FXUS63 KIND 241900 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 300 PM EDT Fri Oct 24 2025 .KEY MESSAGES... - Periodic chances for rain Sunday through the middle of next week with the highest chances being Tuesday into Wednesday - Temperatures to remain near to below normal this weekend into next week - Mostly dry and cool conditions expected for Halloween && .SHORT TERM (This evening through Saturday)... Issued at 259 PM EDT Fri Oct 24 2025 In the wake of the deep longwave trough along the eastern CONUS, below normal temperatures will continue through Saturday across central Indiana. This will be a result of both increasing high cloud cover ahead of the slow moving southern rockies shortwave trough that will gradually move into the southern plains and remnant cool airmasss/surface high pressure that will move over and just east central Indiana. Ahead of the shortwave trough over the southern plains, a few light showers aided by mid level waa area expected to be over IL. These showers will make a valiant attempt to make into the southern portions of the forecast area during the day Saturday. However a very dry airmass between the surface and about 10kft should preclude any precip reaching the ground with virga as a result. Therefore have continued the mostly cloudy forecast with no pops. && .LONG TERM (Saturday night through Friday)... Issued at 259 PM EDT Fri Oct 24 2025 The aforementioned shortwave trough over the southern plains on Saturday will continue to slowly trudge eastward into the SE CONUS through Monday. Forecast soundings suggest that sufficient top down saturation will occur that by Sunday the expectation is for scattered light showers to develop along the northern periphery of the associated mid level deformation zone across southern portions of the forecast area. Although the confidence on exact location is still uncertain, with the development of a upper high over the Great Lakes, there is likely to be a fairly narrow transition zone to isolated showers over the central portions of the forecast area and dry conditions over the north for both Sunday and Monday. Attention then turns to the next and stronger storm system which will move into the Pac West/Rockies this weekend and into the Plains on Monday. By late October standards, a strong W-NW mid-upper level jet /100 kts at 500 mb and 140 kts at 300 mb/ over the Rockies will aid in the development of a lee trough/low over the high plains by late Sunday. In addition, the combination of strong/channeled flow will support significant mid level positive vorticity generation on the northern periphery of the mid level jet as it edges into the plains by Monday. There is excellent agreement among the GFS and Euro deterministic and ensembles for the fairly rapid intensification of a deep layer cyclone over the MS valley into the SE CONUS during Tue-Wed time period. The only major uncertainty in the evolution beyond this time frame will be the interaction of this system with the preexisting eastern CONUS long wave trough. The net result will be a return to much cooler than normal and wetter weather likely for Central Indiana Tue-Wed with highs mainly in the low-mid 50s and lows in the 40s. In addition, depending on the eventual track of the surface low/mid level deformation zone, some areas of central Indiana may see much needed rainfall amounts as well as moderately strong winds. Although the timing of the eventual progression of this system, related to the phasing with the eastern CONUS longwave remains uncertain, the chances appear relatively high that drier weather will move into the region just in time for Halloween. with the hope that the atmosphere doesn't have any tricks up its sleeve. && .AVIATION (18ZTAF Issuance)... Issued at 131 PM EDT Fri Oct 24 2025 Impacts: - None Discussion: VFR conditions through the period. Increasing cloud cover driven by the warm advection pattern associated with the southern plains shortwave trough will be the only sensible aviation weather of note through the period. Surface winds will shift from NW to NE through the evening hours before becoming easterly by tomorrow morning. Winds speeds are expected to remain general AOB 5 kts through tonight with a slight increase in the wind speeds expected tomorrow afternoon. Although ceilings will gradually fall through the period as the atmosphere saturates from the top down, ceilings will remain well into the VFR category through forecast period. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Crosbie LONG TERM...Crosbie AVIATION...Crosbie