FXUS63 KIND 160511 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 111 AM EDT Fri Oct 16 2026 .KEY MESSAGES... - Line of showers and few thunderstorms crossing southeastern central Indiana through the early overnight - Strong post-frontal northwest winds will gust between 30 and 40 mph late tonight into Friday - Widespread frost and localized freeze conditions are likely Saturday night into Sunday morning && .FORECAST UPDATE... Issued at 1009 PM EDT Thu Oct 15 2026 Triple point of baroclinic system will continue to steadily cross east-central Indiana through the late evening...while warm sector occupying central Indiana's far southern/southeastern zones will continue to promote showers and an isolated t-storm, although with a quickly fleeting non-zero severe threat...with better wind shear around the system occlusion to the northwest of Indianapolis, offset from lingering instability mainly under 1000 J/kg well to the south. Cold front pushing main line of convection east...will usher in winds veering to west-northwest through the overnight before increasing to at least 10-15 mph with gusts increasing to 20-30 mph by daybreak. Patchy, transient mist will clear out by 06Z on the increasing flow. Noticeably drier, and almost seasonable dewpoints to arrive by dawn, with temperatures in the upper 40s west and northwest of Marion County...and lows down to the mid-50s for southeastern zones. && .DISCUSSION (This evening through Thursday)... Issued at 305 PM EDT Thu Oct 15 2026 This afternoon through Friday Night... Current surface analysis depicts a low pressure system approaching from the west while an associated warm front lifts north. Scattered showers and a few embedded thunderstorms are now beginning to push into central Indiana. Additional convective development can be expected as the disturbance pushes across the area later today into tonight. Surface observations suggest the warm front is near far southern portions of central Indiana where dewpoints are now in the lower 70s. The warm front will continue lifting northward towards the I-70 corridor. Low-level theta-e advection combined with diurnal heating is expected to promote MLCAPE values of 750 to as high as 1250 J/KG locally later this afternoon into the evening. Meanwhile aloft, a mid-level jet streak from the parent trough continues to shift eastward promoting stronger deep-layer shear. Increasing deep-layer shear in addition to modest destabilization could result in isolated severe thunderstorms. Effective shear values exceeding 40 kt are expected which favors the potential for supercells or organized storm clusters. Enlarging low-level veering hodographs from the warm front lifting north could support isolated tornadoes. Damaging wind gusts also appear possible with organized storm clusters. One caveat limiting confidence for the overall severe weather threat is uncertainty on the degree of low-level buoyancy. Forecast soundings from the latest CAMs depict poor lapse rates and relatively long-skinny CAPE profiles. This suggest updraft strength may be limited. However, even weak to modest low-level buoyancy in the favorable kinematic environment could support isolated damaging wind gusts or tornadoes so mesoscale trends will be monitored closely. Modest instability will greatly limit the threat for severe hail though sub-severe hail still appears possible. Expect a cold front to move through late tonight advecting cooler- drier air into the area. Look for precipitation chances to diminish from west to east during the late overnight. Increasingly breezy conditions are likely due to a tightening pressure gradient behind the departing front and steepening low-level lapse rates. Wind gusts between 25 to 35 mph should be common into Friday with sporadic gusts as high as 40 mph. Steepening lapse rates and marginal low- level moisture ahead of a backdoor cold front moving through late Friday will promote scattered convective showers. The parent mid- upper level trough overhead by this point should provide additional forcing for convection. Scattered lingering showers are possible early Friday night, mainly across northwest portions of central Indiana, before the aforementioned system shifts further east. Temperatures will drop into the upper 30s and low 40s Friday night due to the additional shot of cooler air. Patchy frost cannot be ruled out in sheltered locations into Saturday morning, but breezy conditions should mostly limit the threat elsewhere. Saturday through the middle of next week... A broad longwave trough will anchor across the eastern CONUS on Saturday as a strong surface anticyclone shifts from the Upper Mississippi Valley southeastward across the Ohio Valley through Sunday. The core of the cold pool will sit overhead Saturday, keeping 850 mb temperatures around 0C to +2C. Despite clearing skies and subsidence, daytime highs on Saturday will struggle to reach out of the mid 50s, 10-15 degrees below normal. Saturday night into Sunday morning represents the primary frost and low-end freeze window of the period. The surface high center will settle directly over central Indiana by 09Z Sunday, decoupling the boundary layer and yielding calm winds, clear skies, and a very dry ambient air mass with dew points in the upper 20s to low 30s. Strong radiational cooling will cause overnight minimum temperatures to drop into the lower to mid-30s across the entire forecast area, with rural drainage basins and traditional cold spots likely dropping near freezing. Widespread frost is expected across central Indiana, and freeze conditions are probable in sheltered rural areas. Frost and freeze headlines will likely be required as confidence remains high across deterministic GFS, ECMWF, and their respective ensemble suites. The anticyclone will drift eastward toward the Mid-Atlantic on Sunday, allowing insolation to rebound highs into the upper 50s and lower 60s. Lows Sunday night will remain cool, in the upper 30s to lower 40s, with patchy frost confined to far eastern rural valleys before low-level winds back to the south. For Monday through Wednesday, the synoptic pattern transitions as upper-level ridging builds over the eastern states and a deep trough carves out over the western CONUS. Steady south-southwesterly return flow will drive a significant warm air advection regime across the Ohio Valley. 850 mb temperatures will moderate to +10C to +13C, pushing daytime highs into the upper 60s and lower 70s by early next week. Overnight lows will moderate into the upper 40s to mid-50s. Long range guidance generally supports quiet weather conditions persisting through the middle of next week as surface high pressure remains in control. Return flow should continue to provide a gradual moderation in temperatures. && .AVIATION (06Z TAF Issuance)... Issued at 106 AM EDT Fri Oct 16 2026 Impacts: - MVFR ceilings 07Z-19Z - Wind shifts to NW early in the period. - Wind gusts to 30kt after 15Z. Discussion: Much of the area is within a brief period of VFR between two weak confluence boundaries. A cold front will quickly push to the E/SE tonight shifting winds from SW to NE. Cold air advection and trapped lower level moisture will provide MVFR cigs across Central Indiana later tonight through 15Z, with some lifting likely within diurnal heating in the afternoon. Winds will be brisk after frontal passage, sustained between 12-15kt with gusts nearing 30kt after 15Z. Friday night, winds will shift towards northerly with gusts waning. Scattered showers will be possible at KLAF. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...AGM AVIATION...Updike DISCUSSION...White/Melo