Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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882 FXUS63 KIWX 290953 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 553 AM EDT Tue Sep 29 2026 .KEY MESSAGES... - While it is possible spotty showers creep into areas north of US-6 on Wednesday, a majority of the area remains dry. - Rain is expected late Thursday into early Friday. Around an inch is anticipated for most locations. No severe weather or significant flooding is expected. - A warming trend takes mid to upper 70 degree high temps today into the 80s for areas south of US-30 by Thursday. - Trends are towards a dry and cooler weekend which looks to continue into next week. && .DISCUSSION... Issued at 125 AM EDT Tue Sep 29 2026 Surface high pressure is shifting east underneath mid level ridging and this keeps the area dry once again. One thing that does happen, though, is that warm advection commences bringing a return to upper cloudiness for this evening and tonight. This warm advection also helps southern areas get into the upper 70s to around 80 degree highs for Wednesday. This is especially the case because the vorticity is more focused to our north and west as opposed to overhead. The best of the instability (still less than 100 J/kg of MUCAPE) finally arrives around 00z in our northwest, but surface dew points are still below 60F and the best forcing has moved more northeastward instead of eastward into southwest Lower MI. All of this to say that it is possible that rain gets into the area Wednesday afternoon/evening, but severe weather is expected to be limited and thunderstorm chances are low, if not non-existent. This is why we have good chances to see those 80 degree highs on Wednesday is that, despite cloud cover, we have limited rain chances down south there. By the time we get to Thursday, the stalled front to our west slides eastward slowly as a trough moves east- southeastward across southern Canada. Later Thursday and Thursday night is our best thunderstorm chance of this rainy period as the NAM brings through areas of instability up to 1000 J/kg of MUCAPE. Rain may linger into Friday morning, otherwise, the trend will be to dry out Friday afternoon as a surface high pressure system moves in. This dry period also looks to last a while as the later Saturday/Saturday night rain chance doesn`t have much model agreement at this point. So, a series of high pressure systems move through and the area remains underneath an area of subsidence as a result. Highs in the 70s to around 80 today through Thursday, trend lower, behind the cold front Thursday night, allowing for a return to highs in the 60s and lows in the 40s for Friday through early next week. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 552 AM EDT Tue Sep 29 2026 We have been watching fog form this morning that`s not as dense as yesterday morning`s. Even still the potential is there for at least shallow ground fog at one or both of the terminals. NAM bufkit soundings indicate perhaps FWA is more shallow ground fog, whereas SBN gets denser fog. However, LAV guidance indicates it`s FWA that gets the denser fog. This creates quite a bit of uncertainty with these TAFs. At this point, given the uncertainty and current observations, have gone with tempo MVFR fog up to 13z. Otherwise, surface high pressure is shifting east underneath mid level ridging and this keeps the area rain-free once again and cloud free for the first part of the TAF period. One thing that does happen, though, is that warm advection commences bringing a return to upper cloudiness for Tuesday evening. As such, expect north winds to become more southerly this morning, staying below 10 kts sustained through the day again. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Roller AVIATION...Roller