105 FXUS63 KIND 061056 AFDINDArea Forecast Discussion National Weather Service Indianapolis IN 656 AM EDT Mon Oct 6 2025
.KEY MESSAGES...
- Sunny morning, followed by increasing clouds and arriving rain showers.
- Widespread rain with some thunderstorms Monday night into Tuesday
- Dry and seasonable weather Wednesday through Friday, warmer into early next week
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.SHORT TERM (Today and tonight)... Issued at 302 AM EDT Mon Oct 6 2025
Surface analysis early this morning shows strong high pressure in place over the middle Atlantic States, extending east into the Atlantic. This broad high continued to influence the weather across Indiana, providing warm but light southerly winds, subsidence and clear skies. A cold front was found stretching from eastern WI, across IA to eastern KS. Water Vapor imagery shows subsidence in place across Central Indiana with southwest flow in place aloft. An area of moisture was found near the previously mentioned cold frontal boundary, and additional moisture was found over the deep south and gulf coast. Dew points remained quite moist, in the upper 50s and lower 60s.
Today...
A changeable weather day is in store today. The day will begin similarly to how the past few days have, sunny and warm. However, by the end of day clouds will have invaded along with scattered to isolated showers, with more widespread rain tonight.
Two weather features will be approaching Central Indiana today. Models show moisture and forcing advecting northward from the deep south, amid the southwest flow aloft and southerly surface flow. Additional moisture and forcing will approach from the northwest, associated with an approaching upper trough and its previously mentioned cold front. As these features come together today, forecast soundings show gradual saturation, with deep saturation achieved by late afternoon and early evening. Pwats have consistently shown favorable moisture with values near 1.7 inches. HRRR shows scattered shower development arriving in Central Indiana from the south this afternoon...associated with the mid level moisture advection from the deep south. Coverage should become more widespread toward 00Z. Confidence is high for rain late today and tonight.
Thus will start out with dry pops today and begin ramping pops upward from south to north through the afternoon hours. Cloud cover will also have a similar trend. Given the warm start to the day and plentiful morning sunshine, highs at or just below persistence, in the lower 80s will be expected.
Tonight...
Confidence for rain tonight is quite high as all the previously mentioned rain making ingredients are suggested to converge over Indiana. Again, these ingredients being the moisture surge from the south and the approaching upper trough and cold front. Forecast soundings through the overnight hours remain saturation from nearly 00Z-09Z as these feature arrive. Again pwats show plentiful moisture with values near 1.6 inches. Some top down subsidence appears to arrive after 09Z as the upper trough pushes some of its moisture and forcing farther east. Still, plenty of saturation appears to remain within the mid and lower levels. Thus will continue with very high pops this evening and overnight, ever so slightly backing off after 09Z as some subsidence arrives.
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.LONG TERM (Tuesday through Sunday)... Issued at 302 AM EDT Mon Oct 6 2025
A brief break in the abnormally dry conditions expected on Tuesday as a frontal system brings widespread rain and a few storms to Central and South Central Indiana. More seasonable October weather arrives midweek with a warming trend back to the 70s for next weekend. Watching for the possibility of patchy frost in North Central Indiana and Wabash River Valley late Wednesday and Thursday night.
A frontal boundary pushes through the state Tuesday bringing rain and thunderstorms to much of Central and South Central Indiana. The heaviest rain is expected across southern Indiana during the early morning hours as a surge of Gulf air moves northward associated with a strengthening low level jet aloft. Forcing from the surface front lags behind the stronger lift associated with the LLJ, keeping precipitation chances into the daytime hours on Tuesday as the front passes through. Not expecting a complete washout of a day for Central and North Central Indiana as precipitation is expected to be more scattered in nature, ending from NW to SE in the afternoon. Most widespread rain and storms should be south of the I-70 corridor, shifting toward the Ohio River through the day. The heaviest rain will be confined to the southern portions of the state, but expect much of the area to see amounts of 0.5 to 1.0 inches with some locally higher amounts of around 1.5 inches. A sharp QPE gradient likely will exist north of I-70, with amounts diminishing further north.
Much cooler weather will move in behind the frontal passage with the potential for lows in the upper 30s and low 40s Wednesday and Thursday night and highs in the upper 60s to low 70s through Friday. Surface high pressure will dominate the weather pattern through the second half of the week with dry weather expected. Coolest night should be Thursday night as lighter winds and clear skies make for better radiational cooling. Patchy frost may occur outside of urban areas in Central and North Central Indiana by Friday morning.
Next Weekend...
A similar pattern will persist Friday into the weekend with a broad and weak upper low across the Eastern US and surface high pressure being the dominant weather influence locally. Long term guidance has been consistent in showing a gradual warming trend back to the 70s by the weekend as the cooler Canadian airmass shifts east and southerly flow brings a warmer airmass northward. Despite a warning trend, temperatures do not look as anomalously warm as things have been to start the month. The pattern continues to favor drier than normal conditions with little to no signs for additional appreciable rainfall.
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.AVIATION (12Z TAF Issuance)... Issued at 656 AM EDT Mon Oct 6 2025
Impacts:
- Deterioration to MVFR conditions late this afternoon and tonight. - Scattered showers developing this afternoon, continuing Tonight
Discussion:
Satellite imagery shows clear skies across Central Indiana early this morning. Mid and upper level moisture over the south will continue to surge northward leading to an increase in mid and upper level clouds through the day. While VFR cigs and vis should prevail through the rest of the day, expect scattered showers to begin developing from south to north later this afternoon and evening. Conditions then deteriorate overnight tonight into tomorrow morning as rain and a few storms become more widespread, especially south of I-70. Have all sites with MVFR conditions overnight, but possibility is there for periods of IFR cigs and vis under heavier showers and storms.
Winds remain southerly through the period increasing to around 10 kts this afternoon.
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.IND WATCHES/WARNINGS/ADVISORIES... None. &&
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SHORT TERM...Puma LONG TERM...CM AVIATION...CM
NWS IND Office Area Forecast Discussion