Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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220 FXUS63 KIND 211755 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 155 PM EDT Tue Jul 21 2026 .KEY MESSAGES... - Thunderstorms exiting by mid to late afternoon. - Dry and cooler weather through at least Thursday, with warmer temperatures returning this weekend. && .DISCUSSION (This evening through Tuesday)... Issued at 155 PM EDT Tue Jul 21 2026 Surface analysis early this afternoon shows low pressure over northern Ontario with a cold front that extended SW to Indiana and southern IL. Radar shows convection developing ahead of the front over southern Central Indiana, quickly moving SE. Southwest flow was in place ahead of the front across southern Indiana, while flow shifted to the west or NW across the northern half of the state. Late this afternoon, convection ahead of the front is expected to continue across the southern parts of the forecast area and exit by 20Z or earlier. Storms may produce heavy rain and gusty winds within this moisture rich air mass and marginal dynamics in place. Tonight through Thursday... Quiet and cooler weather will settle across Central Indiana starting tonight and continue through at least Thursday. This will be due to strong upper ridging building across the western CONUS and the resultant NW flow and lee-side subsidence across the upper midwest spilling across Indiana. Models suggest a strong and large area of high pressure building across Indiana through Thursday, along with cooler north or northeast flow. This Canadian high will provide mostly sunny days and mostly clear nights through Thursday. Below normal temperatures will be expected with highs in the middle 70s on Wednesday before rising to around 80 on Thursday. Friday through Tuesday... Dry weather with a warming trend looks in store for Friday through Sunday, while minimal, uncertain rain chances return on Monday and Tuesday. During this period, models continue to suggest strong ridging aloft building over the western CONUS. This will result in continued northwest flow and lee side subsidence forming over the Upper midwest, spilling southeast to Indiana and the Ohio Valley. This will result in a large area of high pressure settling and lingering across Indiana and the Ohio Valley through Sunday. Northeasterly winds on Friday and Saturday will allow cooler temperatures to spill into Central Indiana, resulting in below normal temperatures through the first part of the weekend. By Sunday, reorganization of the high pressure systems east of Indiana will allow for warmer, southerly surface flow to return to Central Indiana. This will allow highs to return to the middle and upper 80s for Sunday. Yesterday/s runs suggested weak waves moving across Indiana within the flow aloft on Sunday and Monday, which could provide forcing for rain. However today, models have shifted these features farther east and slower. Models now suggest Indiana will continue to be protected by ridging aloft on Monday and NW flow on Tuesday. Confidence for rain during those times remains low until a stronger and more significant signal appears. && .AVIATION (18Z TAF Issuance)... Issued at 122 PM EDT Tue Jul 21 2026 Impacts: - VFR conditions will be predominate this period. Discussion: A cold front sagging across Central Indiana may generate a TSRA near BMG through 19-20Z. Otherwise, expect VFR conditions across the TAF sites as the cold front exits to the south. Strong high pressure will build across the TAF sites late this afternoon and overnight, leading to unlimited cigs. Wind gusts this afternoon to around 20 knts will be possible in the wake of the front, but will subside this evening. Convective temps on Wednesday should be reached allowing some SCT VFR CU. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ AVIATION...Puma DISCUSSION...Puma