level ridge dominant over the area. There are no clear signs of fall in any of the long range guidance as our forecast area looks to remain sandwiched between hot and humid air to our south and cooler, drier air to our north for the foreseeable future. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 633 PM EDT Thu Sep 10 2026 Slow moving cold front sinking through KFWA early this evening with showers/sprinkles and low chances for a brief period of MVFR ending at or shortly after issuance. Some concern once again for patchy BR formation toward daybreak tomorrow at mainly KFWA, though confidence is low regarding coverage/impact. Dry/VFR otherwise as a drier air mass filters in. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Johnson AVIATION...Steinwedel