785 FXUS63 KIND 241051 AFDINDArea Forecast Discussion National Weather Service Indianapolis IN 651 AM EDT Wed Sep 24 2025
.KEY MESSAGES...
- Scattered to numerous showers and isolated thunderstorms at times through tonight
- Thursday will transition from this week`s final showers...back to another warm and rain-free pattern
- Dry and warm conditions Friday into next week, with slight moderation from mid-70s to low 80s
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.SHORT TERM (Today and tonight)... Issued at 300 AM EDT Wed Sep 24 2025
Early This Morning...
The initial wave of stronger forcing has moved east of central Indiana at the moment, with mainly scattered light showers across the area. Regional radar does show another area of rain across south central Illinois, which will move east in the predawn hours.
Will have some likely PoPs south for the area of rain moving in from Illinois, with lower PoPs elsewhere for the scattered showers.
Today...
The upper trough will remain west of the area today but could still send some weak energy into the area at times. The surface boundary will set up near the far southern forecast area early in the period. A weak surface low will ride along the front, bringing scattered to numerous showers to the southern forecast area this morning, with scattered showers north.
After the wave passes, northerly winds will strengthen a bit, bringing in some drier air. This plus only weak forcing possible with any upper energy that moves through leads to lowering PoPs during the afternoon, down to slight chance for some areas.
Any decent instability will be kept south of the boundary, so any strong convection should stay south of the area. A few storms are possible in the southern forecast area, but elsewhere the thunder threat looks minimal.
Clouds and rain will keep highs in the 70s today.
Tonight...
The upper trough and an upper jet will move into the area, helping another surface wave to ride along the boundary to the south.
Best forcing will be near and south of the surface wave, so will go with highest PoPs in the south tonight (low likely category far south).
Better moisture will be confined south of the area, and the stronger 850mb winds are more parallel to the front. This will keep the threat for heavy rain south of central Indiana. This setup also keeps most of the thunder south as well.
Cooler air will come in behind the wave, bringing low temperatures back to the upper 50s north and lower 60s south.
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.LONG TERM (Thursday through Tuesday)... Issued at 300 AM EDT Wed Sep 24 2025
Thursday through Saturday...
The long term will begin with central Indiana transitioning back into another extended duration of dry and warm conditions. The stubborn upper trough that has provided periods of much needed rainfall this week...will finally depart to the east on Thursday. However, this wave`s corresponding surface trough will already be aligned over Ohio before the short term ends...blocking some of the recent humidity and precipitable water to south/east of the local region. Nevertheless the H500 axis will cross the CWA through Thursday evening, promoting the week`s final scattered showers, mainly east of I-69. At times moderate northwesterly breezes will bring decreasing clouds Thursday afternoon and dewpoints down into the 50s for most locations.
Late this week will feature a zonal ridge slowly sliding east across the central CONUS into the Midwest. Weak surface high pressure will provide a dry column and rain-free conditions while light northwest winds and H850 temperatures around 12 degrees Celsius will promote a subtle moderation through slightly above normal levels, with highs nearing 80F by Saturday. Humidity will also be slightly above normal for late September, yet reasonable...with both dewpoints and morning lows in the 50s.
Sunday through Tuesday...
The dry and warm pattern will continue into next week...as stronger high pressure slowly sliding north over Ontario...helps to build the next subtropical ridge over the Quad Cities/Great Lakes region. This should be the center of another, albeit disorganized, omega block over the central US. Indiana will likely find itself situated between the very warm, stationary ridge just to our north...and a small disturbance retrograding west through the Tennessee Valley, making up the southeast corner of the block.
This should translate to light easterly breezes under partly to mostly clear skies and above normal readings often reaching the low 80s. The disturbance expected to pass to our south bares watching, yet the dry column should suppress any low rain chances to south of the Ohio River. Some guidance members suggest a tropical system nearing Cape Hatteras by the end of the long term...may eventually supply moderate humidity levels into the Midwest courtesy of the persistent easterly flow, although lower confidence here for the time being.
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.AVIATION (12Z TAF Issuance)... Issued at 650 AM EDT Wed Sep 24 2025
Impacts:
- Very low SCT/BKN stratus will fluctuate between VFR/IFR through 14Z - CIGs expected to lift to MVFR by 15Z...VFR by 17Z-20Z - Scattered/numerous -SHRA throughout the period...isolated TSRA possible at KHUF/KBMG - CIGs likely deteriorating again to MVFR pre-dawn Thursday
Discussion:
IFR/VFR this morning over central Indiana terminals...will improve to VFR this afternoon. Surface low pressure passing to the southeast of the region will provide periods of additional scattered -SHRA. Very light N/NE surface winds this morning...will be sustained around 7-10KT at most terminals this afternoon.
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.IND WATCHES/WARNINGS/ADVISORIES...None. &&
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SHORT TERM...50 LONG TERM...AGM AVIATION...AGM
NWS IND Office Area Forecast Discussion