853 FXUS63 KIND 250659 AFDINDArea Forecast Discussion National Weather Service Indianapolis IN 259 AM EDT Thu Sep 25 2025
.KEY MESSAGES...
- Scattered showers linger this morning
- Fog is possible overnight tonight
- Warm and dry weather resumes Friday...through most if not all of next week, with above normal highs often near the low 80s
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.SHORT TERM (Today and tonight)... Issued at 259 AM EDT Thu Sep 25 2025
Early This Morning...
The upper trough axis remains to the west of the area early this morning, while a surface low is moving northeast through Kentucky. Forcing from these are producing rain across Kentucky and southern Indiana, with some of it in the southern forecast area.
Similar conditions should continue through the predawn hours with forcing continuing. Some forcing from deformation will add to the mix, possibly allowing the rain to spread farther north. Will have chance PoPs across the south and far eastern forecast area, with lower PoPs northwest.
Lower level moisture will work southwest into the area, bringing in lower ceilings. However, at the moment, it appears that the bulk of any fog will remain east of central Indiana.
Today...
As the upper trough axis shifts east through the forecast area this morning, forcing will continue mainly across the southeastern forecast area. Better forcing and moisture will be east of the area, so will keep PoPs on the lower end. PoPs will diminish as the trough moves east.
Drier air will work in from the northwest, breaking up the clouds. Temperatures will peak in the mid and upper 70s.
CAMs are trying to generate isolated showers in the east this afternoon with lingering weak instability, but confidence is not high enough to include these.
Tonight...
Skies will become mostly clear this evening, and winds will diminish. This will set the stage for some fog development. At the moment, uncertainty in how much low level moisture will be around is enough to only mention patchy fog overnight. However, if enough moisture lingers, areas of dense fog are possible, especially north.
Temperatures will be cooler, with lows in the lower to middle 50s expected. Favored cold areas in the north could dip into the upper 40s.
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.LONG TERM (Friday through Wednesday)... Issued at 259 AM EDT Thu Sep 25 2025
Dry and rather warm conditions will prevail across central Indiana through September`s final days...as another subtropical ridge builds northward while crossing the central CONUS...building into the Midwest and Great lakes by early next week. The staunch jet retracted north of the Canadian border, and a disturbance attempting to lift northward through the Rockies...will promote a disorganized, yet blocked omega pattern. Weak but broad surface high pressure will be aligned from the Midwest to the Northeast. Unseasonably high 1000-500 mb thickness values will glide above 570 dm over the CWA late this weekend.
This will all translate to what is considered pleasant late summer weather for the region...or a tad warm and perhaps a touch humid for early autumn. The last of this week`s weather system`s clouds should depart Friday morning...with mostly clear skies then prevailing through the weekend. Light winds will veer through northerly directions into early Monday...promoting dewpoints and morning lows in the 50s...and afternoon highs slowly moderating from upper 70s to low 80s by Sunday.
The long term`s second half is expected to remain rain-free, while systems well to our east and north weakly influence local conditions. Atlantic tropical system(s) approaching the Mid-Atlantic coast through about the Tuesday timeframe should couple with mainly light east-northeasterly breezes to bring more moderate humidity to at least a portion of the CWA, under some mid/high clouds. The northern jet should spill south off the eastern side of the blocked ridge by the end of the period, trending to at least modest decreases in dewpoints and readings, albeit still a bit above seasonal levels. The normal max/min at Indianapolis through the long term is 73/52.
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.AVIATION (06Z TAF Issuance)... Issued at 115 AM EDT Thu Sep 25 2025
Impacts:
- MVFR ceilings return overnight, low chance for IFR - VFR returns late morning into early afternoon Thursday - Showers possible overnight, mainly at KBMG
Discussion:
Lower clouds will continue to develop overnight, falling into the MVFR category. IFR cannot be ruled out, but confidence is not high enough to include at this time. As low pressure exits and some heating occurs, ceilings will mix out, allowing VFR to return by early afternoon.
A few light showers will mainly be around the southern sites into Thursday morning, with KBMG the most likely to see any rain.
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.IND WATCHES/WARNINGS/ADVISORIES... None. &&
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SHORT TERM...50 LONG TERM...AGM AVIATION...50
NWS IND Office Area Forecast Discussion